Selamectin is a topical macrocyclic lactone antiparasitic medication marketed under the brand name Revolution (in North America) or Stronghold (in Europe). Originally developed and labeled for dogs and cats, selamectin has become an essential tool in rabbit medicine for treating external parasites, particularly Cheyletiella fur mites, Psoroptes cuniculi ear mites, and fleas. While its use in rabbits is extra-label, it has an excellent safety record and is considered the treatment of choice for several common rabbit parasitic conditions. This is a prescription medication in most regions and should be used under veterinary guidance.
What Is Selamectin Used For?
In rabbits:
- Cheyletiella parasitovorax (fur mites) — also known as “walking dandruff,” causes scaling, dandruff, and pruritus along the back and shoulders
- Psoroptes cuniculi (ear mites) — causes thick, crusty ear canal lesions and head shaking
- Fleas — Ctenocephalides species
- Some nematode parasites
In dogs and cats:
- Flea prevention and treatment
- Heartworm prevention
- Sarcoptic mange (dogs)
- Ear mites (Otodectes cynotis)
- Intestinal roundworms and hookworms
- Lice
How Does Selamectin Work?
Selamectin is an avermectin compound that acts on the parasite’s nervous system. It binds to glutamate-gated chloride channels in parasite nerve and muscle cells, causing an influx of chloride ions. This leads to hyperpolarization of the cell membrane, paralysis, and death of the parasite. Mammalian cells are largely unaffected because the blood-brain barrier prevents selamectin from reaching similar receptors in the central nervous system, and mammals have different channel structures.
Selamectin is absorbed through the skin and distributed systemically, providing protection against both external parasites (through systemic circulation into the skin) and internal parasites (through distribution to target tissues). It is stored in sebaceous glands and slowly released, providing approximately 30 days of activity after a single topical dose.
Dosage
Dosing for rabbits is extra-label and must be determined by your veterinarian.
| Species | Typical Dose | Route | Frequency |
|---|---|---|---|
| Rabbits | 6—20 mg/kg | Topical (skin) | Every 30 days, typically 2—3 applications |
| Dogs | 6 mg/kg minimum | Topical | Monthly |
| Cats | 6 mg/kg minimum | Topical | Monthly |
For rabbit parasites:
- Cheyletiella: Typically 2 to 3 monthly applications at the higher end of the dose range (12—20 mg/kg)
- Psoroptes cuniculi ear mites: 2 to 3 monthly applications; do NOT attempt to manually remove ear crusts, as this is extremely painful and unnecessary — the crusts will resolve as the mites die
- Fleas: Monthly application during flea season
Application technique:
- Part the fur at the base of the neck (between the shoulder blades)
- Apply the liquid directly to the skin (not on the fur)
- Do not bathe the rabbit for 2 hours before or after application
- Allow the application site to dry before handling
- Wear gloves during application
Product selection: The appropriate Revolution product should be chosen based on the rabbit’s body weight. Revolution for Cats (0.75 mL for small/medium rabbits) is commonly used. Your veterinarian will help select the correct product.
Side Effects
Selamectin is very well tolerated in rabbits and other species. Side effects are rare and mild:
- Temporary hair loss at the application site — cosmetic only, resolves with normal hair regrowth
- Mild skin irritation — redness or scaling at the application site
- Transient lethargy — uncommon
Serious side effects are extremely rare:
- Allergic reactions — hives, facial swelling, or respiratory distress
- Neurological signs — extremely rare at appropriate doses; more concerning in breeds with MDR1 gene mutations (collies and related dog breeds), but not a significant concern in rabbits
Treating Rabbit Parasites
Cheyletiella parasitovorax (walking dandruff):
- Common in pet rabbits, especially those with underlying health issues (arthritis, obesity, dental disease) that prevent normal grooming
- Causes characteristic scaling and dandruff, most prominently over the back and shoulders
- Mites are visible under a microscope and sometimes with the naked eye as moving flakes (“walking dandruff”)
- Zoonotic — can cause transient skin lesions in humans
- Environmental cleaning is important as mites can survive off the host for several days
Psoroptes cuniculi (ear mites):
- Causes thick, crusty, brown-yellow lesions in the ear canals
- Rabbits with ear mites may scratch at their ears, shake their heads, or develop head tilt
- Secondary bacterial infections are common and may require concurrent antibiotic treatment
- Do not manually remove the crusts — this is extremely painful and unnecessary; the crusts will shed on their own as the mites die during treatment
- Some veterinarians recommend topical analgesics or oral pain management during treatment
Fleas:
- Less common in indoor rabbits but possible, especially in multi-pet households
- Selamectin effectively kills adult fleas on rabbits
- Environmental flea control is important for multi-pet homes
Species-Specific Considerations
Rabbits:
- Extra-label use; dosing and product selection should be made by a rabbit-savvy veterinarian
- Generally very well tolerated
- Environmental cleaning should accompany treatment (wash bedding, vacuum thoroughly)
- All in-contact rabbits should be treated simultaneously
- Monitor for improvement — skin condition and ear health should improve within 2 to 4 weeks
Dogs and cats:
- Labeled use — follow product instructions
- Dogs require heartworm testing before starting preventive therapy
- Selamectin is one of the few topical flea preventatives safe for cats (many canine products are toxic to cats)
Drug Interactions
Selamectin has minimal drug interactions due to its topical application and specific mechanism of action. However:
- Other macrocyclic lactones (ivermectin, moxidectin, milbemycin) — avoid concurrent use to prevent additive toxicity
- Contact with other topical medications — allow space between application sites for different topical products
Important Precautions
- Do not apply to broken or irritated skin
- Keep away from the rabbit’s eyes and mouth
- Prevent other animals from grooming the application site until dry
- Wear gloves during application
- Wash hands thoroughly after handling
- Keep rabbits separated from young children for several hours after application
- Store in original packaging, away from children and pets
Storage
Store selamectin at room temperature in its original packaging. Protect from extreme temperatures. Check expiration dates. Do not use if the product has changed color or consistency. Dispose of used applicators safely according to local regulations.
Always consult your rabbit-savvy veterinarian before starting any parasite treatment. Proper diagnosis of the specific parasite is essential for effective treatment. This information is for educational purposes and does not replace professional veterinary advice.