Aussies and MDR1

DO NOT GIVE YOUR AUSSIE IVERMECTIN!!!

Ivermectin is a class of dewormer.  It is used in many different brands of flea/tick/heartworm prevention.

It can be lethal to aussies and other collie breeds.

Our dogs are all tested negative for carrying or having the mdr1 mutation, BUT I strongly recommend playing it safe and NOT using any ivermectin products.

  I like nexgaurd and nexgaurd spectra, and interceptor.

Other drug sensitivities to be aware of in australian shepherds:

  • Ivermectin (found in heartworm medications)
  • Loperamide (Imodium over the counter antidiarrheal agent)
  • Doxorubicin
  • Vincristine
  • Vinblastine (anticancer agents)
  • Cyclosporin (immunosuppressive agent)
  • Digoxin (heart drug)
  • Acepromazine (tranquilizer)
  • Butorphanol (“Bute” pain control)


The following drugs may also cause problems:

  • Ondansetron
  • Domperidone
  • Paclitaxel
  • Mitoxantrone
  • Etoposide
  • Rifampicin
  • Quinidine
  • Morphine

Always be sure to make your vet aware of your aussies MDR1 status!!!  And talk to them about what is safe and what isn’t!!!

©2026 RLValley Ranch