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My dog reacts to flea/tick meds. Is switching to Nexgard safe?

Updated on September 23rd, 2025

Pet's info: Dog | Miniature Poodle | Male | neutered | 1 year and 1 month old | 15 lbs

First of all thank you for this app and your answers, this has been a life saver. I’m trying to find a flea/tick medication that agrees with Jack. He seems get lethargic and sick at his stomach on Simparica. I switched to Vectra3D and he seems to be fine but possibly a little itchy? He keeps trying to chew his back. But the smell bothers me. Someone suggested Nexguard. If I try that next month, is it safe to have been on 3 diff flea meds in a 3 month period? Is Nexguard good/safe?

2 Answers

Most Helpful Answer

Destini R. Holloway, DVM

Answered By Destini R. Holloway, DVM

Veterinarian

Published on February 5th, 2019

No worries. You can safely switch up flea medication every 2-4 weeks no problem. All flea prevention is labeled as safe for dogs but pets can have adverse reactions to just about any medication unfortunately. But these are not expected to happen. I have seen fewer reactions with Nexgard if that is any consolation. : )
Best wishes with your pet Jack moving forward and I hope that he tolerates Nexgard well! Take care.
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Related Answers from Veterinarians

  • Answered By Sara Farmer, DVM

    Veterinarian

    Published on March 7th, 2017

    Nexgard lasts 30 days so it is possible he could get fleas and ticks if his dose is delayed by a few days. You may want to see if your veterinarian would be able to dispense a single dose so he gets it on time - you may be able to skip a month of your automatic refills.

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    1Pet Parents found this answer helpful

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