Dirofilariasis in a captive wolf pack
Pratt, S.E.; Mall, J.J.; Rhoades, J.D.; Hertzog, R.E.; Corwin, R.M.
Veterinary Medicine-Small Animal Clinician 76(5): 698-699
1981
ISSN/ISBN: 0042-4889 PMID: 6913305 Document Number: 177373
Adult Dirofilaria immitis were found in 2 Canis lupus which died in December 1978 and March 1979 in Kansas City Zoo, Missouri, USA. The 15 wolves remaining in the pack were then found positive for D. immitis microfilariae (one wolf did not recover from tranquilization and adult heartworms were found in the heart). Caparsolate was given intravenously at 0.1 ml/lb twice/day for 3 days (beginning April 20, 1979) to the surviving wolves; one died from the stress of being kept in isolation. Dithiazonine was mixed with various meats, but the pack refused to eat it. Levamisole hydrochloride was mixed with the ration (at 104 ml/12.7 to 14.5 kg feed) from May 30 to June 22; all the wolves ate well. On June 22, 6 wolves were negative and 7 positive for microfilariae (one of the latter did not recover from tranquilization). Treatment with levamisole was resumed from June 28 to August 1. On July 5, 2 females removed from the pack for unrelated reasons were negative for microfilariae. On August 1, 5 wolves were negative and 5 positive (one of the latter did not recover from tranquilization and live adult D. immitis were found in the pulmonary arteries). A female died on November 26, and although no adult heartworms or microfilariae were seen, intimal fibrosis of the pulmonary arterioles, typical of chronic dirofilariasis, contributed to death. On April 8, 1980, a male died; the heart was enlarged and numerous live D. immitis were found in the right atrium and ventricle and in the pulmonary arteries. Histopathology of the lung indicated chronic passive congestion and oedema with numerous haemosiderin-laden alveolar macrophages and occasional intravascular microfilariae.