Department of Pathobiology
Pathology of the Respiratory
Disclaimer: Images from this presentation come from
different sources: Mc Gavin ‘s Pathologic Basis of Veterinary
Disease, Dr. King files, Noah’s arkive ,OVC, AVC, author’s
own files etc. This presentation is for teaching purposes only,
please do not distribute.
Overview of the diseases that affect the respiratory system of
how to recognize the morphologic changes present within
tissues in specific diseases/ conditions
most common respiratory diseases
how to arrive to the proper morphologic or etiologic diagnosis
for the lesion
Disease pathogenesis, if known
Differential diagnosis, if applicable.
A. Lόpez:“ Respiratory System” in Pathologic Basis ofVeterinary
Disease, McGavin & Zachary, editors, 5th ed., Mosby, p458-,
J Caswell & K.Williams:“Respiratory System” in JKP
Pathology of Domestic Animals,Vol 2, edited by MG Maxie, 5th
ed., Saunders, p523-653, 2007
Anatomic division of the respiratory
Upper & Lower respiratory
tract. In general the upper respiratory
tract is the portion of the respiratory
system located outside the thoracic
Physiologically the respiratory tract
is divided into three independent
but continuous systems:
1.- Conducting system: Includes the
nasal cavity, paranasal sinuses, larynx, trachea
and bronchi.The mucosa of this system
is primarily lined by pseudostratified ciliated
and goblet cells.
2.-Transitional system : consists
exclusively of bronchioles which are
lined by Clara cells (detoxification of xenobiotics),
non-ciliated secretory cells and only a few ciliated
cells. Healthy bronchioles do not have
3. Exchange system: Composed of alveolar
ducts and millions of alveoli; thin-walled
structures enveloped by a rich network of
capillaries, the pulmonary capillaries.
Alveoli are lined by epithelial
type I (membranous) and type II (granular)
pneumocytes (also called pneumonocytes).
Each of these systems has a
characteristic susceptibility to injury
and specific type of host response and
The lungs have a dual blood supply:
Through the pulmonary arteries which
conduct deoxygenated blood from
the right side of the heart, and the bronchial
arteries, which carry oxygenated blood.
In addition to gas exchange, the respiratory system is
also involved in phonation, olfaction, temperature
regulation, acid–base balance, blood pressure
Several of these functions may be affected by
Pictures from Dr. Thomas Caceci’s histology
Pictures from Dr. Thomas Caceci’s histology
Normal Flora – Restricted only to the most
proximal region of the conductive system: nasal
cavity, nasopharynx, larynx and trachea.
The distal portions of the respiratory tract are
considered to be sterile.
Even though the majority of
the organisms of the normal
respiratory flora are harmless
others are potentially
pathogenic; e.g.: Mannheimia
“The air that we inhale
every day in a healthy
billions of suspended
particles, spores, bacteria,
viruses and noxious gases
that are constantly carried
deep into the
lungs have a very efficient
defence system to deal
with the environmental
hazards present under
Experimental studies have demonstrated that bacteria
from the nasal flora, including some potentially
important pathogens, are constantly being carried into
the lungs by inspired air. In spite of this constant
bacterial bombardment, the lower respiratory tract remains
essentially sterile due to the presence of
highly effective respiratory defence mechanisms.
Defence mechanisms of the
Non-specific (non immune-
Mucociliary clearance (mucociliary
Air turbulence (generated by
coughing and sneezing).
ruminants,cats,pigs and horses)
In dogs, humans and laboratory
rodents the cells responsible for removing
circulating bacteria and other particles from
blood are the Kupffer cells (liver) and splenic
Animals suffering from a respiratory viral infection
have notably suppressed defence mechanisms which make them
susceptible to bacterial colonization within the airways.
Viruses are not the only factor known to predispose to bacterial
pneumonia, other causes are:
Post-mortem examination of the respiratory
Thorough systematic examination and appropriate sampling are
very important. Microbiology results should always be interpreted
carefully taken into account clinical and post-mortem findings.
