Reason 3 -
While rare, BSD
(short for Black Skin Disease) is a medical issue that causes drastic changes to the coat. There is hair loss, often uneven over the whole body. With many Pomeranians that have this, there are signs before any thinning occurs...the coat does not look quite right. Fortunately, this is not painful at all. Unfortunately, there is not yet a cure. This can develop at any age, however the most typical time is at the 2 year mark. If your Pom has short hair, please do not automatically assume that it is due to this issue... Most commonly it will be due to age as explained above.
Reason 4 - Genetics. It may be in the genes. In some cases, a pup or dog may not be a purebred Pomeranian. If there is a mix somewhere in the bloodline, even a few generations back, it can affect appearance. For this reason, it is recommended to only obtain a pup from an AKC breeder who is established and reputable.
In many parts of the country, puppy mills are being wiped out...That is a good thing. However, we have noticed that pet stores (that people once shunned away from) are now popping up again in some areas....Many claim to only do business with small home breeders. While this may be the case, if you cannot see the parents (dam and sire) and you cannot see the living conditions and environment that existed from birth to 8-weeks-old, proceed with caution.
Another possible gene issue is that the dog in question may indeed be a purebred, however one must be aware that not all Poms are going to fit the standard. A caring, responsible and serious breeder will breed "for the betterment of the breed", with the goal to produce litters that met the standards set by the AKC.
With this said, there are people who give this zero regard, producing litters with faulty coats and other problematic elements. Those who do follow the expectations of excellent practices will still occasionally have an "odd-ball" pup.