Have you tried giving them a thorough wash ? - they may have had some unpleasant tasting chemicals on them (eg mold releasing agents).
Alternatively your dogs may be smart enough to know they'll get in trouble for playing with any of your MTs

Thanks for the tip, it partially worked. The dogs are still a little indifferent to the toys.
Champ my dog is here watching Holly my wife's Yorkie steal the toy. He does not care and she does not steal it. Champ did carry the toy to his bed from the house after it got washed.


Here is a picture of Timmy my daughter's Yorkie, at least he chewed one for a couple of minutes.

Tomorrow I think I will try smearing them with Bacon!
Bruce