Exam 3 - Diarrheal Disorders

Question 1

what 4 diseases are common causes of acute diarrhea of adolescent-to-adult cattle?

Answer 1

BVD, mucosal disease, salmonellosis, & winter dysentery

Question 2

what are 4 diseases that cause chronic diarrhea & weight loss?

Answer 2

paratuberculosis, eosinophilic enteritis, mucosal disease, & salmonellosis

Question 3

what disease causes acute diarrhea with oral erosions in cows?

Answer 3

mucosal disease/BVD

Question 4

what is the etiology of BVD?

Answer 4

pestivirus - RNA virus

cytopathic & non-cytopathic strains - antigenic diversity & high rate of mutation

Question 5

what is the pathophysiology of BVD?

Answer 5

contact with infected excretions/secretions - virus is taken up by reticuloendothelial cells & replication occurs in lymphocytes & macrophages

virema occurs in the gi tract, respiratory tract, & reproductive tract & the virus is shed

Question 6

what are the clinical signs of BVD?

Answer 6

subclinical infection, diarrhea +/- blood, fever, decreased feed intake, decreased milk production, & oral erosions

Question 7

what signs of hemorrhage are seen with BVD?

Answer 7

petechiae/ecchymoses, bleeding from injection sites, bloody diarrhea, epistaxis, & destruction/sequestration of platelets

Question 8

what signs of immunosuppression are seen with BVD?

Answer 8

transient leukopenia/lymphopenia, altered T/B lymphocyte/neutrophil/monocyte/macrophage function, & decreased resistance to infection

Question 9

how do you end up with a PI calf from BVD?

Answer 9

dam gets infected with the virus 80-100 days into gestation with the non-cytopathic strain of the virus, so the fetus is immunotolerant - affected calves may be normal or stunted

Question 10

how does a PI calf develop mucosal disease?

Answer 10

the non-cytopathic virus either mutates to the cytopathic type (most common) or the animal comes into contact with the cytopathic virus & develops an overwhelming viremia with severe clinical signs causing death

Question 11

what happens if a dam gets infected with BVD 50-100 days into gestation?

Answer 11

abortion/stillbirth

Question 12

what happens if a dam gets infected with BVD 80-100 days into gestation?

Answer 12

has a PI calf with persistent viremia, can be normal or stunted

Question 13

what happens if a dam gets infected with BVD 100-180 days into gestation?

Answer 13

birth defects

Question 14

what happens if a dam gets infected with BVD <125 days into gestation?

Answer 14

immunotolerant calf

Question 15

what happens if a dam gets infected with BVD >125 days into gestation?

Answer 15

immunocompetent calf

Question 16

what happens if a dam gets infected with BVD >180 days into gestation?

Answer 16

no ill effects

Question 17

when would you use IHC of skin biopsies for BVD?

Answer 17

testing for PI calves

Question 18

when would you use PCR testing for BVD?

Answer 18

PI calf or an acutely affected calf

Question 19

T/F: calves that nurse seropositive cows for BVD will have positive titers for BVD regardless of infection status

Answer 19

true

Question 20

what are the control measures used for BVD?

Answer 20

removal of PI calves - test suspected calves & whole herd when they are open instead of when they are pregnant, not wasting money

vaccination of breeding herd - MLV vaccine type I & II, not when they are stressed/pregnant because they can cause immunosuppression/viremia/abortion

Question 21

how is salmonellosis transmitted?

Answer 21

fecal oral transmission

Question 22

T/F: salmonella is a ubiquitous organism & most infections are subclinical

Answer 22

true

Question 23

what salmonella is host-adapted to cattle?

Answer 23

s. dublin

Question 24

what is important about salmonella typhimurium?

Answer 24

**

Question 25

cattle & sheep are the most common host for what salmonella?

Answer 25

serovar c - s. newport

Question 26

what is eosinophilic enterocolitis?

Answer 26

IBD with eosinophilic infiltrates causing a malabsorptive diarrhea that isn't well understood

Question 27

eosinophilic enterocolitis presents similarly to what other disease?

Answer 27

johne's disease - causes diarrhea, weight loss, & similar age of onset

Question 28

what is the treatment for eosinophilic enterocolitis?

Answer 28

steroids

Question 29

what is the agent that causes johne's disease?

Answer 29

mycobacterium avium sub species paratuberculosis - acid fast organism

Question 30

what is in this picture?

Answer 30

mycobacterium avium sub species paratuberculosis

Question 31

why is mycobacterium avium sub species paratuberculosis persistent in the environment?

