Thank you for your enquiry on such matter.
Fipronil, which is the active ingredients of the product you used to your cat ,may be associated with some unwanted reactions such as skin issues with or without pruritus (intense itching or hair loss). It does not imply however, that the product causes such reactions at all times, but its occurence is minimal and possible.
In relation to skin and coat supplements, high contents of omega fatty acids such those from fish oils or flaxseed oils may help regain and foster skin and coat health. There are available products containing such ingredients which are intended for pets.
In addition, we suggest further to refer to your veterinarian, regarding the occurence of such reactions from your cat for proper assessment and appropriate clinical treatment steps. This referral is important in order for your attending vet to be aware of the reactions, so alternative medications may be prescribed.
For other related information, please visit and talk to our Pet Care Consultants in all our PLC Outlets.
With Best regard,
Eliezer M. Bauzon, DVM RN