Collie

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Collies

Breed Description - see AKC for detailed standard
Life span - 8-12 years
Breed problems can be both inherited or diseases and disorders seen frequently in a breed and mode of inheritance unknown. Both are listed.

Breed problems
Deafness
Dermatomyositis
Dwarfism
Umbilical hernia, Inguinal hernia
Nasal Pyoderma, Demodecosis
Epilepsy
Patent Ductus Ateriosus
Hemophilia A
Microphthalmia (seen in Merles) ,Optic nerve hypoplasia, Corneal dystrophy
Progressive retinal atrophy
Ectasis syndrome (Collie eye anomaly)
Autosomal recessive cyclic Neutropenia (grey collie syndrome)
Pemphigus erythematosus is much less common then Pemphigus foliaceus and seems to affect collies more than other breeds.Lesions are similar but usually stay on the face
and may cause loss of color (depigmentation) of nose. M.R.
Another similar disease is bullous pemphigus, which affects primarily
collies, shelties and dobermans. This disorder affects a different layer of
the skin but otherwise looks a lot like pemphigus vulgaris. Treatment is
the same.

Collies do seem to react badly to high stress and illness of any kind, at least in our practice. I always worry more when I am treating a collie for any serious illness than I would with many other dog breeds. It could just be the collies I have seen, though. M.R.

Collies are just one of the breeds that carry the MDR1 gene but it occurs in three out of every four Collie and the drugs are commonly used veterinary drugs so it really is a lifesaving test.
This is a multi-drug resistance gene (MDR1) not just a sensitivity to Ivermectin as previous thought. The other drugs are listed below.

This Gene shows up in a variety of mixed breed dogs as well as Collies and some of its expected and surprising relatives. So please don't forget Your devoted companion who has mixed ancestry that may be anyone's guess.

Explanation of 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 will pass on the mutant 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).

Veterinary Clinical Pharmacology Laboratory
PO Box 609
Pullman, WA 99163-0609
(Phone/FAX 509-335-3745) VCPL@vetmed.wsu.edu
* PCR for this service is performed pursuant to an agreement with Roche Molecular Systems, Inc.
US and foreign patents pending for MDR1 testing.

"Why are some breeds more sensitive to the effects of drugs than other breeds? Which drugs have been reported to cause problems? At Washington State University's College of Veterinary Medicine you can get your dog tested for drug sensitivity and keep up with the latest research.
The main sections of the VCPL web site are listed on the navigation menu at your left. Click on a link to visit that section of the VCPL web. The current page is highlighted in crimson.

It is well known that Collies and related breeds can have adverse reactions to drugs such as ivermectin, loperamide (Imodium®), and others. It was previously unknown why some individual dogs were sensitive and others were not. Advances in molecular biology at the Veterinary Clinical Pharmacology Laboratory at Washington State University's College of Veterinary Medicine have led to the discovery of the cause of multi-drug sensitivity in affected dogs. The problem is due to a mutation in the multi-drug resistance gene (MDR1). This gene encodes a protein, P-glycoprotein, that is responsible for pumping many drugs and other toxins out of the brain. Dogs with the mutant gene can not pump some drugs out of the brain as a normal dog would, which may result in abnormal neurologic signs. The result may be an illness requiring an extended hospital stay--or even death.

A test has recently been developed at Washington State University to screen for the presence of the mutant gene*. Instead of avoiding drugs such as ivermectin in known susceptible breeds, veterinarians can now determine if a dog is normal, in which case the drug can be administered or abnormal, in which case an alternative treatment can be given.

Owners and breeders can submit samples for testing. All that is needed for the test is a cheek brush sample that can be obtained by the owner and sent by mail for analysis.
Affected Breeds

Approximately 3 of every 4 Collies in the United States have the mutant MDR1 gene. The frequency is about the same in France and Australia, so it is likely that most Collies worldwide have the mutation. The MDR1 mutation has also been found in Shetland Sheepdogs (Shelties)., English Shepherds, Australian Shepherds, Old English Sheepdogs, German Shepherds, Long-haired Whippets, Silken Windhounds, McNabs and a variety of mixed breed dogs. The only way to know if an individual dog has the mutant MDR1 gene is to have the dog tested. As more dogs are tested, more breeds will probably be added to the list of affected breeds."

