Issue Description Neosporosis is an infectious disease primarily
of dogs and cattle. Due to the similarity of Neospora caninum to
Toxoplasma gondii, neosporosis for many years was misdiagnosed as
toxoplasmosis. Neosporosis was first described in dogs in Norway in
the mid-1980's as causing neuromuscular degeneration leading to hind
limb paralysis. Neosporosis now appears to a major cause of abortion
in dairy cattle worldwide. The disease has been found in many
countries around the world, but appears to be an important cause of
reproductive failure in cattle in the U.S., Netherlands and New
Symptoms and Diagnosis Neospora caninum infects domestic dogs
worldwide with varying prevalence. Studies testing dogs for antibodies
to the parasite suggest that more than 30% of dogs are infected in
some areas, with the highest numbers in South American countries and
in rural dogs, especially those living on cattle farms.
Most infected dogs have no symptoms. When symptoms occur, neosporosis
is most severe in newborn puppies, infected during gestation when the
parasites move from the bitch's tissues to the fetus. Puppies suffer
paralysis, particularly of the hind legs, and often do not survive.
Adult dogs may suffer from an illness similar to toxoplasmosis in
cats, or they may develop dermatitis.
Treatment Information on effective therapy for this
disease is limited. Clindamycin, sulfadiazine, and pyrimethamine alone
or in combination have been administered to treat canine neosporosis.
However, clinical improvement is not likely in the presence of muscle
contracture or rapidly advancing paralysis. To reduce the chance of
illness, all dogs in an affected litter should be treated as soon as
the diagnosis is made in one littermate. Older (>16 weeks) puppies and
adult dogs respond better to treatment. There is no known therapy to
prevent a bitch from transmitting infection to her pups.
Prevention In dogs, N. caninum can be transmitted
repeatedly through successive litters and litters of their progeny. This should be considered when
planning the breeding of Neospora-infected bitches. Dogs should not be fed uncooked meat, especially
beef. There is no vaccine to combat neosporosis. No drugs are known to prevent transplacental transmission.