NexGard is an oral medication designed to protect dogs from fleas and ticks. It offers a convenient and effective solution for controlling these external parasites. This monthly treatment works systematically to protect dogs from infestations.
How the Active Ingredient Works
The effectiveness of NexGard stems from its active ingredient, afoxolaner, which belongs to a class of compounds called isoxazolines. It targets the nervous systems of arthropods like fleas and ticks. Once ingested, afoxolaner is absorbed into the bloodstream.
Afoxolaner works by interfering with gamma-aminobutyric acid (GABA)-gated and glutamate-gated chloride channels within the nerve cells of these parasites. This disruption leads to uncontrolled activity and hyperexcitation of the arthropod’s central nervous system, ultimately resulting in paralysis and death. Afoxolaner is selectively toxic to insects and mites due to its low binding affinity for mammalian GABA receptors, contributing to its safety for dogs.
Mechanism of Tick Elimination
When a tick feeds on a dog treated with NexGard, it ingests the afoxolaner circulating in the blood. The active ingredient rapidly affects the tick’s nervous system, leading to its death. Tick death typically occurs within 24 to 48 hours after infestation.
NexGard does not repel ticks, meaning a tick may still bite a treated dog. However, by killing ticks shortly after they bite, the medication prevents the transmission of disease-causing pathogens, such as those causing Lyme disease. This mechanism breaks the parasite’s life cycle and reduces the risk of tick-borne diseases.
Administration and Duration
NexGard is formulated as a palatable, beef-flavored chewable tablet, making it easy for dogs to accept. It is administered orally once a month, and can be given to dogs with or without food. Monthly dosing ensures continuous protection against fleas and ticks.
Each dose of NexGard provides effective protection for a full month. It is suitable for puppies as young as eight weeks of age, provided they weigh at least four pounds. If a dose is missed, it should be given as soon as remembered, and then the regular monthly schedule should be resumed.
Safety Considerations
NexGard is well-tolerated by dogs when used as directed. Some dogs may experience mild side effects, such as vomiting, diarrhea, lethargy, or a temporary decrease in appetite. These effects are mild and typically resolve on their own.
Isoxazoline-class drugs, including afoxolaner, have been associated with neurological adverse reactions such as muscle tremors, ataxia (loss of coordination), and seizures in some dogs. Dogs with a history of seizures or other neurological disorders should be given NexGard with caution. NexGard is formulated for dogs and should not be used in other animal species. Consult a veterinarian if concerns arise or side effects persist.