Are there side effects when combining Nexgard and Sentinel for dogs?

Hello and thank you for your post! This combination will not likely cause any side effects. Ideally only one should be given at a time but not nexgard and frontline together should be ok. I would, however, monitor your dog for any symptoms such as tremors, seizures, excessive salivation, lethargy and get your dog seen as soon as possible by an emergency vet for treatment. Please feel free to consult with me with any further questions or concerns you may have!

Thank you for submitting your question regarding Cujo. It is fine to give both medications. The Sentinel and Nexgard work in different ways for controlling fleas. The benefit of giving both is the boarder spectrum of protection as each product covers a variety of parasites. I hope this information helps!

We typically recommend waiting 3 weeks between product changes but if she is miserable, you are probably OK to give it to her now. Just be sure you are home to monitor her for any possible reactions. Hope this helps. If you have more questions you can always opt for a private consultation where we can chat back and forth. That way you can ask as many questions as you'd like. Best wishes!

Sentinel is a very safe and effective medication. Allergic reactions could potentially occur quickly after giving the medications or a day or so later. If your puppy is healthy then the chance of a reaction is very low.

Reported side effects include vomiting, itching, diarrhea, lethargy and lack of appetite. Use with caution in dogs with a history of seizures. So if your dog has a history of seizures it might trigger a seizure. The following adverse reactions have been reported following the use of HEARTGARD: Depression/lethargy, vomiting, anorexia, diarrhea, mydriasis, ataxia, staggering, convulsions and hypersalivation. It may be a good idea to have your dog tested for the Mdr1 defect, which is a genetic mutation that causes more side effects than usual in those dogs that carry the mutation when they receive a variety of medications, especially avermectins.

The combination of the products is known to be safe, so there would be no worry of it causing any adverse effects. I assume the vet meant to give the capstar to quickly kill any adults and to give the nexgard to ensure he doesn't get re-infested from fleas in the environment. This would be an effective way to kill all the fleas and perhaps your vet has other reasons for prescribing the combination (maybe they have experience using one versus the combination). The Nexgaurd alone should work though, so if you really don't want to just give one, then that would be the one would recommend. I would recommend calling the veterinarian and asking if this is OK though. It's also good to treat the environment for fleas, because fleas can reproduce and nest in the environment and continually cause an issue. Below is a link to a short article that explains treating the dog and environment for fleas: https://www.petcoach.co/article/5-tips-to-get-rid-of-fleas/ I hope that helps and Josh gets better soon.

Hello and thank you for reaching out to Petco Pet Education Center, formerly Petcoach. No, your dog should not get sick from these medications combined. While they are not needed together, they do not interact negatively, so Mario should be just fine! I hope this is helpful!