Farm Animal Diarrhea Flashcards
What is the importance of diarrhea in farm animals?
Major economic loss
Significant welfare issue (painful death, carrier states)
Major environmental cost
Greatest factor in calf mortality
Public health risk
What is the major unseen cost associated with farm animal diarrhea?
Sub-optimal growth
What are the 3 factors involved in causing farm animal diarrhea?
Pathogens
Host factors (Immune system, stress)
Environment and Management (cleanliness, nutrition, colostrum)
What is the DDx for Calves with ACUTE diarrhea?
E. coli
Cryptosporidium
Rotavirus
Coronavirus
Coccidia
Salmonella
What is your top differential for a calf ACUTE with diarrhea <5 days of age?
E. coli
What is your top differential for calves with ACUTE diarrhea after 3 weeks of age?
Coccidia
What are your top differentials for an adult cow with ACUTE diarrhea?
Salmonellosis
Coronavirus (Winter dysentery)
Acidosis/SARA
Malignant Catarrhal Fever
Poisons (Ragwort, Arsenic)
Mucosal Disease
BVD - Notifiable
What are your top differentials for an adult cow with CHRONIC diarrhea?
Johne’s Disease (mycobacterium avium sbsp. paratuberculosis aka MAP)
Ostertagiosis
Fluke
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?
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
What part of the intestine does rotavirus inhabit? What age of calf is most susceptible? Does rotavirus cause greater morbidity or mortality?
Duodenum and jejunum
1-3 week old calves
High morbidity, Low mortality
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?
Builds up in dirty bedding (husbandry)
Clinical signs at 5-14 days
Inhabits lower part of SI/Colon
Causes intestinal villus atrophy = malabsorption
What viruses does cryptosporidium usually present with? What happens to calves as they get older?
Paired with rotavirus/coronavirus
As calves get older they develop resistance to crypto
What is so significant about salmonella?
Not a normal commensal
ALWAYS pathogenic
ZOONOSIS - public health issue
Is a culture of salmonella always significant? Which species of salmonella is cattle host adapted?
Yes
S. enterica serotype dublin
What are the clinical signs associated with salmonella
Systemic illness
Pyrexia
Severe diarrhea
What are the range of clinical signs associated with coccidiosis? What age of calves are we looking at?
Older calves
May give blood strained feces or might just be subclinical disease giving poor growth rate
What is a non-pathogenic cause of poor growth/thrift and possibly diarrhea in calves that you should ALWAYS consider?
What are the clinical signs associated with BVD? What type of virus is BVDV?
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
What are the signs of BVD when it infects a naive adult animal?
Bloody diarrhea, high fever (105–107 degrees), off- feed, mouth ulcers, and often pneumonia
What is this?
What is this?
Rotavirus
What is this?
Coronavirus
Give the most common differentials for lambs < 3 wks old with diarrhea
Watery mouth
Poor milk production
Give the most common differentials for lambs 3-12 wks old with diarrhea
Coccidiosis
Nematodirus
Give the most common differentials for post-weaned lambs with diarrhea
PGE (parasitic gastroenteritis) in adult sheep
What are the less common (but still on DDx list) causes of diarrhea in lambs <3 weeks of age
Rotavirus
Coronavirus
Cryptosporidium parvum
E. coli
Salmonellosis
Lamb dysentery
Which bacteria is the cause of lamb dysentery?
Clostridium perfringens Type B
Which animals should you sample when there is diarrhea on a farm?
Both healthy and affected animals
What are the most important aspects of calf/lamb management?
Clean, fresh water
Adequate colostrum ESSENTIAL
Clean environment
Good hygiene
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?
50% - 4x more likely to die
How do you find out if calves are getting adequate colostrum supply? What do you do if they are not?
Test calves - Ab status
Either milk mother and bottle feed colostrum or feed milk replacer (make sure to read label and mix replacer properly)
What should ALWAYS be accessible for calves (and cows)?
Fresh, clean water
Are vaccines an appropriate solution for calf/lamb diarrhea cases? Are there specific vaccine protocols all farms should follow?
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
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?
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
Is Johne’s Disease zoonotic?
Possibly - MAP might be involved in Crohn’s Disease (humans drinking infected milk = inflammatory bowel disease)
How do cows usually contract Johne’s Disease?
Usually acquired by young stock, but only becomes clinical several years later
What is control of Johne’s Disease primarily focused on? What should you keep calves from coming in contact with?
Preventing young animals from becoming infected from feces of older animals (or infected colostrum)
Avoid pooling of colostrum
Can you detect subclinical Johne’s Disease? How reliable is a positive vs. negative ELISA blood test for MAP Ab?
Subclinical disease very difficult to detect due to variable Ab status
Positive test ALWAYS reliable (high specificity) but negative test NOT reliable (low sensitivity)
Does MAP ELISA Ab blood test have higher or lower sensitivity to clinically infected cows?
Higher due to higher circulating Ab
When testing for Johne’s Disease - rank these tests from highest to lowest sensitivity/specificity
Which bodily fluids can you use to test a cow for Johne’s Disease?
Blood, Milk
What is the major downside of fecal culture?
Takes a very long time
What is different about the clinical signs in goats/sheep vs cows?
Diarrhea is NOT a common feature in small ruminants
What are the specific strains of MAP which cause Johne’s Disease in goats? Can cross-infection occur?
C and S strains exist in goats
Cross infection can occur between sheep and cattle
What is the name of the vaccine available for control of Johne’s Disease in goats? At what age can you give the injection?
Gudair - single injection from 3-6 months of age
