Department of Pathology
Faculty of veterinary medicine
Mechanism of bacteriainduced injury:

Intracellular bacteria 
Extracellular bacteria
Intracellular bacteria

Damage the host tissues

by:
invasion to host cells and
may form toxins.
Extracellular bacteria
Damage the host tissues 
:by
their ability to adhere to
the host cells and
produce toxins.
Bacterial toxins

Endotoxines
Exotoxines
Endotoxines
(a) Lipopolysaccharide ( LPS ) in nature. 
(b) Structural components of the outer cell wall
of gm –ve bacteri...
Exotoxines
Harmful product secreted by 
bacteria.
Specific for each bacteria. 
Includes different Enzymes as; 
Hemolysi...
Inflammatory Response To
Bacterial agents
Suppurative Polymorphnuclear 
Inflammation.
Mononuclear inflammation. 
Granulo...
Suppurative Polymorphnuclear
Inflammation

Neutrophils attracted to 
pyogenic bacteria which
release chemo attractants
th...
Mononuclear inflammation
Mononuclear cells is a------ 
i) Common features of All chronic



inflam. Process. As in Lepto...
Granulomatous inflammation

Distinctive form of 
mononuclear inflam.
Evoked by slow dividing
infectious agents as
M. tube...
Necrotizing inflammation
Rapid and Severe tissue 
damage in which cell death is
the dominant feature evoked
by v.strong t...
Pasteurellosis
Definition:
A group of diseases affecting 
different species of An.
caused by; P. multocida 
P. hemolytic...
Pasteurellosis
Cattle:
Hemorrhagic septicemia . 
Pneumonic pasteurellosis. 
Meningitis in calves. 
Mastitis in cows. 
Pasteurellosis
Sheep:
Septicemia. 
Enzootic pneumonia. 
Mastitis in ewes.
Pasteurellosis
Poultry: Fowl cholera. 
Horse: Hemorrhagic septicemia. 
Rabbit: Snuffles. 
Man and Rodents: 
Tularemia ...
Hemorrhagic septicemia
Definition: 
*Per acute fatal disease of cattle
*Caused by P.multocida
*Characterized by
(i) Fibri...
Hemorrhagic septicemia
Pathogenesis 
The organism is a normal inhabitant in 
the nasopharyngeal mucosa.
Impaired local o...
Hemorrhagic septicemia
Lesions: 
1. Per acute edematous form
Characterized by subcutaneous edema of the throat and
briske...
Hemorrhagic septicemia
Hemorrhagic septicemia
Pneumonic pasteurellosis
(shipping fever)(OAT CELL Pnumonia )

Definition: 
*Severe acute disease of cattle
*Caused by P....
Pneumonic pasteurellosis
Pathogenesis: 
*Impaired defense mechanism (transportation)
Proliferate in nasopharynx then Inva...
Pneumonic pasteurellosis
Lesions (i) MACRO: 
1-Reddish black to grayish brown consolidated
areas in the cranioventral reg...
Pneumonic pasteurellosis
Pneumonic pasteurellosis
Pneumonic pasteurellosis
Lobar pneumonia(Pasteurellosis)
Lung hepatization(Pasteurellosis)
Pneumonic pasteurellosis
(ii) MICRO: 
Severe fibrinous pleuropneumonia with 4 stages 
Severe thickening of the interlobu...
Lung hepatization (Pasteurellosis)
Lung hepatization (Pasteurellosis)
(OAT CELL Pnumonia )
Mycoplasmosis
Definition:
A group of diseases
affecting different species
of animals caused by
Mycoplasma organism.
Mycoplasmosis
Goats: 
*Contagious Caprine PleuroPneumonia.

( C.C.P.P )
*Poly arthritis.

Sheep and swine: 
* Enzootic p...
Mycoplasmosis

Cattle: 
Contagious Bovine PleuroPneumonia 
( C.B.P.P ).
Mycoplasmal bronchitis and pneumonia 
in calves...
Contagious Bovine PleuroPneumonia

(CBPP)

Definition: 
*Contagious infectious disease of cattle
*Characterized by
(i) Fi...
Contagious bovine
pleuropneumonia
Cause: 

Mycoplasma mycoides bovis
( Small Colony )
Contagious bovine
pleuropneumonia
R.O.I :
Deep Inhalation of infected
droplets as upper respiratory
tract is quite resista...
Contagious bovine
pleuropneumonia

Pathogenesis : 
1- Mycoplasma inhaled deeply into the small
bronchioles
inflammation o...
Pathogenesis :
2- Necrosed area become demarcated
&surrounded by f.c.t---------Sequestrum
3. Mycoplasma remain viable in s...
Contagious bovine
pleuropneumonia
Lesions (i) MACRO: 
1. Severe fibrinonecrotic pneumonia
(caudal lobes) with fibrinous p...
Contagious bovine pleuropneumonia
Contagious bovine pleuropneumonia
Contagious bovine pleuropneumonia
Contagious bovine pleuropneumonia
Contagious bovine pleuropneumonia
Contagious bovine
pleuropneumonia
Lesions (ii) MiCRO: 
a- Fibrinous pleuropneumonia.
b- Marked distension of interlobular...
Contagious Caprine
PleuroPneumonia (CCPP)
* Acute disease of goats similar to CBPP of cattle
Caused by Mycoplasma Capri •
...
Fibrinous pleuricy with adhesions(CCPP)
Mycoplasmal bronchitis and pneumonia
in calves(Cuffing pneumonia)

Definition: 
* Mycoplasmal disease of calves
* Charact...
Mycoplasmal bronchitis and pneumonia
in calves(Cuffing pneumonia)

Cause: 
Mycoplasma dispar

R.O.I:
Inhalation of infect...
(Cuffing pneumonia)
Lesions

(i) MACRO: 

Patch purple red atlectatic foci in the cranio
ventral region.

(ii) MICRO:
Cat...
(Cuffing pneumonia)
(Cuffing pneumonia)
(Cuffing pneumonia)
(Cuffing pneumonia)
Strangles(Shipping fever of equines)
Adenitis equerium

Definition: 
Acute contagious disease of young equines (2m – 5y )...
Strangles

Cause:

Streptococcus equi produce
(hemolycin & leucocydin).

R.O.I:

Inhalation.
Strangles

Pathogenesis:

Inhalation of the M.O
nasal mucosal penetration
lymphatics
regional lymph nodes.
Strangles
Lesions
Purulent rhinitis, pharyngitis, laryngitis, 
and sinusitis.
Purulent bilateral creamy yellow nasal 
d...
Strangles
Strangles
Strangles
Lesions
Suppurative inflammation of the 
submaxillary and retropharyngeal L.N
which may ruptured:
(i) On skin To Outside....
Strangles
Strangles
Strangles
Strangles
Strangles
Strangles
Strangles
Strangles
Strangles
Complications: 
The disease is not fatal unless
complicated by :
1- Suppurative bronchopneumonia,
pleuritis and...
Strangles
Complications: 
3- Purpura hemorrhagica (Petechial
fever) resulting from intoxication and
allergy (arthus react...
Colibacillosis
Definition : 
Infectious disease of man and animals.

Cause :
E.coli.


