I gave my cat flea drops and now he has leg spasms? Any connection there?

I decided to try some flea/tick drops to prevent infestation and dripped it on the back of my cat’s neck as directed. The next morning I noticed the area turned pink with a small red spot. Now, when he gets up from a sitting position his hind legs seem to spasm, either that or he just shakes them. This never happened before the drops. Is there any connection to the drops and nerve/muscle damage? Is this serious?

Hi Kent…this isn’t uncommon especially with over the counter spot-on flea infestation topicals such as Hartz, Sentry and similar products which are not prescribed by a veterinarian. The products contain "pyrethrin’s" which have been considered lethal in pet animals. Side effects have been paralyzation, seisures to even death.

Please consider reading the following: http://www.hartzvictims.org/modules.php?name=News&file=article&sid=49