Calf Diarrhea (NOT FINISHED)

When is the highest incidence of calf diarrhea in dairy calves?

2nd week of life

What is the goal of managing calf diarrhea?

<3% mortality due to diarrhea

Diarrhea has a 56% —-, 32% —-, and 5% ———————.

Morbidity

Mortality

Case fatality rate

There is a 10.6% of —- in calf diarrhea cases and they have a higher risk for BRD.

Sepsis

What kind of disease affects nursing beef calves in east central Kansas?

Respiratory disease (okay?)

What are the THREE major risk factors for neonatal calf disease that become the mainstay of prevention?

1. Dystocia

2. FPT

3. Poor management of calving pen/pasture (high stocking density/poor husbandry)

True or False: Dystocia is associated with up to 40% of pre-weaning beef calf mortality.

True!

The overuse of what drugs are heavily related (75%) to diarrhea and BRD (95%)?

Antimicrobials

What is considered the most important risk factor for calf diarrhea?

FPT

___: inadequate absorption of immunoglobulins from maternal colostrum during the first 24 hours of life

Failure of passive transfer (FPT)

What is considered FPT in dairy calves and beef calves, respectively?

Dairy calves: 10 g/L (<1000 mg/dL)

Beef calves: 24 g?L (<2400 mg/dL)

What is the goal of managing FPT?

<10% of calves

True or False: You should move only cows that have not calves to a different pasture when calf diarrhea is present in a herd.

True!

True or False: E. Coli is not normally found in the GI flora of cattle.

False! E. Coli is NORMAL flora of the GI tract of cattle.

What are the THREE virulence factors of E. Coli?

1. Adhesins

2. Cytotoxins

3. Enterotoxins

Pathogenic strains of E. Coli shed by adult cattle at —-.

Calving

What amplifies environmental contamination in E. Coli cases?

Sick neonates

ETEC causes disease in calves at what age?

4 days of age or younger

What allows attachment of ETEC to immature enterocytes, which is why disease is typically caused in very young calves?

Fimbria (pilus) F5 (K99) or F41

What are the TWO major enterotoxins of ETEC?

Thermolabile (LT) and thermostable (STa and STb)

What major role does ETEC thermostable (STa or STb) play in disease?

Stimulate hypersecretion in crypt cells (SI)

What are THREE of the hypersecretions of ETEC caused by thermostable enterotoxins?

1. Bicarbonate

2. Chloride

3. Potassium-containing fluid

Other E. Coli types, like STEC, EPEC, EHEC, and AEEC can disease in calves at what age?

2 day to 4 week old calves

Muco-hemorrhagic enteritis (SI AND LI) and blood-tinted feces are characteristic of what E. Coli type?

EPEC

E. Coli can have zoonotic potential, where cattle are a major reservoir of —- and —- with hemorrhagic colitis and hemolytic syndrome seen in humans.

STEC

EHEC (O157:H7)

True or False: Salmonella causes disease through serogroups B, C, D, and E >95% of the time.

True!

What serotype of Salmonella is typically subclinical? What serotype is associated with fulminant septicemia and death?

Subclinical: D (dublin)

Fulminant septicemia and death: B (typhimurium)

What is a classic sign of Salmonella diarrhea?

Blood-stained feces (hemorrhagic diarrhea)

What clinical sign is unique to S. Dublin in calves?

Hemorrhagic pneumonia

Salmonella involves severe —-, —- necrosis, and —- deposition in both the SI and LI with —- potential.

Enteritis

Mucosal

Fibrin

Zoonotic

True or False: Adults may serve as endemic carriers of S. Dublin and host-adapted disease.

True!

How is Salmonella shed?

Body fluids (+ colostrum and milk)

What TWO Salmonella groups cause endemic disease and morbidity/mortality in all age groups?

Groups B and C

What are the THREE types of Clostridia?

What THREE exotoxins do they have?

Type A, C, and D

Alpha, beta, and epsilon

When does disease occur with Type C Clostridia? Types A and D?

Type C: <10 days of age

Type A and D: 2-4 months

What are the TWO major clinical signs of Clostridia infections in calves?

1. Necrotic enteritis (enterotoxemia)

2. Abomasitis (ulcers)

Type C and D Clostridia are associated with —- signs and are seen at greater proportions in what food animal species?

