We use Frontline on the dogs and Advantage on the cats. Frontline kills ticks, and Advantage does not. The cats don't leave the back yard, and we really don't have ticks in our yard. The dogs go all over the place, and could get ticks.
We used BioSpot once a cat years ago, and she had a horrible reaction. Foamy mouth, running around like crazy, it was horrible. I don't even know how they can still sell the stuff.
When our cat was diagnosed with kidney disease, a holistic vet suggested spraying a combination of oils (citronella, peppermint, lavender and a few more, mixed with water and vinegar). The cat got fleas anyway, we caught it early and put her back on Advantage.
Teresa |