Genetic Sensitivity: Ivermectin Toxicity in Some Dog Breeds

Jack Russell Terrier Lying On A White Pillow; ivermectin toxicity

A dog is more than just a pet. They’re a furry child. They become a huge part of your life and your heart whether you’ve had them since they were a puppy, or they’re a new addition to your family. As part of your family, it’s only natural that you dedicate the time and effort required to keep them healthy and happy. You happily groom them, take them for walks or to the dog park to keep them active, buy high-quality food, and take them to the vet when they’re sick. And since dogs are at risk for heartworm, ear mites, and fleas, you give them preventive medicine to keep them safe. It’s the smart thing to do, as it’s the only line of defense against such parasites. But, did you know some medications may endanger particular dogs more than help? Let’s discuss ivermectin toxicity.

What is Ivermectin?

Ivermectin is an incredibly efficient medication that is used to kill a number of different internal and external parasites. It can treat ear and hair mites, and is most commonly used as monthly heartworm prevention in dogs. Sounds like an amazing product, right? Yes, but it’s important to note that if your dog is given an excessive dose of ivermectin (10 to 20 times the recommended dose) your dog could fall victim to toxicity. Additionally, you should know that certain dogs are genetically hypersensitive to this medication. These breeds are at high risk of falling ill if given ivermectin as a preventive medication.

Which Dog Breeds are in Danger?

There are several dog breeds that suffer from a genetic sensitivity to ivermectin, but it’s most commonly seen in the following breeds:

  • Collie
  • Old English Sheepdog
  • Shetland Sheepdog (Sheltie)
  • Australian Shepherd
  • German Shepherd
  • Longhaired Whippet
  • Silken Windhound
  • Border Collie
  • Dogs of mixed breeds that include herding breeds

Sensitivity to Ivermectin

Dog breeds with a genetic sensitivity to ivermectin toxicity suffer from it because of a mutation in what is called the MDR1 Gene. This mutation can also make you pup sensitive to several other medications,  so you should check with your vet before administering any type of medication at home. If your dog is one of the unlucky ones sensitive to ivermectin and is given the drug, it can pass directly to your pup’s brain. This is extremely dangerous and toxic, and the results can be fatal. If your dog has ever had an overdose on a similar medication before, that could also cause them to be sensitive to ivermectin. If you adopted your dog from a shelter, you should ask for his medical history to discover if any such overdose has ever occurred.

How Do You Know if Your Fur Baby is Sensitive?

It should be noted that if you have one of the dog breeds mentioned above, that doesn’t necessarily mean that your furry friend has this gene mutation and subsequent sensitivity. The only way to know 100% that your dog suffers from the mutant MDR1 gene is to have your dog tested at the vet. It’s a quick and simple procedure, in which your vet will scrape cells from the inside of your dog’s cheek. This sample will be sent to a lab for genetic testing.

Symptoms of Ivermectin Toxicity

If you’ve given your dog ivermectin recently and are wondering if they’re sensitive and suffering from toxicity, keep an eye out for the following symptoms:

  • Lethargy
  • Depression
  • Drooling
  • Vomiting
  • Dilated pupils
  • Loss of appetite
  • Disorientation
  • Tremors/Seizures
  • Blindness
  • Trouble standing
  • Slow heartbeat
  • Difficulty breathing
  • Coma

What to Do if You See Signs of Toxicity

If you suspect your dog might be suffering from toxicity due to ivermectin, it’s not a waiting game. Take your pup to the vet immediately. Do not wait around for symptoms to worsen. Ivermectin toxicity cannot be reversed, but your vet may be able to stop the symptoms from getting worse.

What Your Vet Will Do if Your Dog is Suffering From Toxicity

If you administered the drug to your dog within the past 4-6 hours, your vet may be able to induce vomiting to minimize the amount of ivermectin that is absorbed into their body. He may also administer activated charcoal to help absorb the ivermectin. Your vet will keep your dog as comfortable as possible and treat any symptoms that develop as they arise.

To stay one step ahead of the symptoms, your vet will likely check your dog’s kidney, liver, and pancreatic functions. These tests will help determine the extent of the damage and inform him which treatment options will be needed moving forward. Your vet may also conduct a blood test and electrolyte test. These will rule out blood-related conditions and dehydration. While under observation, your pup will be given plenty of fluids (administered intravenously, so they go directly into the vein) and nutritional support (through a feeding tube if necessary). If your dog is having trouble breathing, he will need to be placed on a ventilator. Your vet will also keep your dog’s temperature regulated and administer medication to control any seizures the toxicity may cause.

Preventive Medication

Preventive medication is not bad. In fact, it’s necessary. Your dog can’t live a healthy life, free from fatal parasites without it. But it’s important to choose the right medicine and give the correct dose to prevent toxicity. If your dog is one of the breeds that are more susceptible to ivermectin toxicity, bring him to the vet and talk to your veterinarian about the benefits and risks of the medication before administering it to your pup. Your veterinarian can perform the necessary cheek swab test and inform you whether ivermectin is a safe choice. If not, he can recommend an alternative that is a better fit for your furry friend.

If you are worried about choosing the right medication for your dog, or you simply want to know more about ivermectin and the mutant MDR1 gene, please don’t hesitate to contact us today. It’s always better to be safe than sorry in these situations, and we are happy to answer any of your questions and help give your dog the best care possible.

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Abigail Lee
Abigail Lee
posted 3 weeks ago

We absolutely LOVE Tipp City Vet! All of the staff are professional and friendly, always happy to see us and my girl, Ollie! I have been bringing Ollie here for care for about 2 years and always had a wonderful experience. They are thorough and make sure you feel at ease about your pet.
About two months ago, we started bringing my girl here for doggy daycare once or twice a week and she loves it! She has a chance to get all her Aussie energy out while I'm at work. She's always so happy when I pick her up!!
My family has also utilized their lodging services several times. You can board your pets separately or together. They offer extra play sessions, bathing, etc. And if you're still worried about your pet, you can text their lodging phone number and they will send you pictures of your pet! Great for nervous Dog Moms like me!
Can't say enough good things!

Amy Walker
Amy Walker
posted 3 weeks ago

Anytime we go out of town we keep one of our dogs at the boarding portion of the hospital. She LOVES it. After a couple of stays she has realized how much she loves this place and no longer tries to pull us out the door when we arrive (this in my book is a good sign)! She’s always exhausted when we pick her up, so that reassures me that they take the time to play with her and that she doesn’t have any built up energy she needs to release once home as attention was not given. The staff is amazing and take great care of the animals. Also very reasonable pricing on boarding for what they offer!

posted 1 month ago

Great clean facility, super friendly staff! Dr Joel was really nice, attentive and knowledgeable! Love that they have Sunday hours and that they see small pets like our guinea pig. They took great care of her and were able to get us a Sunday appointment right before closing on Saturday. Would recommend and go back.

Liz Cress
Liz Cress
posted 1 month ago

The staff and vets are always pleased when I bring our Boston Terrier in. It’s awesome to have them stop and pet her before we even get into our appointment. During the appointment, the Vet (have had 3 different ones) treats her so special and sweet talk her to calm her down (all of them have). They care about how we feel and how she feels! Love it!

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