How Long Can a Cat Take Mirataz? Duration and Safety

Name: How Long Can a Cat Take Mirataz? Duration and Safety
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Most cats stay on Mirataz for a short course, often around one to two weeks, while your veterinarian works on the problem that caused the appetite loss. It is not meant to be a long-term fix on its own. How long can a cat take Mirataz depends on the reason it was prescribed, how your cat responds, and what your veterinarian decides at recheck.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Mirataz (mirtazapine transdermal ointment) is an appetite stimulant applied to the inner surface of your cat's ear. It is used to restart eating, not to treat the underlying disease.
In one survey of owners, about half used the ointment for less than 14 days [1]. A common research protocol applies it daily for 14 days after chemotherapy [2].
Your veterinarian sets the dose and the stop date based on your cat's weight, diagnosis, and progress.
If your cat is still not eating after a few days on Mirataz, that is a reason to call your vet, not a reason to keep applying more ointment.
Never extend a course or repeat a prescription without talking to your veterinarian first.

What Mirataz Is and What Veterinarians Use It For

Mirataz is a brand of mirtazapine, a medication originally developed as an antidepressant in people. In cats, it is used mainly as an appetite stimulant and anti-nausea medication [3]. The transdermal form comes as an ointment you rub on the inside of the ear flap, where it absorbs through the skin.

Veterinarians prescribe it when a cat has stopped eating or is eating far less than normal. The most common reason in one owner survey was chronic kidney disease [1]. Other reasons include recovery from illness or surgery, cancer treatment, and any condition where nausea or poor appetite is slowing recovery.

It is also used alongside chemotherapy. In cats with lymphoma receiving chemotherapy, transdermal mirtazapine was applied daily for 14 days after treatment to reduce gastrointestinal side effects and weight loss [2]. In another study of cats receiving doxorubicin chemotherapy, mirtazapine given every 48 hours for 2 weeks led to significantly higher appetite and activity scores and increased body weight compared with a placebo [3].

The medicine does not fix the disease. It buys your cat time and comfort while your veterinarian treats the real problem.

How Mirataz Works

Mirtazapine blocks certain receptors in the brain that control nausea and appetite. Blocking them reduces the feeling of sickness and makes food more appealing. It also has anti-vomiting effects, which is why it shows up in chemotherapy protocols [3][2].

Because it works on the brain and gut signaling instead of on the stomach itself, it can help a cat eat even when the underlying illness is still active. That is also why it can mask a problem. A cat that eats because of the medication may still be sick underneath.

The transdermal ointment is absorbed through the skin of the ear. Owners in one survey found ear application easy, and 91 percent followed instructions to alternate ears [1]. Absorption can vary between cats, so the response you see at home is one of the things your veterinarian will ask about at recheck.

How Long Can a Cat Take Mirataz?

There is no single official answer, and that is the honest truth. The length of treatment depends on why your cat stopped eating and how quickly the underlying issue improves.

What the research shows is a short course. In a survey of 70 owners whose cats received transdermal mirtazapine, about half administered it for less than 14 days [1]. In a lymphoma study, the ointment was given daily for 14 days after chemotherapy [2]. In a chemotherapy study, oral mirtazapine was given every 48 hours for 2 weeks [3]. These are treatment windows used in research settings, not rules for every cat.

In practice, many veterinarians prescribe a short course, often 1 to 2 weeks, then reassess. Some cats need a second course. Some need a different plan entirely if the appetite loss keeps coming back.

The pattern matters as much as the calendar. If your cat eats well for several days and then stops again as soon as the medication stops, that is information your veterinarian needs. It usually means the underlying problem is not controlled yet.

When to Stop

Stop when your veterinarian tells you to stop, or sooner if you see signs of a serious reaction. Do not keep applying the ointment because your cat had one good day. Do not stop and restart on your own either.

If your cat is eating normally again and the original problem is being treated, your vet may taper or simply end the course. If your cat is not eating despite the medication, more ointment is not the answer. That is a phone call.

What If You Miss a Dose?

Ask your veterinarian what to do about a missed dose, because the answer depends on the schedule. Do not double up to make up for a missed application. If you are not sure whether the last dose went on the ear or on your finger, treat it as missed and call your vet's office for guidance.

Dosing Basics

Your veterinarian calculates the dose from your cat's weight and health, and sets how often it is applied. Do not use a dose meant for another cat, and do not adjust the amount on your own.

The ointment goes on the inner surface of the ear flap, not deep in the ear canal. Alternate ears between doses unless your veterinarian tells you otherwise. In one survey, 91 percent of owners followed the alternating-ear instructions [1]. Wear gloves or wash your hands well after applying it, since the medication can be absorbed through human skin.

Keep the tube away from children and out of reach of other pets. If a person accidentally contacts the ointment, wash the area with soap and water and call a poison control center or physician if any symptoms appear.

Side Effects: What to Watch For

Side effects were reported by 20 percent of owners in one survey, most often increased vocalization, redness of the ear, or restlessness [1]. In a lymphoma study, mirtazapine-related adverse events occurred in 20 percent of cats and did not require stopping the medication [2].

