I'm asking this on behalf of a fellow dog-owner who hasn't a computer.

She has an 8-year-old shih-tzu x pug which has suffered from skin irritation since 3 years old, starting with his feet and now affecting his face and belly.  He has been on anti-biotics and is now on steroids.  The owner was very distressed this morning as someone (not sure if vet or not) had suggested he should be put to sleep.  The dog, while seemingly happy enough in himself, presents as a very old dog - walks slowly, no energy or "spark".

I was just wondering if anyone had any ideas which might be helpful (stupid of me to get involved, I know, but the lady was so upset ...).  Thank you.

I would be looking at his food.   It's surprising how what we and they eat can affect health.

Were it my dog, I'd be doing an elimination diet and only adding things back in once the dog was stable.   This can take months/years.    There is also allergy testing which the vet can do, and I'm assuming skin scrapings have already been done to eliminate the obvious mites etc?

Tell your friend to hang
in there...there is an answer,she just has to be determined to find the cause.She may want to have his thyroid tested too...I've just done this,cost me 70 euro,and my dog was hypothyroid. .....the fact here dog is lethargic and also has skin problems  at least merits a test to eliminate this condition.
I hope it is the case,as the dog does a fast turnaround once its hormones are back on track.
Also I had an elisa blood test ran ,this told me my dog was intolerant to potato and also beet root. the thing was the food she was eating ,for sensitive dogs,contained both those ingredients....things certainly improved after a change of diet.

We also had skin punch biopsies done ..which told us the problem was a deep seated bacterium..in our case proteus.

Another  thought was to keep him in a very short clip and give a weekly  shampoo with an anti bacterial shampoo one week,then an anti fungal the next..does he have any scabs ,bumps etc on the skin? has the vet done a skin scrape to see if the cause is fungal,mites etc?

Dill, Thank you very much, I'll pass your suggestions on to the owner.

Bellamia, Thank you for your posts, plenty to consider.  I will pass the suggestions on to the owner.  Especially regarding the thyroid, as one of my own dogs has just had a blood test for hypothyroid (vet appointment on Monday for results), as she may be able to take some comfort from that.
The dog is kept clipped (short pet-clip), but I don't know if he has a bathing routine.

Just a thought I suppose the vet has done a scrape for dermedetic mite (sorry spelling probably wrong)

Very many thanks to all who have offered suggestions for this little chap.  I have passed them on to his owner, and hope that somewhere in there is the solution.  He has a vet appointment tomorrow, so I have emphasised that the vet can carry out tests.  His owner is very grateful for your kindness in offering all the helpful ideas. :)

Just to complicate things, it seems that this dog came from rescue at 3 years old already on medication for these skin problems, so has never been insurable.  I would like to have a major rant at this point about a rescue which would home a dog like this, but (you'll be glad to know) words, polite or rude, utterly fail me.