Ethmoidal hematoma – cause of
epistaxis in horses
Pedunculated tumor-like lesion in
older horses.The exact etiology of
this lesion is unknown.
Dr.King’s show & Tell
Fibrinous rhinitis – mid-sagittal section of the
head – Calf with IBR
Infectious Bovine Rhinotracheitis (formation of
Oestrus ovis, nasal bot in sheep
– worldwide distribution
From McGavin, Zachary.
Aberrant migration of Oestrus ovis larva, sheep-TexasA&M.
Atrophic rhinitis in pigs.
Multifactorial disease in growing pigs.
Currently is thought to be the result of a
combined infection of Bordetella
bronchiseptica and Pasteurella multocida
types D andA.
Atrophic Rhinitis – UCVM, OI
Right: Affected pig
The toxigenic strains of P.multocida produce cytotoxins which inhibit
osteoblastic activity and promote osteoclastic reabsorption of the nasal
turbinates. “The ventral scroll of the ventral nasal turbinate is the area
most commonly and consistently affected”…
Inclusion Body Rhinitis –
Porcine Cytomegalovirus (suid
herpesvirus 2 [SHV-2])
infection, Pig, AVC, OI
Usually in pigs 3-5 weeks of age.
Fatal systemic infection occurs
occasionally in younger suckling pigs
(less than 3 weeks of age).
Nasal submucosal glands
with large basophilic
Inflammation of the guttural pouch,
horse (guttural pouch empyema) due
Caused by infection with
Aspergillus fumigatus or
other Aspergillus species.
Involvement of cranial
nerves (VII, IX, X, XI, XII)
is common and result in a
variety of clinical signs.
Erosion of the wall of the
internal carotid artery can
lead to epistaxis or fatal
Guttural Pouch mycosis
Necrotic laryngitis (Calf
Secondary infection by
following trauma or viral
infection (IBR). Can also
occurs as part of oral
necrobacillosis in calves and
Plaques of ulceration covered
by fibrinonecrotic exudate.
(paralysis) – “roaring”
horses.Atrophy of the left
Usually the result of an
affecting the left recurrent
*From McGavin „s Pathologic Basis of Veterinary Disease book.
Trachea - bronchi
Tracheal collapse: Mainly in toy and miniature dog
breeds; occasionally seen in horses, cattle and goats.
Dorso-ventral flattening of the trachea and
concomitant widening of the dorsal tracheal
May result in coughing and exercise
Canine infectious tracheobronchitis
A variety of infectious
agents are often isolated
from affected dogs but
there is consensus that
usually plays a primary
CAV-2, CPIV-2 and to a
lesser extend canine
distemper virus and
Mycoplasma spp., have
Horses and ponies– chronic bronchiolitis-emphysema
complex, “heaves”, “broken wind”, Recurrent Airway
Obstruction (RAO). Asthma-like syndrome (used to be
known as Chronic Obstructive Pulmonary Disease (COPD)
From: « Recurrent airway obstruction – heaves ». The
Veterinary Clinics, Equine Practice, 19: 63-86, 2003. Renaud
Léguillette, DMV, MSc, DACVIM. McGill University, UCVM- Canada.
Severe heaves. The head &neck are
extended and the horse shows nasal
flaring with mucoid nasal discharge. „„Heave line.‟‟ The hypertrophy of external abdominal oblique
muscles as a result of expiratory efforts suggests that the horse
has been chronically affected by heaves.
Other similar disease in veterinary
medicine : Feline asthma,
a.k.a. feline allergic bronchitis.
“Hyperactive airway disease”
Composed of the
basement membrane of
the endothelial cell,
basement membrane of
the type I pneumocyte
and the cytoplasm of the
of the type I
Circulatory disturbances: Pulmonary
Exercise-induced pulmonary haemorrhage (EIPH):
Relatively common condition in race horses.
Follows strenuous exercise.
