# Selamectin for Dog Ear Mites: Does It Work and How to Use It Yes, selamectin for dogs ear mites can work, but only when a veterinarian confirms ear mites are the problem and sets the correct dose for your dog. Ear mites are contagious and stubborn, so guessing at treatment often leaves the infestation half-treated and the itching continues. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Selamectin is a prescription parasiticide that kills ear mites (Otodectes cynotis) and several other parasites, so it is not available over the counter. - Your veterinarian calculates the dose from your dog's weight, and the medicine is applied to the skin between the shoulder blades. - Most parasite treatment plans for ear mites involve more than one dose, because eggs and newly hatched mites survive the first treatment. - Itching and head shaking often improve within days, but the ears can stay irritated for a week or two while inflammation settles. - If your dog is still scratching after treatment, or the ears smell bad or stay red, book a recheck instead of repeating the dose on your own. ## What Selamectin Is and What Veterinarians Use It For Selamectin is a topical antiparasitic medicine applied to your dog's skin. It belongs to a class of drugs called avermectins, which are widely used in veterinary medicine to kill parasites on and inside the body. In dogs, veterinarians use selamectin for flea control, some tick control, sarcoptic mange, and ear mites. It is also commonly combined with other drugs in prescription parasite products, such as a selamectin and sarolaner combination [1][2]. Ear mites are not a minor nuisance. Otodectes cynotis is described as a highly contagious ectoparasite and a significant cause of otitis externa (inflammation of the outer ear canal) in dogs [3]. The mites live in the ear canal, feed on debris and skin, and cause intense itching. Dogs scratch, shake their heads, and sometimes scratch the ear flap raw. Because ear mites spread easily between pets, your veterinarian may recommend treating every dog and cat in the household. Mites can also survive briefly in the environment, so bedding and shared toys are worth cleaning at the same time. ## How Selamectin Works Against Ear Mites Selamectin is absorbed through the skin and distributed through the bloodstream. It then reaches the ear canal and other tissues, where it interferes with the parasite's nervous system. The mites become paralyzed and die. This is the same basic mechanism used by other prescription acaricides (mite-killing drugs) such as fluralaner, lotilaner, and tigolaner, which also paralyze and kill arthropods [4][5][6]. One practical point matters here. Selamectin kills adult mites that are present when the medicine is active, but it does not instantly destroy every egg. Ear mite eggs hatch over the following days and weeks. That is why a single application often is not enough, and why your veterinarian will set a repeat schedule. If you want a broader overview of how ear mites are diagnosed and treated, see [Dog Ear Mites Treatment](/knowledge/veterinary-medicine/parasitic-diseases/dog-ear-mites-treatment). ## Selamectin Dose for Ear Mites in Dogs ### Who decides the dose Your veterinarian decides the dose. Selamectin is a prescription product, and the correct amount depends on your dog's body weight, age, health status, and other medicines your dog takes. Do not split a tube meant for a large dog, and do not borrow a dose from another pet. Giving too little can leave mites alive, and giving too much raises the risk of side effects. ### How it is given Selamectin comes as a liquid applied to the skin. Part the hair between your dog's shoulder blades, place the tip of the applicator against the skin, and squeeze out the full contents. Apply it where your dog cannot lick it off. Wash your hands afterward, and keep children away from the treated spot until it dries. Do not put selamectin directly into the ear canal unless your veterinarian specifically tells you to. The product is designed for skin application, and putting it in the ear can irritate the canal. ### How long it takes and how many doses Owners often ask how long selamectin takes to clear ear mites. The honest answer is that it depends on the product, the schedule, and how severe the infestation is. In studies of other prescription acaricides, treatment effect was visible by day 14, with mite counts evaluated weeks later [7]. A single oral dose of lotilaner in cats produced a 99.6 percent reduction in mites by day 28 [6]. These are different drugs, but they show the general timeline: improvement starts within about two weeks, and full clearance is judged at four weeks or later. Your veterinarian will tell you how many doses your dog needs and how far apart to give them. If you miss a dose, apply it as soon as you remember, then ask your vet whether the schedule should shift. Do not double up to catch up. For owners weighing options, selamectin vs ivermectin ear mites is a common question. Both are