Warble fly: how to spot and report the disease

Warble fly mainly affects cattle. It can also affect horses and deer. Warble fly does not affect humans.

Clinical signs

The main sign of warble fly is large, soft and painful swellings on the back of the animal of up to 3mm wide.

How warble fly is spread

The disease is spread by the warble fly, which lays eggs on the hide of animals.

Human health implications

There are no human health implications, although there have been some isolated cases of accidental infection of laboratory personnel working with the virus.

Disease control

If the disease is confirmed the outbreak will be controlled in line with the contingency plan for exotic notifiable diseases.

An approved list of products to treat warble fly can be found on the Veterinary Medicines Directorate product information database.

Legislation

The main legislation on warble fly is the Warble Fly (Scotland) Order 1982.

Biosecurity

Biosecurity is about being aware of the ways disease can spread and taking every practical measure to minimise the risk of disease spreading. The advice details practical things you can do on your farm to help prevent the introduction and spread of warble fly to and from your animals.