We have received several letters from TLBAA members with questions about cattle warts and how to properly treat them. Most have heard of various methods of treatment and prevention, but they're not really sure which procedures are necessary or which ones are a waste of time and money. Understandably, you never want warts on your cattle, but there is a good chance that at some point in time, one or more of your Longhorns might develop warts. If and when that happens, don't panic…warts are ugly, but they can be treated successfully.
What do warts look like and where do they develop on cattle?
Papillomatosis (warts) are dry, rough-surfaced protruding growths usually white, grey or light tan colored. The most commonly affected areas are the nose, chin, lips, neck, shoulder and brisket. There are 6 strains of this virus and several of these strains are specific to wart development on the teats, genitals, bladder and digestive tract. Warts can also appear on the abdomen, back and inside the ears. There are 4 types of wart growth: tag-shaped -- small slender warts, often resembling blunt-ended thorns; pedunculated (stalked) -- a wart with a narrow base and larger body; sessile (squat) -- a raised wart with a wide firmly fixed base; and flat -- frequently overlooked because they are smaller and not as noticeable as the other types of warts. They can be as small as a pea (when they first emerge on the skin) and as large as a tennis ball (if left untreated).
What causes cattle warts and are they a serious problem?
Cattle warts are caused by a highly contagious virus. There are 6 strains of the bovine papilloma virus (BPV) and each strain affects a different part of the animal's anatomy. Warts are generally more of an unsightly appearance issue rather than a serious physical problem. Chronic wart infections may cause cattle to become stunted and lose body condition and in rare cases cause death.
Show cattle are not allowed in conformation shows if they have visible warts. The chance that they can infect other animals is high, so they pose a health risk to other entries.
How are warts spread from animal to animal?
Cattle with visible warts as well as carriers of the virus (those not exhibiting warts) can transmit it to unaffected cattle by direct physical contact with each other. Indirect transmission is possible when ‘clean' cattle come into contact with feed and water troughs, fence posts, trees and pens used by infected animals. The use of tagging pliers, halters, tattoo pliers and grooming brushes can also help spread the virus from animal to animal. In most instances warts are introduced to the animal's body via an abrasion.
At what age can warts appear on cattle?
Depending on the age of the animal, it may take anywhere from 1 to 12 months after being exposed to the virus for warts to develop. Calves under a year old can have warts, but most cases are seen in cattle around 2 years of age. Older cattle have immunity to the virus since more than likely they were exposed to warts when they were younger. It's uncommon to see warts in cattle over 3 years old.
What is the most effective treatment for warts?
Old-timers say that leaving warts alone is about the best solution. As the animal ages it builds immunity to the virus and in time the warts will disappear on their own. For cattle owners who want to speed up the process and get rid of the warts quicker, removing them with either a very sharp pair of surgical scissors or a razor blade will work. Removal should only be done on mature growths, since removing warts too soon can stimulate the growth and spread the virus. Large pedunculated warts can be removed slowly by tying a ligature around the base. The wart will dry up and fall off within a month.
If done quickly, laceration of small warts will not be painful to cattle. Removal of larger warts or a large number of them can cause discomfort, so deadening of the treatment area is possible with an injection of Lidocaine Consult your veterinarian for the purchase and proper administration of Lidocaine because it is a prescription drug.
If most of the cattle in a herd are infected and removing the warts from all the animals is not possible, then an autogenous vaccine can be made from warts removed from a few of the cattle. The serotype vaccine produced from these warts will contain the same set of antigens of the virus strain that has infected the herd. Your vet can usually prepare the vaccine and tell you how to administer it properly to your cattle.
Commercial wart vaccines are sometimes effective as a cure, but since they don't contain all 6 of the strains, they are not as effective as a serotype autogenous vaccine. A commercial vaccine has to be administered multiple times at two-week intervals until the warts are in regression.
Another method of treatment is cutting off the wart and feeding it back to the infected animal. The ingestion of the ‘live' virus helps the animal build immunity to the particular virus strain that has attacked its body. Many old-timers swear by this method of curing warts.
Warts can also be frozen off and over-the-counter wart remedies intended for humans have also been successfully used on cattle.
Can warts be prevented?
Prevention is possible by vaccinating all cattle with a commercial vaccine that have not been previously infected by warts. Since young calves are prone to developing warts, they should be started on a vaccine at an early age as young as 4 to 6 weeks old. These vaccines may not be 100% effective in preventing the outbreak of warts since they don't contain all strains of the virus. For this reason, the majority of ranchers do not use these vaccines because they are expensive. Introduction of a new animal into the herd that is carrying a different strain of the wart virus will still cause some animals to grow warts. So overall, the best form of prevention (or actually the spread) of warts is to know what they look like and to be ready to quarantine infected animals and treat them immediately.
**Note: If you are ever in doubt about any suspicious skin growth on your cattle, contact your veterinarian.
**This article is the property of Gail Kocian and the Texas Longhorn Trails and cannot be copied without our express permission.