After you wash as much of the permethrin containing product as possible off of Sinclair, it is important that you watch him closely for the following signs and **rush him to a veterinarian immediately if any of them develop** for aggressive treatment and supportive care:
Loss of appetite, vomiting, diarrhea
, drooling, dilated and/or fixed pupils, facial twitching, skin twitching, ear
flicking, paw shaking, disorientation, hyperactivity, staggering/incoordination/problems moving or walking, tremors, seizures, unresponsiveness, difficulty breathing
**Please note that while in most cases signs develop within the first few hours, it is possible for signs to develop as late as 72 hours later, so monitor Sinclair closely for the next few days**
Lastly, if Sinclair ingested any of this toxic (either directly or through grooming) he should be rushed to a veterinarian immediately so they can remove as much as possible from his GI tract and monitor and treat symptoms which are very likely in that scenario.
Again, this class of compounds is HIGHLY toxic to cats so prompt removal of as much as possible and aggressive treatment by a vet if he shows any signs are imperative for his survival.
Please let me know how Sinclair does- I hope all turns out ok. Please feel free to respond with additional questions and once you are satisfied with my answer please don't forget to rate me so I receive credit for my time.
All the best to you and Sinclair,