Colibacillosis

The organism produce the disease by 5 mechanisms :

Pathogenesis :

1-Enterocyte-adherent Colibacillosis ...
Colibacillosis
Pathogenesis : 

1-Enterocyte-adherent Colibacillosis
E.coli colonizing the surface of
enterocytes withou...
Colibacillosis
Pathogenesis 

2-Enterotoxic colibacillosis 
E.coli colonizing the mucosa
producing enterotoxines
diarrhe...
Colibacillosis
Pathogenesis
3-Enterotoxaemic colibacillosis
E.coli colonizing small intestine

Produce toxins w’ has a p...
Colibacillosis
Pathogenesis
4-Enteroinvasive colibacillosis 
E.coli invade intestinal epithelium
Acute exudative enterit...
Colibacillosis
Pathogenesi
5-Septicemic colibacillosis 
E.coli produce bacteraemia,
endotoxaemia and localization
in dif...
i.Enterotoxic colibacillosis
Definition: 
The major cause of neonatal diarrhea in •
calves , pigs and lambs.
Also cause d...
i.Enterotoxic colibacillosis
i.Enterotoxic colibacillosis
Pathogenesis : 
The organism adheres to the surface •
of enterocytes
enterotoxines
hyper sec...
i.Enterotoxic colibacillosis
Macro: Non specific 
Microscopic appearance : 
1) Degeneration of enterocytes in
( jejunum ...
i.Enterotoxic colibacillosis
Diagnosis: 
Bacterial isolation for L.N & other 
organs.
Presence of gm –ve bacilli in smea...
ii.Enteroinvasive colibacillosis

Pathogenesis : 
Affect Age < 2w 
E.coli invade the enterocytes of the 
lower small an...
ii.Enteroinvasive colibacillosis

P.M. lesions : 
1. Congestion of lower parts of S.I 
& caecum.
2. Mucosal erosions and...
ii.Enteroinvasive colibacillosis
ii.Enteroinvasive colibacillosis
ii.Enteroinvasive colibacillosis
Microscopic appearance : 
Enterocytes become cuboidal or 
flattened (villous atrophy).
...
iii.Septicemic colibacillosis
Definition: 
Generalized Systemic infection with •
E.coli mainly occurs in calves either as...
iii.Septicemic colibacillosis

P.M. lesions :



(i) Omphalitis.
(ii) Pneumonic lung.
(iii) Firm spleen.
iii.Septicemic colibacillosis
Microscopic appearance 

(i) Per (more) acute cases.
(ii) Acute cases.
(iii)Subacute and ch...
iii.Septicemic colibacillosis

Microscopic appearance : 
Per(more) acute cases 
due to endotoxemia-----vascular permeabi...
Microscopic appearance:
Acute cases 

1- Interstitial pneumonia with fibrinous
exudate and Neutrophiles in alveoli.
2- Ne...
Microscopic appearance:
Subacute and chronic cases 

1- Fibrinous Pleuritis, Peritonitis, and
Pericarditis.
2- Mucopurule...
Salmonellosis
Definition:
* An infectious disease of man 
and animals. 
* Characterized by septicemia, 
Gastroenteritis...
Salmonellosis
Cause : 
Gram – ve organism
( S.typhimurium, entritides and duplin).

Route of infection :



Ingestion of...
Salmonellosis
Predisposing factors : 
Stress 
(starvation, transportation,
crowdness, parturition etc.).
Young animals ...
Salmonellosis
Pathogenesis :
Ingestion of M.O Enterocyte
M.O by macrophages in L.P Cross
the mucosa Lymphatics Blood
strea...
Salmonellosis
Pathogenesis :
In Carriers

M.O remain localized in Gut
L.N & Payer's patches till stress factors.
The organ...
Salmonellosis


Forms :

(i) Septicemic, (ii) Acute or Enteric,
(iii) Chronic.

Sheep :



(i) Fibrinohemorrhagic enteri...
Salmonellosis

Cattle :
(i)Per acute Septicemic form
Ch’Ch’:

*Septicaemia,
* Meningioencephalitis
* Polyarthritis.
Salmonellosis
(ii) Acute or enteric form
i. Intestine
Post mortem lesions : 
-Fibrinonecrotic or fibrinohemorrhagic enter...
(Salmonellosis)

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Fibrinonecrotic enteritis
(Salmonellosis)

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Fibrinonecrotic enteritis
(Salmonellosis)

gross
more

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Fibrinonecrotic enteritis
(Salmonellosis)

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Salmonellosis
(ii)Acute or enteric form 
ii. Liver
Pathognomonic lesion is the presence 
of paratyphoid nodules in the l...
Paratyphoid nodule (Salmonellosis)

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Paratyphoid nodule (Salmonellosis)

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Salmonellosis

(iii) Chronic form
Ch’Ch’:
* Bronchopneumonia
* purulent synovitis

N.B: 
Salmonella is an important cause...
Salmonellosis
Horse :
(i) Septicemic form
*Occurs in foals 1-6 month
Characterized by •
Septicemic lesions
as in cattle.
Salmonellosis
(ii)Acute or enteric form 
* Occurs in older animals.
Characterized by diarrhea, fever •
and recovery. •
P....
Salmonellosis
(iii) Chronic form
Ch’Ch’:
Ulcerative typhlocolitis
Necrobacillosis
Definition:
* Infectious disease of 
animals.
* Characterized by 
necrotizing lesions in the
alimentary ...
Necrobacillosis
* Different conditions produced by
the organism in different
animals:
i- calf diphtheria in calves.
ii- ul...
foot rot
Micro

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foot rot
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Necrotic Stomatitis

Micro

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Necrotic Stomatitis

Micro

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Necrobacillosis
Cause : 
Fusobacterium necroforum.

Route of infection :



Secondary invasion following mucosal damage
...
Necrobacillosis
Pathogenesis :

The organism invade the 
damaged mucosa and
produce
Endo&Exo toxine Necrosis. 
Necrobacillosis
Spread of infection:
Aspiration of necrotic material
Gangrenous Pneumonia.

Ingestion of necrotic material...
Necrobacillosis
Spread of infection:
Hepatic necrobacillosis observed in 
lambs and calves following
omphalophlebitis or ...
Necrobacillosis
P.M lesions : 
Large well demarcated yellowish gray 
dry areas of necrosis surrounded by a
hyperaemic zo...
Necrobacillosis
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Hepatic necrobacillosis

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Hepatic necrobacillosis

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Pulmonary necrobacillosis

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Necrobacillosis
Microscopic appearance : 
Structureless area 
surrounded by hyperaemic
zone and leucocytes,
later by thi...
Hepatic necrobacillosis

Gross
High
power

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Hepatic necrobacillosis

Gross
High
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Leptospirosis
Definition:
Acute infectious septicemic
disease of cattle, dog and man.
Ch’Ch’: septicemia, hepatitis,
Icter...
Leptospirosis
Cause : 

Leptospira icterohemorrhagica,
Pomona and canicola
( spiral m.o.).

Route of infection :



(i) ...
Leptospirosis
Pathogenesis :
M.O penetrates the mucosa
blood

Septicaemia
If animal not die during septicemia
Localizatio...
Leptospirosis
Cattle 
P.M lesions : 
Lesions of septicaemia ( petechial hemorrhages 
on serous membranes and S/C edema ...
Leptospirosis
Leptospirosis
Leptospirosis
Dog
P.M lesions :



Liver showed atrophy and fibrosis. 
Subcapsular hemorrhages in the 
kidney. In chro...
Leptospirosis
Cattle
Microscopic appearance :
1. Necrosis of hepatic cells around central vein 
with hyperplastic kupfer ...
Leptospirosis
Leptospirosis
Leptospirosis
Dog
Microscopic appearance :
1- Dissociation of hepatic cells which appear 
Dark and atrophied.
2- Regenera...
Anthrax(splenic fever)
Definition:
Highly septicemic infectious 
disease of man and animals.
Characterized by septicemia ...
Anthrax(splenic fever)
Cause :

Bacillus anthracis, spore forming Gram + ve
bacilli.

Route of infection :
(i) Inhalation,...
Anthrax(splenic fever)
Pathogenesis :
1- Ingestion Pharynx Regional L.N
Lymphatics Blood Septicemia
2. The organism produc...
Anthrax(splenic fever)
Forms : 

(i) Septicemic form
In Cattle and Sheep. •
*Ch’Ch’ sudden death and dark tarry
unclotted...
Anthrax(splenic fever)
Forms :

(i) Septicemic form
4. Lymph nodes swollen, edematous
and hemorrhagic.
5. Liver and kidne...
Anthrax(splenic fever)
Forms : 
(ii) Localized form
In horse, pigs and dogs: 
Pharyngitis, lymphadenitis and Edema of
fa...
Anthrax(splenic fever)
Anthrax(splenic fever)
Anthrax(splenic fever)
Anthrax(splenic fever)
Anthrax(splenic fever)
Anthrax(splenic fever)
Anthrax(splenic fever)
Clostridial diseases
Group of diseases caused by Clostridia
organisms, gram + ve, spore forming bacteria.

