MDR1: the mutation that endangers our sheepdogs

Today Lou, a member of Yummypets wanted to take my place and write an article on a subject dear to her heart: the MDR1 mutation.

What is drug sensitivity?

The drug sensitivity is a severe or even fatal reaction to a molecule present in certain anesthetics or worming medicine. It was discovered in the 1980s. After several years of research, the cause responsible for this sensitivity was discovered: A genetic mutation in a gene called MDR1 that appears in the dog from birth. In the case of the MDR1 mutation, the dog's absorption of chemical molecules will increase, and therefore side effects of these treatments increase tenfold.

Three levels of sensitivity

MDR1 + / + Dogs with no mutation called "Healthy"
MDR1 + / - heterozygote. The dog is a healthy carrier of the genetic mutation, however, you should remain cautious.
MDR1-/ - homozygous mutant. The dog is a carrier of the genetic mutation, the risks are fatal.

Ingredients to avoid and precautions to take 

First, always tell your veterinarian before any injection, anesthesia or medication.

Here is the master list of drugs to avoid:

Pest Control with Ivermectin
Antidiarrheal with Loperamide
Certain anticancer drugs with doxorubicin, vinblastine, vincristine.

You should also prevent injected anesthesia and therefore must ask for gas anesthesia! A dog with MDR1 - / - would not survive!

Is my dog affected?

The list of breeds affected:

Collie
Australian Shepherd (standard and miniature)
White Swiss Berger
Shetland
English Shepherd
Longhaired Whippet
McNab
Old English sheepdog
Silken Windhound
Wäller
Border Collie (some cases)

My dog ​​is one of the breeds concerned, what should I do?

There is a DNA test to determine the drug sensitivity of the dog. Testing your dog also helps to identify the amount of dogs affected by this mutation. This is a service to science and research on this genetic mutation!

What are the symptoms?

Vomiting, tremors, dilated pupils, blindness, convulsions, difficulty moving. If symptoms develop, it is obviously a veterinary emergency! There are currently no antidotes for ivermectin but if only a very small amount has been ingested it is possible to save the dog. In all cases caution is the best antidote. Avoid riding stables where the horses are dewormed with ivermectin. All dogs love dung and are sure to ingest a lethal dose.

How to deal with the increase in carriers of the MDR1 mutation dogs?

MDR1 mutation is transmitted genetically, the only solution is therefore to avoid homozygous mutant (- / -) or hétérozygte (+ / -) dogs for breeding.

Talking about it and spreading the word is already saving lives!

 More and more breeds carry this mutation, perhaps because of the lack of genetic diversity in each breed.

Finally, the discovery of a dog MDR1 - / - is by no means a reason for abandoning them!

These dogs have no health problem and a simple monitoring during annual visits to the vet will insure that they lead a perfect life with you!