Shaking and teeth chatter

Question
I have a 9 yr old neutered "shorty" named Calvin. His teeth chatter at various times of the day.  Then there are times when his whole body just shakes.  When standing sometimes his back legs will shake.  Could this be something serious? I also have a 6 yr old neutered "Parson" named Buster.  His body is white with black on his face and rump.  He recently started scratching and his eyes were red.  The vet told me he has allergies - So just a reminder to everyone - when you dog comes in from outside, wipe them down with a damp towel to remove the pollen. I enjoy reading your column,  Thank you for your help with my shorty.  Rita  

Answer
Hi Rita,

You didn't mention if this shaking was something new or if he has always been that way. Shaking is definitely common in Jack Russells, but if this is a new development, you should take him to the vet to be examined to rule out sickness. I love that name Calvin, very cute.
Unfortunately Jack Russells are HIGHLY allergic dogs too - and you're smart to wipe him down when he comes inside! Good luck with your jacks!