Accepted Answer

Hi,
I would be concerned about either gastroenteritis (where he ate something that didn't agree with him) or an obstruction (even old labs will swallow the occasional sock, toy, etc).

The straining could be either caused by diarrhea or constipation (has he gotten into any chicken bones?), the lethargy because he doesn't feel well, and the panting because he is painful.

Because he is an older dog (and more prone to kidney failure or other organ problems) and hasn't eaten for 2 days, I would have him seen by your vet yet today, if you can. I would anticipate an x-ray being taken to look for an obstructions, and a stool sample obtained to see if there is diarrhea or if the stool is very hard. Bloodwork should also be recommended because of his age and possibility of other problems that might be contributing (especially if he is constipated).

Good luck!

Expert:	vetlori
Pos. Feedback:	100.0 %
Accepts:
Answered:	11/2/2009

Dog Veterinarian

I am a practicing small animal veterinarian with 13 years experience.