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Parasites are not something to ignore. Not only can they make your pet very uncomfortable, but they may lead to serious illness if left untreated. Many preventive medications can help you kill parasites before they begin cause problems for your pet, including selamectin. 

Often sold under the brand name Revolution or Revolution Plus, selamectin may be prescribed by your veterinarian for the prevention or treatment of heartworms, fleas, ticks, lice, ear mites or sarcoptic mange.  

What is selamectin? 

Selamectin for cats and dogs is sold under a variety of brand names, including Revolution Plus. This medication is a topical parasiticide that is typically sold in single-use tubes. It is used for many reasons, including as a dog and cat flea & tick treatment and must be prescribed by your veterinarian.  

Selamectin is considered a long-acting medication. It is usually applied monthly and provides extended parasite protection. Year-round parasite protection is recommended, so make sure to use selamectin all 12 months of the year.

What does selamectin treat? 

Your veterinarian may recommend selamectin for dogs, cats or other pets in your home. It can be used as a preventive for pets at risk for heartworms, fleas, ticks and mites, or it may be applied to pets currently infected with some parasites. Most commonly, selamectin is prescribed to help your pet combat the following. 

  • Fleas 
  • Heartworms 
  • Ear mites 
  • Scabies 
  • Ticks 
  • Lice 
  • Hookworms 
  • Roundworms 

If your pet spends time outdoors or around other pets in areas known to support parasites, selamectin treatment can be a vital part of overall dog and cat health & wellness. Consider applying it on the first of the month to keep your beloved friend safeguarded.  

How fast does selamectin work? 

The speed at which selamectin will work depends on what parasite you’re treating in your pet. Revolution flea treatment for dogs tends to act quickly. Fleas can start dying as soon as four hours after you apply the medication. Ticks, on the other hand, can take up to five days to die.  

Keep in mind that even as the parasites start to die, the medication may not reach peak efficacy for several more days.  

How to apply selamectin to cats and dogs 

This medication is normally applied topically to your pet, so you don’t have to worry about using pill pockets or dosing their food. To apply selamectin, begin by parting the hair on the back of your pet’s neck. Put the tip of the medication tube against your pet’s skin and squeeze until you have entirely emptied the contents. Watch them closely to make sure they don’t roll around or do anything to remove the dose. After applying selamectin to your pet, you need to wash your hands thoroughly.  

A few notes about all dog flea & tick drops—do not apply these medicines to a pet when their hair is wet or when they have broken skin in the application area. Don’t give more medicine than recommended—this won’t necessarily speed up the effectiveness of the medication, and it could harm your pet. And while you may be tempted, you should not massage the medication into your pet’s skin.  

Selamectin dosage recommendations 

You want to pay special attention to the selamectin dosage for cats and dogs. The appropriate dose of medication will depend on your pet’s weight and the concentration of selamectin.  

Revolution is sold in various tube colors, and each tube has a different amount of medication. For cats, Revolution is sold in these varieties: 

  • Mauve: 15 mg per tube, 60 mg/mL, for cats up to 5 pounds  
  • Blue: 45 mg per tube, 60 mg/mL, for cats between 5.1 and 15 pounds  
  • Taupe: 60 mg per tube, 60 mg/mL, for cats more than 15.1 pounds  

For dogs, the medication tubes vary in volume and potency. Canine Revolution doses come in these options:

  • Mauve: 15 mg per tube, 60 mg/mL, for dogs up to 5 pounds  
  • Purple: 30 mg per tube, 120 mg/mL, for dogs between 5.1 and 10 pounds  
  • Brown: 60 mg per tube, 120 mg/mL, for dogs between 10.1 and 20 pounds 
  • Red: 120 mg per tube, 120 mg/mL, for dogs between 20.1 and 40 pounds  
  • Teal: 240 mg per tube, 120 mg/mL, for dogs between 40.1 and 85 pounds  
  • Plum: 360 mg per tube, 120 mg/mL, for dogs more than 85 pounds  

Closely follow the dosing instruction on whatever selamectin-containing solution you purchase for your pet. 

While selamectin is most often used in cats and dogs, it may also be prescribed to other pets at risk for parasites. Check out our ferret shop to learn more. 

Possible selamectin side effects 

Most pets can tolerate selamectin without experiencing any significant issues. If your pet has a previous sensitivity to it, do not try to use it again. Some rare side effects include: 

  • Localized hair loss 
  • Loss of appetite 
  • Vomiting 
  • Loose stools 
  • Drowsiness 
  • Drooling 
  • Rapid breathing 

If you notice any troubling side effects in your pet, call your veterinarian.

Where can I buy selamectin? 

You can find selamectin online at Petco, but keep in mind that it is a prescription medication. You will need your veterinarian’s authorization to order this medication from your favorite store.  

How should I store selamectin? 

This flea & tick medication should be kept at a temperature below 86 degrees Fahrenheit. If kept in hot temperatures, selamectin can begin to break down and become less effective. The same is true when it becomes damp. For this reason, storing selamectin medication in a bathroom, near a kitchen sink or in humid areas may not be the best idea.  

Reviewed by Dr. Whitney Miller, DVM, MBA, DACVPM 

As Petco’s Chief Veterinarian, Dr. Miller is the lead veterinary subject matter expert, overseeing the company’s standards of excellence in animal care and welfare, growth in pet services and much more. Dr. Miller leads Petco’s medical team, supporting over 200 full-service hospitals and mobile vaccination clinics operating in over 1,000 Petco Pet Care Centers nationwide. 

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