MDR1 Genetic Mutation in Dogs

MDR1 Drug Sensitivity

The MDR1 gene, also known as the ABCB1 gene, plays a crucial role in how dogs process certain medications and protects the brain from potentially harmful drugs. A mutation frequently found in Australian Shepherds and other herding breeds can lead to heightened sensitivity to specific medications affecting dogs.

It’s important to clarify that MDR1 is not a disease; dogs carrying one or even two copies of the ABCB1 mutation can still lead normal, healthy lives. It simply means that extra caution is necessary when certain medications are prescribed.

What Do MDR1 Results Mean?

Genetic testing can identify the well-known MDR1/ABCB1 mutation.

- Clear / Non-Carrier: No copies of the tested mutation.

- Carrier: One copy of the mutation, indicating potential for medication sensitivity.

- Affected: Two copies of the mutation, representing the highest potential for drug sensitivity.

Understanding your dog’s status is invaluable for you and your veterinarian when making decisions regarding medications affecting dogs.

Why We Take Precautions With Every Ivy Meadows Puppy

Additionally, it’s vital for our families to understand that testing clear for the currently recognized ABCB1 mutation doesn’t ensure that a dog will never experience similar drug reactions. Cases of drug-sensitive dogs without the commonly tested MDR1 mutation have been documented, and researchers are exploring other ABCB1 variants and mechanisms that influence drug sensitivity. Therefore, while genetic testing is a powerful tool, it may not reveal everything we need to know at this time.

Because of this, we require every Ivy Meadows puppy to be treated using MDR1-carrier precautions, regardless of their genetic testing results. This does not suggest we view every puppy as MDR1-positive; it simply means we prefer taking an easy precaution rather than risk a serious medication reaction based on a clear genetic test.

What We Ask Our Puppy Families To Do

Please inform your veterinarian that your dog is an Australian Shepherd and that Ivy Meadows requests the use of MDR1-carrier precautions, irrespective of their genetic testing status. We highly recommend that this information be permanently noted in your dog’s veterinary record.

This approach does not imply avoidance of necessary medications. Many medications associated with MDR1 can still be used safely, depending on the specific drug and dosage. All medication decisions should be made collaboratively with your veterinarian.

Know their status. Inform their veterinarian. Take the extra precaution.

For further details about the ABCB1 gene, current medication recommendations, and insights into drug sensitivity affecting dogs, we encourage you to explore the resources provided by the Washington State University Program in Individualized Medicine regarding MDR1.