Additives used in the production of vaccines may include. 1  suspending fluid (e.g. sterile water, saline, or fluids containing protein); 2  preservatives and stabilizers to help the vaccine remain unchanged (e.g. albumin, phenols, and glycine); and. 3  adjuvants or enhancers to help the vaccine to be more effective.
The other element is a standard Yorkie that falls under or over the expected weight and/or size range. Breed standards have changed. The AKC used to list a minimum weight of 4 pounds (1.81 kg). Now, there is only a maximum weight of 7 pounds (3.17 kg) for a full grown, adult Yorkie. Even with this change on paper, most Yorkshire Terriers fit into the 3 to 7 lb. (1.36 kg to 3.17 kg) range. A dog smaller than this, fully grown, would be considered too small and may have size related health issues.
When the adult size of the teacup yorkie is very important remember, that the older the puppy is, the more accurate the estimated weight of the adult teacup yorkie will be. From a bone structure point of view a teacup yorkie is usually full grown at 6 - 9 months of age.