Epistaxis is present in only 1-10% of affected horses.
Frequency increases with age and the severity of exertion.
Probably the result of marked elevations in arterial and capillary
pressures during strenuous exercise.
Haemorrhage occurs in the dorso-caudal portions of the caudal
Massive pulmonary haemorrhage may be the only detectable
lesion in horses that die during exercise .
Epistaxis and pulmonary hemorrhage are relatively
common in cattle with vena cava thrombosis
* From McGavin’s Pathologic Basis
of Veterinary Disease
HE-stain, dark brown pigment within the cytoplasm of alveolar macrophages,
Iron (Perl‟s) stain –
macrophages (“heart failure
within alveoli – UCVM.
From McGavin’s Pathologic Basis of Veterinary Disease
Pigmentary disturbances: Pulmonary anthracosis
From McGavin’s Pathologic Basis of Veterinary Disease
Incomplete expansion of the lungs or portions of the
Pulmonary parenchyma appears dark-red and sunken in
comparison to aerated lung. Consistency is fleshy and the
lung tissue does not float.
Congenital, acquired, compressive (caused by space-
occupying lesions like hydrothorax, hemothorax,
pleuritis), massive (pneumothorax).
Pulmonary atelectasis – bovine fetus; also in
Aspiration of amniotic fluid
“Meconium is the dark-green
in the intestine of a full term
fetus –a mixture of secretions
from intestinal glands and
Patchy pulmonary atelectasis due to aspiration of
meconium and amniotic fluid-calf, 1 day old,AVC.
“Permanent enlargement of
air-spaces distal to the terminal
bronchiole, accompanied by
destruction of alveolar walls”
Important primary disease in humans where often co-exists with
COPD attributable to cigarette smoking.
“It is thought to be an imbalance between proteases and anti-
proteases (like α1 antitrypsin) Neutrophil-derived serine
proteases, particularly elastase and matrix metalloproteinases from
a variety of sources are the likely culprits.Their concentrations are
enhanced by neutrophil and macrophage activation induced in
chronic bronchitis” –JKP, 2007 –G Maxie, ed.
The emphysematous lung is dysfunctional since the loss of alveolar
septa reduced the alveolar surface area Reduction in gas
In animals is always secondary to obstruction of outflow of
air or agonal at slaughter.
Frequent in animals with bronchopneumonia airflow
imbalance the volume of air entering the lungs exceeds
the volume exiting the lung during expiration.
Classified also as alveolar of interstitial (the latter mainly in
Bullous emphysema: Large focal
air-filled spaces (bullae) rupture
may lead to fatal pneumothorax.
Cow, pulmonary edema emphysema,
No universal classification in
veterinary medicine –quite
Right: Diagram of common
patterns of pneumonia:
A: Normal lung
C: Fibrinous bronchopneumonia
D: Interstitial pneumonia
E: Embolic pneumonia
F: Granulomatous pneumonia A. Lopez, Atlantic Veterinary
Aerogenous (airborne) route and
Pneumonias in cattle:
Infectious Bovine Rhinotracheitis (IBR): Caused by BoHV-1.
Para-influenza-3 virus (PI-3 virus) and Bovine Respiratory
Syncytial virus (BRSV) cause a transient rhino-tracheitis and
broncho-interstitial pneumonia with the formation of eosinophilic
intracytoplasmic inclusions bodies in bronchial, bronchiolar and
alveolar epithelial cells and alveolar macrophages. Formation of
syncytial cells occurs in both, BRSV and PI-3 virus infection.
BRSV and PI-3 should be considered in calves with necrotizing
Diagnosis is confirmed by virus isolation, PCR or detection of
viral antigens by fluorescence antibody test (FAT) or
BRSV. Right: IHC stains demonstrates
widespread injury to the airway
Bovine enzootic pneumonia (chronic
Disease caused by a variety of
etiologic agents which include
respiratory viruses, Mycoplasmas,
Chlamydophila, followed by
opportunistic bacteria such as
Mannheimia haemolytica and E.coli.