Answer 31

persists in soil up to 1 year - alkaline soils decrease survival resists pasteurization at 63 C for 30 minutes several strains persist

Question 32

what is the host range of johne's?

Answer 32

cattle, sheep, goats, other feral & domestic ruminants with occasional reports in camelids

Question 33

how is johne's disease transmitted?

Answer 33

fecal oral is the biggest!!! colostral, milk, transplacental, & coital

Question 34

what are the risk factors associated with age & infectious dose in regards to johne's disease?

Answer 34

neonates are at risk increased dose = increased likelihood of infection & decreased time to patency

Question 35

what breeds are predisposed to johne's?

Answer 35

dairy > beef channel island breeds & shorthorn

Question 36

what concurrent disease/stressors add a risk factor to developing johne's disease?

Answer 36

dietary imbalance, immunosuppressive disease, parturition, & transportation

Question 37

what is the silent stage of infection of johne's disease?

Answer 37

no clinical signs/ill effects - generally seronegative but may be culture positive

Question 38

what is the subclinical stage of infection of johne's disease?

Answer 38

potential mildly decreased productivity, often seronegative, 20% culture positive

Question 39

what is the clinical stage of infection of johne's disease?

Answer 39

decreased production & BCS, diarrhea, normal appetite, excessive thirst

Question 40

what is the advanced clinical disease stage of infection of johne's disease?

Answer 40

emaciation, fluid diarrhea, +/- edema, & weakness

Question 41

for each stage 3 johne's cows, what can you expect? what about stage 2? stage 1?

Answer 41

stage 3 - 1-2 animals not yet known to be infected stage 2 - inapparent carrier adults, 6-8 animals affected stage 1 - infected calves/livestock, 10-15 animals

Question 42

what are the common clinical signs of johne's disease in cows?

Answer 42

'old cow' disease, clinical signs are rare before 2 years of age, chronic progressive weight loss, good appetite, singular animals ill at any time, calving precipitates clinical signs because of stress diarrhea - intermittent progressing to persistent watery without blood or casts increased external parasite burden, dependent edema, bottle jaw

Question 43

what clinical signs are seen in sheep/goats with johne's?

Answer 43

chronic weight loss, watery feces are rare, younger at presentation, goats are sicker at presentation

Question 44

what are some differentials for johne's in sheep & goats?

Answer 44

endoparasitism, CL internal abscesses, starvation, CAE/OPP, organ failure

Question 45

what tests are commonly used to diagnose johne's disease? less commonly used tests?

Answer 45

serology - ELISA fecal culture - herrold's egg yolk & TREK liquid media, fecal PCR less common - rectal biopsy/acid fast stain & intestinal/ileocecal lymph node biopsy culture/histopathology

Question 46

what is the clinical course of winter dysentery? how long until the herd outbreak resolves?

Answer 46

clinical course - 3 days 2 weeks for herd

Question 47

T/F: there is high morbidity & mortality associated with winter dysentery

Answer 47

false - only high morbidity, no mortality

Question 48

what are the clinical signs of winter dysentery?

Answer 48

fever, fulminate diarrhea that is dark/bloody & rapid spreads, decreased milk production, inconsistent respiratory signs, & most severe in young

Question 49

what is the etiology of winter dysentery?

Answer 49

undetermined - suspected to be similar to coronavirus because corona-like virus particles are found in feces, rising titers are seen following clinical disease, corona virus antigen in the crypt cells, & corona virus is isolated from feces

Question 50

what clinical signs are associated with acute enteritis of salmonellosis?

Answer 50

fever, anorexia, diarrhea that is bloody/has mucus/casts, & dehydration

Question 51

what clinical signs are associated with chronic enteritis of salmonellosis?

Answer 51

chronic or intermittent diarrhea - ill thrift in some cases

Question 52

T/F: salmonellosis can cause septicemia

Answer 52

true

Question 53

how is salmonellosis diagnosed?

Answer 53

characteristic clinical signs, microbiological isolation from tissues, isolation from feces (clinical vs. carriers & hematologic changes), & isolation from milk in DUBLIN ONLY

Question 54

what is the treatment for salmonellosis?

Answer 54

do not treat the carriers!!!!! clinical disease - appropriate antibiotics (ceftiofur), NSAIDS (flunixin), fluid therapy, acid base correction, & cull

Question 55

how is salmonellosis prevented?

Answer 55

environmental hygiene, prevent transmission, minimize predisposing stressors, removal of carriers/reservoir, & improve passive transfer in calves