What to use to kill lice on a cat? - briefly
Use a veterinarian‑approved topical insecticide (e.g., fipronil or selamectin) applied exactly as directed on the label. If a topical option is unsuitable, a prescribed oral medication such as milbemycin oxime can be used.
What to use to kill lice on a cat? - in detail
Effective control of feline lice requires a veterinarian‑confirmed diagnosis, a product specifically labeled for cats, and a systematic treatment plan.
The most common species are Felicola subrostratus (chewing lice) and Trichodectes canis (sucking lice). Both are external parasites that live on the skin and coat, causing itching, hair loss, and secondary infections.
Approved topical treatments
- Pyrethrin‑based shampoos or sprays (e.g., K9 Advantix, Frontline Spot‑On). Apply to a damp coat, lather, and leave for the time indicated on the label before rinsing.
- Selamectin (Revolution) – a monthly spot‑on solution that eliminates lice and prevents reinfestation. Apply a measured dose to the base of the skull, avoiding the eyes and mouth.
- Imidacloprid + moxidectin (Advocate) – a spot‑on formulation with rapid lice kill. Follow the dosing chart based on weight.
Oral options
- Lufenuron (Program) – a systemic insect growth regulator. Administer as a tablet or chewable, dosage per kilogram body weight. Effective against lice eggs and larvae.
- Spinosad (Comfortis) – primarily for fleas but shows activity against lice; use only under veterinary guidance.
Prescription‑only products
- Fipronil (Frontline Plus) – broad‑spectrum ectoparasiticide, safe for cats when applied as directed.
- Chlorhexidine‑based shampoos – useful for secondary bacterial infections; not a primary lice killer but aids skin healing.
Application protocol
- Weigh the cat to determine the correct dose.
- Clean the environment: wash bedding at ≥60 °C, vacuum carpets, and treat household surfaces with a safe insecticide spray.
- Apply the chosen product according to manufacturer instructions; repeat the treatment after 7–10 days to target emerging lice from eggs.
- Inspect the coat daily for live lice or nits; continue monitoring for at least three weeks.
Precautions
- Do not use dog‑specific products; many contain ingredients toxic to cats.
- Avoid products containing permethrin on cats, as it can cause severe neurotoxicity.
- Pregnant or nursing queens require veterinary assessment before chemical treatment.
- If the cat shows signs of severe dermatitis, systemic illness, or adverse reaction, discontinue treatment and seek immediate veterinary care.
A coordinated approach—accurate diagnosis, cat‑safe medication, environmental sanitation, and follow‑up examinations—provides reliable eradication of lice and prevents recurrence.