1.Black disease...
Clostridial diseases
1.Black disease(Infectious necrotic hepatitis)
Definition:

*Infectious disease of
sheep,goat ,Cattle...
1.Black disease
(Infectious

necrotic hepatitis)

Cause : C. novyi
Route of infection :
Ingestion of food and water
contam...
1.Black disease
(Infectious

necrotic hepatitis)

Pathogenesis :
Ingestion of spores

Infestation of the animal with fasci...
1.Black disease
(Infectious

necrotic hepatitis)

P.M Lesions
1.Black coloration of skin due to venous
congestion of subcu...
1.Black disease
(Infectious

necrotic hepatitis)
1.Black disease
(Infectious

necrotic hepatitis)
Clostridial diseases
2. Bacillary hemoglbinurea
Definition:

* Highly fatal infectious disease of
cattle & sheep
*Caused b...
2.Bacillary

hemoglbinurea

Cause : C. hemolyticum
Route of infection :
Ingestion of food and water
contaminated with spor...
2.Bacillary

hemoglbinurea

Pathogenesis :
Ingestion of spores

Infestation of the animal with fasciola

liver necrosis

i...
2.Bacillary hemoglbinurea

Signs:
Icterus and hemoglbinurea

P.M Lesions
Liver contains well demarcated areas of 
necrosi...
2.Bacillary hemoglbinurea
2.Bacillary hemoglbinurea
Clostridial diseases

3. Black leg ( black quarter )
Definition:

Infectious disease of cattle and •
sheep
* Caused by C....
3.Black leg(black

quarter)

Cause :
C. chuvoei.

Route of infection :
Ingestion.
3.Black leg(black

quarter)

Pathogenesis :
Ingestion of spores

intestine

Infestation of the animal with fasciola

muscu...
3.Black leg(black quarter)

P.M Lesions
Early or wet stage : Muscles are 
necrosed appear dark red and
separated by seroh...
3.Black leg(black quarter)
3.Black leg(black quarter)
3.Black leg(black quarter)

Micro
1. Extensive coagulative necrosis 
(zenker's necrosis) of muscle fibers
with edema and ...
Clostridial diseases

4. Gas gangrene OR malignant edema
Definition:

* Infectious disease of cattle, sheep & equine
* Cau...
4.Gas gangrene OR

malignant edema

Cause :
Separate or mixture of
C.chauvei, perfringes or septicum.

Route of infection ...
4.Gas

gangrene

OR

malignant edema

Pathogenesis :
Deep wound infection 
(anaerobic conditions)
Germination of spores
M...
4.Gas

gangrene

OR

malignant edema
4.Gas

gangrene

OR

malignant edema
Clostridial diseases

5. Tetanus (lock jaw)
Definition:
* Infectious disease of man and
animals.
Characterized by stiffnes...
Clostridial diseases

5. Tetanus (lock jaw)
Cause :
C. tetani.
Route of infection :

Deep wound.
Clostridial diseases
5. Tetanus (lock jaw)
Pathogenesis :
Deep wound infection (anaerobic 
conditions)
Germination of spo...
Tetanus (lock jaw)
Tetanus (lock jaw)
Tetanus (lock jaw)
Clostridial diseases

5. Tetanus (lock jaw)
PM lesions :
Not characteristic.
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)
Group of enteric diseases in cattle & sheep caused...
Clostridial diseases
6. Enteric Clostridial infections Enterotoxaemia)
(

Action Of C.perfringens exotoxins:
& toxin: - Le...
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)

C. Perfringens type C (Struck)
* Disease of 
Adu...
C.Perfringens type C(Struck)
C.Perfringens type C(Struck)
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)
C. Perfringens type B (Lamb dysentery)
Affects lam...
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)
C. Perfringens type B (Lamb dysentery)
P.M lesions...
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)

C. Perfringens type D (Pulpy kidney-overeating di...
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)
C.Perfringens type D (Pulpy kidney-overeating dise...
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)
C. Perfringens type D (Pulpy kidney-overeating dis...
C. Perfringens type D
(Pulpy kidney-overeating disease)
C. Perfringens type D
(Pulpy kidney-overeating disease)
Clostridial diseases
6. Enteric Clostridial infections (Enterotoxaemia)
C.Perfringens type D (Pulpy kidney-overeating dise...
Listeriosis
Definition:
* Infectious disease of man and
animals.
* Caused by Lesteria monocytogenes.
* Characterized by
Se...
Listeriosis
Cause :

Lesteria monocytogenes.

Route of infection :
Ingestion.
BEHAVE AS 3 SEPARATE DISEASES AS 
IT HAVE 3...
Listeriosis

Forms : (i) Abortion syndrome
Abortion in cattle and sheep occurring during the 
last 3 months of pregnancy....
Listeriosis
Forms :

P.M lesions :
(i) Abortion syndrome

Fetus
Placenta




Necrotic foci in liver and spleen.
Necrosis...
Listeriosis
Forms :
(ii) Septicemic form
*Occurs in early neonatal life and
*Characterized by milliary abscesses
w’ are:ve...
Listeriosis
Forms : (iii) Encephalitic form
* The M.O invade the brain stem.
* Very severe in medulla & pons.

Signs :
*De...
Listeriosis
Forms :
PM lesions:
Meninges are thickened by greenish edema. 
Grayish foci of softening in C/S of medulla. ...
Brucellosis
Definition:
* Infectious disease of animals & man.
* Caused by brucella.
* Ch’Ch abortion.
Cause: Brucella spe...
Brucellosis
Pathogenesis :
Localization
Female

M.O

Pregnant
Spleen
uterus
Mammary gland

Regional L.N
Male & Female
Syno...
Brucellosis
Abortion in cattle
Occurs in the 7th & 8th m of gestation. 
In severe cases, abortion or 
premature birth oc...
Brucellosis
P.M lesions :
(i) Placenta
Edema of intercotyledonary area (between fetal 
membranes and uterine mucosa) with...
Brucellosis
P.M lesions :
(i) Placenta
Micro :
Edema and cell infiltration of the 
intercotyledonary area.
Vasculitis due...
Brucellosis
P.M lesions :
(ii) Fetus
Catarrhal or fibrinous bronchopneumonia. 
Fibrinous inflammation of serous membrane....
Brucellosis
P.M lesions :
(iii) Udder (Bang's disease)
Characterized by focal interstitial mastitis. 

(iv) Bull
Orchitis...
Vibriosis(Campylobacter

fetus)

Definition:
* Infectious disease of cattle and sheep. 
* Ch’ch’ ; Abortion and infertili...
Vibriosis(Campylobacter

fetus)

In Cattle:
Signs
* Abortion 4-6 months of gestation. 
* Temporary sterility or repeat

...
Vibriosis(Campylobacter

fetus)

In Cattle:

R.O.I
*By coitus and artificial insemination. 
*Bulls can act as carriers by...
Vibriosis(Campylobacter

fetus)

In Cattle:
Lesions
Gross and microscopic 
picture is similar to those 
of brucellosis b...
Vibriosis(Campylobacter

fetus)

In Sheep:

Pathogenesis:
Ingestion
Bacteremia
Localization in gut,bile,or uterus 
of pre...
Vibriosis(Campylobacter

fetus)

In Sheep:
Signs
Abortion 4 months of gestation 
( late). 
Vibriosis(Campylobacter

fetus)

In Sheep:
Lesions
*DAM

Endometritis, Cervisitis, and Vaginitis

*Placenta
*Fetus

Placen...
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed
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Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed

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This part i teach it to my undergraduate students in the fourth level, veterinary medicine, Pathology DPT. course no. 401.

