A few weeks ago, we detected heartworm disease in a cat and a dog in the same week.  Unfortunately, there is not cure for heartworm disease in cats, there is only a preventative medication that is administered at home once per month.  There is a treatment for heartworms in dogs however the medication contains arsenic and is extremely painful to the poor dog while it is killing the adult heartworms.  It is also expensive!  Heartworm prevention costs as little as $3.50 per month plus the cost of the heartworm test once yearly of $30.00, so your cost is very little, less than a Starbucks Latte!  Heartworms are carried by mosquitos and can be fatal if not treated.