Bovine Papillomaviruses

Also known as: Bovine warts — Papomaviruses — Papillomatosis — Fibropapillomatosis — BPV

Introduction

There are at least five strains of papillomavirus, each of which has a specific predilection site on the cow.

• BPV type I causes wart like lesion on the nose, teats or penis and affect young cattle and will usually regress over time.
• BPV type II causes warts all over the skin of the head and neck of young cattle and will usually regress over time.
• BPV type III causes atypical warts which are smooth and white in appearance and occur mainly on the teats and udders of older cows.
• BPV type IV causes papillomas in gut, especially the rumen, and bladder, as well as lesions on the eye. This particular systemic form can be refered to as papillomatosis. The papillomas caused by this strain can undergo malignant transformation to alimentary carcinomas, however, this transformation is usually concurrent with grazing bracken (co-carcinogen) and ingesting quercetin (immunosuppressant). In Hereford cattle, the papilloma can transform to a squamous cell carcinoma of the eye, where UV light acts as the co-carcinogen.
• BPV type V causes tiny warts on the teat.

Infection is spread by direct contact from cow to cow or by indirect contact from fomites. With most strains, calves are most commonly affected.

Clinical Signs

These will obviously vary depending on which strain of the virus is contracted. In BPV type IV signs will be concurrent with the body system affected e.g. haematuria if in the bladder or diarrhoea and bloat if in the rumen.

On the skin, the virus will at first appear as small, smooth raised nodules in the characteristic regions, which will then enlarge. Some will become rough and cauliflower like in appearance, whilst others may become pedunculated.

A characteristic feature of this disease is that the warts will regress spontaneously over a period no longer than one year.

Diagnosis

Lesions are characteristic in appearance and location along with the signalment of the animal are enough to make a presumptive diagnosis.

Treatment and Control

Often no treatment is required as spontaneous regression usually occurs. If the cow traumatises a wart then a short course of antibiotics or anti inflammatories may be used to aid its immediate relief. Any other treatment is only of cosmetic value and so is generally only performed by those wishing to show their cattle. Treatment of warts would include injection with lithium antimony thiomalate 6%, removal by cryosurgery or cold steel surgery.

Control measures are not usually necessary due to the mildness of the disease.

References

Andrews, A.H, Blowey, R.W, Boyd, H and Eddy, R.G. (2004) Bovine Medicine (Second edition), Blackwell Publishing

Blowey, R, Weaver, A.D, (2003) Colour Atlas of Diseases and Disorders of Cattle, Mosby Publishing

Radostits, O.M, Arundel, J.H, and Gay, C.C. (2000) Veterinary Medicine: a textbook of the diseases of cattle, sheep, pigs, goats and horses Elsevier Health Sciences