Calves with bovine leukocyte
adhesion deficiency (BLAD), which
prevents the migration of
neutrophils from the capillaries, are
highly susceptible to
Abscessation and bronchiectasis are
Common sequels of chronic suppurative
Pneumonic mannheimiosis (“shipping
Acute respiratory disease that
occurs in cattle several days or
weeks after shipment.
Because Mannheimia haemolytica
(formerly Pasteurella haemolytica) is
typically isolated the term
penumonic mannheimiosis or
pneumonic pasteurellosis have
Most economically important
respiratory disease of cattle in
NorthAmerica, particularly in
Mannheimia haemolytica biotype A,
serotype 1 is responsible for the
severe pulmonary lesions (areas of
What type of necrosis?
Part of the Histophilus somni
disease complex (TME,
myocarditis, arthritis, abortion
May cause suppurative or
The later may be
undistinguishable from the
caused by Mannheimia haemolytica.
Mycoplasma bovis pneumonia
Important cause of chronic
respiratory disease in feedlot
cattle – common inAlberta.
The organism causes a chronic
which is quite characteristic.
M.bovis also causes severe chronic
Chronic necrotizing bronchopneumonia, heifer,
UCVM. Mycoplasma bovis was cultured from
the lesions, OI, 2008.
UCVM, O.I., 2008.
What type of necrosis?
Positive immunoperoxidase staining of M. bovis antigens,
from McGavin‟s, 2012
Caused by M.bovis. It has been suggested
that the termTB should be limited to
diseases caused by M.tuberculosis (human)
and M.bovis (cattle); other conditions
should be referred as “Mycobacteriosis”.
In NorthAmerica the disease has been
almost eliminated but there still outbreaks
that often originate from wild life (M.bovis
not only affects cattle and humans but also
deer, elk, bison etc. wild ruminants).
Lesions are more common in
retropharyngeal lymph nodes, lungs,
thoracic and mesenteric lymph nodes.
Lesions in cervids often contain prominent
suppurative exudate and may resemble
Multifocal granulomatous pneumonia, M. bovis, cow,
Dr. King-Cornell’s file.
Verminous bronchitis/ pneumonia
In cattle is caused by infection with Dictyocaulus viviparus. Varies from
interstitial pneumonia (larval migration) to chronic bronchitis
(intrabronchial adult parasites) to granulomatous pneumonia (eggs,
Terminal bronchi from the right caudal lung lobe, pig. Slaughterhouse specimen,
St. Kitts. Lung worms are admixed within slightly turbid mucoid exudate.
Morphologic dx?.., etiologic dx?...
Lung worms in pigs:
Numerous thin and elongated worms within the terminal bronchi of the
caudal (diaphragmatic) lung lobes: Metastrongylus spp. Pig,
slaughterhouse specimen, St. Kitts, 2012.
Same pig as in the previous image. Numerous Metastrongylus spp. are
present within a bronchus, caudal lung lobe. Possible morphologic dx:
catarrhal bronchitis; Etiologic dx: Verminous (or parasitic) bronchitis;
pulmonary metastrongylosis. RUSVM, OI.
Atypical Interstitial Pneumonia (AIP) of cattle
Pneumonias that did not fit any of the “classical” forms of
Characterized by the presence of edema, interstitial
emphysema, hyaline membranes, type II pneumocyte
hyperplasia and interstitial fibrosis with cellular infiltrates
These types of pneumonias have specific etiologies.
Investigators have proposed that these syndromes previously
clustered underAIP be named according to their specific
cause or pathogenesis.
Diffuse alveolar damage –formation of hyaline
membranes – AIP, cow. From McGavin’s
Atypical Interstitial Pneumonias -
Bovine pulmonary edema & emphysema (“fog fever”)
Extrinsic allergic alveolitis (hypersensitivity pneumonitis)
Reinfection syndrome (hypersensitivity to Dictyocaulus sp.
