Tackling pesky livestock warts in your dairy herd

Dear Dr Othieno,

I enjoy reading your articles as  a livestock farmer based in Navakholo, Kakamega County.

I have observed wart-like growths on the neck of one of my cows, both in the past and more recently. In the most recent case, there were only a few, and they dropped off after about two months. My question is: is there anything that can be done to prevent them? Could they take a fatal form in future and kill my cows?

Sylvanus Shikuku,

Kakamega

Thank you, Sylvanus, for reading and for your question. Yes, warts are quite common in livestock and can take different forms. Fortunately, many are harmless and disappear on their own. However, depending on their location and extent, they can have negative effects on production and productivity.

Warts are common in cattle, and I am pretty sure you have all already come across them, or your stock has been a past victim.  

Warts in livestock are caused by a virus known as the Bovine Papillomavirus, which spreads easily from one animal to another.

The virus is very hardy and can survive for weeks or even months in the environment, especially when attached to materials such as shed warts, dirt, or tissue on equipment.

Because of its highly contagious nature, it is good husbandry practice to isolate infected animals from the healthy ones.

Young animals, especially calves, are most affected, while cases in cattle older than two years are uncommon.

In some cases, dairy cows may develop warts on their teats.

The virus enters the body through small cuts or wounds on the skin, making calves particularly vulnerable during routine procedures such as ear tagging or tattooing when equipment is not properly cleaned.

Warts often develop around tattooed areas, sometimes growing heavily around the marks.

After infection, warts may appear within one to six months, usually starting on the ears and spreading to the head and neck.

Even cattle that do not show visible warts can still carry and spread the virus.

The main source of infection is infected cattle, but the virus can also spread mechanically via contaminated equipment such as ropes, halters, tagging tools, and other farm instruments.

This makes hygiene on the farm very important. Farmers are encouraged to disinfect all equipment before it is used on another animal.

Tools such as tagging or tattooing pliers can be cleaned with a formalin solution, ensuring that any blood or tissue is first washed off.

Having two sets of tools and alternating between them allows sufficient time for proper disinfection. It is also advisable to wear gloves during handling to protect the handler and prevent the spread of the disease.

Although vaccines are available in developed countries, I have not seen this locally.

Vaccines can help prevent warts in animals that have not yet been infected.

Are warts a serious condition? In most cases, warts are not serious and will shrink and fall off on their own after a few months.

Many traditional treatments appear to work, but this is often because the warts are already healing naturally.

However, if the warts are large or causing problems, they can be carefully removed surgically using clean cutting tools.

Any bleeding can be controlled, and the area treated to prevent infection and flies.

Healing is usually quick, and once removed, the warts rarely recur.

Good farm hygiene, careful handling of animals, and proper disinfection of equipment are the most effective ways to control and prevent the spread of warts in cattle.

Farmers are encouraged to seek advice from a veterinary officer if the problem persists or becomes severe.

[Dr Othieno is a veterinary surgeon and the head of communications at the Food and Agriculture Organisation of the United Nations (FAO) Kenya. The views expressed here are not necessarily FAO’s but his own]