MY 4-5 MONTHOLD BEARDIE SPIKE IS WALKING FUNNY. HE IS FAVORING HIS BACK LEFT LEG. HE IS STILL EATING GOOD AND EVERYTHING BUT FOR SOME REASON HE IS NOT WALKING. WHAT DO I DO? IS HE SICK, HOW COULD HE HAVE HURT HIS LEG, OR SHOULD I TAKE HIM TO A VET. PLEASE HELP. I HAVE ONLY HAD HIM FOR ABOUT 2...