Hepatozoonosis in Dogs: Tick-Borne Protozoan Disease

Hepatozoonosis causes severe muscle pain, fever, and debilitation in infected dogs through tick ingestion rather than bite, with welfare management requiring long-term treatment.

Key Facts

Caused by Hepatozoon canis (mild) or H. americanum (severe) acquired by ingesting infected ticks
H. americanum causes severe myositis, periosteal proliferation, and extreme muscle pain
Unlike most tick-borne diseases, hepatozoonosis is acquired by eating infected ticks
Long-term combination antiprotozoal treatment is required but rarely curative
Prevention includes tick control and preventing dogs from eating ticks or infected prey

Welfare Considerations

Hepatozoonosis welfare management centers on controlling the severe muscle pain that characterizes H. americanum infection. Affected dogs experience profound muscle weakness and pain that prevents normal movement and activity. NSAIDs and corticosteroids provide partial pain relief. The underlying protozoal infection requires months of antiprotozoal combination therapy. H. americanum infection is typically not curable, requiring long-term welfare management rather than elimination. Preventing dogs from ingesting ticks and prey animals reduces transmission risk significantly.

What You Can Do

Implement comprehensive tick prevention in endemic areas
Prevent dogs from eating ticks or hunting small mammals that may harbor ticks
Provide multimodal pain management for muscle pain in affected dogs
Commit to long-term antiprotozoal treatment as directed by your vet
Monitor disease progression with regular clinical assessment and bloodwork