First of all, I need to tell you that if you are going to take this cat in and care for him properly, it is going to cost a good deal of $$$$.
I would go to who you think owns him, explain what all is wrong with him and what will need to be done to fix it, and that you are willing to pay for it if they are willing to surrender the cat to you - if that's the case. The heart murmur at this point is of concern to me. I have a kitty with heart disease, and she can't have vaccines nor her teeth pulled. I would have an echo done to determine the cause of the heart murmur. This will be $280+. It could be benign or it could indicate heart disease. If he has heart disease he shouldn't have vaccines or his teeth pulled due to the risks of anasthesia, however the health benefits of being neutered might outweigh the risks of being under anasthesia. If he is able to be vaccinated, I'd wait until the series was done, then mix, but that's obviously a personal decision. Outside he is at risk of being run over by a car, eaten by a wild animal, God forbid taken by an animal hater and killed, drinking antifreeze and dying, being shot, etc etc. All worse than FELV IMHO. Kelley -- Rescuties - Saving the world, one cat at a time. http://www.rescuties.org Vist the Rescuties store and save a kitty life! http://astore.amazon.com/rescuties-20 Please help George! http://rescuties.chipin.com/george I GoodSearch for Rescuties. Raise money for your favorite charity or school just by searching the Internet with GoodSearch - www.goodsearch.com - powered by Yahoo!

