Affiliation:
1. Virology Laboratory Elizabeth Macarthur Agriculture Institute Menangle New South Wales 2568 Australia
2. Northern Tablelands Local Lands Services Inverell New South Wales 2360 Australia
3. Northern Tablelands Local Lands Services Glen Innes New South Wales 2370 Australia
4. North‐West Local Lands Services Tamworth New South Wales 2340 Australia
5. Inverell Veterinary Clinic Inverell New South Wales 2360 Australia
6. Animal Biosecurity NSW Department of Primary Industries Orange New South Wales 2800 Australia
Abstract
In 2016, bluetongue virus (BTV), serotype 16 (BTV‐16), was detected in New South Wales (NSW) in sentinel cattle for the first time. Over the next 6 years, BTV‐16 has been detected regularly and over an increasing area of the BTV zone in NSW. In April 2023, disease was reported in sheep on two farms on the Northern Tablelands of NSW. The consistent clinical signs included reduced exercise tolerance, facial swelling, serous nasal discharges with encrustation of the nasal plane, subcutaneous oedema of the neck and brisket and variable congestion of the coronary band. Affected sheep were mainly mature ewes and rams, with an estimated morbidity of 20% over a period of 6–8 weeks. Although there were several unexpected deaths, no veterinary examination was sought. Predominantly BTV‐16 RNA was detected in sick sheep, with an incidence of infection of approximately 40% in a cross section of one flock. These events represent the first confirmation of disease due to bluetongue virus in NSW. As these cases occurred in a region with a high density of sheep, if there is ongoing transmission of BTV‐16 during subsequent summers, further disease might be expected.
Funder
Animal Health Australia
NSW Department of Industry
Subject
General Veterinary,General Medicine