I have 2 Cavalier KC Spaniels,and the youngest one aged 2 has  what I would call a sweaty socks smell off her. It seems to  be round her mouth and face and if she licks us we can smell it off her saliva. She is also prone to frantic scratching  behind her ears usually at night.  they have both had their anal glands emptied 2 weeks ago at the vets but she is still scooting even though hardly anything came out.I did mention the smell  to the vet but he just said some dogs smell stronger than others.I have been putting some  oat bran in their feeds as advised by the vet to help the anal gland problem,but again it seems to be having the opposite effect.I know these are 2 different conditions,but my daughter thought they might be linked.

Have you checked the lip folds - about half way along from front to corner of the mouth?

That's a key place for getting moist and smelly - very much like the smelly foot smell ;-)  Sometimes it can get infected and look quite sore too.

My friend's old Cocker used to get it.

After many visits to  the vet, she found the best cure was to clean with salt water, then put a slick of Johnson's Tea Tree cream for dogs in the fold.  This acts as a barrier and stops infection, and also bacteria/ viruses are dealt with by the Tea Tree :-)

Its caused by kinked tear ducts which cause spillage of tears.....this then gets infected with red yeast.
Buy a product called Kleen Face and wipe down and away from the corner of tge eyes and outer lip folds ( this will come away red stained) ...at least twice a day.

Entirely unrelated I'm sure but I'm a little concerned with the " frantic scratching" and would certainly have that investigated.

>I have been putting some  oat bran in their feeds as advised by the vet

I was advised the same with a bitch that had an anal gland problem.

It triggered a severe reaction, the dog turned out to be allergic to oats and bran.

thank you to everyone who replied. I will clean her mouth as well as her eyes now. I do their eyes every morning and  keep them  clear throughout the day. She has also been scooting a lot  despite the oat bran  I have  been adding to her feeds,and as I said only  seems to scratch at her ears at night I have checked them and they are clean so cant see why she is scratching. they were at the groomers 3 weeks ago and their coats are short now,so no sign of fleas or anything untoward. I am going to go back to the vet this week ,and see what they say. they have both been on JWB dry food  with a spoonful of their wet food on top,and  they have never had any side effects.Actually my daughter said  that it was probably because Ailsa has a small snout,and  her tear ducts are prob not draining away properly.  Will see what the vets says Thanks again