[hotpotato]

Westies are good dogs, gotta watch out for deafness though,

I think you have that confused with another breed. It's not a common ailment for westies.

the breed was naturally dark, but they bred the white into it, and sometimes (as in bull terriers or dalmations) deafness is a side effect.

The darker variety you refer to is the Cairn terrier. Occasionally, they whelped white puppies which originally were destroyed. Eventually, an advantage was seen to keeping the white offspring (less likely to be confused with the prey they were hunting and getting shot) and the whites were bred to whites. That's where westies came into being. I have no idea where you got the idea about the deafness. It's simply not the case.

I just worry that with their rising popularity there will be a rise in bad breeders.

There are bad breeders for all variety of breeds and even those that breed hybrids. Lot of puppy mills out there. Avoid them. Look for a good breeder. They are not difficult to find.

[Central Scrutiniser]

The westie is a breed that has a higher rate of cogenital deafness than other breeds. But its not as bad as dalmations or bull terriers. Its a genetic trait for white coated dogs. That's why I wince when I see good breeds like the westie in a sleazy pet store in the front window. The Irish Terrier group used to buy the dogs whenever they saw one at a pet store from bad breeders and spay or neuter it so that it couldn't pass on the genes.