Multidrug Resistance 1 (MDR1) drug sensitivity is the result of a genetic variant that can place dogs at risk of severe or life-threatening complications after taking particular medications at specific doses.
In dogs who possess the MDR1 mutation, defective p-glycoproteins allow higher levels of drugs to enter the brain, increasing neurologic effects of some medications. Ivermectin and other related drugs (milbemycin, selamectin) are commonly used in the prevention and treatment of parasites.
What clinical signs should I watch for? When there has been a buildup of toxins in the brain, your dog will start to show neurological symptoms, such as weakness, lethargy, ataxia, disorientation, tremors, seizures, blindness, and death. When any of these symptoms occur, call your veterinarian immediately.
MDR1 is the abbreviated name of a gene called Multi-Drug Resistance 1. A mutation of this gene causes sensitivity to Ivermectin and a number of other drugs. Dogs with the mutation will react to those drugs. Whether a dog reacts depends on the dosage of the drug.
The manufacturer of Nexgard has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. Dogs with the MDR1 mutation are not at increased risk for adverse effects.
Approximately 70% of collies carry the MDR1 gene mutation. Other affected breeds include long-haired whippets, Australian shepherds, silken windhounds, McNab shepherds, English shepherds, Shetland sheepdogs, German shepherds, and old English sheepdogs.
Both Interceptor and Milbemax contain: Milbemycin oxime and praziquantel which are both safe in use for dogs that are positive for MDR1 gene.
Tell Your Vet. The MDR1 genetic test offered by WSU will determine if your pet has the MDR1 mutation. For dogs and cats with the MDR1 mutation, common medications can be potentially deadly. Share the results with your veterinarian to let them know to avoid or adjust the dose of certain medications.
With our new Dog Multidrug Resistance 1 (MDR1) Test , you can determine if your dog carries the gene mutation, allowing you to take better care of your pet's health. The price of the Dog MDR1 Test starts from $69.
A test for the MDR1 mutation is available through the laboratory that first discovered the mutation, the Veterinary Clinical Pharmacology Laboratory at Washington State University (vcpl.vetmed.wsu.edu). The test can be performed with a cheek swab test kit or EDTA whole blood.
Some breeds of dogs (e.g., collies, sheepdogs, and collie- or sheepdog-cross breeds) are more sensitive to ivermectin than others. This is typically due to a specific genetic mutation (MDR1) that makes them less able to tolerate high doses of ivermectin.
Dogs of some herding breeds and some mix-breed dogs can have a genetic mutation that makes them dangerously oversensitive to ivermectin, the active ingredient in some commonly used heartworm prevention medicines for dogs.
Drugs to avoid in dogs with the MDR1 gene mutation: The tranquilizer acepromazine; a pain medication called butorphanol; the anti-cancer drugs doxorubicin, vinblastine and vincristine; the antibiotics erythromycin and rifampin; anti-parasitic drugs such as ivermectin (in high doses), milbemycin, moxidectin and ...
NexGard and NexGard SPECTRA have been shown to be safe and effective in various breeds of dogs (including Collie breeds) when used as directed and, can be given to puppies from 8 weeks of age, providing they weigh at least 2 kg.
Multidrug Resistance 1, also called MDR1, is an inherited condition affecting several breeds of dogs, especially herding dogs such as the border collie.
When considering the use of macrocyclic lactones such as ivermectin or moxidectin in dogs, veterinarians have followed the adage, “white feet, don't treat.” This refers to the known sensitivity of Scotch collies (both rough and smooth) to neurotoxicity when administered these drugs at higher than label doses.
MDR1 drug sensitivity occurs when dogs inherit a genetic variant in their ABCB1 gene (formerly known as the MDR1 gene). This variant causes a change in a protein called P-glycoprotein (P-gp).
The best products for flea treatment in Australia include NexGard Spectra for Dogs, Bravecto Chews and ADVOCATE for Dogs.
Dogs with a mutation in the MDR1 (multidrug resistance 1) gene may have severe and life-threatening reactions to some common drugs. Research has shown the mutation occurs more frequently in certain breeds. Approximately three of every four collies in the United States have the mutant MDR1 gene.
Drugs such as ivermectin, selamectin, milbemycin, and moxidectin, are commonly used to treat and prevent parasites like heartworms. At low doses, such as those used in heartworm prevention, these drugs have been shown to be safe even for dogs with the MDR1 mutation.
In the 1800s, the Basques began migrating to Australia to keep sheep. Their Pyrenean Shepherds crossbred with other working dogs, including Collies and Border Collies, creating the modern version of the Australian Shepherd.
Based on their color, Australian Shepherds are classified into four broad categories: the Black Australian Shepherd, the Red Australian Shepherd, the Red Merle Australian Shepherd, and the Blue Merle Australian Shepherd. Aussies are an intelligent breed of dogs.
Both products are safe for dogs when following directions and Nexgard has been approved by the FDA to treat and prevent flea and tick infestations. However, unlike Frontline Plus, Nexgard has not yet been evaluated for use in breeding, pregnant, or lactating dogs.