Milk allergy: type I hypersensitivity in cows sensitized to
their own milk casein and lactalbumin.
Ingestion of moldy potatoes contain 4-ipomeanol which
is metabolized by mixed function oxydases in the lung
(Clara cells) to a potent pneumotoxicant.
Bovine pulmonary edema &
emphysema (“fog fever”) occurs
in cattle grazing “fog” pastures (re-
growth pasture after a hay or silage
has been cut or lush green grass). L-
tryptophan present in the pasture is
metabolized in the rumen to 3-
methylindole → absorbed into the
blood and carried to the lungs →
metabolized by the mixed function
oxidases of non-ciliated bronchiolar
epithelial cells (“Clara” cells) into a
highly pneumotoxic compound that
causes extensive necrosis of
bronchiolar epithelial cells and type I
pneumocytes (diffuse alveolar
“Extrinsic Allergic Alveolitis”
Common; mainly seen in adult dairy cows in the winter.The human
counterpart is referred to as “farmer’s lungs”.
Type III hypersensitivity reaction to inhaled organic antigens, most
commonly fungal spores present in moldy hay (local deposition of Ag-
Ab complexes in the lungs).
Gross lesions vary from subtle gray subpleural foci of granulomatous
inflammation to severe lesions in which the lungs acquire a “meaty
appearance” due to alveolar epithelial hyperplasia, interstitial
inflammation and fibrosis.
Pathogenesis of toxic and allergic pneumonias
(“AIP”) in cattlle.
* From McGavin’s pathology book
Pneumonias of Sheep
Viral pneumonias: Like in cattle PI-3 virus and RSV can produce
pneumonitis in sheep.
Maedi (maedi-visna): Lifelong, persistent disease of sheep that
occurs in most countries with the exception of Australia and New
Zealand. It is also known as Ovine Progressive Pneumonia (OPP).
The disease is caused by a retrovirus of the lentivirus subfamily
(ovine lentivirus) similar to the agent of CAE. Infection results in a
lymphocytic interstitial pneumonia (LIP).
The virus may also cause a non-suppurative encephalitis (Visna),
lymphocytic arthritis, lymphofollicular mastitis and vasculitis.
Maedi is characterized by dyspnea and an insidious slowly
progressive emaciation despite good appetite.
In goats, CAE virus can cause a lymphocytic interstitial pneumonia
similar to OPP in sheep.
Bacterial Pneumonias - Sheep
Multifactorial disease –rarely
fatal. In general it affects animals
younger than 1-year-old.
Etiologic agents include
adenovirus, reovirus, RSV,
Chlamydophila, and Mycoplasmas
Suppurative bronchopneumonia, sheep –
Pasteurella multocida – from McGavin’s.
Ovine pneumonic Mannheimosis: Similar to
shipping fever in cattle.
Septicemic pasteurellosis: Caused by
Mannheimia haemolytica (biotypeA) usually in lambs under 3
Bibersteinia (Pasteurella) trehalosi (biotypeT) usually in lambs 5 to
Lesions:necrotizing pharyngitis and tonsilitis, septicemia with
disseminated intravascular thrombosis and bacteremia.
Multifocal subpleural pneumonitis – Muellerius capillaris sheep, Cornell files
Verminous bronchitis also occurs in sheep and goats. The etiologic agent
Is Dictyocaulus filaria.
Pneumonias of horses
Viral pneumonias: Equine viral rhinopneumonitis (EHV-1, EHV-
4) and equine influenza are important diseases in horses
worldwide. In addition, equine viral arteritis (EVA) virus and
equine adenovirus can also cause pneumonia in horses.
These viruses often cause only a transient broncho-interstitial
pneumonia but impair the pulmonary defences and make horses
susceptible to secondary bacterial pneumonias (P.Multocida,
Streptococcus spp.,E.coli,Klebsiella pneumoniae,Rhodococcus equi etc.).
