Toxoplasma gondii‐like organisms in skin aspirates from a cat with disseminated protozoal infection

Abstract

An 8-year-old, male domestic shorthair cat was referred to the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania with a 3-day history of lethargy, inappetance, hyperemic skin nodules, coughing, and vomiting. Laboratory results included nonregenerative anemia, lymphopenia, thrombocytopenia, hypoalbuminemia, hyponatremia, and increased alanine aminotransferase and aspartate aminotransferase activities. Cytology of the skin nodules revealed many spindle- to crescent-shaped protozoal organisms, with morphology consistent with Toxoplasma gondii or Neospora caninum. Gross necropsy, histopathologic, immunohistochemical, and transmission electron microscopic findings confirmed a systemic protozoal infection; however, the organism exhibited characteristics of both N caninum and T gondii. Diagnosis of a T gondii-like infection was based on internal structures of the organism and positive reaction to rabbit polyclonal antibodies to T gondii. Reports of toxoplasmic dermatitis are rare in the cat and dog, and this is the first reported diagnosis of T gondii-like protozoa in skin aspirates.

Toxoplasma gondii-associated cholecystitis in a cat receiving immunosuppressive treatment

“…The main pathologic features of systemic toxoplasmosis in cats include interstitial pneumonia, hepatitis, splenitis, lymphadenomegaly, ophthalmitis, myocarditis and disorders of the central nervous system [7]. Thrombocytopenia, which was present in this specific cat, before signs of cholecystitis developed, has been reported as a clinicopathological feature in cats with systemic toxoplasmosis [23][28] [33]. In humans, thrombocytopenia constitutes an occasional finding with congenital toxoplasmosis [26].…”

Clinical Toxoplasmosis in Dogs and Cats: An Update

“…Reports of clinical protozoal infections resembling toxoplasmosis have been published, including cutaneous neosporosis in a dog (81); a cutaneous infection by a T. gondii -like parasite in a dog and a cat (42, 82, 83); congenital infections in dogs by S. neurona (84) and N. caninum (85); generalized disease showing pneumonia in dogs by Sarcocystis spp. (86), N. caninum (85), and lungworms (87); hepatitis in dogs by Sarcocystis spp.…”

Skin and Subcutaneous Tissues

“…Cutaneous toxoplasmosis is uncommon but has been recently reported in cats (Little et al, 2005;Park et al, 2007). These presented as multiple and single nodules.…”