Bovine Abortion: Investigation

Question 1

When investigating abortion, what questions do you want to ask/what information do you need to know

Answer 1

• Abortion incidence = aborted / 100 calved
• Record management group sizes – to determine sampling later
• Remember the bull as a source!
• HACCP analysis

Question 2

List 2 examples of questions to ask to gather information about direct transfer within the herd

Answer 2

• Are sick cattle isolated immediately from the rest of the herd when they become sick, and prevented from contact with breeding females that may be pregnant until fully recovered?
• Are breeding bulls checked to ensure they are of no risk to breeding females before they are introduced to the herd?

Question 3

What are some issues surrounding vaccination compliance?

Answer 3

• Vaccines given at the incorrect time related to service
• Wrong dose or route
• Incorrect interval
• Vaccines kept open for too long
• Farmers not referring to the data sheet
• Buying persistently infected animals in

Question 4

How does thyroid weight relate to foetal weight?

Answer 4

Thyroid weight (g) = foetal weight(kg)/ 2 to 3

Question 5

Which PM samples is used for which disease:
1. Spleen
2. Liver
3. Kidney
4. Brain

Answer 5

1. Spleen = BVD
2. Liver = IBR
3. Kidney = Leptospirosis
4. Brain = Neospora

Question 6

Bulk milk samples can only be used diagnostically in what cases?

Answer 6

When diseases haven’t been vaccinated against

Question 7

Sheath washings of the bull is used to detect?

Answer 7

Campylobacter

Question 8

What are your objectives when testing herd?

Answer 8

• An initial classification of herd status
• Identification of individual infected animals
• Monitoring to confirm “free” status
• Establishment of biosecurity

Question 9

Bulk milk screens can be used for which diseases?

Answer 9

BVD
IBR
Leptospirosis
Neospora

Question 10

Following a single bulk milk sample for BVD the herd can be categorised in one of three ways, what are they?

Answer 10

1. Antibody +ve, Antigen +ve
2. Antibody +ve, antigen -ve
3. Antibody -ve, antigen -ve

Question 11

Describe the suggested protocol if the bulk tank results for BVD is antibody negative

Answer 11

Review biosecurity
Risk assess revaccination
Quarterly monitoring

Question 12

Describe the suggested protocol if the bulk tank results for BVD is antibody positive and further tests are negative

Answer 12

Check test on heifer groups
First lactation screen

If above are negative:
- Review biosecurity
- Risk assess revaccination
- Quarterly monitoring

Question 13

Describe the suggested protocol if the bulk tank results for BVD is antibody positive and further tests are positive

Answer 13

Check test on heifer groups
First lactation screen

If above are positive:
- Bulk tank PCR
- Screen groups for PI

Question 14

Describe the suggested protocol if the bulk tank results for Leptospirosis is antibody positive and further tests are positive

Answer 14

Use sampling frame to estimate prevalence
- Review biosecurity
- Risk assess revaccination

Question 15

How are campylobacter infections treated in bulls?

Answer 15

Systemic: Streptomycin 10mg/kg
Sheath lavage: 100 mls pen/strep

Question 16

How are campylobacter infections diagnosed in females?

Answer 16

• Select 12 females most recently identified as problem Vaginal mucus collection
• Detects IgA
• From 7 weeks to 10 months PI
• Only 50% of infected females will ever produce positive response
• 50% of positives become negative within 6 months