Canines are infected following bites from infected ticks. Dogs do not develop a sufficient enough rickettsemia to act as a reservoir and as such are not involved in the direct transmission of the organism. They do serve as an ideal sentinel indicating infection rates in specific areas. Early clinical signs in the dog are often nonspecific. Laboratory testing generally indicate a thrombocytopenia.
Serologic testing is necessary to confirm infection.
Treatment with tetracycline and chloramphenicol for 14 to 21 days is effective. Differentiation of RMSF cases from canine ehrlichiosis is often difficult. Both diseases are characterized by fever, depression, lymphadenopathy, and signs of neurologic disfunction. Petechial hemorrhages and other signs of hemorrhagic diathesia are not common in either disease. RMSF tends to be more seasonal, effects younger dogs, and is a more rapid and severe clinical disease.