In normal healthy dog brain tissue and central nervous system the brain and cns is protected against high concentrations of toxic substances (eg drugs) that circulate in the blood. The “Multidrug Resistance gene 1″ (the MDR1 gene) plays an important role in the barrier between blood and brain tissue. It encodes the protein P-glycoprotein that is part of the membrane into the blood-brain barrier. P-glycoprotein causes various toxic substances (including drugs such as Ivermectin) from brain cells back into the blood.

The phenomenon of “Ivermectin sensitivity in Collies, and Collie-like breeds” was first described in 1983. Ivermectin (an anti-parasitic) causes poisoning in the brains of some of the Collies. This occurs at doses one to two hundredth part of the other dogs at doses that cause damage. The animals that will often excessive salivation, vomiting, they get epileptic seizures, digestive and respiratory disorders. They can slip into a coma and even die.

Dogs who suffer from sensitivity to Ivermectin, appear to be hypersensitive to a range of drugs.

For instance:

At the Veterinarian
1. Butorphanol – analgesic
2. Cyclosporin – inhibits immune
3. Digoxin – heart medications
4. Doxorubicin – cell growth inhibitor
5. Etoposide – cell growth inhibitor
6. Ivermectin – against aphids, mites and worms
7. Loperamide (Imodium ®) – for diarrhea – druggist
8. Mitoxantrone – cell growth inhibitor
9. Ondansetron – for nausea and vomiting
10. Paclitaxcel – cell growth inhibitor
11. Quinidine – heart medications
12. Rifampicin – antibiotic
13. Vinblastine – cell growth inhibitor
14. Vincristine – cell growth inhibitor

15. Acepromazine – anesthetic – pet shop

16. Domperidone – for nausea and vomiting – pharmacy
17. Loperamide (Imodium ®) – for diarrhea – druggist

Medications for People
18. Morphine – anesthetic, analgesic – (medicine people)

It is very likely that this list is not complete and that in the course
time of the new substances are added.

defective MDR1 gene
The problem is caused by a defect in the DNA a particular gene. This gene causes the production of a substance (P-glycoprotein). The task of this substance in order to ensure that toxic only at low levels in brain cells. Increases the concentration of this protein than pumping the excess back into the bloodstream.
It will therefore not surprising that this substance, this protective pump, is located in the cells that line the inside of blood vessels forms (the so-called endothelial cells).

The gene has been named to the task he has: Multi-Drug Resistance 1 gene, often abbreviated as MDR1 gene.

When the gene is not working, of course, the pump for this piece because the substance (P-glycoprotein) is simply not created.

Now a Dog 2 of these genes, one from their father and one of his or her mother. When a dog has at least one good gene (we call them a carrier), then this dog is still able to make the fabric and the fewer risks. There are indications that these dogs at high doses certain drugs are still in trouble. Does the dog However, two bad genes, then the fabric is not created. This called sufferers, they suffer from the defect and the normal dose of these medicines will be fatal. They will in any case, neuro-toxic phenomena.

Important reassurance!
It is reassuring to know that dogs have such bad genes, more completely healthy dogs are completely normal function! As long as they not in contact with the substances are nothing will happen. And with this substances they come into contact not just (in feed for example) – they are all drugs. When such a dog is sick and some need medication, it is important to the search for alternatives.

Important warning:
The list You can see that a number of resources readily available at the pharmacy or the pet. We think especially of Imodium ® for diarrhea and Acepromazine narcotic drug that is often used to combat fireworks anxiety or fear of driving. You can use these substances is itself just buy without good advice and administer to your dog. It is obvious that collie-like this for a very dangerous business can be! So what always, is now certain: Never give your pet medicine without a good advice from your veterinarian!

The defective gene is shown in the following varieties:

Australian shepherd, Australian miniature shepherd, collie (Collie) English Shepherd Dog McNab, Old English Sheepdog (Bobtail), Shetland Sheepdog (Sheltie), Longhaired whippet, Silken Wind Hound and crossbreeds thereof. German shepherd and White shepherd. Border Collie, Bearded Collie and the Australian Cattle Dog.

Important tip:
If you have any of the above breeds or a cross is held then we strongly recommend you to your dog what blood sample taken for determination of the MDR1 gene. You will receive a official statement of the laboratory stating that your dog is free, carrier or suffers from. The main benefit is that you are sure you (and your vet) does or does not take account of the administration of certain drugs. In addition, the course also information useful for taking the decision whether or not to breed your animal. Especially breeder when you will use this information to do anything to prevent dogs are born suffering from this defective gene.

Source: Genetic Couceling Services & Veterinary Clinic Leusden