How old is she and what problems is she having rght now? Did he say why he advised against it? Did he do any xrays or lab work? Towards the end the dog will fill up with fluid. The belly gets very large with fluid retention, the dog may urinate blood and may even vomit blood. If it gets to this point then you are definatly at the point to make a decision to not let your friend suffer any more.

she is about 15 years old, she has lost a lot of weight, but still appears happy--i.e. meets us at the gate or back door, follows us around at a trot (she hasn't been running for a few years), with her tail wagging and barking, she still goes to her food and eats and rubs against us to be petted. i didn't take her to the vet, so i don't know what they did, but i was told he said she was so old that treatment wouldn't make sense. i guess what i need to know is, would you expect to see increased lethargy, decreased appetite or anything like that before it got to a point as you described above?

OK 15 is a senior and I can understand why they elected not to treat her. Yes, she should have increased lethergy, decreased appetite-just feeling really poor before the final stages. If she is eating, drinking happy and not filling up with fluid or urinating blood or having difficulty breathing then by all means let her live her life with the family she loves a little longer. You'll know when it is time. Just do the humane thing when the time comes and help your friend to th Rainbow Bridge. She'll thank you for it. If you have found my answers helpful please remember to accept it. Good luck and it will be hard but at least you are prepared to do the right thing.

one last question...is there any chance of my indoor cats catching it? (dog is outdoor, but obviously we do have to go in and out and mosquitos occasionally get in) If so, is there a preventative treatment for cats?

Your cats cannot catch it from your dog. They can get heartworms just like the dog can- from infected mosquitos. Heartguard does make a heartworm preventative for cats. I would ask my vet how likely it is that your cats would get infected since they are inside. It depends on where you live. In SC we do see some cats with heartworms but not a lot. That could be because people don't think about it as much in cats and they are not routenly tested like dogs also. Unfortunity the ones we have seen was after the fact and the owners had us do a necropsy (autopsy).