Marley's Heart worm treatment

Marley shouldn't be here.  There was no reason for him to catch our eye and no reason to pull a heartworm positive dog who was breaking down in the shelter and might not be fit for adoption.  But he did catch our eye and in doing so captured our hearts.  He is a sweet, loving dog who is full of life and has nothing but love to give.  
Marley's foster dad is a first time foster and after meeting Marley we know why fate intervened.  He needed Marley as much as Marley needed him.  They are best buds and constant companions.  
Marley's heart needs a bit of help in fighting those nasty worms.
 Our boy is on a slow-kill regimen for his heart worms which will span several months and we sure could use a hand. Please, if you've been following along with Marley's story and you have a couple of dollars to spare, we would certainly appreciate it.