death of a pekingese

My 13 year old peke died on july 2 2009, he was very active up untill he puntcured his eye in the lawn, my mom brought him into the vet who wanted to put him to sleep, he had some fleas on him but was taking capstar. he went without flea meds for 2 weeks. He was on enaparil for his heart and had tested heartworm positive. The temp was very hot that week upwards of 90-100 degrees which didnt help either when he went out to pee. I found him 8 years ago someone had dumped him in the street. Could he go from active and okay to dead in two days. what the heck happened??????????????? Needless to say i am crushed by his death, any info would help    thanks

[Jim Humphries, B.S., D.V.M.]

We are all sorry for your loss.  It is very hard to lose a pet especially after 13 years.

ANY guess as to a cause would be pure speculation, and we cannot do that here.  I will say that heat stroke is seen this time of year, heart attacks can be caused by heartworms and age was not in his favor.  

If you get another dog, be sure it is on heartworm prevention early!!! and I would choose another method of flea control (like Frontline or Advantage).    Just my opinion.