🐾 Discovering DNA- Congenital Macrothrombocytopenia (CMTP)

Congenital Macrothrombocytopenia (CMTP) is a harmless inherited trait where a dog has fewer, but larger, platelets in their blood.

Key Points:

• CMTP does not cause excessive bleeding or health problems.

• Most dogs with CMTP live long, healthy lives without any impact on daily activities.

• It’s usually found during routine blood tests, where platelet counts appear “low” to labs unfamiliar with the breed.

Why the Confusion Over the Name?

Historically, breeders sometimes referred to CMTP simply as “CM” — but this abbreviation is now more commonly used to mean Chiari-like Malformation (a neurological condition).

To avoid confusion, we now always use the full term CMTP when talking about the platelet trait.

Understanding DNA Test Results

DNA results for CMTP are usually reported as:

• Clear (N/N): No copies of the mutation.

• Carrier (A/N): One copy of the mutation; will not be affected but can pass the trait to offspring.

• Affected (A/A): Two copies of the mutation; the dog will have CMTP but remain healthy.

Why Do Breeders Test for CMTP?

At Sielle Place Cavaliers, we include CMTP testing because:

• It avoids accidental confusion during future vet visits or bloodwork.

• It helps ensure accurate interpretation of lab results.

• It’s part of our commitment to full health transparency.

Should Owners Worry About CMTP?

In short — no.

CMTP is not a disease. It’s simply a quirk of the blood that’s important to be aware of for vet record accuracy.

As CMTP is completely benign, Cavaliers with CMTP live full, happy lives with no restrictions or negative health impacts at all.

💖 At Sielle Place Cavaliers, our priority is keeping our families informed and confident about their dog’s health.

If you have questions about CMTP or any DNA test result, we’re always happy to help explain