I’ve been using Advantage for Dogs on cats for many years by purchasing the Dogs derivative and splitting it into smaller doses appropriate for my cat’s weight. This seemed to be a common practice with vets as the Active Ingredients of the Dogs and Cats derivatives were identical.
When Advantage II came out, I continued with the practice of using the Dog product on Cats only adjusting the dosage.
However, after a while, Bayer added a “Do not use on Cats” warning on the packaging of Advantage II for Dogs.
I can understand why Bayer would put such a warning from a marketing point of view. However, as the non-active ingredients are not listed on the packaging of either product, I’m not sure whether there might be another reason.
I was wondering if you had any insight on this question of using Advantage II for Dogs on Cats.
I look forward to hearing from you,
Sorry for the late response. I was having hosting server issues.
Before answering your question, I want to state that I don’t recommend off label use of any kind, for any medication.
You’re correct. The ingredients are identical in Advantage II for both cats and dogs. And they’re in the same concentrations. The main difference is the amount of product used. Make sure you’re applying the correct dosage, or toxicity problems will likely occur.
Here are the dosage charts:
I don’t think it’s necessarily a marketing tactic to label dog treatments with “Don’t use on cats”. It’s probably more of a safety/legal issue. If everyone did what you’ve been doing, I’m sure at least a handful would poison their pets by applying the wrong dosage through lack of diligence and care.
Additionally, while Advantage II doesn’t contain permethrin, many other flea products do (such as Advantix II). Permethrin is highly toxic to cats. This is probably another reason why Bayer doesn’t want pet-owners getting in the habit of swapping treatments.
Hope this was useful!