Prevention.—Prevention is the only method by which this disease can be eradicated. Prevent the sheep from becoming infected with these parasites. Stray dogs, wolves or coyotes should be killed whenever found, and dogs too valuable to kill should be kept free from tapeworm. Meat should not be fed to dogs unless cooked or known to be free from tapeworm cysts.
GRUBS IN THE HEAD.
(Head Maggot)
Cause.—Grubs in the head of sheep are produced by the Sheep Gadfly which is yellowish-gray in color with five well divided rings around its body, covered over with fine hair and the lower portion of the head white. This fly is somewhat larger than the ordinary house fly. It attacks sheep and goats during the Summer and Fall and deposits its larva about the sheep’s and goat’s nostrils. This larva attaches itself to the mucous membrane of the nostrils with two hooklets by which it gradually works into the air cavities of the head, remaining there for about ten months. Then it again passes from the nostrils, burrows into the ground and becomes a fully matured Gadfly in six or eight weeks, which completes its life cycle, the head of the sheep or goat being its intermediate host where the newly born Gadfly again attaches its larva.
Symptoms.—When sheep or goats are attacked by this Gadfly, they run, strike at the nose with their front feet, rub the nose on the ground or against other sheep. In case only three or four larvae gain entrance to the sinuses of the head, they produce very little, if any, ill effects, but where they become numerous, they cause the animal to cough and sneeze continually, discharge from the nose, which is occasionally tinged with blood. The appetite becomes impaired, the animal shows signs of emaciation, becomes very weak, raises the nose in the air, but eventually becomes so weak it reels when walking and finally lies down. It becomes so weak it cannot toss the head or rise, and dies.
Prevention Treatment.—Very successful. Paint the sheep’s or goat’s nose with Pine Tar, or better still, place salt in a trough, covering it with boards, with holes bored in them just large enough for the animal to insert its nose. Smear Pine Tar about the holes once or twice a week. This treatment has proven very efficient in localities where sheep Gadflies are numerous.
Medical Treatment.—After the animal once becomes infected with these grubs, bore holes (trephine) through the skull with a sharp instrument made for this purpose and remove the grubs.
HOVEN.
(Bloating—Acute Tympanites—Acute Indigestion)
Cause.—Hoven is caused by various kinds of food which produce indigestion or fermentation and resultant gases in the rumen or paunch. When sheep are first turned into young clover, they eat so greedily of it that bloating frequently results. Turnips, potatoes and cabbage may also produce it. Middlings and corn meal also frequently give rise to it. In this connection it may be stated that an excessive quantity of any food, before mentioned, may bring on this disorder, or it may not be due to excessive eating but to eating too fast. Sometimes the quality of food is at fault. Grass, clover or alfalfa, when wet with dew or rain soaked, frequently produce digestive disorders and bloating follows. Frozen roots or potatoes covered with white frost should be regarded as dangerous. When food has been eaten too hastily or when it is cold and wet, the digestive process is imperfectly performed and the food contained in the paunch ferments, during which process large quantities of gas are formed. This same result may follow when a sheep is choking, as the obstruction in the gullet prevents the eructation or passing of gas from the stomach so that the gas continues to accumulate until severe bloating results.
Symptoms.—The swelling of the left flank is very characteristic, as in well marked cases the flank at its upper part rises above the level of the backbone and when struck with the tips of the fingers emits a drum-like sound. The animal has an anxious expression, moves uneasily and is evidently distressed. If relief is not obtained in time the sheep breathes with difficulty, reels in walking or standing and in a short time falls down and dies from suffocation. The distention of the stomach or rumen may become so great that it pushes the diaphragm (the membrane separating the lung and intestinal cavity) forward against the lungs, so as to squeeze and stop their movements, thus preventing the animal from breathing and in some instances the case may be complicated by a rupture of the stomach.
Treatment.—Do not waste any time. Puncture about three inches downward and forward from the point of the hip bone with a clean sharp knife, or any instrument that is clean and sharp. A special instrument made for this purpose, the trocar, is a very useful instrument.