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Pathology of bacterial diseases. course no. 401. by dr. sherein saeid abdelgayed

  1. 1. Department of Pathology Faculty of veterinary medicine
  2. 2. Mechanism of bacteriainduced injury: Intracellular bacteria  Extracellular bacteria
  3. 3. Intracellular bacteria Damage the host tissues by: invasion to host cells and may form toxins.
  4. 4. Extracellular bacteria Damage the host tissues  :by their ability to adhere to the host cells and produce toxins.
  5. 5. Bacterial toxins Endotoxines Exotoxines
  6. 6. Endotoxines (a) Lipopolysaccharide ( LPS ) in nature.  (b) Structural components of the outer cell wall of gm –ve bacteria. (c) Non specific toxines. (d) Their biological activity include induction of  fever, septic Shock, and acute respiratory distress syndrome.
  7. 7. Exotoxines Harmful product secreted by  bacteria. Specific for each bacteria.  Includes different Enzymes as;  Hemolysins, Leucocidins, Coagulases,and Hyalourinidase, Fibrinolycins.
  8. 8. Inflammatory Response To Bacterial agents Suppurative Polymorphnuclear  Inflammation. Mononuclear inflammation.  Granulomatous inflammation.  Necrotizing inflammation. 
  9. 9. Suppurative Polymorphnuclear Inflammation Neutrophils attracted to  pyogenic bacteria which release chemo attractants that evoke this response.
  10. 10. Mononuclear inflammation Mononuclear cells is a------  i) Common features of All chronic  inflam. Process. As in Leptospira ii) In response to intracellular  bacteria & spirochetes in acute inflam. Process.
  11. 11. Granulomatous inflammation Distinctive form of  mononuclear inflam. Evoked by slow dividing infectious agents as M. tuberculosis.
  12. 12. Necrotizing inflammation Rapid and Severe tissue  damage in which cell death is the dominant feature evoked by v.strong toxins which secreted from C. perfringens.
  13. 13. Pasteurellosis Definition: A group of diseases affecting  different species of An. caused by; P. multocida  P. hemolytica.
  14. 14. Pasteurellosis Cattle: Hemorrhagic septicemia .  Pneumonic pasteurellosis.  Meningitis in calves.  Mastitis in cows. 
  15. 15. Pasteurellosis Sheep: Septicemia.  Enzootic pneumonia.  Mastitis in ewes.
  16. 16. Pasteurellosis Poultry: Fowl cholera.  Horse: Hemorrhagic septicemia.  Rabbit: Snuffles.  Man and Rodents:  Tularemia ( P. tularenses)
  17. 17. Hemorrhagic septicemia Definition:  *Per acute fatal disease of cattle *Caused by P.multocida *Characterized by (i) Fibrinohemorrhagic interstitial Pneumonia. (ii) Hemorrhagic gastroenteritis.
  18. 18. Hemorrhagic septicemia Pathogenesis  The organism is a normal inhabitant in  the nasopharyngeal mucosa. Impaired local or systemic defense  mechanism ( stress,transportation,bad environment,crowding) Invasion Proliferation of the m.o  of the mucosa to blood Septicemia
  19. 19. Hemorrhagic septicemia Lesions:  1. Per acute edematous form Characterized by subcutaneous edema of the throat and brisket resulting in asphyxia and death. 2. Petechial hemorrhages all over the serous membranes. 3. Accumulation of bloody stained fluid ( serosanguinous fluid ) in body cavities. 4. Swollen and hemorrhagic L.N. 5. Fibrinohemorrhagic interstitial pneumonia. 6. Acute hemorrhagic gastroenteritis.
  20. 20. Hemorrhagic septicemia
  21. 21. Hemorrhagic septicemia
  22. 22. Pneumonic pasteurellosis (shipping fever)(OAT CELL Pnumonia ) Definition:  *Severe acute disease of cattle *Caused by P. hemolytica. *Characterized by fibrinous or fibrinonecrotic bronchopneumonia (lobar) *Usually following transportation (shipping fever)
  23. 23. Pneumonic pasteurellosis Pathogenesis:  *Impaired defense mechanism (transportation) Proliferate in nasopharynx then Invade the lung *The m.o release endotoxines ( leukotoxin) and (cytotoxins ) Capillary thrombosis, necrosis and fibrinous pneumonia. *Leukotoxin & Cytotoxin affect leucocyte w’ accumulate in the inflamed alveoli transforming them into oat like plant ( oat cells).
  24. 24. Pneumonic pasteurellosis Lesions (i) MACRO:  1-Reddish black to grayish brown consolidated areas in the cranioventral region of the lungs. 2-Gelatinous thickening of the interlobular septa. 3-Areas of necrosis with white boundaries &deep central red zone. 4-Marbling appearance of the lung as a result of septal edema and congestion intermixed with different stages of pneumonia (red and grey hepatization), necrotic areas, and normal areas.
  25. 25. Pneumonic pasteurellosis
  26. 26. Pneumonic pasteurellosis
  27. 27. Pneumonic pasteurellosis
  28. 28. Lobar pneumonia(Pasteurellosis)
  29. 29. Lung hepatization(Pasteurellosis)
  30. 30. Pneumonic pasteurellosis (ii) MICRO:  Severe fibrinous pleuropneumonia with 4 stages  Severe thickening of the interlobular septa with  serofibrinous exudates & dilated bl.vs. Vasculitis&Thrombosis of capillaries& arterioles  Areas of coagulative necrosis with macrophages  inside the alveoli (oat shaped cells) ( PATHOGNOMONIC LESIONS ) OAT CELL PNEUMONIA
  31. 31. Lung hepatization (Pasteurellosis)
  32. 32. Lung hepatization (Pasteurellosis)
  33. 33. (OAT CELL Pnumonia )
  34. 34. Mycoplasmosis Definition: A group of diseases affecting different species of animals caused by Mycoplasma organism.
  35. 35. Mycoplasmosis Goats:  *Contagious Caprine PleuroPneumonia. ( C.C.P.P ) *Poly arthritis. Sheep and swine:  * Enzootic pneumonia.
  36. 36. Mycoplasmosis Cattle:  Contagious Bovine PleuroPneumonia  ( C.B.P.P ). Mycoplasmal bronchitis and pneumonia  in calves (Cuffing pneumonia) Poly arthritis in calves.  Abortion in cows. 
  37. 37. Contagious Bovine PleuroPneumonia (CBPP) Definition:  *Contagious infectious disease of cattle *Characterized by (i) Fibrinous pleuropneumonia in acute cases. (ii) Sequestra formation in  subacute and chronic cases. 
  38. 38. Contagious bovine pleuropneumonia Cause:  Mycoplasma mycoides bovis ( Small Colony )
  39. 39. Contagious bovine pleuropneumonia R.O.I : Deep Inhalation of infected droplets as upper respiratory tract is quite resistant.
  40. 40. Contagious bovine pleuropneumonia Pathogenesis :  1- Mycoplasma inhaled deeply into the small bronchioles inflammation of bronchial wall invasion of the interlobular Connective tissue septa inflam.followed by edema then…………… spread to alveoli ………then secrete toxin w’ lead to …….. acute vasculitis, thrombosis & necrosis.
  41. 41. Pathogenesis : 2- Necrosed area become demarcated &surrounded by f.c.t---------Sequestrum 3. Mycoplasma remain viable in sequestra for years and severe coughing rupture of the fibrous capsule of the sequestra liberating organism to lymph space reinfection of the animal occurred or expelled outside and infect or other animals.
  42. 42. Contagious bovine pleuropneumonia Lesions (i) MACRO:  1. Severe fibrinonecrotic pneumonia (caudal lobes) with fibrinous pleuritis. 2. Gelatinous thickening of the interlobular septa. 3. Dilated lymphatics (beaded appearance). 4. Typical marbling appearance in acute stages. 5. Sequestra formation ( PATHOGNOMONIC LESION ) (necrotic areas surrounded by C.T. capsule).
  43. 43. Contagious bovine pleuropneumonia
  44. 44. Contagious bovine pleuropneumonia
  45. 45. Contagious bovine pleuropneumonia
  46. 46. Contagious bovine pleuropneumonia
  47. 47. Contagious bovine pleuropneumonia
  48. 48. Contagious bovine pleuropneumonia Lesions (ii) MiCRO:  a- Fibrinous pleuropneumonia. b- Marked distension of interlobular septa with serofibrinous exudates & dilated Bl.vs & lymphatics c- Marked dilatation of lymphatics. d- Vasculitis and thrombus formation in capillaries and arterioles. e- Sequestra formation.
