Selamectin is a broad-spectrum antiparasitic active ingredient used in veterinary medicine in dogs and cats against external parasites (lice, mites, fleas, some tick species) as well as against internal parasites (e.g. heartworms and roundworms). However, it is ineffective against tapeworms and flukes. It belongs to the chemical class of the macrocyclic lactones.

Selamectin It is the only macrocyclic lactone that is effective against dog & cat fleas as well as against some tick species at the usual therapeutic dose.

Selamectin is used mainly in ready-to-use spot-ons for dogs and cats. So far it is not used in livestock. It is not used either against agricultural or household pests.

However, resistance of heartworm microfilariae to ivermectin has been reported in the USA (particularly in the South), with cross-resistance to all macrocyclic lactones, including selamectin.

The table below indicates some usual dosing recommendations for selamectin issued by manufacturers or documented in the scientific literature. They may not be approved in some countries.

Dosing recommendations for SELAMECTIN
DOGS
Warning!: Tolerance and safety margin in dogs with the MDR-1 mutation (e.g. Collies) sensitive to ivermectin are higher for selamectin than for ivermectin. Consequently the recommended dose can be admnistered to dogs with de MDR-1 mutation. Such dogs treated at 5x the recommended selamectin dose didn't show adverse reactions.
Delivery Parasites Dose (against selamectin-susceptible parasites)
Spot-on Ancylostoma caninum 6-12 mg/kg
Spot-on Dirofilaria immitis prevention 6-12 mg/kg monthly
Spot-on ToxocaraToxascaris 6-12 mg/kg
Spot-on Ticks (R. sanguineus, D. variabilis) 6-12 mg/kg monthly
Spot-on Fleas 6-12 mg/kg monthly
Spot-on Otodectes cynotis 6-12 mg/kg 1x, not into the ears
Spot-on Pneumonyssoides caninum 6-24 mg/kg, 3x wit 2-4 weeks interval
Spot-on Sarcoptes scabiei 6-12 mg/kg 2x with 1 month interval
Spot-on Lice 6-12 mg/kg 1x
CATS
Delivery Parasites Dose (against selamectin-susceptible parasites)
Spot-on Gastrointestinal roundworms 6-17 mg/kg
Spot-on Dirofilaria immitis prevention 6-17 mg/kg monthly
Spot-on Otodectes cynotis 6-17 mg/kg 1x, not into the ears
Spot-on Fleas 6-17 mg/kg monthly
Spot-on Lice 6-17 mg/kg 1x

DISCLAIMER: Liability is denied for any possible damage or harm to persons, animals or any other goods that could follow the transmission or use of the information, data or recommendations in this site by any site visitor or third parties.

Dosing recommendations for antiparasitics depend on national regulations. National regulatory authorities determine whether a product is approved for a given indication, i.e. use on a particular host at a specific dose and against a specific parasite. Check the labels of the products available in your country for specific information on approved indications.


  • Click here to view the technical summary of this active ingredient
  • Click here to view the safety summary of this active ingredient
  • Click here to view the list of all technical summaries of antiparasitic active ingredients in this site.