Shaking Jack Russell

by David
(Milford, Ohio)

My Jack Russell Terrier, a 7 year old male, occasionally has spells where he lays and shakes intermittently, and he won't eat (even his treats), and when I take him outside he "grazes" on grass. It seems his stomach might be upset. I gave him an Interceptor worm pill today, and yesterday he did eat some yogurt, which seemed to make him feel better, but he will not eat it today. Any suggestions or advice?