  49. 49. Contagious Caprine PleuroPneumonia (CCPP) * Acute disease of goats similar to CBPP of cattle Caused by Mycoplasma Capri • * But Differs in : No widening of interlobular septa.  No sequestra formation.  Marbling is less common.  Pericarditis, & Septicemia are common.  The exudates in the chest is more thick and tend  to clot easily.
  50. 50. Fibrinous pleuricy with adhesions(CCPP)
  51. 51. Mycoplasmal bronchitis and pneumonia in calves(Cuffing pneumonia) Definition:  * Mycoplasmal disease of calves * Characterized by (i) Chronic catarrhal bronchitis and bronchiolitis (ii) Development of lymphofollicular sheath around air ways giving the name of cuffing pneumonia.
  52. 52. Mycoplasmal bronchitis and pneumonia in calves(Cuffing pneumonia) Cause:  Mycoplasma dispar R.O.I: Inhalation of infected droplets.
  53. 53. (Cuffing pneumonia) Lesions (i) MACRO:  Patch purple red atlectatic foci in the cranio ventral region. (ii) MICRO: Catarrhal bronchitis and bronchiolitis.  Peribronchial and peribronchiolar  accumulation of lymphocytes and plasma cells (cuffing). Interstitial pneumonia. 
  54. 54. (Cuffing pneumonia)
  55. 55. (Cuffing pneumonia)
  56. 56. (Cuffing pneumonia)
  57. 57. (Cuffing pneumonia)
  58. 58. Strangles(Shipping fever of equines) Adenitis equerium Definition:  Acute contagious disease of young equines (2m – 5y ) * Characterized by: (i) Suppurative inflammation of the upper respiratory tract. (ii) Abscessation of the retropharyngeal and submaxillary L.N (iii) Systemic dissemination to internal organs.
  59. 59. Strangles Cause: Streptococcus equi produce (hemolycin & leucocydin). R.O.I: Inhalation.
  60. 60. Strangles Pathogenesis: Inhalation of the M.O nasal mucosal penetration lymphatics regional lymph nodes.
  61. 61. Strangles Lesions Purulent rhinitis, pharyngitis, laryngitis,  and sinusitis. Purulent bilateral creamy yellow nasal  discharge. Chronic empyemia of paranasal sinus and  guttural pouch if inflam. Extend from nasal cavity. Catarrhal conjunctivitis. 
  62. 62. Strangles
  63. 63. Strangles
  64. 64. Strangles
  65. 65. Lesions Suppurative inflammation of the  submaxillary and retropharyngeal L.N which may ruptured: (i) On skin To Outside.  (ii) On Trachea To Lung (supp.pneumonia)  (iii) On Blood To Circulation  (metastatic abscess)
  66. 66. Strangles
  67. 67. Strangles
  68. 68. Strangles
  69. 69. Strangles
  70. 70. Strangles
  71. 71. Strangles
  72. 72. Strangles
  73. 73. Strangles
  74. 74. Strangles Complications:  The disease is not fatal unless complicated by : 1- Suppurative bronchopneumonia, pleuritis and peritonitis with abscessation in different organs. 2-Damage of recurrent laryngeal nerve paralysis Roaring disease.
  75. 75. Strangles Complications:  3- Purpura hemorrhagica (Petechial fever) resulting from intoxication and allergy (arthus reaction). characterized by sub acute edema and hemorrhage allover serous membranes. 4- Septicemia, pyaemia, valvular endocarditis and meningitis.
  76. 76. Colibacillosis Definition :  Infectious disease of man and animals. Cause : E.coli. 
  77. 77. Colibacillosis  The organism produce the disease by 5 mechanisms : Pathogenesis : 1-Enterocyte-adherent Colibacillosis  2-Enterotoxic colibacillosis  3-Enterotoxaemic colibacillosis  4-Enteroinvasive colibacillosis  5-Septicemic colibacillosis 
  78. 78. Colibacillosis Pathogenesis :  1-Enterocyte-adherent Colibacillosis E.coli colonizing the surface of enterocytes without producing toxins.
  79. 79. Colibacillosis Pathogenesis  2-Enterotoxic colibacillosis  E.coli colonizing the mucosa producing enterotoxines diarrhea
  80. 80. Colibacillosis Pathogenesis 3-Enterotoxaemic colibacillosis E.coli colonizing small intestine  Produce toxins w’ has a pathogenic effect in ts. Other than gut. Increase permeability of blood vessels (edema disease of swine)
  81. 81. Colibacillosis Pathogenesis 4-Enteroinvasive colibacillosis  E.coli invade intestinal epithelium Acute exudative enteritis Endotoxaemia.
  82. 82. Colibacillosis Pathogenesi 5-Septicemic colibacillosis  E.coli produce bacteraemia, endotoxaemia and localization in different organs.
  83. 83. i.Enterotoxic colibacillosis Definition:  The major cause of neonatal diarrhea in • calves , pigs and lambs. Also cause diarrhea in man. * It occurs in the 1st. 2-3 days of life as the older resist the adhesion of coli by antibodies in milk
  84. 84. i.Enterotoxic colibacillosis
  85. 85. i.Enterotoxic colibacillosis Pathogenesis :  The organism adheres to the surface • of enterocytes enterotoxines hyper secretion of sodium chloride and water from crypt Absorption by villi Secretory diarrhea occurs.
  86. 86. i.Enterotoxic colibacillosis Macro: Non specific  Microscopic appearance :  1) Degeneration of enterocytes in ( jejunum & ileum ) villous atrophy (Enterocytes become cuboidal). 2) Fusion of intestinal villi. 3) Neutrophiles in intestinal lumen.
  87. 87. i.Enterotoxic colibacillosis Diagnosis:  Bacterial isolation for L.N & other  organs. Presence of gm –ve bacilli in smear of  ileal scraping. Electron microscopy.  Flurescent Ab test for frozen Ts. 
  88. 88. ii.Enteroinvasive colibacillosis Pathogenesis :  Affect Age < 2w  E.coli invade the enterocytes of the  lower small and large intestine producing acute exudative enteritis and endotoxaemia.
  89. 89. ii.Enteroinvasive colibacillosis P.M. lesions :  1. Congestion of lower parts of S.I  & caecum. 2. Mucosal erosions and ulcers.  3. Fluid content of intestine  tenged with blood.
  90. 90. ii.Enteroinvasive colibacillosis
  91. 91. ii.Enteroinvasive colibacillosis
  92. 92. ii.Enteroinvasive colibacillosis Microscopic appearance :  Enterocytes become cuboidal or  flattened (villous atrophy). Congestion and edema of lamina  propria with neutrophilic infiltration. Thrombosis of proprial capillaries and  submucosal lymphatics.
  93. 93. iii.Septicemic colibacillosis Definition:  Generalized Systemic infection with • E.coli mainly occurs in calves either as peracute ,acute, or subacute. Route of infection : (a) Navel in neonates OR (b) Upper respiratory tract and nasopharynx.
  94. 94. iii.Septicemic colibacillosis P.M. lesions :  (i) Omphalitis. (ii) Pneumonic lung. (iii) Firm spleen.
  95. 95. iii.Septicemic colibacillosis Microscopic appearance  (i) Per (more) acute cases. (ii) Acute cases. (iii)Subacute and chronic cases.
  96. 96. iii.Septicemic colibacillosis Microscopic appearance :  Per(more) acute cases  due to endotoxemia-----vascular permeability-  -----hemorrhage & thrombosis P/M lesions:  1- Picture of septicemia. 2- Abomasal ulcers. Micro:  Edema, Congestion & Thrombosis in lung and other ts.
  97. 97. Microscopic appearance: Acute cases  1- Interstitial pneumonia with fibrinous exudate and Neutrophiles in alveoli. 2- Neutrophiles in the hepatic sinusoids and lungs. 3-Fibrinous thrombi in hepatic sinusoids, glomeruli and pulmonary capillaries. 4- Focal interstitial nephritis (white spotted kidney).
  98. 98. Microscopic appearance: Subacute and chronic cases  1- Fibrinous Pleuritis, Peritonitis, and Pericarditis. 2- Mucopurulent to hemorrhagic sinusitis in lambs. 3- Fibrinopurulent arthritis & meningitis.
  99. 99. Salmonellosis Definition: * An infectious disease of man  and animals.  * Characterized by septicemia,  Gastroenteritis and enterocolitis. 
  100. 100. Salmonellosis Cause :  Gram – ve organism ( S.typhimurium, entritides and duplin). Route of infection :  Ingestion of contaminated materials.
