Guidance for vets on investigating poor reproductive performance in sheep and cattle, when bluetongue virus (BTV) should be considered as a potential cause.
Guidance for vets on investigating poor reproductive performance in sheep and cattle, when bluetongue virus (BTV) should be considered as a potential cause.
Background
This document is intended to provide guidance on investigating poor reproductive performance in sheep flocks and cattle herds, during periods where bluetongue virus (BTV) should be considered as a potential cause. Poor reproductive performance may be characterised by all or one of lower-than-expected scanning or pregnancy diagnosis rates, infertility abortion or stillbirth.
There is a statutory requirement to report all bovine abortion cases:
- In England, via the Defra Rural Services helpline: 03000 200 301
- In Wales: 0300 303 8268
- In Scotland, via your local APHA Scotland Field Services office
Suggested test protocols may vary depending on whether there is one clinical sign or a range of reproductive signs and, is not exhaustive or intended to be wholly inclusive. Guidance is intended to aid sampling and testing in combination with clinical judgement and consideration of the flock or herd history. Veterinary Investigation Officers (VIOs) at your local surveillance pathology centre are happy to discuss cases and advise on sampling and testing.
Since the incursion of bluetongue virus serotype 3 (BTV-3) to England in 2024, consideration of BTV as a cause of infertility, abortion, stillbirth, and/or dummy animals is recommended. Clinical suspicion of BTV may depend on seasonality, herd or flock history, or vaccination status.