It has also been suggested that viral respiratory infections may
predispose horses to “airway hyper-responsiveness” and “chronic
obstructive respiratory disease” (COPD).
EquineViral Arteritis (EVA) virus – Arterivirus.
Sporadic pansystemic disease of foals and horses:
May result in interstitial pneumonia with
vasculitis, pulmonary edema, hydrothorax and
Equine Morbillivirus (Hendra virus disease): Fatal
respiratory disease in horses and humans (high mortality rates
were seen in both horses and humans) which appeared in
1994 in Australia. Classified as a Morbillivirus, subfamily
Paramyxoviridae.Affected horses have severely edematous
lungs. Histologically there is vasculitis and the presence of
multinucleated syncytial cells, typical of morbillivirus
infections, in the endothelium of small pulmonary blood
vessels and alveolar capillaries. No inclusion bodies are seen.
Clinical signs are non-specific and include fever, anorexia,
respiratory distress and nasal discharge
Interstitial pneumonia due to adenovirus or
Pneumocystis carinii Infection are common complication
in Arabian foals with SCID (Inherited disorder-
autosomal recessive trait- characterized by lack of B and
T lymphocytes die before 5 months of age)
Right: Pneumocystosis, Pig, AVC. Foamy eosinophilic
proteinaceous material within alveoli. Fungal organisms are
detected with Gomori’s methenamine silver stain (GMS).
“Pneumocystosis is one of
the most common and often
fatal complications in AIDS patients”.
Jack Russell Terrier
Interstitial pneumonia due to Pneumocystis carinii infection with
concomitant Rhodococcus equi infection in a foal (Arabian CID foal).
Important cause of morbidity and
mortality in foals worldwide.
Facultative intracellular gram positive
bacterium that causes two major
The organism may become enzootic in
farms where the organisms has been
shed earlier by affected foals.
Virulence factors encoded by plasmids
(virulence-associated proteins) appear
to be responsible for the survival of
the organism within macrophages
(avoid phagocytosis by inducing
6-week-old foal, Chronic pyogranulomatous
pneumonia –Rhodococcus equi, Texas A&M
6-week-old foal, Chronic
pneumonia –Rhodococcus equi,
Texas A&M University.
Cytokines, lysosomal enzymes and bacterial toxins are responsible for extensive caseous
necrosis of the lungs and recruitment of large numbers of neutrophils, macrophages and
giant cells containing numerous intracytoplasmic organisms. Affected foals develop chronic
coughing and weight loss.
“Any foal with bronchopneumonia unresponsive to routine broad-spectrum antibiotic
therapy should be suspected of having R. equi bronchopneumonia” Equine practice, vol 14
(1): 15-18, 1992.
R.equi can infect people undergoing
immunosuppression (AIDS, chemotherapy,
because of organ transplantation).
Horse, idiopathic broncho-interstitial pneumonia. Note prominent
Type II pneumocyte hyperplasia., HE
Horse, embolic Aspergillus infection (Mycotic
pneumonia), Texas A&M, Dr. John Edwards.
Multifocal, necrotizing and hemorrhagic (or necro-hemorrhagic)
Pneumonias of pigs
• Viral Pneumonias:
Porcine reproductive and respiratory syndrome (PRRS): First recognized in Europe in
1987. PRRS is characterized by late-term abortions, stillbirths and respiratory disease in
young pigs (interstitial pneumonia).
Swine Influenza: Resulted from adaptation of the typeA influenza virus that caused the
pandemic of human influenza duringWorldWar I. Low mortality unless complicated
with secondary bacterial infections. H1N1 influenza pandemic in 2009.
Postweaning multisystemic wasting syndrome (PMWS):
Causes progressive emaciation in weaned pigs.The causative agent is PCV-2. May result
in interstitial pneumonia.
Porcine Respiratory Coronavirus (PRCV): Sporadic cause of mild bronchointerstitial
pneumonia with necrotizing bronchiolitis.
