TOLAZRUN

AUSTRALIAN SHEPHERDS

DNA Tests

To ensure we can produce sound Australian Shepherd dogs, we have undertaken a number of tests to examine the soundness of our breeding stock.  All dogs that we use for breeding are hip scored and eye tested.  In addition, we have commenced DNA testing our breeding stock. 

MDR1

The first test we have undertaken is to determine if our dogs carry the gene for MDR1 - Multi-Drug Sensitivity Mutation.  It is estimated that 25% of all Australian Shepherds suffer from MDR1.  What this means is that these dogs are sensitive to a number of drugs and if treated with these drugs, they could have an adverse impact upon the dog being treated.  We have undertaken this test so we can inform potential puppy purchases if their dog is effected.  It is important to note that this may never pose a problem for your dog, but knowing that they are potentially effected, means that should your dog require veterinary treatment, you can forewarn the vet, to ensure your dog does not suffer any adverse side effects from the treatment.

Explanation of DNA Test results:

Normal/Normal- These dogs do not carry the mutation, and will not pass on the mutation to their offspring.  These dogs would not be expected to experience unexpected adverse drug reactions to normal doses of ivermectin, loperamide (Imodium®), and some anticancer drugs.

Mutant/Mutant- These dogs carry the mutation and can not pass on a normal gene to their offspring.    These dogs would be expected to experience toxicity after normal doses of loperamide (Imodium®), and some anticancer drugs, and high doses of ivermectin (greater than 50 micrograms per kilogram).

Mutant/Normal- These dogs carry the mutation and may pass on the mutant gene to their offspring.  These dogs may experience toxicity after normal doses of loperamide (Imodium®), and some anticancer drugs, and high doses of ivermectin (greater than 50 micrograms per kilogram).

Current list of drugs that have been documented to cause problems:

• Ivermectin (Antiparasitic agent)

• Loperamide (Imodium®; over-the-counter antidiarrheal agent)

• Doxorubicin (Anticancer agent)

• Vincristine (Anticancer agent)

• Vinblastine (Anticancer agent)

• Cyclosporin (immunosuppressive agent)

• Digoxin (heart drug)

• Acepromazine (tranquilzer)

• Butorphanol (pain control)

Potential problem drugs:

The following drugs may potentially cause problems when given to dogs that have the mutation. Biochemical studies have shown that this gene has the potential to act on over 50 different drugs.

• Ondansetron

• Domperidone

• Paclitaxel

• Mitoxantrone

• Etoposide

• Rifampicin

• Quinidine

• Morphine

For more information on MDR1 visit:    http://www.vetmed.wsu.edu/depts-VCPL/