[Sled dog hotel]

Never have noticed any problem with mine after spaying and neutering and not particularly heard of it, although in some breeds spaying and neutering can seem to cause changes to the coat itself.

There is demodex mites, that live in the hair follicles that can cause localised patches of baldness and they are not usually itchy.

What breed is he? Have you looked up health problems in the breed to see if there is any breed related problems causing hair loss.

 

[Sled dog hotel]

He is a Chihuahua x mini Dachshund and they dont generally have problems (except alopecia in blues, but he's ginger!).
I did think of mites but the timing is 2 weeks after his neutering op and hair loss does happen apparently, although it is rare. It seemed more likely that the change in hormone levels had affected his hair growth.

A lot of dogs have demodex mites, but a healthy immune system keeps them down in small numbers so you don't get problems or symptoms. If the immune system is below par as in illness, stress, or maybe even going through the stress of the operation then the mites can multiply so it may be possible.

I thought I had read about certain skin problems in the daxie to do with hairloss, so I had a quick look and apparently in the Mini wirehaired and smooth there is Pattern baldness,, ear pinnae alopecia, Malessesia dermatitis.
Causes and modes of inheritance though I didn't go into.

The only skin problems having a quick look in chis seems to be atophy sensitivity to pollens, and other protein particles but that mentioned causing intense itching.