Feline Leishmania infections have been observed all over the world, caused by the species commonly found in other animals in that region; the prevalence in cats is usually lower than that in dogs in the same area. L infantum is most likely transmissible from cats to sand flies, because sand flies have been shown to feed on cats and to be infected after feeding on naturally infected cats. To date, nonvectorial transmission has not been described in cats, but blood transfusion may be a source of infection in cats similar to humans and dogs. Host factors predisposing to susceptibility include immunocompromise secondary to feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV) infection, immunosuppressive therapies, or debilitating concomitant diseases.
Clinical Findings of Feline Leishmaniosis
Feline leishmaniosis is a chronic disease with clinical signs and clinicopathologic abnormalities mirroring those found in dogs. FeLV/FIV testing is warranted in potential cases, because approximately 50% of reported cases have been positive for one of these viral infections. The two most common clinical findings are skin and/or mucocutaneous lesions and lymphadenopathy, and the most common clinicopathologic abnormality is hypergammaglobulinemia.
Diagnosis of Feline Leishmaniosis
Cats with clinical signs consistent with leishmaniosis should have their diagnosis confirmed via quantitative serology. If serology is negative but the clinical picture is highly suggestive, particularly if the cat is FeLV or FIV positive, cytology, histology, quantitative PCR, or culture should be considered, because immune compromise may inhibit the ability to produce specific detectable antibodies.
Treatment of Feline Leishmaniosis
There are no published controlled studies of treatment of cats for leishmaniosis. In the absence of evidence indicating otherwise, empirical treatment using allopurinol (10 mg/kg, PO, twice daily for at least 6 months) has been used most frequently without reported adverse effects.
Prevention of Feline Leishmaniosis
Most pyrethroid-based products are toxic to cats. Flumethrin collars are licensed for use in cats. There is no experimental proof that these collars repel sand flies when worn by cats, however.
For More Information
Also see pet health content regarding leishmaniosis in cats.