Drugs that have been documented to cause problems in dogs with the MDR1 mutation include:

Ivermectin (antiparasitic agent)-While the dose of ivermectin used to prevent heartworm infection is SAFE in dogs with the mutation (6 micrograms per kilogram), higher doses, such as those used for treating mange (300-600 micrograms per kilogram) will cause neurological toxicity in dogs that are homozygous for the MDR1 mutation (mutant/mutant) and can cause toxicity in dogs that are heterozygous for the mutation (mutant/normal).
Selamectin, milbemycin, and moxidectin (antaparasitic agents)-Similar to ivermectin, these drugs are safe in dogs with the mutation if used for heartworm prevention at the manufacturer’s recommended dose. Higher doses (generally 10-20 times higher than the heartworm prevention dose) have been documented to cause neurological toxicity in dogs with the MDR1 mutation.
Loperamide (ImodiumTM; antidiarrheal agent)-At doses used to treat diarrhea, this drug will cause neurological toxicity in dogs with the MDR1 mutation.This drug should be avoided in all dogs with the MDR1 mutation.
Acepromazine (tranquilizer and pre-anesthetic agent)-In dogs with the MDR1 mutation, acepromazine tends to cause more profound and prolonged sedation.We recommend reducing the dose by 25% in dogs heterozygous for the MDR1 mutation (mutant/normal) and by 30-50% in dogs homozygous for the MDR1 mutation (mutant/mutant).
Butorphanol (analgesic and pre-anesthetic agent)-Similar to acepromazine, butorphanol tends to cause more profound and prolonged sedation in dogs with the MDR1 mutation.We recommend reducing the dose by 25% in dogs heterozygous for the MDR1 mutation (mutant/normal) and by 30-50% in dogs homozygous for the MDR1 mutation (mutant/mutant).
Vincristine, Vinblastine, Doxorubicin (chemotherapy agents)-Based on some published andongoing research, it appears that dogs with the MDR1 mutation are more sensitive to these drugs with regard to their likelihood of having an adverse drug reaction. Bone marrow suppression (decreased blood cell counts, particulary neutrophils) and GI toxicity (anorexia, vomiting, diarrhea) are more likely to occur at normal doses in dogs with the MDR1 mutation. To reduce the likelihood of severe toxicity in these dogs (mutant/normal or mutant/mutant), we recommend reducing the dose by 25-30% and carefully monitoring these patients.

Drugs that are known to be pumped out of the brain by the protein that the MDR1 gene is responsible for producing but appear to be safely tolerated by dogs with the MDR1 mutation:

Cyclosporin (immunosuppressive agent)-While we know that cyclosporin is pumped by P-glycoprotein (the protein encoded by the MDR1 gene), we have not documented any increased sensitivity to this drug in dogs with the MDR1 mutation compared to “normal” dogs. Therefore, we do not recommend altering the dose of cyclosporin for dogs with the MDR1 mutation, but we do recommend therapeutic drug monitoring.
Digoxin (cardiac drug)- While we know that digoxin is pumped by P-glycoprotein (the protein encoded by the MDR1 gene), we have not documented any increased sensitivity to this drug in dogs with the MDR1 mutation compared to “normal” dogs.Therefore, we do not recommend altering the dose of digoxin for dogs with the MDR1 mutation, but do recommend therapeutic drug monitoring.
Doxycycline (antibacterial drug)- While we know that doxycycline is pumped by P-glycoprotein (the protein encoded by the MDR1 gene), we have not documented any increased sensitivity to this drug in dogs with the MDR1 mutation compared to “normal” dogs.Therefore, we do not recommend altering the dose of doxycycline for dogs with the MDR1 mutation.

Drugs that may be pumped out by the protein that the MDR1 is responsible for producing, but appear to be safely tolerated by dogs with the MDR1 mutation:

Morphine, buprenorphine, fentanyl (opioid analgesics or pain medications)-We suspect that these drugs are pumped by P-glycoprotein (the protein encoded by the MDR1 gene) in dogs because they have been reported to be pumped by P-glycoprotein in people, but we are not aware of any reports of toxicity caused by these drugs in dogs with the MDR1 mutation.We do not have specific dose recommendations for these drugs for dogs with the MDR1 mutation.

The following drugs have been reported to be pumped by P-glycoprotein (the protein encoded by the MDR1) in humans, but there is currently no data stating whether they are or are not pumped by canine P-glycoprotein.Therefore we suggest using caution when administering these drugs to dogs with the MDR1 mutation.
Domperidone
Etoposide
Mitoxantrone
Ondansetron
Paclitaxel
Rifampicin

There are many other drugs that have been shown to be pumped by human P-glycoprotein (the protein encoded by the MDR1 gene), but data is not yet available with regard to their effect in dogs with the MDR1 mutation.

Thanks to http://www.vetmed.wsu.edu/ for research/testing and information on the MDR1 gene.

This page was last edited 04/29/08

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Breed information and descriptions were researched and authored by Michal Justis.
Opinions are those of Ms. Justis