Idiopathic, asymptomatic thrombocytopenia in Cavalier King Charles spaniels: 11 cases (1983-1993)

The medical records of 11 Cavalier King Charles spaniels with idiopathic, asymptomatic thrombocytopenia and large-to-giant platelets were identified from a 10-year retrospective search using the Veterinary Medical Data Base at Purdue University. Eight of the dogs had been treated with various immunosuppressive drugs. Six of the treated dogs remained thrombocytopenic, one was not reevaluated, and one developed a normal platelet count. The underlying etiology of idiopathic, asymptomatic thrombocytopenia in Cavalier King Charles spaniels has not been identified, but this condition could represent a congenital macrothrombocytopenic disorder.