avermectins, and both can kill ear mites, but ivermectin is used off-label in dogs in many situations and has a narrower safety margin, especially in certain breeds with a genetic sensitivity to avermectins. Your veterinarian is the right person to decide which drug is safer for your dog. ## Side Effects of Selamectin in Dogs Most dogs tolerate selamectin well. In studies of topical selamectin combination products, no treatment-related adverse reactions occurred in any of the treated cats [2]. That does not mean side effects never happen, but serious reactions are uncommon. | Side effect | How common or serious | What to do | |---|---|---| | Mild hair loss or greasy fur at the application site | Common and not serious | Leave it alone, it usually resolves | | Brief itching or redness where applied | Common and not serious | Watch for a day, call your vet if it spreads | | Drooling, vomiting, or loose stool | Uncommon, usually mild | Call your vet if it lasts more than a day | | Lethargy or wobbliness | Uncommon and potentially serious | Call your vet the same day | | Tremors, seizures, or trouble walking | Rare but serious | Treat as an emergency, call your vet or a poison control line now | | Severe skin reaction or facial swelling | Rare but serious | Seek emergency care immediately | Dogs with a genetic mutation affecting the blood-brain barrier (often seen in some collies and related breeds) are more sensitive to avermectins. Tell your veterinarian your dog's breed and any prior reactions to parasite medicines before treatment starts. ## Who Should Not Take Selamectin and What Interacts With It Selamectin is not right for every dog. Your veterinarian may avoid it or adjust the plan if your dog: - Is a puppy below the minimum age or weight on the product label - Is sick, weak, or underweight - Has a history of seizures or neurologic disease - Has had a reaction to selamectin or another avermectin - Is pregnant or nursing, unless your vet specifically approves it Drug interactions matter too. Medicines that depress the nervous system, including some sedatives and seizure drugs, can add to selamectin's effects. If your dog takes any prescription medicine, supplement, or flea and tick product, tell your veterinarian before you start selamectin. Never stack two parasite products that contain the same or similar drugs without veterinary guidance. ## Overdose and When to Call a Veterinarian or Poison Control An overdose can happen if a dog licks off a freshly applied dose, if the wrong size tube is used, or if a dog eats the applicator. Signs to watch for include vomiting, drooling, wobbliness, dilated pupils, tremors, and seizures. If you suspect an overdose, call your veterinarian right away. You can also contact the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661. Both may charge a consultation fee. Have your dog's weight, the product name, and the amount involved ready before you call. Do not wait for symptoms to appear. Avermectin toxicity can worsen quickly, and early treatment is far easier than late treatment. ## Limitations and When to Contact a Veterinarian Selamectin is not a cure-all for itchy ears. Ear mites are only one cause of otitis externa. Yeast infections, bacteria, allergies, foreign material, and tumors can all cause scratching, head shaking, and discharge. If your dog's ears were not examined under an otoscope or checked with a swab, you may be treating the wrong problem. Contact your veterinarian the same day if: - Your dog is scratching so hard that the ear flap bleeds or swells - There is a bad smell, thick pus, or dark discharge that keeps coming back - Your dog tilts the head constantly or loses balance - Your dog yelps when the ear is touched - You see no improvement after the first dose Seek emergency care now if your dog has a seizure, cannot stand, has trouble breathing, or has facial swelling. Book a routine recheck if the itching is mild but has not fully resolved after the treatment course your vet set. A recheck lets your veterinarian look inside the canal again and decide whether mites are gone, whether a secondary infection needs treatment, or whether the diagnosis should be revisited. Every dog is different. The right plan for your dog depends on an exam, and no article can replace that. ## Frequently Asked Questions ### Does selamectin really kill ear mites in dogs? Yes, selamectin is an effective acaricide against ear mites when it is dosed correctly and repeated on the schedule your veterinarian sets. It kills mites by paralyzing their nervous system, the same general way other prescription mite treatments work [4][6]. The catch is that it must actually reach the mites at an effective level, which is why the dose and timing matter so much. ### How many doses of selamectin does my dog need for ear mites? Your veterinarian decides the number of doses based on your dog's weight, the product used, and how heavy the infestation is. Many parasite treatment plans use more than one application because eggs survive the