MITES

If your goat has irritated skin that has formed crusts that have wrinkled, thickened, and/or lost hair on or under its legs, scrotum, udder, genitals, anus, hooves, ears, face, or other areas without a thick hair coat, it may have mange mites.

Sometimes called "scabies," from the Latin word that means "to scratch," this ectoparasite (parasite that largely lives on the surface of its host) should not be confused with "scrapie," which is an incurable brain disease. Mites belong to the arachnid subclass Acari, hence the other term describing mite infestion is Acariasis. Transmission from goat to goat is through direct body contact and is very contagious.

There are three types of manage mites that can affect goats: scarcoptic, psoroptic, and chorioptic. The mite hardest to eradicate is the scarcoptic mange mite (Scarcoptes scabei) because it burrows into the skin, making tunnels in which it lives and lays eggs, feeding off skin cells and sucking lymph fluid. The body parts cited in the first paragraph of this article are starting points for these mites because they can spread over the goat's entire body. Psoroptic and chorioptic mites don't burrow into the skin but still damage to the goat.

Confirmation of mite infestion requires that a skin plug be taken by a vet and examined under a microscope. Skin scrapings are seldom sufficient because the mites burrow deep into the skin. A plug must be pulled to the point of drawing blood. Sometimes mites or their eggs can be found in fecal samples, but examining a skin plug under a microscope is the most accurate method of diagnosis. Note: All skin diseases require vet examination and diagnosis because it is easy to mis-diagnose by visual inspection and decide to treat for one problem but it turns out to be another. Example: Mis-diagnose fungus as staph infection, use steroids as part of the treatment, and the fungus rapidly gets worse.

The mite spends its entire life cycle either on or under the goat's skin. This parasite cannot survive off its host (the goat) for more than a few days. Intense itching follows the development of lesions, thickening of the skin, and formation of dry crusts. Itching is the body's inflammatory response to the mites' fecal pellets. Zinc deficiency may coincide with mite infestation, and a secondary bacterial skin infection can occur, requiring antibiotics. Mite infestation is more common in winter but can occur in summer. Sometimes mite activity will regress in summer and actively reappear in winter. Environmental conditions affect mite activity. Mite infestation on goats spikes in periods of high heat and drought, in areas where goats live in close quarters and are intensively managed, and when the mites' normal hosts are in short supply in nature (deer, rabbits, etc.). Immune-suppressed goats are more likely to have the worst cases of mite infestation, but healthy animals can be infested when the mite population is high. A group of bucks in rut can be sufficiently stressed that their immune systems are compromised enough for mites to attack them.

The most serious problem caused by mange mites is poor semen production in male goats to the point of actively breeding but unable to inseminate the does. Semen production must be done at temperatures lower than the goat's body temperature. The scrotum's design permits heat loss so that semen can be produced outside of the main body of the goat. Scab formation on the scrotum prevents this heat loss, concentrating heat inside and impairing semen production. Interestingly, the buck's sex drive (libido) is not reduced but his body cannot produce sperm capable of inseminating female goats. Once the mites are killed, quality semen production returns. Some people believe that mite infestation in pregnant does reduces number of offspring, but I cannot find any documented evidence to support that conclusion.

Human reaction to these mites is normally limited to superficial skin irritation which usually clears up on its own. Sometimes topical anti-itch medications are needed.

Aggressive treatment is necessary to kill mites on goats and multiple applications are necessary. No one-time-use treatment will work. Hair must be re-growing on the goat's body parts before treatment can be considered effective. Long-haired goats may have to be sheared for mite eradication to be successful. Since mites can live for a few days off the goat and in the environment before they die, sheds and bedding areas must also be cleaned and treated. All goats in the herd must be treated -- not just the ones with obvious mite infestation.

There are several different products that can be used to kill mites on and under the skin of goats. The dewormer Ivermectin can be injected SQ, dosing at one to two cc's per 50 pounds bodyweight weekly for at least three consecutive weeks. Use the 1% strength Ivermectin and inject SQ over the ribs with an 18 gauge needle to minimize discomfort because this product stings when injected. Topical application of Lime Sulphur Dip must be done at the same time. Lime sulphur Dip (97.8% strength) can be purchased from a vet in concentrate form and mixed according to label directions (4 ounces concentrate to 1 gallon water). Lime Sulphur mix is applied by spray or dip and must be done every week for at least three weeks and sometimes weekly as long as six weeks if the skin isn't clearing up. Topical application of 1% Ivermectin weekly for three or more consecutive weeks is an alternative to Lime Sulphur Dip. A third topical application product is Prolate; follow label directions. There are other products available to treat mange mites, including so-called "organic" or "natural" products. I am leery of them because mites are hard to kill and most of these products use as a selling point that they do not have "harsh chemcials" in them. On the other hand, some of the chemically-based products are very strong, so I favor the Lime Sulphur Dip approach as the beginning method of treatment. Several other products for applying to the goat's skin are available. Check suppliers for products that kill mites.

Livestock guardian dogs (and all other dogs) are also subject to mite infestation and may have to be treated. There is some confusion about the species specificity of mange mites; some research indicates that certain mites are specific to a single species and other literature implies that mites may not be species specific after all. So I think it is wise to check out and possibly treat your livestock guardian dogs. Remember that Ivermectin is toxic to some dog breeds and cannot be used on them.

The important fact to remember is that goats must be treated for sub-cutaneous mite infestation AND on the surface of their bodies at the same time and repeatedly weekly for at least three consecutive weeks.

Suzanne W. Gasparotto, ONION CREEK RANCH, Lohn, Texas 1-9-12