As the hot summer months approach, we are again faced with the yearly battle against parasites. Internal parasites in goats or sheep are seldom noticed until the degree of infestation becomes rather severe. Most losses from internal parasites are caused by roundworms. About nine common species of roundworms infest the stomachs and intestines of goats and sheep. Economic losses from these infestations result from a lower rate of weight gain (in the case of meat goats or feeder lambs), higher feed costs, lower wool or hair production (angora goats), and a higher mortality rate, all of which reduce profits and increase the level of anxiety experienced by the herdsman.
Roundworm symptoms include: bottlejaw (a swelling under the lower jaw accompanying severe infestations), anemia (check for pale gums), weakness, general unthriftiness, lack of appetite, low milk production, poor wool groth or hair production, and diarrhea (excessive scouring).
Roundworm infestations are heaviest during the hot, humid days of summer (June, July, and August in Tennesseeand other Southern states). Moisture and warm weather (above 80 degrees Fahrenheit) speed up egg production and larvae growth, causing the degree of infestation to become greater. As a keeper, be aware that there can be a "bloom" of parasites just after kidding or lambing. Always treat your doe or ewe for worms a day or two after she has presented you with progeny (and after you have harvested the colostrum).
A combination of herd management and medication can break the life cycle and eradicate roundworms. This can be done by: 1) preventing the animals from ingesting the larvae (by pasture rotation), 2) reducing the production of eggs and larvae(medication and pasture rotation),and 3)destroying worms within the animals (medication).
Numerous compounds and drugs have been compared and evaluated for roundworm control in ruminants. In most cases, close attention has been paid to the degree of efficiency, toxicity levels, method of administration, buildup of immunity and costs. We have had particularly good results with zimecterin, Safeguard, and Valbazon. Be certain to consult your veterinarian prior to the administration of any of these drugs so that you understand the limitations of each drug.
To minimize problems with internal parasites, follow these management tips:
So be vigilant and persistent. Your animals will reward you with higher production. You will also experience far less aggravation if you manage your herd to minimize the production of parasites.