terrier as assistance dogs

Question
When I lived in SE Asia as a child I had a wonderful dog who was either a toy fox terrier or a rat terrier. She had all the characteristics I'd love to have when/if I can have a dog again.
Now I am disabled (not in wheelchair). Particularly, I have great difficulty in picking up dropped objects like keys,etc. I am also only interested in a breed that I know I can care for properly.
Are these breeds ever used for assistance dogs? therapy dogs? Any other comments?
I live in a climate w/ hot summers and mild winters.

Answer
HI MARK
TRUTHFULLY I HAVE NEVER SEEN ANY USED NOR HEARD OF ANY OF THEM FOR USEFUL DOGS.  MOST LIKELY BECAUSE THE TERRIER GROUPS TEND TO BE SO HIPER AND TOO MUCH ENERGY AND HAVE THEIR OWN TRAINING TECHNIQUES SUCH AS THE JR'S LOVE TO TUNNEL, ETC.
MOST OF YOUR MEDIUM SIZED DOGS ARE USED FOR UTILITY, BLIND, SEIZURES, NARCOTICS, K-9 WORK, ETC.  MOSTLY BECAUSE OF THE LINES WE CAN GET OF THE WORKING ABILITIES IN THEM.  NOT ALL OF DOBES, LABS, RETREIVERS, SHEPHERDS AND ROTTWEILERS HAVE GOOD WORKING LINES TO DO THINGS USEFUL.  TOO MUCH DRIVE CAN DESTROY THE ABILITY TO TRAIN THEM, BUT THEY DO NOT REQUIRE AS MUCH DAILY EXERCISE AS THE TERRIER GROUPS.  I KNOW I HAVE OWNED THEM AND NOW RAISE WEST GERMAN SHEPHERDS, MOST OF THEM ARE IN SEARCH N RESCUE, K-9 AND NARCOTIC WORK, SOME ARE DOING AGILITY, FLY BALL AND OBEDIENCE OF COURSE.
I AM NOT SAYING THAT MAYBE ONE OF TEN MIGHT MAKE A USEDFUL TERRIER FOR YOU TO DO THINGS.  I JUST DO NOT KNOW WHAT LINES U WOULD NEED TO LOOK FOR AS IT IS ALL IN GHE GENES TO WORK, GOOD TEMPERMENTS, ETC.  A GOOD BREEDER OF THESE WOULD BETTER GUIDE YOU AND ALSO LIE TO YOU TO SELL, MOST BREEDERS IS ALL ABOUT MONEY, SO BE CAREFUL IN DOING YOUR SHOPPING IF YOU MIGHT BUY ONE SOME DAY.

WARM REGARDS
PATT
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