Dealing me too with a problem right now with my roommate (cat). Already using Animal Regeneration and Mental Health for Animals. Will re-add Devic too, thanks for reminding it.
I suspect that the last pack of food that I bought was a fake one. Counterfeit is a big hobby in my country.
Found a post written by Lunamoon regarding mosquitos. So your servitors can maybe help for fleas and bugs too.