However, a dog with Ivermectin may not be safe for collies and similar herding breeds at higher dosages that would be safe in other dogs
The therapeutic monthly dose for heartworm prevention that utilizes ivermectin is well below the established doses of ivermectin toxicity
The authors documented no evidence of CNS toxicity in doses up to 10 times the highest FDA-approved dose of 200 µg/kg
All Collies were given ivermectin at dosages of 100 and then 200 micrograms/kg of body weight
In sensitive breeds
Ivermectin is widely used in veterinary medicine as an anthelminthic and generally has a wide margin of safety, but Collies are prone to ivermectin toxicity
In some breeds of dogs such as collies, which are homozygotes for a nonsense mutation in ABCB1, and in Abcb1-knockout mice, ivermectin induces
The aim of this study was to determine the mechanistic basis for this
Three of the dogs developed mild clinical signs of toxicosis (salivation, vomiting, confusion
A retrospective study was completed, which evaluated canine exposures to ivermectin from 1998 to 2005
Four received care in an intensive care unit, and none died
Results of these trials “Use that rhyme to remember which breeds are especially sensitive [to ivermectin
The increased sensitivity of these breeds is a result of a mutation of the MDR1 (multi-drug resistance) gene
Retreatment may be considered at intervals as short as 3 months
After the 200 micrograms/kg dosage, 7 dogs (including 1 smooth-coated Collie) developed severe All Collies were given ivermectin at dosages of 100 and then 200 micrograms/kg of body weight
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Also, some breeds have a gene that can make them extremely sensitive to ivermectin and other drugs
Twenty-four Collies sensitive to the toxic effects of ivermectin, when administered at high dosages, were studied to evaluate the effects
Ivermectin sensitivity in collies is associated with a deletion mutation of the mdr1 gene
15 An exception is in collie breeds, which may show toxic effects at dosages as low as 0
Other breeds and medications are linked as well
19 In a study of 382 dogs with HWI receiving melarsomine, none required cessation of therapy due to hepatorenal toxicity, as compared to 15-30% with thiacetarsemide