Sophie was 4 months on the 13th. Three weeks ago when I put her Flea drops on her neck her coat was so think I could hardly find her skin. Today, when I put it on her coat seems thinner, and I notice the backs of her thighs the hair looks thin....could she be shedding her puppy coat?
If she's shedding her puppy coat, you should notice a difference in the look of her coat. Puppy coat is fuzzier and may be a slightly different color than adult coat, which appears shinier.
When pups grow up, their puppy coat becomes their undercoat and they get the longer stiff guard hairs over that coat. They should not be shedding their puppy coat BEFORE they've even gotten their adult coat in....unless you've had some excessively hot weather.