We are switching our dog from regular Simparica to Simparica Trio. If he's already been on one Simparica, he should be ok without the risk of seizures, right? He's never had a bad reaction, but I'm paranoid.
Hi, Sueanoi here
Active Ingredient of Simparica is sarolaner. and TRIO is Sarolaner, moxidectin, and pyrantel.
Sarolaner's toxic dose is 3 times over that of the therapeutic dose. As long as you don't pick the wrong size of the medicine, side effects chances are very low. [cite]
There is a study that states there is more reports of Adverse effects on dogs that are on medications in the isoxazoline group (Sarolaner is in the group) than previously claimed by the manufacturer[cite]. But there is also a report of conflict of interest, where the author of said study is trying to sue the manufacturer [cite]. So take this info as you will.
Pyrantel is antihelminthic drug. It's very poorly absorbed in the gut as its area of desired effect is within the gut. There is very little concern over overdosing as they've tested at 40x therapeutic dose and found no toxicity effects. There's basically no risk if ingested at the correct dose. [cite1, 2]
Moxidectin is a neurological medication aiming to attack the parasites, while sparing the host because of mammalian physiology prevents it from being absorbed to the brain. (Except MDR-1 gene defective dogs, like Collie). This medication is in the same family as ivermectin, but even the dogs with MRD-1 defect, they still tolerate Moxidectin much better then IVM. At 30x of therapeutic dose, there was still no side effects seen in MRD-1 defective dogs. [cite]
For female dogs, there are no studies on pregnancy and nursing safety. There is no evidence of danger (also no evidence of safety). I tell my client to skip it too just in case.
If you are using the CORRECT dose, there shouldn't be any ADDITIONAL concern over neurological side effects.
If your dog gets sick for whatever reason at all, delay the dose until healthy.
I have not personally see any dog gets into neuro trouble over long term of sarolaner. If your dog tolerates the regular formula well, and your dog is not a MDR-1 gene defective dog , I see no reason that your dog would react badly to TRIO version.
I hope this helps!
