NexGard

Keymaster

“NEXGARD kills adult fleas and is indicated for the treatment and prevention of flea infestations (Ctenocephalides felis), and the treatment and control of American Dog tick (Dermacentor variabilis) infestations in dogs and puppies 8 weeks of age and older, weighing 4 pounds of body weight or greater, for one month.”

“Mode of Action:
Afoxolaner is a member of the isoxazoline family, shown to bind at a binding site to
inhibit insect and acarine ligand-gated chloride channels, in particular those gated
by the neurotransmitter gamma-aminobutyric acid (GABA), thereby blocking pre- and post-synaptic transfer of chloride ions across cell membranes. Prolonged afoxolaner-induced hyperexcitation results in uncontrolled activity of the central nervous system and death of insects and acarines. The selective toxicity of afoxolaner between insects and acarines and mammals may be inferred by the differential sensitivity of the insects and acarines’ GABA receptors versus mammalian GABA receptors.”
“Adverse Reactions:
In a well-controlled US field study, which included a total of 333 households and 615 treated dogs (415 administered afoxolaner; 200 administered active control), no serious adverse reactions were observed with NEXGARD.

Over the 90-day study period, all observations of potential adverse reactions were recorded. The most frequent reactions reported at an incidence of > 1% within any of the three months of observations are presented in the following table. The most frequently reported adverse reaction was vomiting. The occurrence of vomiting was generally self-limiting and of short duration and tended to decrease with subsequent doses in both groups. Five treated dogs experienced anorexia during the study, and two of those dogs experienced anorexia with the first dose but not subsequent doses”

“Use with caution in dogs with a history of seizures”

“A structurally unique isoxazoline class compound, A1443, exhibits antiparasitic activity against cat fleas and dog ticks comparable to that of the commercial ectoparasiticide fipronil. ”

Here are my thoughts. Nexgard is taken by mouth so that makes it systemic. So that is a big difference between it and the similar pesticide fipronil used in Frontline. Frontline works by distributing the pesticide in the oil glands of the skin and is not systemic.

Both pesticides act on neurotransmitters in fleas and ticks to cause nervous system disruption that leads to death. Pesticides of this nature are considered safe to mammals because their nervous systems are so different. However some breeds seem more sensitive because of a genetic difference. All vets should know which breeds these are and should exercise caution when prescribing this pesticide or any other.

While Nexgard claims it is effective against the American Dog Tick, that would, in a sense make it seem to be ineffective against the Deer Tick or the Lone Star Tick because the literature does not mention them. Is this true or not? Is it possible they did not mention this because they didn’t test for these ticks? American Dog Ticks are now carrying some diseases but my fear where I live is the Deer Tick. That’s the one that carries some nasty diseases.

Fleas are not life threatening, ticks can be. I am reluctant myself to put something inside my dog in order to get rid of fleas. I feel more comfortable putting Frontline on them and being vigilant about checking them.

I do use other protection that is extremely effective and safe. Permethrin is a man-made derivative of Chrysanthemum flower extract that is impregnated into clothing fibers. It usually lasts through up to 70 washings. And before you ask, no it can’t weep onto the skin or into water. They have tested this significantly since it is used for American Military clothing and have found that the only way Permethrin leaves the clothing is via dryer lint. So both of us have head to toe ExOfficio clothing and I put big red bandannas on the dogs. Search for Doggles Insect Shield Bandana, but there are many brands.
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patrice

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