Milbemycin oxime

From Dog

Milbemycin oxime is a macrocyclic lactone anthelmintic produced by fermentation of the soil bacteria, Streptomyces spp.

It has a similar mechanism of action but longer half-life than ivermectin.

Milbemycin opens glutamate sensitive chloride channels in neurons and myocytes of invertebrates, leading to hyperpolarisation of these cells and blocking of signal transfer.

Moxidectin belongs to the same class of drugs.

It is registered for heartworm control (Dirofilaria immitis) but has also been used extra-label for treatment of:

A long-acting preparation (Proheart; microsphere sustained-release formulation) is commonly used as a once or twice yearly injection and shows good efficacy as a larvicidal drug with heartworm disease and Dirofilaria repens[2]. This preparation can be safely used in dogs from 10-weeks of age[3].


  1. Rossi L et al (2007) Use of sustained-release moxidectin to prevent eyeworm (Thelazia callipaeda) infection in dogs. Vet Rec 161(24):820-821
  2. Genchi M et al (2010) Efficacy of moxidectin microsphere sustained release formulation for the prevention of subcutaneous filarial (Dirofilaria repens) infection in dogs. Vet Parasitol 170(1-2):167-169
  3. Heaney K & Lindahl RG (2005) Safety evaluation of moxidectin sustained-release injectable in 10-week-old puppies. Vet Parasitol 133(2-3):227-231