Cats
Permethrin is toxic to cats; however, it has little effect on dogs. Pesticide-grade permethrin is toxic to cats. Many cats die after being given flea treatments intended for dogs, or by contact with dogs having recently been treated with permethrin. In cats it may induce hyperexcitability, tremors, seizures, and death.Toxic exposure of permethrin can cause several symptoms, including convulsion, hyperaesthesia, hyperthermia, hypersalivation, and loss of balance and coordination. Exposure to pyrethroid-derived drugs such as permethrin requires treatment by a veterinarian, otherwise the poisoning is often fatal. This intolerance is due to a defect in glucuronosyltransferase, a common detoxification enzyme in other mammals, that also makes the cat intolerant to paracetamol (acetaminophen). The use of any external parasiticides based on permethrin is contraindicated for cats. Aquatic organisms
Permethrin is listed as a "restricted use" substance by the US Environmental Protection Agency (EPA) due to its high toxicity to aquatic organisms, so permethrin and permethrin-contaminated water should be properly disposed of. Permethrin is quite stable, having a half life of 51–71 days in an aqueous environment exposed to light. It is also highly persistent in soil. See also
Benzyl benzoate
DEET
Methoprene
Pyrethrin
Pyrethrum

References
External links
Permethrin in the Pesticide Properties DataBase (PPDB)
Permethrin General Fact Sheet – National Pesticide Information Center
Permethrin Technical Fact Sheet – National Pesticide Information Center
Permethrin-treated Clothing Hot Topic – National Pesticide Information Center
"Health Effects of Permethrin-Impregnated Army Battle-Dress Uniforms", National Research Council (1994, US)
Permethrin Pesticide Information Profile – Extension Toxicology Network
"Permethrin". Drug Information Portal. U.S. National Library of Medicine.
This hypothesis is based on the findings that some but not all individuals with the disorder have abnormally high levels of one or two of the agents, alpha-1 antitrypsin and alpha-2-Macroglobulin, which inhibit the naturally occurring fibrinolytic agent, plasmin. 2) The blood of individuals has an increased ability of the pro-coagulant thrombin to bind fibrinogen and thereby promote coagulation. 3) The blood of individuals, particularly those with cryofibriognemic disease associated with other severe disorders, has high levels of immunological elements such as immunoglobulins or immune complexes that interact with fibronectin to promote blood clotting. This hypothesis is base on findings that some patients with cyrofibrinogenemic disease improve when treated with immunosuppressive drugs. Further basic research into this area is required. Asymptomatic cryofibrinogenemia
The occurrence of cryofibrinogenemia as defined by a 4 °C-induced formation of fibrinogen-based precipitation in plasma occurs in 2% to 9% of asymptomatic individuals and 8% to 13% of hospitalized patients without symptoms attributable to this precipitation. Most of these cases have relatively low levels of cold temperature-induced fibrinogen precipitate levels (<50 milligram/liter of fibrinogen) and do not have a disorder associated with the development of cryofibrinogenmia. Associated disorders
Cryoglobulinemia may occur without evidence of an underlying associated disorders, i.e. primary cryoglobulinemia (also termed essential cryoglobulinemia) or, far more commonly, with evidence of an underlying disease, i.e. secondary cryoglobulinemia. Secondary cryofibrinogenemia can develop in individuals with infection (~12% of cases), malignant or premalignant disorders (21%), vasculitis (25%), and autoimmune diseases (42%).