Hi. My 9 year old Jack Russell Chihuahua has been acting strange lately, however it is not constant. It started a few weeks ago, he would walk very slowly, refuse to lift his head and be reluctant to listen if you call him. If he is up on a high-ish place like a sofa, he will refuse to jump up or down on his own accord, and sometimes yelps if picked up and put down. That first time, he returned to normal after 2 hours or so, and was back to being healthy for the next coming weeks. But yesterday morning he began to do the same, he would just lie down and want to be undisturbed, shiver, make slight whimpering noises and be reluctant to move or follow anybody. After a few hours of lying down, he returned to normal. Again the next day, the same problem, and it subsided after a few hours. I don't know if it's relevant but, after urinating his condition seems to improve. I'm worried, but I have no idea how much a trip to the vet would run us, or if they could even find anything wrong. Thank you.