VTS257: Lg Animal Diseases & Nursing

1. Dairy Cattle

2. Terminology
• Cow- female that has had one or more calves
• Bull- intact sexually mature male
• Calf- newborn of either sex or intact male that
has not reached sexual maturity
• Calve-verb, to give birth
• Heifer- female that has not had a calf
• Steer- neutered male of any age

3. • Freemartin- genetic female born twin to a
male, sterile as a result of arrested
development of the reproductive tract.
Ovaries are hypoplastic and most lack a cervix.
More common in cattle than in sheep and
goats.

4. • Polled- born without horns
• Shrink- weight loss, ( leading to financial loss)
associated with stress, transportation,
weaning
• Freshen- verb, to give birth
• Pasteurize- flash heating to kill bacteria
• Homogenize- blending technique used to
prevent cream from separating from milk

5. Breeds of Dairy Cattle
• Holstein- black and white or red and white
• Jersey- soft brown, small cow, fat and protein
production higher in milk
• Ayrshire- brick red and white, looks like a small
Holstein
• Guernsey- butterscotch color, lots of white, skin is
yellow, resemble jersey
• Brown Swiss- largest, chocolate milk color, late to
mature

6. Industry Facts
• Average milk production per cow is 18,200 lbs
• 305 day lactation period ( 10 mos) and a 60
day dry period ( 2 mos) equals a 12 month
calving interval
• Milk production peaks 4-6 weeks after
freshening
• Milked 2 times a day

7. Dairy Products
• Milk and milk by products
• Replacement heifers ( average 30-40% of the
herd is replaced each year)
• Veal calves
• Dairy steers fed out as beef cattle

8. Nutrition
• Water- most important nutrient, average 20
gallons per head per day
• Factors that increase water consumption
- Environmental heat and humidity
- Lactation
- Exercise
- diet

9. Factors that decrease water
consumption
• Palatability
• Temperature
• Salinity/mineral content
• Medication
• Availability/ competition
• illness

10. Body Scoring System
• Monitoring body score to maximize
production
• Monitoring body score to minimize disease

11. Conditions associated with high body
scores ( 4 or 5)
• Dystocia- impeded fetal passage through birth
canal
• Retained placenta, metritis
• Ketosis- increase in ketone bodies in tissues
and body fluids
• Displaced abomassum, liver abcesses
• Milk fever- acute flaccid paralysis after calving,
need emergency ca

12. Conditions associated with low body
scores ( 1 or 2)
• Infertility/ delayed conception
• Prolonged interval before resuming normal
estrus cycles post calving
• Decreased milk production
• Decreased milk fat content

13. When to assess body score
• Midway through the period
• At freshening
• 45 days into lactation
• 90 days into lactation
• 180 days into lactation
• 270 days into lactation

14. Body Score Goals
• Midway through dry period 3.5
• At freshening 3.5
• 45 days into lactation 3.0
• 90 days into lactation > 2.5
• 180 days into lactation 3.0
• 270 days into lactation 3.5

15. Terminology
• Vector- individual ( arthropod, mammal, avian
etc) which transfers and infectious agent
• Fomite- inanimate object which mechanically
transfers an infectious agent
• Intermediate host- an organism passes
through its larval or asexual stages of
development
• Dead end host- organisms life cycle is
interrupted, disease not transmitted

16. • Definitive host- host in which organism attains
sexual maturity and is able to be transmitted
• Reservoir host- host, other than definitive, in
which organism can exist, usually w/o causing
clinical disease
• Latency- presence of a pathogenic organism
without clinical disease but with the potential
for clinical disease to develop when triggered

17. • Pre-patent period- interval from exposure to
onset of clinical symptoms
• Infective period- period during which a
disease is able to be transmitted from one
definitive host to another
• Lateral/horizontal transmission- transmission
other than by placental transfer or lactation
• Vaccination- the administration of a vaccine

18. • Immunization- the development of protective
immunity through challenge with pathogen,
with vaccine or natural exposure
• Bacterin- vaccine derived from killed bacteria
or bacterial fragments
• Index case- initial case of disease outbreak
• Endemic- present in the population at a
steady rate
• Epidemic- disease occurrence rises

19. • Morbidity- incidence of disease in a
population, stated as a percentage
• Mortality- incidence of death ( as caused by a
specific disease) stated as a percentage

20. Disease Outbreak Management
• Index case
• Symptomatic animals
• Asymptomatic animals
• Latency
• resevoirs

21. Disease Containment
Organism identification-
virus/bacteria/parasitic/other
- Prepatent period
- Infective period
- Environmental persistance/viability
- Mode of disease transmission
- Source of organism

22. Hosts immune response to pathogenic
organisms
• Does natural infection confer immunity?
• What is the duration of immunity?
• Vaccinal immunity?
a. Vaccinate prior to exposure
b. Vaccinate in face of outbreak
c. Vaccination intervals

23. • Reinfection
• Chronicity
• Residual effects of disease after organism has
been eliminated from the body
• Mitigating/exacerbating conditions
a. Immunocompentency
b. Stress
c. Nutrition
d. Sanitation/hygiene

