Newly recognized fatal protozoan disease of dogs.
Histologic sections and case histories from 23 dogs with proven fatal toxoplasmosis-like illness at the Angell Memorial Animal Hospital were reviewed. Toxoplasma gondii was identified in 13 dogs. A newly identified parasite, Neospora caninum, structurally distinct from T gondii, was found in 10 dogs. The newly discovered organism, belonging to a new genus and new species, formed meronts in many tissues of the dogs, especially the brain and spinal cord. Neospora caninum was located directly in the host cell cytoplasm without a parasitophorous vacuole; it divided by endodyogeny, contained more than 11 rhoptries, and did not react with the anti-T gondii serum in the immunoperoxidase test. Meningoencephalomyelitis and myositis were the main lesions associated with N caninum. Ulcerative and fistulous dermatitis was the major lesion in 1 dog.
Dubey
J P
JP
Livestock and Poultry Sciences Institute, Beltsville Agricultural Research Center-East, MD 20705.
Carpenter
J L
JL
Speer
C A
CA
Topper
M J
MJ
Uggla
A
A
D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis / Q000401:mortality / Q000469:parasitology* / Q000473:pathology; D004285:Dogs; D005260:Female; D008297:Male; D011528:Protozoan Infections / Q000175:diagnosis / Q000401:mortality / Q000473:pathology; D011529:Protozoan Infections, Animal; D014124:Toxoplasmosis, Animal / Q000175:diagnosis / Q000473:pathology