Help give these rescues a second chance at life!!

Hi my name is Ashley and I just recently found out that 3 of my rescue dogs and one foster pup have heart worm which they have had for quite some time probably before I received them. These four pups (Whitey, Maggie,Big Mac and Sammy) mean the world to me and my four year son and have become family to us. Unfortunately I'm a single mother and it'll cost $600 EACH in which I just cannot afford at the moment so even if I do not get the full amount any amount would help me as I am not going to give up on my four babies and let them down as they have been let down in the past. Every penny will be going to their treatment and aftercare. I want all four of them to have a fair chance at beating this and getting on a preventative pill afterwards so they never have to go through this again. Unfortunately time is of the essence and the sooner they get going the better chance they have. Any amount is greatly appreciated. If you cannot donate then prayers are also appreciated by everyone! Thank you and God bless.