Hepatozoonosis in a dog with skeletal involvement and meningoencephalomyelitis

Abstract

A 15-month-old, female mongrel dog was presented with a 6-week history of inappetence, weight loss, and tetraparesis. Physical examination revealed weakness, poor body condition, mild fever, pale mucous membranes, and diffuse muscle atrophy. The right hind limb was painful and edematous, with large ecchymoses. The femur was irregular on palpation and moderate popliteal lymphadenopathy was evident. Results of a CBC showed severe anemia with mild regeneration, an inflammatory leukogram with 90% of neutrophils parasitized by Hepatozoon sp. gamonts, and moderate thrombocytopenia. A bone marrow aspirate had myeloid hyperplasia and contained a few extracellular Hepatozoon meronts and a few intracellular gamonts within neutrophils. Serum chemistry abnormalities included hypoalbuminemia, hyperglobulinemia, hypoglycemia, hypercalcemia, hyperphosphatemia, and elevated alkaline phosphatase activity. Radiologic findings of the right femur included periosteal bone proliferation and lesions compatible with osteomyelitis. A fine needle aspirate specimen from the bone lesion had neutrophilic inflammation; 36% of the neutrophils contained Hepatozoon gamonts. Results of cerebrospinal fluid analysis included a protein concentration of 37 mg/dL and marked mononuclear pleocytosis (243 cell/microL) with a predominance of lymphocytes. An ELISA was positive for Hepatozoon canis and PCR results with DNA sequencing confirmed infection with this organism. A diagnosis of hepatozoonosis with skeletal involvement and meningoencephalomyelitis was made. The dog recovered almost completely neurologically and had no gamonts in the blood after 60 days of therapy with imidocarb dipropionate and prednisone. This is an unusual case of canine hepatozoonosis involving neurologic signs and a periosteal reaction more typical of H. americanum infection and rarely reported in dogs infected with H. canis.

Multiple myeloma in a dog with multiple concurrent infectious diseases and persistent polyclonal gammopathy

“…24,29 Although dogs with H canis may have skeletal involvement, cytologic evaluation of lytic bone lesions in these cases reveals osteomyelitis with neutrophils containing H canis gamonts, which was not seen in this dog. 28,30 H canis infection may therefore have contributed to polyclonal gammopathy, but was unlikely to have caused the clinical and radiologic signs in this case.…”

“…Given that H canis is not endemic in Switzerland, the dog was likely infected in Spain and may have suffered reactivation of latent infection because of a compromised immune system due to MM and subsequent chemotherapy . Although dogs with H canis may have skeletal involvement, cytologic evaluation of lytic bone lesions in these cases reveals osteomyelitis with neutrophils containing H canis gamonts, which was not seen in this dog . H canis infection may therefore have contributed to polyclonal gammopathy, but was unlikely to have caused the clinical and radiologic signs in this case.…”

An Australian dog diagnosed with an exotic tick-borne infection: should Australia still be considered free from Hepatozoon canis?

“…Clinical signs associated with high parasitaemia include anaemia, cachexia, emaciation, fever and lethargy (Baneth et al, 1995;Baneth and Weigler, 1997;Karagenc et al, 2006;Mundim et al, 2008). Hepatozoon canis meronts can infect bone marrow, kidneys, liver, lungs, lymph nodes, periosteum and the spleen, while gamonts infect leukocytes (Baneth et al, 1995;Baneth and Weigler, 1997;Marchetti et al, 2009). Clinical biochemical abnormalities include hyperproteinaemia, hypoalbuminaemia, polyclonal gammopathy, and increased serum creatine kinase and alkaline phosphatase activities (Baneth, 2011).…”

Canine hepatozoonosis in southeastern Bahia, Brazil

“…However, clinical and hematological alterations such as weight loss, pale mucous membranes, hyperthermia, anorexia, diarrhea, gait abnormalities, polyuria, polydipsia, anemia, leukocytosis with neutrophilia and thrombocytopenia have also been reported (Gondim et al, 1998;Paludo et al, 2003;Aguiar et al, 2004;Mundim et al, 2008;Marchetti et al, 2009).…”