  101. 101. Salmonellosis Predisposing factors :  Stress  (starvation, transportation, crowdness, parturition etc.). Young animals  susceptible to septicemic form whereas adults are carriers.
  102. 102. Salmonellosis Pathogenesis : Ingestion of M.O Enterocyte M.O by macrophages in L.P Cross the mucosa Lymphatics Blood stream Septicemia (Fatal in young animals) Bacteraemia Liver, spleen, gall bladder
  103. 103. Salmonellosis Pathogenesis : In Carriers M.O remain localized in Gut L.N & Payer's patches till stress factors. The organism secretes both:  Cytotoxins Deg. & necrosis of enterocytes Endotoxins Vascular damage (vasculitis) & thrombosis. 
  104. 104. Salmonellosis  Forms : (i) Septicemic, (ii) Acute or Enteric, (iii) Chronic. Sheep :  (i) Fibrinohemorrhagic enteritis (ii) Septicaemia. (iii) Abortion and death of ewes. Cattle : Not Occur Less Than 1w In  Contrast To colibacillosis.
  105. 105. Salmonellosis Cattle : (i)Per acute Septicemic form Ch’Ch’: *Septicaemia, * Meningioencephalitis * Polyarthritis.
  106. 106. Salmonellosis (ii) Acute or enteric form i. Intestine Post mortem lesions :  -Fibrinonecrotic or fibrinohemorrhagic enteritis ( ileum, jejunum and colon ) . -Enlarged mesenteric lymph nodes. Microscopic appearance :  - Fibrinonecrotic or fibrinohemorrhagic enteritis. - Thrombosis of proprial capillaries ( vasculitis). - Necrosis of payer's patches.
  107. 107. (Salmonellosis) micro quit previous
  108. 108. Fibrinonecrotic enteritis (Salmonellosis) micro quit previous
  109. 109. Fibrinonecrotic enteritis (Salmonellosis) gross more quit previous
  110. 110. Fibrinonecrotic enteritis (Salmonellosis) gross quit previous
  111. 111. Salmonellosis (ii)Acute or enteric form  ii. Liver Pathognomonic lesion is the presence  of paratyphoid nodules in the liver (focal areas of coagulative necrosis surrounded by macrophages) Similar nodules are found in kidneys,  spleen, lymph nodes and bone marrow. Fibrinous cholecystitis. 
  112. 112. Paratyphoid nodule (Salmonellosis) quit previous
  113. 113. Paratyphoid nodule (Salmonellosis) quit previous
  114. 114. Salmonellosis (iii) Chronic form Ch’Ch’: * Bronchopneumonia * purulent synovitis N.B:  Salmonella is an important cause of abortion in cattle in the majority of cases and the abortion is not associated with disease in the DAM.
  115. 115. Salmonellosis Horse : (i) Septicemic form *Occurs in foals 1-6 month Characterized by • Septicemic lesions as in cattle.
  116. 116. Salmonellosis (ii)Acute or enteric form  * Occurs in older animals. Characterized by diarrhea, fever • and recovery. • P.M and microscopic findings  are similar to those in cattle but involves cecum and colon ( Fibrinohemorrhagic typhlocolitis)
  117. 117. Salmonellosis (iii) Chronic form Ch’Ch’: Ulcerative typhlocolitis
  118. 118. Necrobacillosis Definition: * Infectious disease of  animals. * Characterized by  necrotizing lesions in the alimentary tract and liver.
  119. 119. Necrobacillosis * Different conditions produced by the organism in different animals: i- calf diphtheria in calves. ii- ulcerative enteritis in foals. iii- Fistulus withers in horses. iv- necrotic stomatitis, foot rot and liver necrosis in cattle and sheep.
  120. 120. foot rot Micro quit previous
  121. 121. foot rot Micro quit previous
  122. 122. Necrotic Stomatitis Micro quit previous
  123. 123. Necrotic Stomatitis Micro quit previous
  124. 124. Necrobacillosis Cause :  Fusobacterium necroforum. Route of infection :  Secondary invasion following mucosal damage ( oral wound, trauma, eruption of teeth) (predisposing causes).
  125. 125. Necrobacillosis Pathogenesis : The organism invade the  damaged mucosa and produce Endo&Exo toxine Necrosis. 
  126. 126. Necrobacillosis Spread of infection: Aspiration of necrotic material Gangrenous Pneumonia. Ingestion of necrotic material Stomach Intestine. Emboli Circulation different organs. lung  Oesophagus  Necrotic lesions in 
  127. 127. Necrobacillosis Spread of infection: Hepatic necrobacillosis observed in  lambs and calves following omphalophlebitis or as a complication after ruminitis in cattle. Infection of vagina and uterus after  parturition as contamination after inflammatory genital ds.
  128. 128. Necrobacillosis P.M lesions :  Large well demarcated yellowish gray  dry areas of necrosis surrounded by a hyperaemic zone on the tongue, gum, palate ,cheeks and pharynx. Necrotic areas project above the mucosal  surface Sloughs Deep ulcer
  129. 129. Necrobacillosis Micro quit previous
  130. 130. Hepatic necrobacillosis Micro quit previous
  131. 131. Hepatic necrobacillosis quit previous
  132. 132. Pulmonary necrobacillosis quit previous
  133. 133. Necrobacillosis Microscopic appearance :  Structureless area  surrounded by hyperaemic zone and leucocytes, later by thick capsule of granulation tissue.
  134. 134. Hepatic necrobacillosis Gross High power quit previous
  135. 135. Hepatic necrobacillosis Gross High power quit previous
  136. 136. Leptospirosis Definition: Acute infectious septicemic disease of cattle, dog and man. Ch’Ch’: septicemia, hepatitis, Icterus, nephritis, meningitis & abortion in swine & ruminant
  137. 137. Leptospirosis Cause :  Leptospira icterohemorrhagica, Pomona and canicola ( spiral m.o.). Route of infection :  (i) Ingestion, (ii) Abraded skin, (iii) Intrauterine ( transplacental ).
  138. 138. Leptospirosis Pathogenesis : M.O penetrates the mucosa blood  Septicaemia If animal not die during septicemia Localization Liver Icterus Kidney Interstitial nephritis Localization  Pregnant uterus Abortion 
  139. 139. Leptospirosis Cattle  P.M lesions :  Lesions of septicaemia ( petechial hemorrhages  on serous membranes and S/C edema & hemorrhage ,ect…………) Liver enlarged, anemic, bile stained and showed  hemorrhage and necrotic foci. Kidney showed grayish foci of interstitial  reaction. Aborted fetuses showed advanced autolysis &  putrifaction.
  140. 140. Leptospirosis
  141. 141. Leptospirosis
  142. 142. Leptospirosis Dog P.M lesions :  Liver showed atrophy and fibrosis.  Subcapsular hemorrhages in the  kidney. In chronic cases the capsule become adherent.
  143. 143. Leptospirosis Cattle Microscopic appearance : 1. Necrosis of hepatic cells around central vein  with hyperplastic kupfer cells containing hemosiderin. 2. Cellular infiltration of portal area while bile  canaliculi distended with bile. 3. Interstitial nephritis with tubular  degeneration and necrosis.  4. Placentitis and meningitis. 
  144. 144. Leptospirosis
  145. 145. Leptospirosis
  146. 146. Leptospirosis Dog Microscopic appearance : 1- Dissociation of hepatic cells which appear  Dark and atrophied. 2- Regeneration evidenced by cytomegally,  binucleation & mitoses 3- Kidney showed similar changes as in  cattle but more chronic with decreased interstitial exudate and increased fibrosis.
  147. 147. Anthrax(splenic fever) Definition: Highly septicemic infectious  disease of man and animals. Characterized by septicemia  and sudden death.
  148. 148. Anthrax(splenic fever) Cause : Bacillus anthracis, spore forming Gram + ve bacilli. Route of infection : (i) Inhalation, (ii) Wound infection, (iii)Vaccination(if the vaccine is not sufficiently attenuated). (iv) Ingestion
  149. 149. Anthrax(splenic fever) Pathogenesis : 1- Ingestion Pharynx Regional L.N Lymphatics Blood Septicemia 2. The organism produce toxin Endothelial injury Hemorrhage. 3. The organism acts on the respiratory center Asphyxia Death. 4. The capsule of the organism has a fibrinolytic properties (unclotted blood).
