Ask a Dog Vet and Get Answers to Your Dog Health Questions
I hope you can see my answer; it looks like there is some technical difficulty?
Now it looks like my whole answer just went away!!
Whimpering and shaking can mean that he is hurting somewhere.
Dogs can get sudden onset of back pain, without any known injury or fall. Is he moving around normally? Or is he reluctant to go up or down stairs?
If he is eating, he is probably not constipated, but he may not be defecating because it hurts. Checking his anal glands might be a good idea; these are glands inside the rectum that can become swollen or infected, and cause him not to want to pass stool, and to whimper and shake.
The best thing would be to have him checked out by your veterinarian. Until then, you could try giving him baby or low dose aspirin: 1 for every 15 to 20 pounds of body weight, with food. If he vomits, do not give any more aspirin. Do not give any other medication for people other than baby aspirin.
If that helps, then he is hurting somewhere.
I would also try to take his rectal temperature; normal is between 101 and 102. If he is over 103, he may have a fever causing him to whimper and shake.
I hope you are seeing my answer! Is there anything else I can help with or answer? How is he doing?