Kazacos RR, Boyce WM: 1989, Baylisascaris larva migrans. J. Outbreaks similar to the 1 ... Sharon Patton, Malcolm D. McCracken. The heartworm, DiroJilaria ...
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Examination of raccoon feces from haylofts in Ontario has usually revealed large numbers of B. procyonis eggs (Lautenslager P, personal communication). Treatment of infected animals with various anthelminthics including thiabendazole, fenbendazole, levamisole, and ivermectin has not been effective.2 Outbreaks similar to the 1 reported here will continue to occur as raccoons become more common as pets and coexist with human beings in urban and rural areas. It is important that physicians, public health officials, veterinarians, and the general public be made aware of the Zoonotic potential and take necessary precautions when handling or harboring raccoons.
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References 1. Fox AS, Kazacos RR, Gould NS, et al.: 1985, Fatal eosinophilic meninogoencephalitis and visceral larva migrans caused by the raccoon ascarid Baylisascaris procyonis. N Engl J Med 312:16191623. 2. Kazacos RR, Boyce WM: 1989, Baylisascaris larva migrans. J Am Vet Med Assoc 195:894-903. 3. Kazacos RR, Reed WM, Kazacos EA, Thacker HL: 1983, Fatal cerebrospinal disease caused by Baylisascaris procyonis in domestic rabbits. J Am Vet Med Assoc 183:967-971. 4. Richter CB, Kradel DC: 1964, Cerebrospinal nematodosis in Pennsylvania groundhogs (Marmota monax). Am J Vet Res 25: 1230-1235.
J Vet Diagn Invest 3:79-80 (1991)
Prevalence of Dirofilaria immitis in cats and dogs in eastern Tennessee Sharon Patton, Malcolm D. McCracken The heartworm, DiroJilaria immitis, is enzootic in dogs in the United States. Diagnostic tests for heartworm disease are usually included in the evaluation of dogs presented with respiratory insufficiency, chronic cough, and exercise intolerance. Heartworm disease in cats is not as common as it is in dogs, but an increasing number of cases are reported each year. Currently, infection with D. immitis is usually included in the differential diagnosis of cats with coughing, dyspnea, or intermittent vomition. 2,4-8,14 The frequency of heartworm infection in cats in a particular location correlates with that in the dog population but at a lower incidence.13 The objective of this study was to determine the prevalence of heartworms in dogs and cats in eastern Tennessee based on the Knott’s concentration technique for microfilariae and the enzyme-linked immunosorbent assay (ELISA) for antigen of adult heartworms. Two populations were examined: (1) dogs and cats brought to the small animal clinic at the University of Tennessee, College of Veterinary Medicine (VTCVM) and (2) stray dogs and cats from random sources. Blood was collected from the dogs in the clinic as part of the routine physical examination and from both dogs and cats with signs of heartworm disease. All samples were collected and examined between November 1985 and February 1990. The diagnosis of heartworms was based on the presence of D. immitis microfilariae in blood examined by Knott’s concentration technique or by the presence of antigen of adult heartworms detected in the serum with a commercial ELISA kit.a When the stray cats in the study were euthanitized by an animal shelter, they were necropsied and examined for D. immitis in the heart or other areas of the body to validate the usefulness of the diagnostic
From the Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37901- 1071. Received for publication April 2, 1990.
tests. The results of the Knott’s tests and the ELISA tests for D. immitis antigen for both dogs and cats are shown in Table 1. From the clinic population, 1/23 cats (4.35%) and 135/ 2,658 dogs (5.08%) had circulating D. immitis microfilariae; 93/673 dogs (13.82%) and 9/95 cats (9.47%) were positive for heartworm antigen. In the stray dog population, 78/950 (8.2 1%) were positive for D. immitis. No D. immitis microfilariae were found in 122 stray cats examined, although 3 (2.5%) of the cats had 1 adult female worm in the right ventricle. One of the cats with an immature female worm in the heart was positive for D. immitis antigen. All the other stray cats, including the 2 with adult D. immitis, were negative for D. immitis antigen. Other reports have indicated that ELISA tests for D. immitis antigen in cats are more likely to give a false negative than a false positive result. 1,3,11 As in our study, when
