bare with me a sec
Okay. A few comments. I am a little suspicious for the heartworm issue causing all of these symptoms as well.
With a really low platelet count, I would also be strongly considering an autoimmune thrombocytopenia.
Autoimmune conditions are when the body attacks itself.
This can happen with only the platelets resulting in a thrombocytopenia, as your pet has. Sometimes, it only happens with the red blood cells, and that is called a autoimmune hemolytic anemia.
Now, the collapsing episode would NOT be connected to his low platelet count.
That, in fact, probably could be induced by a dying heartworm.
I like the plan to do the initial slow kill program. The only thing of question may be the prednisone dose. Ask your vet about "autoimmune thrombocytopenia". If they think it is possible, they may suggest doing a higher dose of prednisone initially.
Again, sorry for delay. As you can see, I was typing to you, and it wasn't going through.
Thank you for using JustAnswer. I also greatly appreciate positive feedback, after you click accept, if you have found the advice helpful or informative. JustAnswer will only credit my time, if you click accept. Thanks. Dr. Andy
If I can be of any further assistance, just let me know.