Bald armpits - cause for concern?

The skin in my dogs' "armpits" - front legs - is bald and sometimes develops scabby bits. I treat the skin problem but they remains hairless there. They are Dalmatians so very short coated anyway.
Is this normal? I don't think Polly had this condition so I was wondering whether (a) it was something to be concerned about and (b) the best way to deal with it.

I thought all dogs had hairless pits??

Most of the dogs I've known have had very thin armpit hair, but not totally bald. Are the scabby bits caused by chafing? If so, you could probably prevent it with a dusting of talc without having to resort to anything else.

The first I knew about damage to the skin was when I found a large area of yukky scabby messy broken skin in the area. I put it down to Deccy getting silly on his walks where he would tangle himself up in the extending lead, which is nylon tape. However, Polo has it on one side and he never gets tangled, being relatively sensible, and they only go out on extending leads once a week sometimes less as they are loose most of the time.

are they walked on harnesses ? Bruno used to get this from his old harness - since switching he still has slightly balder armpiuts but doesnt have any scabs

Lupi harnesses are a common cause [ hate those ], but a normal harness should`nt do it at all, the body strap should be well back from the pits - if your does`nt adjust that way you can get harnesses which have an adjustment under the chest for that - I have a couple for my Lurcher as he is so long-bodied

Teagan is totally hairless under her pits!

no this was a normal canic harness or whatever they are called - but its cos bruno has such a deep chest that the harness on him is a completely different position than on most other dogs - he now has a walkezee which doesnt go under his legs at all so much better.

But yes Lupi's are terrible for it - cos they are so thin - no wonder they burn !!

also think it didnt help that bruno would pull like a train on his harness so it would rub even more !!!

One of my crew did have bald scabby pits very recently, turned out [ or as near as can be pinpointed between me and the vet ] that it was an allergic reaction to some new supplements I gave him which it turned out contain fish but didnt say so on the pack - he can`t have fish at all because of allergy

Might well be worth considering a food allergy in yours as well ?

At the same time as my boy, someone else I know had the same thing with her dog but no easily pinpointable cause in his case.

Treatment was the same for both though, near enough, protective gel to help healing, a steroid shot to stop itching from inside and from the scabbing, a course of antibiotics for the skin itself and in case it was infection related to be on the safe side, and we put T-shirts on them for a few days to stop them licking [ the licking was more the cause of the baldness and redness than whatever the original causes were ]. The t-shirts really did the trick to finally break the itch / lick cycle.

Any of that potentially relevent ?

Possibly.... although their food has changed since the condition was noticed, not before, so still a mystery He is getting supplements but only in the last week and this was first seen back in August.
As for using harnesses - they are loose 99% of the time and on collars/extending leads occasionally as I said earlier. The only thing that may have been in contact is the nylon tape of the extending lead if they tangle themselves and run off before I can free it.
I looked at Deccy's patch of yukkiness last night, it had scabbed up a bit in streaks like he had been clawed, and the surface was sticky. I find even when there is no break to the skin, he is sticky there - maybe he's just a sweaty dog (although I thought sweat went out via the feet pads).
I'll treat it with a suitable cream for now.