I have a Westie that does this too. I just think it is a part of the digging behavior an deeply ingrained. He doesn't actually swallow the dirt but does rip it out with his teeth and spit it out.
My vet jokes that 'mud' is the reason his teeth are alwasy so clean!
I don't know how to stop it. Some folks suggested I get a sandbox and bait it with toys so he could get used to digging in it instead of the dirt. Haven't tried it.
__________________  Mommy to Lucy, Ringo, and Matthew |