Farm Animal Diarrhea

Question 1

What is the importance of diarrhea in farm animals?

Answer 1

Major economic loss
Significant welfare issue (painful death, carrier states)
Major environmental cost
Greatest factor in calf mortality
Public health risk

Question 2

What is the major unseen cost associated with farm animal diarrhea?

Answer 2

Sub-optimal growth

Question 3

What are the 3 factors involved in causing farm animal diarrhea?

Answer 3

Pathogens
Host factors (Immune system, stress)
Environment and Management (cleanliness, nutrition, colostrum)

Question 4

What is the DDx for Calves with ACUTE diarrhea?

Answer 4

E. coli
Cryptosporidium
Rotavirus
Coronavirus
Coccidia
Salmonella

Question 5

What is your top differential for a calf ACUTE with diarrhea <5 days of age?

Answer 5

E. coli

Question 6

What is your top differential for calves with ACUTE diarrhea after 3 weeks of age?

Answer 6

Coccidia

Question 7

What are your top differentials for an adult cow with ACUTE diarrhea?

Answer 7

Salmonellosis
Coronavirus (Winter dysentery)
Acidosis/SARA
Malignant Catarrhal Fever
Poisons (Ragwort, Arsenic)
Mucosal Disease
BVD - Notifiable

Question 8

What are your top differentials for an adult cow with CHRONIC diarrhea?

Answer 8

Johne’s Disease (mycobacterium avium sbsp. paratuberculosis aka MAP)
Ostertagiosis
Fluke

Question 9

Why is a positive culture for E. coli not always significant? What indicates a problem-causing form of E. coli? What age of calves does E. coli typically affect?

Answer 9

Normal commensal of GIT
Look for special strains - ETEC (enterotoxigenic E. coli) kills calves (watery diarrhea, scours)
E. coli O157 huge risk in human population (public health risk)
Calves <5 d at highest risk

Question 10

What part of the intestine does rotavirus inhabit? What age of calf is most susceptible? Does rotavirus cause greater morbidity or mortality?

Answer 10

Duodenum and jejunum
1-3 week old calves
High morbidity, Low mortality

Question 11

How does cryptosporidium cause disease? When are clinical signs seen in calves? What part of the intestine does it inhabit? What does it do to the intestinal villi? What does this do to absorption in the intestine?

Answer 11

Builds up in dirty bedding (husbandry)
Clinical signs at 5-14 days
Inhabits lower part of SI/Colon
Causes intestinal villus atrophy = malabsorption

Question 12

What viruses does cryptosporidium usually present with? What happens to calves as they get older?

Answer 12

Paired with rotavirus/coronavirus
As calves get older they develop resistance to crypto

Question 13

What is so significant about salmonella?

Answer 13

Not a normal commensal
ALWAYS pathogenic
ZOONOSIS - public health issue

Question 14

Is a culture of salmonella always significant? Which species of salmonella is cattle host adapted?

Answer 14

Yes
S. enterica serotype dublin

Question 15

What are the clinical signs associated with salmonella

Answer 15

Systemic illness
Pyrexia
Severe diarrhea

Question 16

What are the range of clinical signs associated with coccidiosis? What age of calves are we looking at?

Answer 16

Older calves
May give blood strained feces or might just be subclinical disease giving poor growth rate

Question 17

What is a non-pathogenic cause of poor growth/thrift and possibly diarrhea in calves that you should ALWAYS consider?

Answer 17

Question 18

What are the clinical signs associated with BVD? What type of virus is BVDV?

Answer 18

Does NOT commonly cause diarrhea
Pestivirus
BVD causes a complex of diseases in cattle, the most important of which can interfere with reproduction, affect the unborn calf (poor growth) and lead to mucosal disease
Clinical signs - fever, lethargy, loss of appetite, ocular dishcharge, nasal discharge oral lesions, diarrhea and decreasing milk production
If naive animals become infected

Question 19

What are the signs of BVD when it infects a naive adult animal?

Answer 19

Bloody diarrhea, high fever (105–107 degrees), off- feed, mouth ulcers, and often pneumonia

Question 20

What is this?

