I live in St. Louis, MO, and have 2 Pyrs. They are inside dogs and I have them shaved regularly. Usually, you can see the spots on the skin for the first couple of weeks and after a month they are 1" long. They both grew back such full coats last fall that I couldn't keep up with the brushing. One Pyr has a heart condition and her canine cardiologist said she would be much more comfortable shaved. They are so much cooler and more comfortable, even in the house, with no panting. It may be startling to see, but they really appreciate it.
Despair not!
Darla and The Gang