I did use something similar last summer to repel fleas. They were coming up from under the house. I'm doing to need it soon. If I can find the recipe, I'll share it. BTW, I sprayed the carpet and furniture, not my pets, but I would not be afraid to do that.

Note: Going off on a tangent so bear with me. I used to get bi-weekly massages. Therapists use essentials oils all the time. Any reputable therapist will tell their customers to NEVER use any essential oil straight from the bottle. Use oils in a much diluted form. Some mix theirs in Olive oil; some use other oils.

So hopefully your fur child will recover soon, and if you choose to use essential oils again, make sure you find a recipe for a few drops per gallons and follow that recipe.

Good luck and best wishes.