Idiopathic Asymptomatic Thrombocytopenia
Idiopathic asymptomatic thrombocytopenia (low platelet count) (IAT) is unique to the Cavalier King Charles Spaniel breed and is present in approximately 50% of Cavaliers. This condition causes low platelet counts in dogs but does not result in any clinical signs (hence "asymptomatic").
Platelets are small blood cells that help your body form clots to stop bleeding. When there are not enough platelets in the blood, you may bleed more than expected after an injury.
Key Facts
- Present in approximately 50% of Cavalier King Charles Spaniels
- Causes low platelet counts with no clinical signs — often misdiagnosed as serious ITP
- Cause: macroplatelets (giant platelets) miscounted by conventional analyzers
- No DNA test available — inform your vet before routine blood work
Cavalier IAT is frequently confused with another form of thrombocytopenia called Immune-mediated thrombocytopenia (ITP), which is a serious condition that can be life-threatening. For this reason, it is especially important for your vet to be aware of this condition before performing routine labs to avoid unnecessary treatments. Vets who are not familiar with Cavalier IAT may misdiagnose and treat as ITP with immunosuppressive drugs, which has severe side effects.
The cause of Cavalier IAT is thought to be macroplatelets or giant platelets. These large platelets are miscounted or not counted at all by conventional hematology analyzers. IAT is thought to be hereditary in Cavaliers. Currently, there is no DNA test available, so your breeder cannot test for this condition, but informing your vet of this Cavalier-specific issue is critically important.
