My dog has recently started to lose hair on his face. First it was the begining area of his eyebrows, now it's spread to his nose. At first I thought it was a scratch that an outdoor cat had given him (happened once before) or that he scratched himself on some tools left over from the construction workers in the backyard (since construction has recently stalled due to some disputes), but the vet said it was allergies. Again, I thought it might be an allergic reaction to the tools outside so I've been letting him out in the front where no tools/chemicals are to avoid exposure but his hair still seems to be falling out. I don't see how it can be an allergic reaction since we've been in the house since early June with the tools in the backyard and no hair has fallen out since reacently and it's at a pretty fast pace (just now his nose area that's thinning had some white stuff on it that looked almost like dandruff or dry skin which I've never seen him have). He's nine years old and has never had such a strange reaction before so I don't see why suddenly it would happen unless it's a parasite. Is it just me or could he have scabbies? How does one test for that? Is there something that tests for all parasites? Any help or info would greatly be appreciated.