  150. 150. Anthrax(splenic fever) Forms :  (i) Septicemic form In Cattle and Sheep. • *Ch’Ch’ sudden death and dark tarry unclotted blood oozing from the natural body orifices. 1. Petechial and echymotic hemorrhages on serous membranes. 2. Subcutaneous edema and hemorrhage. 3. Serosanguinous fluid in body cavities.
  151. 151. Anthrax(splenic fever) Forms :  (i) Septicemic form 4. Lymph nodes swollen, edematous and hemorrhagic. 5. Liver and kidney degeneration (pale and friable). 6. Spleen is markedly enlarged (spleenomegally), PATHOGNOMONIC LESION.
  152. 152. Anthrax(splenic fever) Forms :  (ii) Localized form In horse, pigs and dogs:  Pharyngitis, lymphadenitis and Edema of face, neck, and Throat. In man :  Cutaneous anthrax----------Malignant carbuncle Respiratory anthrax ( via spores inhalation )----------------- wool sorter's disease .
  153. 153. Anthrax(splenic fever)
  154. 154. Anthrax(splenic fever)
  155. 155. Anthrax(splenic fever)
  156. 156. Anthrax(splenic fever)
  157. 157. Anthrax(splenic fever)
  158. 158. Anthrax(splenic fever)
  159. 159. Anthrax(splenic fever)
  160. 160. Clostridial diseases Group of diseases caused by Clostridia organisms, gram + ve, spore forming bacteria. 1.Black disease (Infectious necrotic hepatitis) 2.Bacillary hemoglbinurea 3.Black leg ( black quarter ) 4.Gas gangrene (malignant edema) 5.Tetanus (lock jaw) 6.Enteric Clostridial infections (Enterotoxaemia)
  161. 161. Clostridial diseases 1.Black disease(Infectious necrotic hepatitis) Definition: *Infectious disease of sheep,goat ,Cattle&horse * Caused by : C. novyi. Type B Characterized by necrotic hepatitis and dark skin.
  162. 162. 1.Black disease (Infectious necrotic hepatitis) Cause : C. novyi Route of infection : Ingestion of food and water contaminated with spores.
  163. 163. 1.Black disease (Infectious necrotic hepatitis) Pathogenesis : Ingestion of spores Infestation of the animal with fasciola intestine liver necrosis circulation localization in histeocytes of liver germination suitable anaerobic condition multiplication exotoxines liver necrosis
  164. 164. 1.Black disease (Infectious necrotic hepatitis) P.M Lesions 1.Black coloration of skin due to venous congestion of subcutaneous tissue. 2.Pathognomonic lesion is the presence of yellowish white areas of hepatic necrosis surrounded by hyperaemic zone. 3.Subendocardial hemorrhage in left ventricle. 4.Hemorrhage and congestion of abomasums.
  165. 165. 1.Black disease (Infectious necrotic hepatitis)
  166. 166. 1.Black disease (Infectious necrotic hepatitis)
  167. 167. Clostridial diseases 2. Bacillary hemoglbinurea Definition: * Highly fatal infectious disease of cattle & sheep *Caused by C. hemolyticum spores. *Characterized by hepatic necrosis and intravascular hemolysis.
  168. 168. 2.Bacillary hemoglbinurea Cause : C. hemolyticum Route of infection : Ingestion of food and water contaminated with spores.
  169. 169. 2.Bacillary hemoglbinurea Pathogenesis : Ingestion of spores Infestation of the animal with fasciola liver necrosis intestine circulation localization in histeocytes of liver Exotoxines Remain in suitable anaerobic condition multiplication kupffer cells and produce intravascular hemolysis
  170. 170. 2.Bacillary hemoglbinurea Signs: Icterus and hemoglbinurea P.M Lesions Liver contains well demarcated areas of  necrosis surrounded by hyperaemic zone. Mottling of the kidney due to hemoglobin.  Serous cavities contain straw colored fluid  with fibrin.
  171. 171. 2.Bacillary hemoglbinurea
  172. 172. 2.Bacillary hemoglbinurea
  173. 173. Clostridial diseases 3. Black leg ( black quarter ) Definition: Infectious disease of cattle and • sheep * Caused by C. chuvoei. *Characterized by emphysematous and edematous swelling of subcutaneous tissue with necrosis of muscles specially of hind quarter, Gangrene, Toxemia and Death.
  174. 174. 3.Black leg(black quarter) Cause : C. chuvoei. Route of infection : Ingestion.
  175. 175. 3.Black leg(black quarter) Pathogenesis : Ingestion of spores intestine Infestation of the animal with fasciola muscular fatigue circulation localization in skeletal muscles germination multiplication Muscle necrosis suitable anaerobic condition Exotoxines Gangrene & Toxemia
  176. 176. 3.Black leg(black quarter) P.M Lesions Early or wet stage : Muscles are  necrosed appear dark red and separated by serohemorrhagic exudate. Late or dry stage :  i) Muscles are dark red or nearly black (due to the formation of h2s) with gases ii) Signs of toxemia
  177. 177. 3.Black leg(black quarter)
  178. 178. 3.Black leg(black quarter)
  179. 179. 3.Black leg(black quarter) Micro 1. Extensive coagulative necrosis  (zenker's necrosis) of muscle fibers with edema and hemorrhage. 2.Vasculitis and formation of gas  bubbles between the necrotic muscle fibers.
  180. 180. Clostridial diseases 4. Gas gangrene OR malignant edema Definition: * Infectious disease of cattle, sheep & equine * Caused by Separate or mixture of C.chauvoei, perfringes or septicum. * Characterized by edematous and crepitating swelling of muscles.
  181. 181. 4.Gas gangrene OR malignant edema Cause : Separate or mixture of C.chauvei, perfringes or septicum. Route of infection : Deep wound infection (castration , shearing) .
  182. 182. 4.Gas gangrene OR malignant edema Pathogenesis : Deep wound infection  (anaerobic conditions) Germination of spores Multiplication Exotoxines Muscle necroses.
  183. 183. 4.Gas gangrene OR malignant edema
  184. 184. 4.Gas gangrene OR malignant edema
  185. 185. Clostridial diseases 5. Tetanus (lock jaw) Definition: * Infectious disease of man and animals. Characterized by stiffness of muscles and closure of jaw.
  186. 186. Clostridial diseases 5. Tetanus (lock jaw) Cause : C. tetani. Route of infection : Deep wound.
  187. 187. Clostridial diseases 5. Tetanus (lock jaw) Pathogenesis : Deep wound infection (anaerobic  conditions) Germination of spores Multiplication Neurotoxins (tetanospasmin) inhibit the release of neurotransmitter glycin Stiffness of muscles (maseter and facial) death due to asphyxiation (spasm of diaphragmatic muscles)
  188. 188. Tetanus (lock jaw)
  189. 189. Tetanus (lock jaw)
  190. 190. Tetanus (lock jaw)
  191. 191. Clostridial diseases 5. Tetanus (lock jaw) PM lesions : Not characteristic.
  192. 192. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) Group of enteric diseases in cattle & sheep caused by 5 different toxigenic types of C.perfringens:  C. perfringens type A (& toxin)  Gas gangrene ( malignant edema ). C. perfringens typeB (B toxin)  Lamb dysentery C. perfringens type C (B toxin) Struck  C. perfringens type D (E toxin)  Pulpy kidney, Braxy like ds, Blind staggers. C. perfringens type E (i toxin) Hemorrhagic enteritis 
  193. 193. Clostridial diseases 6. Enteric Clostridial infections Enterotoxaemia) ( Action Of C.perfringens exotoxins: & toxin: - Lecithinase /act on cell membrane/ cause  hemolysis or cell necrosis. B toxin: - Causing necrotizing enteritis & paralyzing  effect on intestine. E & i toxin: Produced as protoxin w’ get activated by  proteolytic Enzymes.
  194. 194. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C. Perfringens type C (Struck) * Disease of  Adult sheep, goat & feed lot cattle. * Symptoms:  Sudden death. * PM lesions:  Hemorrhagic enteritis ( jejunum & ilium) with toxemia.
  195. 195. C.Perfringens type C(Struck)
  196. 196. C.Perfringens type C(Struck)
