Heng L Tham1, Keith E Linder2,3, Alison Tucker4, Ricardo Maggi1, Petra Bizikova1,3. 1. Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, 1052 William Moore Drive, Raleigh, NC, 27607, USA. 2. Department of Population Health and Pathobiology, North Carolina State University College of Veterinary Medicine, 1052 William Moore Drive, Raleigh, NC, 27607, USA. 3. Center for Comparative Medicine and Translational Research, North Carolina State University College of Veterinary Medicine, 1060 William Moore Drive, Raleigh, NC, 27607, USA. 4. Rollins Animal Disease Diagnostic Laboratory, 2101 Blue Ridge Rd., Raleigh, NC, 27607, USA.
Abstract
BACKGROUND: Caryospora bigenetica is an intracellular protozoan parasite in snakes and raptors (primary hosts) and rodents (secondary host). Experimental infection has been documented in mice, pigs and goats; natural infection in dogs is rare. OBJECTIVES: To describe the clinical presentation, histological features, treatment and outcome of a case of protozoal nodular dermatitis and panniculitis in a Rottweiler puppy caused by C. bigenetica. RESULTS: The puppy presented with generalized subcutaneous nodules measuring up to 2 cm in diameter. Histopathology revealed marked suppurative to pyogranulomatous dermatitis and panniculitis with intralesional protozoal organism. PCR and DNA sequencing confirmed infection with C. bigenetica. Treatment with a combination of oral trimethoprim-sulfamethoxazole (TMS), pyrimethamine and high-dose clindamycin (20 mg/kg twice daily) resulted in resolution of lesions in 6 weeks. Discontinuation of the treatment 2 weeks later was followed by a rapid relapse of skin lesions. Clindamycin and TMS were restarted and all lesions resolved within 2 weeks; TMS was discontinued 4 weeks later due to adverse effects. The lesions remained in remission for 2 months while the puppy received clindamycin monotherapy before a second relapse of skin lesions occurred. CONCLUSION AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first documentation of the treatment and outcome of C. bigenetica cutaneous infection in a dog. Although remission of clinical signs can be achieved with combination therapy of clindamycin and TMS, long-term management is challenging and relapses should be anticipated.
BACKGROUND:Caryospora bigenetica is an intracellular protozoan parasite in snakes and raptors (primary hosts) and rodents (secondary host). Experimental infection has been documented in mice, pigs and goats; natural infection in dogs is rare. OBJECTIVES: To describe the clinical presentation, histological features, treatment and outcome of a case of protozoal nodular dermatitis and panniculitis in a Rottweiler puppy caused by C. bigenetica. RESULTS: The puppy presented with generalized subcutaneous nodules measuring up to 2 cm in diameter. Histopathology revealed marked suppurative to pyogranulomatous dermatitis and panniculitis with intralesional protozoal organism. PCR and DNA sequencing confirmed infection with C. bigenetica. Treatment with a combination of oral trimethoprim-sulfamethoxazole (TMS), pyrimethamine and high-dose clindamycin (20 mg/kg twice daily) resulted in resolution of lesions in 6 weeks. Discontinuation of the treatment 2 weeks later was followed by a rapid relapse of skin lesions. Clindamycin and TMS were restarted and all lesions resolved within 2 weeks; TMS was discontinued 4 weeks later due to adverse effects. The lesions remained in remission for 2 months while the puppy received clindamycin monotherapy before a second relapse of skin lesions occurred. CONCLUSION AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first documentation of the treatment and outcome of C. bigeneticacutaneous infection in a dog. Although remission of clinical signs can be achieved with combination therapy of clindamycin and TMS, long-term management is challenging and relapses should be anticipated.