How Advantage Works

The active ingredient in Advantage paralyzes and kills fleas almost immediately.

Each brand of flea control might use a different active ingredient. In Advantage, this active ingredient is imidacloprid. Imidacloprid interferes with insects’ nervous systems, causing a blockage that eventually leads to an over-abundance of a particular neurotransmitter. This causes paralysis and then death. It does not have the same immediate, toxic effect on humans because of differences in the nervous systems. The Extension Toxicology Network states that “imidacloprid is quickly and almost completely absorbed from the gastrointestinal tract, and eliminated via urine and feces” in humans and animals. However, some people have reported side effects from Advantage.

Side Effects

Some pet owners have reported numbness after having contact with Advantage. According to the Extension Toxicology Network, in addition to irritating the skin and eyes, other symptoms can include “fatigue, twitching, cramps and muscle weakness, including the muscles necessary for breathing.

Symptoms of Poisoning

  • The neurotoxins in flea preventives target nerve cells, muscles and brain tissue in pets. Some side effects of flea-preventive toxicity include hyperactivity, excessive salivating, dilated pupils, tremors, vomiting, diarrhea, hiding, shivering and skin irritation. Open sores on the skin where you applied spot treatments could emerge as well. More serious symptoms might include breathing difficulties, brain damage, heart attacks and violent seizures that could result in death. Afflicted pets might lose their appetite for food and water, and kidney failure could also occur.

Unknown Risks

It is not just the active ingredient in Advantage, imidacloprid, that can have toxic effects. All flea-control medications have “active” and “inert” ingredients. The EPA registers the active ingredients, like imidacloprid, after rigorous testing. The same comprehensive testing is not mandated for inert ingredients, and flea-control product makers are not required to list those ingredients individually on labels, even though many are toxic. Undisclosed ingredients could have unknown risks. Your best protection against any harmful side effects of Advantage is to avoid contact, so always wear gloves when applying. If you do come in contact with Advantage and experience side effects, remember that there is no first aid treatment and you should contact a physician or go to a clinic for medical attention.