poor Calloway! Keegan can sure sympathasize with him. She is almost 7 and never had one before either and starting Tues/Wed she has had them pop up about 6 of them. We went to the vet and the vet said that he had lost count of how many dogs he had seen since Thursday with them - everyone one of the had to be shaved and said 80% of them are golden retrievers. She has large shaved spots on her side and head now.
I think could be bug bite or something that they just keep itching and itching and then it manifests. That's what her's did. The large one on her side was infected and oozing by the time we got to the vet. Course this all pertains to dogs - cats - not for sure.
Compresses would help it open up - my greyhound had an abscessed anal gland before she died and I had to keep a hot compress on it to get it to open up and get the infection out.
The vet had to shave Keegan's hot spots b/c they want them to stay dry and heal up.
This is just her head -

And here is a pic I took with my phone on Saturday.


Good luck Calloway!