294 DISEASES OF THE SKIN 



acquired a yellowish-white or pink color. The larvse moult 

 and emerge as nymphs provided with eight legs, the body 

 covered with small spines (hence the name). The nymphs 

 remain in the ear from one to seven months. They then 

 drop off to the ground, seek cracks and crevices in buildings, 

 fences, trees, etc., in which they moult again and develop 

 into adult ticks, copulate, and the females lay their eggs. 

 The eggs hatch under favorable conditions in about ten days. 

 The larvse ("seed tick") seek animals soon after hatching. 

 Adult females which have never mated may live a year; 

 seed ticks which have found no host three months. The 

 adult tick has no spine. 



Symptoms. — ^While mild infestations may give rise to no 

 symptoms and thus be overlooked, severe ones produce 

 rather marked symptoms. The infested animal will shake 

 its head, repeatedly turn it from side to side, inverting first 

 one ear and then the other. The patients rub or scratch 

 the ears repeatedly. The badly infested animal appears 

 unthrifty, is losing weight and may show symptoms of a 

 gastro-intestinal catarrh. 



Diagnosis.^If the ticks are very numerous, the ear packed 

 full of them, they are easy to detect. In milder infestations, 

 however, they often escape detection, as they are apt to hide 

 under folds of skin or crawl into the depths of the ear. As 

 their excretions accumulate, mixing with the ear wax, masses 

 of this mixture may entirely occlude the ear canal. 



Where ear tick infestation is suspected, and no ticks are visi- 

 ble, the ears should be thoroughly probed with a 6-inch piece 

 of baled-hay wire, one end of which is bent into a | inch loop. 



Treatment. — The best treatment is to syringe out the 

 affected ears with a pine-tar-cottonseed-oil mixture (pine tar 

 2 parts; cottonseed oil 1 part; mix when warm). About one- 

 half ounce should be inj'ected. Before treatment all undue 

 wax accumulation should be scraped out with the wire probe 

 in order that the mixture come in contact with the ticks, 

 otherwise it will do no good. One treatment usually sufBces 

 to produce a cure. Reinfestation, however, occurs as more 

 seed ticks are picked up. It is recommended to treat late 

 in the fall or in early winter to protect against late winter 

 and early spring losses. 



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