Your Yorkie or Maltese puppy has already had his first vaccinations and deworming. We prefer the 4-way combination vaccination to the 7-way combination shot. We are dealing with toy breed dogs and do not want to overwhelm their immune systems. We strongly urge, in fact, insist, dog owners to separate the rabies shot, kennel cough vaccine, and puppy booster shots by several weeks. The vaccinations work by giving the puppy a small amount of the virus and stimulating the pup's immune system to build up immunities to the dog viruses such as distemper and parvo. A recent Wall Street Journal report attributed many illnesses such as Autoimmune Disease to over-vaccination. Texas has recently implemented a 3 year protocol on rabies vaccination instead of the every year shot. Many other states have the same law. We also recommend that you do the heartworm preventative or flea control several days apart. If your Yorkie or Maltese puppy had an adverse reaction, how would you know what caused it? The 6-month heartworm shot had many problems associated with dogs, it was finally recalled. We want your Yorkie or Maltese dog to live a long long time and be very healthy.