Dog out of breath and weak

Question
My schitzu is about 12 years old and is breathing heavily, is very weak and not eating.  I do not want to put him to sleep, and I want to try to help him regain his strength.  A vet charged me $160 today to check him out and suggested more tests for about $500 but added that the dog would not live through the night because he has heart failure. Why do tests if the result leads to nothing? He suggested putting him to sleep.

Answer
Hi there!  I have a little shih tzu too.  They are such a wonderful breed, and I'm sure you must love your little guy to pieces.
It sounds as though your baby has congestive heart failure.  I will explain this disease.  The pulminary sacs around the heart begin to fill with fluid.  The sacs put much pressure on the heart and lungs.  The pressure causes the heart beat to become irregular, and the lungs unable to fill to their full capacity when breathing, hence the labored breathing your baby is experiencing.  As the fluid in these pulminary sacs increases, the heart will end up failing, as the pressure of the fluid has become too much and has weakened the muscles within and around the heart.  
There is no cure for congestive heart failure...but there IS treatment.  The one thing that is causing the biggest problem here is the fluid in the pulminary sacs.  So, what we need to do, is dry that fluid up.  There is a medication called Lasix.  Lasix can be given orally or through injection.  Because of the severity of the condition your dog is in, IV fluids and IV injections of Lasix for a period of 48 hours should improve his condition.
I am unsure of what your financial situation is, as I know how expensive veterinary visits and treatments are, but getting your dog to an ER vet tonight would be best and most beneficial.  They will hook him up to IV fluids and give him the Lasix injections while keeping him on oxygen for a few hours to help his breathing improve.  The sooner this treatment is in effect, the better the prognosis is.  Although there is no cure for this disease, with treatment, animals can live years with this ailment.  Once your dog comes home, he will need the oral lasix medication every day for the rest of his life to control the fluid production.  Lasix is not an expensive medication and may go under different names depending on vendor.
I'm so sorry the veterinarian you saw today did not give you and your dog the help that you both deserve.  I truly hope your baby improves and lives many more happy years with you.  If you have time, please keep me posted.
My heart goes out to you and your baby with the situation that has been dropped upon you.  Please know my thoughts are with you and I wish only the best for you and yours.
Hilary