Neurological

Small ruminants

True or False: Clostridia signs also include acute abdominal distention and colic, as well as sudden death.

True!

What type of C. Perf is found in the GI tract of healthy cattle and environment?

What type is found in the environment and is enzootic in some farms?

GI tract/environment: Type A

Environment/enzootic: Type C

What are TWO major causes of C. Perf infection in calves?

1. Interrupted nursing (large volumes of colostrum, milk, or MR)

2. Repeated esophageal tube feeding

What is involved in the mechanism of interrupted nursing as an etiology of C. Perfringens?

Trypsin inhibitors

Name the toxins produced by type A, B, C, D, and E Clostridia.

A: alpha

B: alpha, beta, epsilon

C: alpha, beta

D: alpha, epsilon

E: alpha, iota

What C. Perf type is associated with hemorrhagic enteritis of cattle, absomasal tympany and ulcers in neonates, gas gangrene, and yellow lamb disease?

C Perf Type A

What C. Perf type is associated with lamb dysentery and enterotoxemia (overeating disease) of foals?

C. Perf Type B

What C. Perf type is associated with necrotic hemorrhagic enterotoxemia of calves, lambs, kids, foals, and piglets?

C. Perf Type C

What C. Perf type is associated with enterotoxemia of sheep, goats, and cattle?

C. Perf Type D

What C. Perf type is associated with abomasal tympany and ulcers in calves, as well as enteritis in rabbits?

C. Perf Type E

What is the most common cause of diarrhea in calves?

How old are these calves typically?

Bovine rotavirus (Serogroup A)

5-21 days

What results in the several serogroups formed in rotavirus?

Surface protein variation

What major pathologic impact is caused by bovine rotavirus (Serogroup A)?

Villi blunting (crypt cell hyperplasia) in SI

What are the THREE clinical/physiologic impacts of the villi blunting seen in bovine rotavirus (serogroup A)?

1. Malabsorption

2. Lactose intolerance

3. Hypersecretion (NSP4)

In rotavirus, adult cows shed the virus at —- and some become —-.

Calving

Carriers

True or False: Cows born to carrier cows have a greater risk of BRoV infection and disease.

True!

Rotavirus is highly stable in the environment as it lacks an —- that makes it highly resistant to infections. It can last up to —- months and remains in calving areas from year to year.

Envelope

9

What disease causes GI and respiratory illness in calves with diarrhea from 5 days to 30 days of age or longer?

When do the respiratory signs predominate?

Beta-coronavirus

5 months

True or False: Bovine coronavirus is characterized by villus blunting and fusion/crypt cell hyperplasia and inflammation localized specifically to the small intestine.

False! It is seen in the SMALL and LARGE intestine.

—-% of clinically normal cows shed coronavirus and it usually occurs in the —- season.

>70%

Winter

What is coronavirus called in adult bovids?

Winter dysentery

What virus is very similar to bovine coronavirus?

What age do these calves typically suffer from diarrhea?

Torovirus

Under 3 weeks (clinical disease up to 4-10 months)

Bovine torovirus is infrequently reported by ————, where 25-30% of fecal samples from calves with diarrhea under 6 weeks of age and also isolated in feces and nasal secretions from healthy calves.

PCR testing

What disease is characterized by villus and crypt cell necrosis in the SI and LI and causes malabsorption with hypersecretion?

Bovine torovirus (Breda-virus)

What is the most common cause of non-bacterial diarrhea in humans?

Bovine norovirus (BoNV)

What bovine norovirus group involves natural and experimental infection causing diarrhea in young calves that are 1 to 2 days old and did not drink colostrum?

Group III (GIII) genotypes 1 (Jena virus) and 2

Is norovirus associated with villus atrophy and crypt hyperplasia in the SI, LI, or both?

Small intestine

How long is duration of norovirus?

What best provides protection against it?

4 days

Colostral antibodies

What are the TWO major types of Cryptosporidium and how do they differ?

1. Type 1: C. Hominis- zoonotic

2. Type 2: C. Parvum- diarrhea in calves 1 to 4 weeks old

What disease is associated with epithelial destruction and villus atrophy in the SI where the microvilli shorten and destroy, malabsorption, and prostaglandin mediated crypt cell secretion?

