Weight loss is a symptom of a variety of different diseases, including hyperthyroidism, kidney disease, liver disease, and intestinal disease. “Nearly all chronic diseases that creep up on cats cause insidious weight loss,” says Dr. Tasi, a homeopathic vet and owner of Just Cats Naturally. It is paramount that the underlying cause of weight loss is identified as early as possible in a disease process, which is why it’s so important to weigh your cat regularly. Depending on the size of your cat, visible changes to her weight may be far too subtle to notice without actually weighing her.

Getting sick cats to eat

Getting a sick cat to eat can be challenging. There are many natural ways to try to entice finicky eaters, and when all else fails, there are medications that stimulate the appetite. The problem with these medications is that they need to be taken orally, which can be difficult for cat parents whose cats are already not eating, and may be difficult to pill.


Now there’s a new transdermal drug on the market that has resulted in significant weight gain in as little as two weeks. Mirataz can be applied to the cat’s ear, where it is absorbed into the bloodstream. The active ingredient medication in  Mirataz, mirtazapine, is not new. It is a human medication and has been used off label in pill or compounded form in cats.

Efficacy of transdermal medications

It’s important to understand that while many medications can be made into transdermal formulas, not all drugs are absorbed well via that route, and unless there are clinical trials that prove efficacy, you may not be giving your cat the medication you think you’re giving her. It is my understanding that the only transdermal medication that has been proven to be effective for cats to date is methimazole, which is given to cats who are hyperthyroid.

Mirataz: proven efficacy

In a clinical trial, Mirataz demonstrated a 3.9% increase in body weight in cats with unintended weight loss in as little as 14 days. 230 cats were enrolled in the field study to assess the clinical safety and effectiveness of the drug. Cats with underlying disease may have received concurrent medications. As with any medication, there were some side effects. The most common ones included application-site reactions, vocalization, hyperactivity, and vomiting (26% of the cats enrolled in the study had vomiting as a symptom at the time of enrollment.)

Mirataz is an appetite stimulant, and will not cure the underlying disease that is causing the weight loss.

Use caution with transdermal medications

When you use any transdermal medication on your cat, you need to be aware that you will absorb some of the medication through your own skin unless you take proper precautions. Wear gloves, and don’t handle the area where the medication was applied for a couple of hours after applying.

For more information about Mirataz, visit KindredBio.com. Mirataz requires a prescription from your veterinarian.

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17 Comments on New Transdermal Drug Can Help Manage Weight Loss in Cats

    • It takes up to 14 days for it to work, but it can work sooner than that. You can give your cat Sub Q fluids which you can get from vet and it will buy more time for your sweetie until the medicine kicks in. Hope this helps.

  1. Yes. Not many people can pill a cat. It’s difficult. Transdermal meds is the way to go for feline medication application.
    I hope drug manufacturers can work it out so more meds can be applied in this manner.

  2. How quickly does it start working? Our cat (who is not eating) is currently a bit stressed by our attempts to tempt her to eat, so we don’t want to stress her further unless the timing is actually right.

  3. We have started our cat on Mirataz. We have seen positive results. We have been dosing at night. Would it be more effective if we start dosing in the morning since we feed her mostly during the day. She still needs prompting to eat thus the day time feeding schedule. Thank you.

        • I guess my real question should have been ” Would a morning dosage fit our day time feeding schedule best?” Does Mirataz have 24 hour effect or is it more likely to be concentrated in the first 8 hours or so? We pretty much are hand feeding using Hartz Delectable Squeeze Ups. So far we ‘think’ we are seeing an increase in appetite. I kind of describe it as similar to a cup of coffee pick me up. Just not sure how long it lasts during the day? thank you.

          • capecodbeachfront, Dosing at night is fine. If you treat them every 24 hours, the least amount of working mirtazapine in their system should be about 25% of a dose and at that point, they would be due for another treatment.

  4. My Moko was diagnosed with hyperthyroidism about two years ago. She hates taking pills – even with Pill Pockets, buried in a piece of cheese, etc. – so we tried a transdermal version of her medication. Unfortunately, she had a serious allergic reaction to something in the gel and we actually nearly lost her. She had been taking the pills for about a year but the difficulty in getting her to take the pills had the vet suggest using a transdermal version of it. While many cats have no issues using something like this, there is a chance your cat could have issues. I recommend keeping a very watchful eye on your cat if you try using a transdermal treatment and contact your vet immediately if there is any reaction.

  5. Great information. My cat Pumpkin has IBD and small cell lymphoma. If if she eats very well she keeps losing weight. She is rough to pill and when given the oral mirtazipine for appetite and nausea, she throws it up and foams at the mouth from it so I stopped. I will be asking my vet to see if she thinks Pumpkin can give this a try.

  6. This is great. I have had cats that were very difficult to give pills too. hopefully more medications will be available in this form in the future.

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