What's bugging your horse? And how to get rid of it.

External horse parasites include a variety of "bugs." Some of them are quite familiar; others are quite rare. But all of them feed upon their host thereby causing discomfort, loss of condition and sometimes actual disease.

Flies

Flies are certainly the most common equine parasite, and no stable is entirely free of them in the warmer months. The stable fly, horsefly and housefly torment and bite horses. The screwworm fly lays its eggs on open wounds. Sand flies and gnats are a problem in some areas, as are face flies, a newly recognized parasite in the United States.

To control the fly problem, it is necessary to have a manure disposal system as well as a fly control program. A wide variety of compounds are available for the latter purpose, and many of them are advertised in horse magazines. They include repellent products to apply directly on the horse, and insecticides to use in and around the stable. Fly baits and traps are also effective.

One word of caution: Never use any of these products without first reading the label very carefully. Most fly control products are safe if used exactly as directed. Common sense must be used to ensure no harm will come to children, pets, other animals, or the horses themselves. Read the label.

During fly season, protect wounds with appropriate fly repellent preparations that are safe to use on or near wounds, or by bandaging if necessary.

Mosquitoes

Mosquitoes not only feed upon horses, but play an important role in transmitting sleeping sickness (encephalomyelitis), therefore if mosquitoes are a problem, institute a control program that includes the use of repellents and insecticides, and treat ponds where mosquitoes breed.

Scabies 

Also known as scab or mange, it is caused by tiny mites that burrow into the skin. They cause lesions which itch intensely, and the condition readily spreads to other parts of the body or to other horses, especially by contaminated equipment. Itchy "rashes" should be examined by a veterinarian who will differentiate scabies from other types of skin diseases. This is done by examining skin scrapings under a microscope and looking for the tiny mites that cause the diseases.

When scabies is diagnosed in a stable, a quarantine program should be implemented at once, and treatment given with the appropriate medications.

Lice

These are tiny insects that spend their entire life cycle on the horse. They lay their eggs, known as "nits" on the hairs next to the skin. When these hatch, the lice feed on the horse's skin.

There are two kinds of lice, biting and sucking. Sucking lice feed upon the horse's blood, and in severe infestations can actually cause serious anemia. With biting lice, the skin is irritated and itchy, causing the horse to rub and bite the infested areas. As a result, large areas of skin become bald and raw. Upon close examination, nits and lice may both be seen.

Lice are most active in winter months and rarely cause any trouble in hot weather. Fortunately, they are easily destroyed by using insecticidal powders, dips, or sprays on the horse. Avoid contamination of mangers and feeding areas when treating the horse by doing this outside the stable or corral.

Ticks

Ticks are a dangerous parasite because they carry a large number of diseases of humans and animals, including horses. Once premises are infested with ticks, they will become an increasingly severe problem. Therefore prompt action should be taken to destroy ticks when they are first found on a horse. The owner will usually not see the larval forms of the ticks, but rather the engorged tick attached to the skin.

When only occasional ticks are seen, the simplest way of handling them is to squirt them with a tick bomb (such as those made for dogs) or dab them with a little screwworm smear. They will then die and fall off, in time. Applying lighted cigarettes or gasoline is unnecessary and unsafe.

Ear ticks

These are especially troublesome in horses because they live deep down in the ear, causing great discomfort to the horse. Horses with ear ticks will shake their heads from side to side, become ear-shy and are hard to bridle.

These ticks are easily killed by instilling in the ear a mixture of mineral oil with a little lindane screwworm smear mixed in. Commercial mixtures are available, too. It is necessary to restrain the horse with a twitch while doing it or he will not allow the medication to be left in the ear and will immediately shake it out.

If the ears have been infested for a long time, there might be considerable debris and a secondary infection present, necessitating veterinarian attention.