Re: I need quick advice re: stray kitten--UPDATE at bottom
I'm sorry to hear this Cindy. I wonder if my post is too late to be helpful.
Is the fluid in the chest? Or she wasn't sure if there was fluid at all? Is the kitten still breathing abnormally? If the cat is dehydrated, that might be why she's constipated. The last foundling I had was backed up quite a bit, and that can happen to cats who are outside and lack clean water to drink. Regarding the heart murmur, loud murmurs (have the vet tell you the "grade" -- I'm thinking more than 3 on a scale of 6) are usually associated with bad disease. There are exceptions to this, but in a very young kitten I'm thinking of congential (born-with) disease. She'll need to see a cardiologist, no question. Do you want to email me the radiographs tonight or tomorrow morning, if they are digital, if it will help? I will send you my work email addy.
I can't tell you that she's a sure goner, but I can tell you that if her heart murmur is severe, her heart is already enlarged, and her breathing is labored, the chances are very high that she has congenital heart disease and that it is going to significantly shorten her lifespan. For sure she'll need a cardiologist and perhaps medication. There is about zero chance that any well-informed rescue group will agree to undertake this expense and effort in a kitten with no prospects of a future home. It's very sad and I hope I'm not being too blunt.
Having trouble breathing is a form of suffering. For sure, I think that in cats who are in heart failure and can be treated, the suffering can be withstood while the cat is stabilized, but in a kitten who was dealt a bad hand (heart?) from the getgo, you may be looking at a suffering without a meaningful recovery. It is NOT wrong to euthanize a kitty whose body is not supporting normal life, esp if there is no hope of a cure. (There are no surgical cardiac interventions for cats right now.) You can let her go, and wish her godspeed back here, if she wishes, in a body that will let her play and eat and be as happy as she deserves.
PS I agree, have the vet listen to the other one's chest for a heart murmur.