Answer 20

Question 21

What is this?

Answer 21

Rotavirus

Question 22

What is this?

Answer 22

Coronavirus

Question 23

Give the most common differentials for lambs < 3 wks old with diarrhea

Answer 23

Watery mouth
Poor milk production

Question 24

Give the most common differentials for lambs 3-12 wks old with diarrhea

Answer 24

Coccidiosis
Nematodirus

Question 25

Give the most common differentials for post-weaned lambs with diarrhea

Answer 25

PGE (parasitic gastroenteritis) in adult sheep

Question 26

What are the less common (but still on DDx list) causes of diarrhea in lambs <3 weeks of age

Answer 26

Rotavirus Coronavirus Cryptosporidium parvum E. coli Salmonellosis Lamb dysentery

Question 27

Which bacteria is the cause of lamb dysentery?

Answer 27

Clostridium perfringens Type B

Question 28

Which animals should you sample when there is diarrhea on a farm?

Answer 28

Both healthy and affected animals

Question 29

What are the most important aspects of calf/lamb management?

Answer 29

Clean, fresh water Adequate colostrum ESSENTIAL Clean environment Good hygiene

Question 30

What proportion of calves do not receive adequate colostrum? How many times more likely are these calves to die than calves with good colostral status?

Answer 30

50% - 4x more likely to die

Question 31

How do you find out if calves are getting adequate colostrum supply? What do you do if they are not?

Answer 31

Test calves - Ab status Either milk mother and bottle feed colostrum or feed milk replacer (make sure to read label and mix replacer properly)

Question 32

What should ALWAYS be accessible for calves (and cows)?

Answer 32

Fresh, clean water

Question 33

Are vaccines an appropriate solution for calf/lamb diarrhea cases? Are there specific vaccine protocols all farms should follow?

Answer 33

No - vaccines are not a solution They will not make up for poor husbandry/management No blanket vaccine protocols - must be tailored to each farm

Question 34

What clinical signs does Johne's Disease cause? What is the treatment for affected cows? What bodily fluid from the cow is the most infectious?

Answer 34

In clinical cases it causes severe diarrhea and weight loss in adult cows Affected adult cows are infectious (especially feces) No treatment or cure - need to be culled on humane grounds

Question 35

Is Johne's Disease zoonotic?

Answer 35

Possibly - MAP might be involved in Crohn's Disease (humans drinking infected milk = inflammatory bowel disease)

Question 36

How do cows usually contract Johne's Disease?

Answer 36

Usually acquired by young stock, but only becomes clinical several years later

Question 37

What is control of Johne's Disease primarily focused on? What should you keep calves from coming in contact with?

Answer 37

Preventing young animals from becoming infected from feces of older animals (or infected colostrum) Avoid pooling of colostrum

Question 38

Can you detect subclinical Johne's Disease? How reliable is a positive vs. negative ELISA blood test for MAP Ab?

Answer 38

Subclinical disease very difficult to detect due to variable Ab status Positive test ALWAYS reliable (high specificity) but negative test NOT reliable (low sensitivity)

Question 39

Does MAP ELISA Ab blood test have higher or lower sensitivity to clinically infected cows?

Answer 39

Higher due to higher circulating Ab

Question 40

When testing for Johne's Disease - rank these tests from highest to lowest sensitivity/specificity

Answer 40

Question 41

Which bodily fluids can you use to test a cow for Johne's Disease?

Answer 41

Blood, Milk

Question 42

What is the major downside of fecal culture?

Answer 42

Takes a very long time

Question 43

What is different about the clinical signs in goats/sheep vs cows?

Answer 43

Diarrhea is NOT a common feature in small ruminants

Question 44

What are the specific strains of MAP which cause Johne's Disease in goats? Can cross-infection occur?

Answer 44

C and S strains exist in goats Cross infection can occur between sheep and cattle

Question 45

What is the name of the vaccine available for control of Johne's Disease in goats? At what age can you give the injection?

Answer 45

Gudair - single injection from 3-6 months of age