  197. 197. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C. Perfringens type B (Lamb dysentery) Affects lambs 10-14 day,  calves less than 10 days and foals 2 days. Symptoms:  Sudden death// Abdominal pain// Passage of semi fluid feces mixed with blood.
  198. 198. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C. Perfringens type B (Lamb dysentery) P.M lesions : Extensive hemorrhagic enteritis.  Single then confluent ulceration intestinal  perforation peritonitis. Congestion and edema of mesenteric lymph nodes.  Signs of toxemia.  Microscopic appearance :  Hemorrhagic enteritis and necrosis which extends to  muscular layer and peritoneum. 
  199. 199. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C. Perfringens type D (Pulpy kidney-overeating disease) Definition :  * Disease of sheep,Goat and sometimes calves. * Usually associated with overload or sudden change in diet to grains or C,H,O. Symptoms : Per acute Acute Subacute Adult 3 forms can be recognized:  Sudden death. Salivation and coma. Neurological signs. Diarrhea
  200. 200. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C.Perfringens type D (Pulpy kidney-overeating disease) Pathogenesis : Over feeding with carbohydrates  fermentation Acidosis (favorable media for the organism to proliferate) Epsilon toxin circulating blood Endothelial injury Edema & hemorrhage in brain and kidney.
  201. 201. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C. Perfringens type D (Pulpy kidney-overeating disease) P.M lesions : Edema in serous cavities.  Subendocardial hemorrhage of left ventricle,  Kidney congested and soft (pulpy) due to  degeneration and rapid autolysis ( NOT IN ADULT) SYMMETRIC Encephalomalacia (not in goats). 
  202. 202. C. Perfringens type D (Pulpy kidney-overeating disease)
  203. 203. C. Perfringens type D (Pulpy kidney-overeating disease)
  204. 204. Clostridial diseases 6. Enteric Clostridial infections (Enterotoxaemia) C.Perfringens type D (Pulpy kidney-overeating disease) Microscopic appearance : Kidney :  Degeneration and necrosis of proximal convoluted tubules. Brain:  Edema and hemorrhage around capillaries symmetric encephalomalacia .
  205. 205. Listeriosis Definition: * Infectious disease of man and animals. * Caused by Lesteria monocytogenes. * Characterized by Septicemia, Encephalitis, and Abortion. * Seasonal ds. As it occurs in winter and early spring.
  206. 206. Listeriosis Cause : Lesteria monocytogenes. Route of infection : Ingestion. BEHAVE AS 3 SEPARATE DISEASES AS  IT HAVE 3 FORMS 1. Abortion  2. Septicemia 3. Encephalitis. Forms :
  207. 207. Listeriosis Forms : (i) Abortion syndrome Abortion in cattle and sheep occurring during the  last 3 months of pregnancy. Early Uterine infection Late uterine infection  Fetal death (septicemia) Dystocia (difficult parturition) Autolysis and Expulsion Metritis and Septicemia of dam Retained placenta (due to metritis)
  208. 208. Listeriosis Forms : P.M lesions : (i) Abortion syndrome Fetus Placenta   Necrotic foci in liver and spleen. Necrosis of placenta which is covered by purulent exudate.
  209. 209. Listeriosis Forms : (ii) Septicemic form *Occurs in early neonatal life and *Characterized by milliary abscesses w’ are:very numerous in liver. less numerous in heart and other organs
  210. 210. Listeriosis Forms : (iii) Encephalitic form * The M.O invade the brain stem. * Very severe in medulla & pons. Signs : *Deviation of head to one side where the animal moves in circles (Circling ds.). *Paralysis of masticatory ms. & pharynx. *Unilateral paralysis of the 7th nerve resulting in drooping of an ear , eyelid and lips. *Unilateral endopthalmitis ( inflammation of ocular cavity)
  211. 211. Listeriosis Forms : PM lesions: Meninges are thickened by greenish edema.  Grayish foci of softening in C/S of medulla.  Micro : Micro abscesses in brain.  Vasculitis in white matter  perivascular cuffing  meningitis.  Areas of malacia (softening) due to thrombosis. 
  212. 212. Brucellosis Definition: * Infectious disease of animals & man. * Caused by brucella. * Ch’Ch abortion. Cause: Brucella species.  Route of infection :  1. Ingestion 2. Conjunctiva 3. Intact or broken skin 4. Coitus.
  213. 213. Brucellosis Pathogenesis : Localization Female M.O Pregnant Spleen uterus Mammary gland Regional L.N Male & Female Synovial structures (tendovaginitis) (arthritis) placental necrosis Blood  Male  Lymphoid tissue testis&Accessory gland (prostate & seminal vesicles) (Bursitis) Formation of granulomes Abortion (Epithelioid cells surrounded by lymphocytes and plasma cells) * Localization of brucella organism in different organs depends on the presence of its carbohydrate content ( erythritol ) as a source of energy for the growth of the M.O. * whenever the organism localized, granuloma develops.
  214. 214. Brucellosis Abortion in cattle Occurs in the 7th & 8th m of gestation.  In severe cases, abortion or  premature birth occurs. In mild cases,calf delivered either  viable or not viable.
  215. 215. Brucellosis P.M lesions : (i) Placenta Edema of intercotyledonary area (between fetal  membranes and uterine mucosa) with coagulative necrosis of maternal (caruncle) and fetal (cotyledon) portions of the placentome. Placenta becomes leathery with brown thick  exudate on the chorionic surface. In animals previously infected with brucellosis,  fibrosis of fetal and maternal portions of the placentome results in retained placenta.
  216. 216. Brucellosis P.M lesions : (i) Placenta Micro : Edema and cell infiltration of the  intercotyledonary area. Vasculitis due to endotoxines.  areas of coagulative necrosis in  fetal and maternal portions of the placentome.
  217. 217. Brucellosis P.M lesions : (ii) Fetus Catarrhal or fibrinous bronchopneumonia.  Fibrinous inflammation of serous membrane.  Micro : Catarrhal or fibrinous bronchopneumonia.  Necrotizing arteritis.  Granuloma with giant cell formation in the  spleen and L.N.
  218. 218. Brucellosis P.M lesions : (iii) Udder (Bang's disease) Characterized by focal interstitial mastitis.  (iv) Bull Orchitis, seminal vesiculitis and prostatitis.  Orchitis characterized by areas of necrosis  which liquefies into pus surrounded by C.T. capsule.
  219. 219. Vibriosis(Campylobacter fetus) Definition: * Infectious disease of cattle and sheep.  * Ch’ch’ ; Abortion and infertility.  Cause: Campylobacter fetus var venerealis in cattle. Campylobacter fetus var intestinalis in sheep. 
  220. 220. Vibriosis(Campylobacter fetus) In Cattle: Signs * Abortion 4-6 months of gestation.  * Temporary sterility or repeat  breeding due to early embryonic death. 
  221. 221. Vibriosis(Campylobacter fetus) In Cattle: R.O.I *By coitus and artificial insemination.  *Bulls can act as carriers by carrying  the organism in the penile mucosa up  to 4-5 years. * M.O can survive in vaginal mucosa  for longer periods.
  222. 222. Vibriosis(Campylobacter fetus) In Cattle: Lesions Gross and microscopic  picture is similar to those  of brucellosis but less severe.
  223. 223. Vibriosis(Campylobacter fetus) In Sheep: Pathogenesis: Ingestion Bacteremia Localization in gut,bile,or uterus  of pregnant ewes
  224. 224. Vibriosis(Campylobacter fetus) In Sheep: Signs Abortion 4 months of gestation  ( late). 
  225. 225. Vibriosis(Campylobacter fetus) In Sheep: Lesions *DAM Endometritis, Cervisitis, and Vaginitis *Placenta *Fetus Placentitis as in brucellosis. Multiple areas of hepatic necrosis with depressed center. •   •

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