Renegade Mini Aussies

Renegade Mini Aussies

AMANDA LELAND* Renegade Mini Aussies ·SUNDAY, FEBRUARY 26, 2017

What is MDR1 and why do I need to know?

Aussies are amazing- no one denies that! BUT there are certain aspects of Aussies that EVERY owner needs to know about, because believe it or not, the consequences of not knowing can be deadly.

If you have done any research at all on Aussies I am certain you have seen this abbreviation. *MDR1* This is by far the most common issue found in Aussies as it has a breed prevalence of 50%! That means that for every two dogs you look at, one of them will have at least one MDR1 mutation.

So what is it? Multi-Drug Resistance Gene, (MDR) codes for a protein that is responsible for protecting the brain by transporting potentially harmful chemicals away from the brain. In certain breeds, a mutation occurs in the MDR1 gene that causes sensitivity to Ivermectin, Loperamide, and a number of other drugs. Dogs with this mutation have a defect in the P-glycoprotein that is normally responsible for transporting certain drugs out of the brain. The defective protein inhibits the dog's ability to remove certain drugs from the brain, leading to a buildup of these toxins. As a result of the accumulation of toxins, the dog can show neurological symptoms, such as seizures, ataxia, or even death.

Now don't panic! It's not nearly as bad as it sounds when you know what you are dealing with.

1. MDR1 mutant dogs must receive the mutant gene from BOTH PARENTS to be "affected". Carriers, dogs with only one mutant gene, are affected to a lesser degree. In this case, simply avoid drugs in the ivermectin family and your dog will live a long, normal life!

2. Whether your dog is N/N ("Negative" or "Clear"), N/M ("Carrier"), or M/M ("Positive" or "Mutant") for MDR1, the breed as a whole is more sensitive than other breeds to the ivermectin based drugs and should avoid them whenever possible.

Please be aware that a general veterinarian may not relate that your dog is an Aussie and may have this gene mutation. Even with their degree, there are simply too many breeds with their own quirks for a single vet to know every single pet species, breed, and all of each breed's nuances. It is up to YOU to advocate for your dog and bring this up with your vet. Even then, not all vets are familiar with this list or the MDR1 mutation so please be prepared and take this to them, ESPECIALLY if your dog is affected!

Drugs to AVOID: Ivermectin (antiparasitic agent) "Heartguard" Loperamide (Imodium: over-the-counter antidiarrheal agent) Doxorubicin (anti-cancer agent) Vincristine (anti-cancer agent) Vinblastine (anti-cancer agent) Cyctosporin (immunosuppressive agent) Digoxin (heart drug) Acepromazine (tranquilizer) Butorphanol (pain control)

Note, Heartguard is on the list because it can cause seizures in sensitive Aussies. Use Interceptor or Sentinel instead. ​​Interceptor® is a non-Ivermectin based heartworm treatment safer for most mini Aussies. For those that can no longer find Interceptor, Sentinel proves to be a good replacement. As always, please seek your own vet’s advice. Sentinel® combines Interceptor® and Program® into one pill.

How to have your dog tested for the MDR1 gene:

*Testing is very simple and does NOT require a vet visit! *

General veterinarians do not have the lab equipment required to perform these specific DNA tests, so they cannot provide this service in their office. (If they say they do- please be aware that they are simply ordering the test from one of the labs that does this service and charging you for the test plus the office visit.)

To get your test kit, please contact PawPrint Genetics at the website below. After purchase, they will send you a test kit in the mail with a prepaid return mailer for sending your sample back to their laboratory. Follow directions on the packet to obtain a cheek swab.

For the MDR1 Test by itself:


Normal instructions are:

1. Be sure the pup hasn't had anything to eat or drink within 30 minutes before swabbing.

2. Place the swab between the gums and cheek, lightly pressing on the cheek, and roll it between your fingers to spin the brush and collect their DNA. For best results, do this for at least 10 seconds on each side of the mouth.

3. Place the swab back in the package provided and drop it in the mail.

That's it! You will have your results uploaded to your online PawPrints account within 3 weeks!

References and Additional Links

Please feel free to ask questions! This isn’t something to be scared of, but it is certainly something you need to understand if you own an Aussie. Get your pups tested so you know, and then carry on with your Aussiesome life! <3