first dose and hatch afterward. Follow the schedule your vet gives you instead of stopping early when the itching calms down. ### Can I use selamectin if my dog's ears are still itchy after treatment? Itching that lingers does not always mean the mites are still there. Ear canal inflammation can take a while to settle even after the mites are dead. However, ongoing scratching can also mean a secondary yeast or bacterial infection, or a different diagnosis entirely. Ask your veterinarian to recheck the ears before you repeat or change any medicine. ### Is selamectin safer than ivermectin for ear mites? Selamectin generally has a wider safety margin than ivermectin in dogs, which is one reason it is a common prescription choice. Ivermectin is sometimes used off-label and can cause serious neurologic side effects in dogs with a genetic sensitivity to avermectins. Your veterinarian can review your dog's breed, history, and other medicines to pick the safer option. ### Do I need to treat my other pets if one dog has ear mites? Yes, ear mites are highly contagious, so other dogs and cats in the home are often treated at the same time [3]. Your veterinarian will choose a product that is safe for each species, since some dog products are toxic to cats. Cleaning bedding and shared toys helps reduce reinfestation while treatment is underway. If you are exploring home options alongside veterinary care, these guides can help you understand what is realistic: [How To Treat Ear Mites At Home For Dogs](/knowledge/veterinary-medicine/parasitic-diseases/how-to-treat-ear-mites-at-home-for-dogs) and [How To Get Rid Of My Dogs Ear Mites At Home](/knowledge/veterinary-medicine/parasitic-diseases/how-to-get-rid-of-my-dogs-ear-mites-at-home). ## Related Articles - [Dog Ear Mites Treatment](/knowledge/veterinary-medicine/parasitic-diseases/dog-ear-mites-treatment) - [How To Treat Ear Mites At Home For Dogs](/knowledge/veterinary-medicine/parasitic-diseases/how-to-treat-ear-mites-at-home-for-dogs) - [Dog With Ear Mites Home Remedy](/knowledge/veterinary-medicine/parasitic-diseases/dog-with-ear-mites-home-remedy) - [How To Get Rid Of My Dogs Ear Mites At Home](/knowledge/veterinary-medicine/parasitic-diseases/how-to-get-rid-of-my-dogs-ear-mites-at-home) - [How To Treat Dog Ear Mites At Home Without Vet Visit](/knowledge/veterinary-medicine/parasitic-diseases/how-to-treat-dog-ear-mites-at-home-without) - [How To Clean A Dogs Ear With Mites](/knowledge/veterinary-medicine/parasitic-diseases/how-to-clean-a-dogs-ear-with-mites) - [Selamectin for Dogs: Dosage, Side Effects, and How to Use It](/knowledge/veterinary-medicine/pet-medication-guide/selamectin-dogs-dosage-side-effects) - [Ivermectin for Dogs With Mange: Does It Work?](/knowledge/veterinary-medicine/parasitic-diseases/ivermectin-dogs-mange) - [Ivermectin and Selamectin for Dog Heartworm Prevention](/knowledge/veterinary-medicine/parasitic-diseases/ivermectin-selamectin-heartworm-prevention-dogs) ## References 1. [A Discrete Choice Experiment to Assess Cat Owners' Preferences for Topical Antiparasitics and the Comparative Ease of Use of a Combined Selamectin and Sarolaner Formulation: An International Survey](https://pubmed.ncbi.nlm.nih.gov/40646884/). Animals : an open access journal from MDPI, 2025. 2. [Efficacy of Revolution® Plus (selamectin plus sarolaner) against Amblyomma americanum (lone star ticks) in cats](https://pubmed.ncbi.nlm.nih.gov/40750907/). Parasites & vectors, 2025. 3. [Efficacy of afoxolaner or the combination of afoxolaner with milbemycin oxime against Otodectes cynotis in naturally infested dogs](https://pubmed.ncbi.nlm.nih.gov/38154391/). Veterinary parasitology, 2024. 4. [Efficacy of a fluralaner-based ectoparasiticide for the control of otodectic and sarcoptic mange in naturally infested dogs, evaluated in randomized, double-blind clinical studies](https://pubmed.ncbi.nlm.nih.gov/41724992/). Parasites & vectors, 2026. 5. [Efficacy of Felpreva®, a new spot-on formulation containing tigolaner, emodepside and praziquantel, applied as a single application to cats artificially infested with ear mites (Otodectes cynotis)](https://pubmed.ncbi.nlm.nih.gov/37554314/). Current research in parasitology & vector-borne diseases, 2023. 6. [Efficacy evaluation of lotilaner (Credelio™) in experimentally induced Otodectes cynotis infestations in cats](https://pubmed.ncbi.nlm.nih.gov/41163194/). Parasites & vectors, 2025. 7. [Field efficacy of a combination of afoxolaner, moxidectin and pyrantel pamoate against natural infestation with Otodectes cynotis in dogs](https://pubmed.ncbi.nlm.nih.gov/41854285/). Parasite (Paris, France), 2026. ## Further Reading - [American Veterinary Medical Association: First Aid Tips for Pet Owners](https://www.avma.org/resources-tools/pet-owners/emergencycare/first-aid-tips-pet-owners) - [Merck Veterinary Manual: Dog Owners](https://www.merckvetmanual.com/dog-owners) - [Cornell Richard P. Riney Canine Health Center: Canine Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information)