Cryptosporidium parvum

Individual calf prevalence in US dairies in —-%, while US dairy herd level prevalence is —-%!

43%

100%

True or False: Comorbidity with C. Parvum is common, often causing a prolonged diarrhea of 4-6 weeks.

True!

Name TWO reasons why C. Parvum is less common in beef cow-calf farms.

1. Outbreaks in beef calves are more severe- up to 30% mortality

2. Lack of herd immunity (colostral antibodies)

What are FOUR major environmental ways to get C. Parvum?

1. Stagnant water

2. Fecal/oral transmission

3. Flies

4. Wildlife (reservoirs)

Oocysts of C. Parvum survive for at least —- weeks in water at <—C.

12

5

True or False: C. Parvum is resistant to chlorination and most disinfectants, so adequate handwashing and scrubbing is imperative.

True!

What protozoan is often found in diarrheic calves in association with other pathogens, like C. Parvum, Eimeria spp, and rotavirus?

Giardia spp (Giardia duodenalis)

When are calves most commonly affected with Giardia spp?

2 weeks to 2 months

True or False: Giardia diarrhea can become chronic for months and colostral antibodies do a great job of protecting for the first two weeks of life.

True!

What drug reduces the duration of diarrhea?

Fenbendazole

What are the THREE major causes of coccidiosis in cattle?

1. Eimeria bovis

2. Eimeria zuernii

3. Eimeria alabamensis

Coccidiosis is most common in —- calves.

How old would this be in dairy and beef?

Weaned

Dairy: 2 months

Beef: 6-8 months

What are TWO common risk factors in weaned calves for coccidiosis?

1. Comingling with older calves

2. Dry pens

Coccidiosis causes destruction of crypt cells in what part of the GI tract?

Large intestine

What are the THREE major clinical impacts of coccidiosis?

1. Inflammation

2. Bloody diarrhea

3. Anemia

True or False: Coccidia oocysts persist in moist/wet environments.

True!

Calves fed —- to ——% of body weight in milk do not develop diarrhea, and infectious diarrhea is thought to be exacerbated by milk overfeeding.

16-20%

Increased milk fermentation causes intestinal osmolarity, which causes —- and —-.

Malabsorption

Maldigestion

What TWO major problems are related to poor milk/milk replacement quality?

1. High bacterial counts (milk from cows with mastitis)

2. Disturbance of commensal GI microbiome (antibiotic overuse)

What are the THREE best sample collection methods for calf diarrhea?

1. Fecal sample

2. Necropsy (outbreak)

3. Multiplex calf-enteric pathogen PCR panel

True or False: Diarrhea-causing pathogens can be found in feces, so fresh fecal samples from calves early in disease is best.

True!

Necropsy involves intestinal sections (no more than —- cm long with formalin ratio —-).

2.5 cm

1:10

What FIVE pathogens are included in a multiplex calf-enteric-pathogen PCR panel?

1. E. Coli K99

2. Salmonella spp

3. BRV

4. BCoV

5. C. Parvum

True or False: SNAP ag-ELISA tests are also available for diarrhea.

True!

True or False: Fecal culture is the gold standard diagnostic for E. Coli in diarrhea.

False! Fecal culture is UNREMARKABLE with E. Coli diarrhea.

How is ETEC best diagnosed?

ID fimbria K99 or F41 via ELISA or PCR

What TWO diagnostics are best for AEEC, EPEC, STEC, or EHEC?

1. Histopath of SI and colon

2. PCR

What would you find on necropsy with Salmonella?

Fibrinonecrotic ulcerative enteritis

What are the TWO best diagnostics for Salmonella?

1. Culture (feces and tissue; subclinically found with group D)

2. Conventional and real-time PCR (feces and tissue)

True or False: Fecal culture is unremarkable for C. Perf.

True!

What is the best diagnostic for C. Perf?

What TWO things would you expect to find?

Necropsy and histopath

1. Gram-positive bacilli (hemorrhagic enteritis)

2. Quantitative bacterial counts at lesion site (> 10^6/ml)

What provides support to a C. Perf diagnosis?

Demonstration of toxin production (a, b, E, etc.) via immunoassay/western blot/PCR

What THREE diagnostics can be ran on feces to ID coronavirus?

1. Electron mmicropscopy

2. Real time RT-PCR

3. Antigen-capture ELISA