Frontline Plus for Dogs Side Effects

Frontline Plus is a liquid supplied in one-dose pipettes used to treat your dog for fleas, ticks and biting lice. Side effects are rarely seen to either of the active ingredients: fipronil, which kills the adult parasites, and (S)-methoprene, which prevents development of the eggs and larvae. The product also contains alcohol as a solvent and many of the side effects relate to this.

  1. Skin Reactions

    • Itching and hair loss over large areas of the body have been reported in some dogs, but reactions most commonly occur at the site of application. This may include hair loss, itching, redness or discoloration of the skin. Usually side effects are transient and start to resolve within a few days.

    Nervous Reactions

    • Signs due to the stimulation of the dog's nervous system including drooling, becoming over-sensitive to noise, touch or light and appearing quiet and depressed may all be seen but your dog will soon return to normal. Vomiting and panting have also been reported in some dogs, but again this passes quickly.

    Correct Usage

    • Make sure that you empty the Frontline Plus pipette on the back of your dog's neck where it cannot lick it off or you will see the dog drool for a brief period and the product won't work. Check your dog's weight before using Frontline Plus and ensure that you are using the correct size of pipette. Any side effects will be increased if you accidentally overdose your dog. Do not treat puppies under 8 weeks of age or weighing less than 2 kg. Ask your veterinarian for advice before treating your dog if it is sick or recovering from illness.

    Reactions in Humans

    • Side effects are rare but most commonly are due to irritation of the eyes, mouth and skin. Wash the area with copious amounts of clean water if you come into contact with the liquid product. Merial, manufacturers of Frontline Plus, recommends that your treat your dog at bedtime so the application can dry before you or your kids cuddle the dog again. They also recommend that you do not let your dog sleep with you after treatment. People that are hypersensitive to insecticides or alcohol should avoid all contact with the product. Severe reactions are extremely rare but include vomiting, agitation and seizures. Seek immediate help from your health care provider if you think you may be at risk.

    Other Species

    • Frontline Plus is also available for cats, who show similar side effects to dogs. Do not use Frontline plus for Dogs on your cat as you may easily overdose it and make any side effects far worse. Frontline Plus may cause severe reactions or death in rabbits and aquatic animals so do not use it in these species. Use the product with care if your dog has contact with pet rabbits, keeping them apart until the application has dried and making sure that your dog does not swim in your pond until at least two days after treatment.