Warts
are caused by the papillomavirus, and they usually appear as blemishes
on the face, mouth, or nose regions in younger horses. They appear as
either single warts, or as clusters of warts that have a "cauliflower"
appearance. While unsightly, they usually pose no threat to the horse's
overall health and are considered merely a cosmetic blemish. In most
cases, the warts will disappear on their own in a matter of time. But
it is important to remember that warts are a viral, contagious disease
and that proper steps should be taken in order to prevent them from
spreading from one horse to another, especially if the horse is kept
in the vicinity of other horses.
Younger horses are more susceptible to warts because they have less-efficient
immune systems than older horses. Their skin also is not as tough, and
they have less hair to ward off the insects that can carry the papillomavirus.
The good news is that once a horse has been infected, it builds up an
immunity and is less susceptible to future infections. Provided the
horse is in good physical condition, has a good nutrition program, is
wormed regularly, and is under good management, the warts should disappear
within six to nine months. Short-term, the warts will not reappear because
of the immunity the horse has developed for the virus.
If a horse on a farm becomes affected with warts, it is best to keep
the youngster away from other horses as much as possible. Also, as a
general management practice, and especially if there is an animal on
the farm that is infected with warts, do not use the same equipment
such as brushes, halters, bridles, etc., on both infected and non-infected
horses. While there might be no way to really isolate the infected horse,
good hygiene practices will help keep the warts from spreading.
Complications that can arise as a result of warts are secondary, but
they do sometimes occur. Some of the most common secondary problems
arise because the warts are banged or scraped on barn doors, fences,
halters, bridles, etc. When this happens, it creates an open sore on
the wart that could allow a secondary infection to enter the open wound.
During hot months, "summer sores" can become superimposed
on the warts if the wart has been rubbed raw. There also is the possibility
that maggots or larvae might take up housekeeping in the warts. Again,
this would be during the summer months when the horse is most active
and there is a greater chance that the horse will aggravate the warts,
allowing these problems to arise.
Generally, however, beyond secondary infections and infestations, there
are no real health consequences associated with warts. The only time
warts become dangerous is when a horse has an immune deficiency such
as CID, which compromises the immune system. In these cases, the warts
could become much more extensive and cover wider areas of the body because
the animal's immune system will not contribute to self-curing. Theoretically,
in these animals, the warts can persist and all sorts of health problems
can occur as a result.
It is thought that warts can be cleared up faster if they are surgically
removed. In many cases, where there are numerous warts present, the
removal of some of the warts seems to accelerate the immune response,
therefore clearing up all the warts more quickly. This does not always
work, and it is hard to prove because warts are a self curing disease
in horses anyway.
Warts rarely go beyond being more than just a cosmetic defect. Most
horses which get warts are youngsters which probably are not out on
the track or in competition. Something to keep in mind when dealing
with warts is your show schedule. If a horse has warts, it is not a
good idea to take it to shows where it will come in contact with other
horses.
Ultimately, warts are a fairly trivial disease, provided the horse is
given good nutrition and care. In most circumstances, the infection
is self-limiting and there should be no complications. The key to managing
warts is management of the horse itself. Management will depend on whether
the horse is stabled alone or with other animals. Since warts are caused
by a highly contagious virus, if the horse is stabled with other animals,
then common-sense hygiene should be utilized because warts appear more
often in this type of situation.