Is it safe to use Bio Spot flea collar and Advantage II on cats?

I'm sorry to hear you've had trouble finding an effective flea med! Most over-the-counter options are not very effective in my experience, including Advantage - although it's probably the best of the currently available OTC options! Flea collars do not work well, and can often be toxic to cats. Instead, I would recommend getting a prescription flea medication like Revolution or Bravecto from your veterinarian. This will be safe for your kitty, and much more effective. If it's been at least 1-2 weeks since you applied the Advantage, it should be safe to go ahead and use a new medication from your vet.

I would recommend only using one. I prefer topical over collars since not all collars work. There are plenty of topical medications for cats that help prevent fleas and ticks. Some topical you can apply monthly while others like Bravecto can be applied once every 3 months. Without knowing what type of collar and which fipronil product you are using I wouldn't use them together. I would also wait 48 hours before and after a bath before putting topical medication on. Thank you for using Petco Pet Education Center, formerly Petcoach.

Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry to hear about the flea problem. Yes, you can use Capstar with any topical flea/tick medicine as far as I know. I don't know of any that Capstar is contraindicated. Great question and good luck.

Hello, yes you can use them together. Most importantly, is that you also treat your environment to rid of the fleas. You can use pet safe environmental insecticides, wash all bedding and clothing with hot water, and replace the vacuum bag after every use. Hope this helps and best of luck.

Cats can be very sensitive to flea treatment products, and toxicity can occur from using two products at the same time. Because of that, it's not safe to give the flea drops and then put on the flea collar. Typically the flea drops should be enough to protect Tinkerbell from fleas, and I recommend using only that. I hope this helps!

In all likelihood, your kitty will probably be safe. However, I would advise using a product such as Capstar instead (nitenpyram) to most safely kill adult fleas without causing any sort of interaction.

Fleas collars do not typically work well. Hartz is not as strong as most other flea medicines and tend to have the most reactions. Advantage is great one that is monthly, Bravecto is another great one and it will last for 3 months but requiers a prescription. I would wait at least 2 weeks in between the topicals for her safety and the flea collar does not matter for timing of products.