I agree with the microchipping being done under anesthesia. They use a big needle to implant that and it can be painful. Teiya is getting hers inserted when she gets spayed and a dental cleaning next month.
I use Interceptor. While it's a little more expensive, Interceptor takes care of heartworms and most parasites in one does and it comes in a 2-10lbs formula. Revolution would be my next choice. I know it seems like a waste of money, but trust me, treat one dog for heartworms and you'll never forsake it again. When in Westie Rescue, I had several of our rescues go through treatment for HW. it's not pretty. The dogs are sick for at least 30 days and it dramatically shortens their lifespan. It only takes ONE mosquito.
__________________  Gina - Mom to Teiya.  One spoiled little Yorkie girl! |