24. Zoonotic Diseases

25. Anthrax
• Bacteria- bacillus anthracis
• Species affected- all warm blooded animals,
cattle especially affected
• Route of exposure- consumption of spores
while grazing, usually in areas where soil has
recently been disturbed ( spores persist in soil
for >35 years)
• Symptoms- sudden death, +/- hemorrhage
from all body openings

26. Anthrax, cont
• Treatment – none
• Carcass disposal- CRITICAL- burial minimum
10 feet covered with lime

27. Anthrax in Humans
• Route of exposure
- Cutaneous Woolsorters disease, bacteria
spores on hair/hide/wool/leather products
enter a wound on skin
- Inhalation pulmonary anthrax, spores inhaled
- Intestinal consumption of contaminated meat

28. Anthrax in Humans
• Symptoms
a. cutaneous- papule resembles insect bite,
progresses to necrotic lesion, 20% mortality
in untreated cases
b. Pulmonary- symptoms resemble common
cold, death occurs in 1-2 days
c. Intestinal- gastroenteritis, mortality 25-60%

29. Anthrax treatment
• Antibiotics if diagnosed early
Comments
Reportable disease in humans and animals
No human to human transmission through
normal contact

30. Brucellosis
• Bacteria- Brucella abortus/Brucella suis
• Bang’s disease in animals
• Route of exposure- direct contact with
reproductive tract secretions from infected
animal
• Infected animals are identified with orange
ear tag in the right ear

31. Symptoms
• Abortion
• Birth of weak calves
• Diminished fertility

32. Control of Brucellosis
Brucellosis Eradication Program
a. Surveillance
- Testing bulk milk containers
- Livestock market testing
b. Vaccination
c. Test and slaughter, no treatment

33. Brucellosis in Humans
Undulent Fever
1. Route of exposure
- oral- consumption of unpasteurized milk or
milk products
- Mucus membranes in contact with aborted
fetuses, placental membranes, uterine
discharges or carcasses of infected animals

34. Symptoms of Brucellosis in Humans
• Fatigue, headaches, fever, chills, drenching
sweats, joint pain,
• Rarely fatal but symptoms persist for months
• Treatment- antibiotics
• Prevention- no vaccine available, wear gloves
and protective clothing

35. Rabies
• Virus- rhabdovirus, affects all warm blooded
animals
Animal symptoms
a. Furious form- aggresssion, hyper- alertness,
excessive response to stimuli
b. Dumb/paralytic form- tail paralysis, loss of
sensation, incoordination, choke, urine
dribbling

36. Rabies Note
• Any warm blooded animal with neurologic
symptoms should be considered a rabies
suspect until proven otherwisess

37. Human Rabies
1. Route of exposure- animal bite, saliva
entering skin wound, defect, mm
2. Prevention- vaccination for individuals at risk
3. Control- post exposure anti serum for
exposed, unvaccinated individuals
4. Treatment- none, once contracted, rabies is
always fatal

38. Ringworm
Fungus - Microsporum
Animal
1. Species affected- cattle, horses, sheep, goats,
swine
2. Route of exposure- organism is ubiquitous in
environment, development of clinical disease
is associated with immunosuppression
3. Symptoms- dermal lesions
4. Treatment- antifungal meds, topical or
systemic, UV light ( sunlight)

39. Human Ringworm
1. Route of exposure- direct contact with skin
lesions of affected animals,
immunosuppression is not necessary to high
conc. Of organisms in lesion
2. Symptoms- skin lesions w/wo pruritis
3. Diagnosis- fungal culture
4. Treatment- antifungal medications, topical or
systemic

40. Salmonellosis
Animal
1. Species affected- cattle, swine, goats, sheep,
horses, poultry, reptiles, amphibians
2. Route of exposure- oral contact with feces
from infected animals
3. Symptoms- profuse watery diarrhea,
endotoxic shock, ( carrier state exists)
4. Treatment- supportive, fluid replacement,
intestinal protectants

41. Human Salmonella
1. Route of exposure- consumption of
contaminated food or water, inadequate
hygiene after handling patient with
salmonella
2. Symptoms- fever, headache, diarrhea,
abdominal pain
3. Treatment- usually requires hospitalization

42. Tuberculosis ( bacteria)
Mycobacterium bovis, tuberculosis
Animal
1. Route of exposure- consumption of
contaminated water, milk from infected cows
2. Symptoms- animals may remain
asymptomatic until disease is advanced,
weight loss, unthriftiness, poor hair coat
3. Post mortem- lung abcesses resulting in
devaluation/condemnation of carcasses

43. Tuberculosis in animals cont
4. Diagnosis- intradermal skin testing
5. Control/prevention- maintain closed herd,
test replacement stock

44. Tuberculosis in Humans
1. Route of exposure- consumption of raw,
unpasteurized milk, aerosol
2. Symptoms- cough, pulmonary disease,
debilitation, “consumption”
3. Diagnosis- tuberculin skin test, chest rads,
culture of sputum
4. Treatment- 95% recovery rate with 6-9
months of antibiotic treatment