What does white feet mean in dogs?

Answered by Douglas Hiatt

I have definitely heard of the saying “white feet, don’t treat” when it comes to dogs. It refers to the fact that if a dog has white feet, it could be an indication that they have a specific genetic mutation known as the MDR1 mutation. This mutation can cause multidrug resistance in dogs, meaning that they may have adverse reactions or be sensitive to certain medications.

The MDR1 mutation affects the function of a protein called P-glycoprotein, which is responsible for transporting drugs and other substances out of cells. Dogs with the mutation have a reduced ability to remove certain drugs from their bodies, leading to potential toxicity or adverse reactions.

One of the main concerns for dogs with the MDR1 mutation is their sensitivity to certain medications, particularly those that are substrates for P-glycoprotein. This includes medications such as opioids, heartworm preventatives, and certain sedatives. Dogs with the mutation may require lower doses of these medications or alternative treatment options to avoid potential side effects.

For example, opioids are commonly used for pain management in veterinary medicine. However, dogs with the MDR1 mutation may experience increased sensitivity to opioids, leading to side effects such as sedation, respiratory depression, or even overdose. It is important for veterinarians to be aware of a dog’s MDR1 status and adjust medication doses accordingly to ensure their safety and well-being.

Heartworm preventatives, such as ivermectin, are another concern for dogs with the MDR1 mutation. Ivermectin is commonly used to prevent heartworm infection in dogs, but dogs with the mutation may be more susceptible to adverse reactions. This can include symptoms such as lethargy, weakness, tremors, and even seizures. Alternative heartworm preventatives should be used in dogs with the mutation to avoid these potential complications.

Sedatives, such as acepromazine, are often used in veterinary practice to calm dogs during procedures or for travel anxiety. However, dogs with the MDR1 mutation may be more sensitive to these medications, leading to prolonged sedation or increased risk of side effects. Alternative sedatives or different approaches to managing anxiety should be considered for dogs with the mutation.

It is important to note that not all dogs with white feet will have the MDR1 mutation, and not all dogs with the mutation will have adverse reactions to medications. However, the presence of white feet can be a clue that further testing for the mutation may be warranted.

If you suspect that your dog may have the MDR1 mutation, it is recommended to consult with your veterinarian and discuss genetic testing options. Genetic testing can confirm whether or not your dog has the mutation, allowing for appropriate medication management and ensuring their safety when it comes to certain drugs.

The saying “white feet, don’t treat” refers to the potential presence of the MDR1 mutation in dogs with white feet. This mutation can cause multidrug resistance and sensitivity to certain medications, including opioids, heartworm preventatives, and sedatives. If you suspect your dog may have the mutation, it is important to consult with your veterinarian and consider genetic testing to ensure their safety and well-being.