Nasal mites in dogs are treated with antiparasitic medications, typically given over a course of two to three weeks. The mites (Pneumonyssoides caninum) live deep inside a dog’s nasal passages and sinuses, so topical nasal sprays or home remedies won’t reach them. Treatment requires systemic medication that travels through the bloodstream or absorbs through the skin to kill the mites where they hide.
Recognizing Nasal Mites
The hallmark sign is reverse sneezing: sudden, loud, forceful inhalations through the nose that last a few seconds, often with the dog extending its neck and splaying its elbows out. It looks alarming, almost like the dog is choking or gasping, but episodes usually pass quickly on their own. Reverse sneezing has many causes, but when it becomes frequent or chronic, nasal mites are one of the top suspects.
Other common signs include regular sneezing, nasal discharge (sometimes with blood), coughing, noisy breathing, and reduced ability to smell. In a study of 30 dogs with reverse sneezing, about 63% also had at least one additional respiratory symptom. Some dogs shake their heads or paw at their nose. The signs can be mild enough that owners dismiss them for months before seeking help.
How Nasal Mites Are Diagnosed
Diagnosing nasal mites is tricky because the mites live deep in the nasal cavity and sinuses, well beyond what a vet can see with a simple look up the nose. The only definitive methods are rhinoscopy (inserting a tiny camera into the nasal passages under anesthesia) or deep nasal flushing, where saline is flushed through the nose and collected to check for mites under a microscope. During rhinoscopy, the mites can sometimes be seen walking along the nasal lining.
Because these procedures require anesthesia and specialized equipment, many vets in regions where nasal mites are common will treat presumptively. If a dog has the right symptoms and responds to antiparasitic medication, that response itself confirms the diagnosis. This is especially common in Scandinavia, where post-mortem surveys have found nasal mites in roughly 20% of dogs.
Primary Treatment Options
Three main medications are used to treat nasal mites, all belonging to a drug class called macrocyclic lactones. Your vet will choose based on your dog’s breed, size, and health history.
- Milbemycin oxime is given orally at a dose of 0.5 to 1 mg/kg, once every 7 to 10 days for three doses. In a clinical study of 20 dogs, 85% had complete resolution of symptoms after treatment, with most improving within 10 days of the first dose. The remaining dogs still showed significant improvement. This is often the first choice because of its strong safety profile.
- Ivermectin is given orally or by injection at 200 to 400 micrograms per kilogram. It’s effective but carries serious risks for certain breeds (more on that below).
- Selamectin is a topical spot-on treatment applied to the skin between the shoulder blades. In a controlled trial, dogs treated three times at two-week intervals were completely cleared of mites by post-mortem examination 33 to 35 days after treatment. All six untreated control dogs still had live mites. This option avoids the need for pills or injections.
Regardless of which medication is used, the treatment involves multiple doses spaced over several weeks. A single dose won’t eliminate the entire population because the drugs may not kill mite eggs, so repeat treatments catch newly hatched mites before they can reproduce.
Breed-Specific Safety Concerns
Some dog breeds carry a genetic mutation (called MDR1) that makes them dangerously sensitive to the same antiparasitic drugs used to treat nasal mites. In these dogs, the medication can cross into the brain at toxic levels, causing neurological symptoms like tremors, blindness, seizures, and in severe cases, death. Two documented cases involved an Australian Shepherd and a Collie, both of which died within five to six days of receiving ivermectin at just 1 mg/kg.
Breeds known to carry this mutation include:
- Collie
- Australian Shepherd and Miniature Australian Shepherd
- Shetland Sheepdog
- Old English Sheepdog
- German Shepherd
- Border Collie
- English Shepherd
- White Swiss Shepherd
- Longhaired Whippet
- Silken Windhound
- McNab
Ivermectin poses the highest risk for these breeds. Selamectin, milbemycin oxime, and moxidectin are considered safer alternatives, but even these drugs have a dramatically reduced safety margin in dogs with the mutation. If your dog is one of these breeds or a mix involving them, a genetic test for the MDR1 mutation can determine whether they carry one or two copies of the defective gene. Dogs with two copies (homozygous) are at the greatest risk. Your vet needs this information before prescribing any treatment.
What to Expect During Treatment
Most dogs start improving quickly. In the milbemycin study, the majority of dogs saw their symptoms resolve within 10 days of the first dose, well before the full treatment course was complete. Reverse sneezing episodes become less frequent, nasal discharge clears up, and breathing sounds normalize.
It’s important to complete every scheduled dose even if your dog seems better after the first one. Stopping early risks leaving surviving mites or unhatched eggs behind, leading to a relapse weeks later. If symptoms haven’t improved at all after the full course, your vet may recommend rhinoscopy to check for other causes like nasal polyps, foreign bodies, or fungal infections that can mimic mite symptoms.
Preventing Reinfestation
Nasal mites spread through direct nose-to-nose contact between dogs. Any dog that has been in close contact with an infested dog should be treated at the same time, even if it isn’t showing symptoms yet. This is especially important in multi-dog households, where leaving one dog untreated virtually guarantees the mites will bounce back.
Dogs that regularly interact with other dogs at parks, boarding facilities, or dog shows face ongoing exposure risk. Some monthly parasite preventatives that contain selamectin or moxidectin may provide incidental protection since these are the same drug classes used for treatment, but no product is specifically labeled for nasal mite prevention. If your dog has had nasal mites before and starts reverse sneezing again, a prompt vet visit and presumptive retreatment can catch a new infestation early.