What are isoxazolines and do they work best?

What are isoxazolines?

Isoxazolines are active ingredients used in veterinary parasite treatments, such as fluralaner, afoxolaner, sarolaner, lotilaner and esafoxolaner. In order to kill parasites, treatments use active ingredients within the formula to ensure they are effective. Isoxazoline treatments include tablets, injections and spot-on treatments, but not oral medicine.

How do isoxazolines work?

These medicines enter your pet’s bloodstream and disrupt nerve signalling in the parasites they are targeting and cause a quick death. Fleas and ticks generally need to attach and start feeding before they are killed by the active ingredient. This means isoxazolines do not repel parasites or prevent every bite, but they can reduce infection and spread of diseases.

How effective are isoxazolines?

Isoxazolines are effective at killing fleas and ticks. Studies show that isoxazolines are better at killing fleas than another common active ingredient, Fipronil but have the same, high level of tick control.

But isoxazoline treatments are not effective at killing flea eggs or larvae which is the reason flea infestations tend to last a long time. Isoxazolines don't kill flea eggs which mean they aren't effective at breaking the flea life cycle which needs to happen in order to get rid of fleas properly. Instead, for effective and quick flea removal, flea treatment that targets all stages of the flea life span to stop an infestation should be used on pets, like Itch Flea Treatment for Dogs or Itch Flea Treatment for Cats.

Are they better than other flea treatments?

It’s not a simple case of comparing “isoxazolines versus spot-on flea treatment”. This is actually misleading because some spot-ons contain isoxazolines. The best thing to do is to compare the active ingredient a.k.a what the treatment kills. Like we've said, if the treatment kills flea eggs is much more effective than isoxazoline-only flea treatments.

Also consider, how easy it is to apply. For example, an oral flea tablet can be tricky for fussy pets, but a spot-on flea treatment is less faff, and requires no force-feeding tablets. Think about what “best” means for you and your pet!

Are isoxazolines safe for cats and dogs?

Isoxazolines are safe to use on pets when treatment instructions are followed. Most pets tolerate these medicines well, but side effects are possible. Depending on the product, these can include vomiting, diarrhoea, reduced appetite or lethargy. And not all treatments with isoxazolines are safe for pregnant and lactating cats, double check this before applying!

Isoxazolines have also been associated with tremors, poor coordination and seizures. Seizures can occur in animals without a previous history. Tell your vet about any neurological condition, previous reaction or other medication before treatment.

Why am I still seeing fleas after using isoxazoline flea treatment?

Seeing fleas after applying treatment does not necessarily mean it’s failed or doesn’t work. Flea eggs, larvae and pupae can remain in carpets, bedding and resting areas, with newly emerged adults jumping onto treated pets. An effective treatment helps interrupt the flea lifecycle, but most household infestations take time to clear, roughly 8 to 12 weeks.

Not sure whether an isoxazoline flea treatment is right for your pet? Chat to a flea specialist at Itch Pet, who can explain all of the flea treatment options and help you decide which is the best for your pet.