Interstitial pneumonia, feeder
pig – highly suggestive of viral pneumonia
Right: Pneumocystosis, Pig, AVC. Foamy eosinophilic
proteinaceous material within alveoli. Fungal
organisms are detected with Gomori’s methenamine
silver stain (GMS). Infections with Pneumocystis
carinii are common in pigs with PRRS and PMWS.
Pig, enzootic pneumonia-Cornell. Multifactorial disease,
Mycoplasma hyopneumoniae is the main pathogen involved. The organism induces
a suppurative or cattarrhal bronchopneumonia with BALT hyperplasia that is quite
characteristic. This highly contagious disease of pigs is influenced by immune status
and management factors such as crowding, poor ventilation, humidity and
temperature fluctuation in the barns. The disease is characterized by low mortality
unless complicated with secondary pathogens.
Mycoplasma pneumonia, young piglet, UCVM, OI. The bronchopneumonia is
mild to moderate (low mortality) unless complicated with Pasteurella multocida,
Arcanobacterium pyogenes, Bordetella bronchyseptica, Haemophilus spp.,
Mycoplasma hyorhinis etc.).
3-month-old pig, fibrinous pleuritis and pneumonia,
may be a component of Glasser’s disease (Haemophilus parasuis)
CVM, Western University of Health Sciences, O.Illanes
Porcine Contagious Pleuropneumonia,
Highly contagious often fatal
of pigs 2-5 months of age.
Dorsal area of the caudal lung
lobes are often affected.
Lesions are severe and
characterized by hemorrhage,
necrosis and thrombosis.
Except for the distribution
lesions are similar to those of
pneumonic mannheimiosis of
Porcine Contagious Pleuropneumonia,
CVM, Western University of Health Sciences, O.Illanes.
Top: Cut surface, contagious
pleuropneumonia, pig. Nebraska Diagnostic
Laboratory – From
Pneumonias of Dogs
Pneumonias are not as common in dogs as in food-
Infectious pneumonias: Infectious tracheobronchitis
(Kennel cough) and canine distemper are the most
Non-infectious: Uremia and paraquat (widely used
herbicide) toxicity are most common
• In addition to distemper, canine adenovirus type 2 (CAV-2),
canine herpesvirus 1 (CHV-1) and canine influenza virus can
produce pneumonias in dogs.
• Bacterial pneumonias are often secondary to distemper virus
infection or aspiration of gastric contents (when pulmonary
defence mechanisms have been impaired). Pasteurella
multocida,Streptococcus spp.,E.Coli,Klebsiella pneumoniae and
Bordetella bronchiseptica can be involved.
Broncho-interstitial pneumonia, canine distemper
From McGavin’s Path. Basis of Vet. Disease
Pneumonias of cats
Upper respiratory infections: Common
The viruses that produce upper respiratory disease may
also induce pneumonia, but unless complicated with
secondary bacterial infections they usually do not pose a
significant clinical problem.
Snails and slugs are the
intermediate hosts. Subpleural
nodules contain larvae and eggs,
In comparison to humans primary pulmonary
tumors are rare in animals
Most are malignant an appear as solitary masses
of variable size
In domestic animals they are most common in
dogs and cats.
Ovine pulmonary carcinoma (pulmonary
3-year-old sheep, University of Zaragoza, Spain – in McGavin’s
Caused by a transmissible retrovirus. Found around the world but not in New
Zealand or Australia. Mainly seen in mature sheep. Slowly progressive signs of
respiratory disease death after several months from the initial onset of
Metastatic neoplasms are relatively
common. Primary pulmonary neoplasms,
largely carcinomas are relatively rare but
more common in aged dogs and cats.
Fibrinosuppurative pleuropneumonia, rabbit –P. Multocida,
Atlantic Veterinary College.
Pasteurellosis is a common disease in domestic rabbits. P.multocida can
result in rhinitis (“snuffles”), pneumonia, abscesses, reproductive tract
infections, ear infections and septicemia.