First of all, I am sorry your dog died.
Regarding causation, several points come to mind:
1. How could he lick Termidor off his back?;
2. I have used Termidor for 6 years, on a dozens and dozens of dogs, and have never had one single animal get sick;
3. Countless other people have used Termidor also, with zero ill effect;
4. Your other dogs did not get sick;
5. I do not think fipronil is a fatal poison, even if ingested;
6. That said, severe individual reactions do happen, for which there is no way for anyone to know "in advance" it might happen (e.g., simple penicillin can kill a dog IF that dog's particular make-up can't handle it, and there is simply no way to know this in advance of giving the shot);
7. Your dog probably died from something else, but he may well have had an anaphylactic reaction, again that no one on earth could predict.
Regardless, I am sorry your dog died.
Jack
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