Side effect	How common or serious	What to do
Increased vocalization	Common, usually mild [1]	Note it, mention it at recheck. Call if your cat seems distressed
Restlessness or pacing	Common, usually mild [1]	Keep the environment calm. Call if it does not settle
Redness or irritation of the ear	Common, usually mild [1]	Stop applying to that ear and call your vet
Vomiting or diarrhea	Possible, often related to the underlying illness or chemotherapy [2]	Call your vet if it is frequent or your cat seems unwell
Sedation or the opposite, agitation	Less common	Call your vet the same day
Tremors, wobbling, or unusual behavior	Uncommon but serious	Call your vet right away or seek emergency care

Some cats become more vocal or restless in a way that is easy to mistake for "feeling better." Watch for signs that your cat is uncomfortable instead of improved.

Who Should Not Take Mirataz

Mirataz is not right for every cat. Tell your veterinarian about every medication, supplement, and topical product your cat receives before starting it.

Cats with known sensitivity to mirtazapine should not use it. Cats with certain liver or kidney conditions may need a different dose or a different medication, and only your veterinarian can make that call. Because the ointment is absorbed through skin, cats who live with people who are pregnant, breastfeeding, or taking certain medications should be discussed with your vet and the household's physician.

Drug interactions matter. Mirtazapine affects brain chemistry, so combining it with other medications that act on the same systems can increase sedation or other effects. Do not add over-the-counter remedies, herbal products, or leftover medications from another pet without asking your veterinarian first.

Overdose and When to Call for Help

An overdose can happen if your cat licks the ointment off the ear, if a tube is chewed, or if too much is applied. Signs can include heavy sedation, agitation, tremors, vomiting, or an unsteady walk.

If you suspect an overdose, call your veterinarian or an animal poison control hotline immediately. Have the tube with you so you can tell them the concentration and how much may have been involved. Do not wait for symptoms to appear before calling.

If your cat collapses, has a seizure, or has trouble breathing, go to an emergency veterinary hospital now.

Limitations and When to Contact a Veterinarian

Mirataz treats the symptom, not the cause. That is its biggest limitation, and it is why the medication is always paired with a plan to find and fix the reason your cat stopped eating.

Call your veterinarian the same day if:

Your cat has been on Mirataz for 2 to 3 days and is still not eating
Your cat is eating less than before, even on the medication
You see ear redness, swelling, or your cat is scratching at the ear
Your cat seems sedated, agitated, or "not themselves"
You miss doses or are unsure about the schedule

Go to an emergency clinic now if:

Your cat has not eaten for 24 to 48 hours, or has not eaten at all since starting the medication
Your cat is vomiting repeatedly, has a swollen or painful abdomen, or is drooling heavily
Your cat is weak, wobbly, having tremors, or is hard to wake
Your cat has not urinated in 24 hours, especially a male cat straining in the litter box. These articles explain the timeline: How Long Can A Cat Safely Go Without Urinating and How Long Can A Cat Go Without Peeing Before It Is Dangerous

Schedule a routine visit if your cat's appetite improves but the original problem is not yet diagnosed or treated, or if your cat needs repeated courses of Mirataz. Repeated appetite loss is a signal, not a coincidence. For a fuller picture of how long a cat can go without food, see Cat Not Eating: How Long Is Too Long?. If your cat is eating again but not passing stool, read Cat Not Pooping: How Long Is Too Long?.

Every cat is different, and your veterinarian is the only person who can set the right duration and dose for your cat.

Frequently Asked Questions

Can I keep giving Mirataz if my cat is eating well?

No, not without checking with your veterinarian first. The medication is meant to be a short course while the underlying problem is treated, and about half of owners in one survey used it for less than 14 days [1]. Once your cat is eating reliably, your vet will decide whether to stop, taper, or continue.

What happens if I stop Mirataz too early?

Your cat's appetite may drop again before the underlying issue has improved. That does not mean the medication failed. It means your cat still needs treatment for the original problem, so call your veterinarian and describe what you saw.

Is the ear ointment safer than the pill?

Neither form is automatically safer. The ointment is easier for many owners to apply, and most owners in one survey found it easier than the oral form [1]. Both contain the same active medication, and both carry the same side effect risks. Your veterinarian will pick the form that fits your cat.

Can Mirataz be used long term for a cat with kidney disease?

Long-term use is not well established in veterinary research. Chronic kidney disease was the most common reason for prescription in one survey, and about half of those owners used it for less than 14 days [1]. If your cat needs ongoing appetite support, your veterinarian will look for a plan that treats the kidney disease itself.

Does Mirataz help with nausea as well as appetite?

Yes, mirtazapine has anti-nausea and anti-vomiting effects in cats, which is why it is used in chemotherapy protocols [3][2]. That said, it does not replace treatment for the cause of the nausea. If your cat is vomiting repeatedly, call your veterinarian.

References

Owner's Perspective About the Use of Mirtazapine Transdermal Ointment in Cats-A Survey-Based Study. Animals : an open access journal from MDPI, 2025.
Appetite Stimulant and Anti-Emetic Effect of Mirtazapine Transdermal Ointment in Cats Affected by Lymphoma Following Chemotherapy Administration: A Multi-Centre Retrospective Study. Animals : an open access journal from MDPI, 2022.
Oral mirtazapine decreases the gastrointestinal adverse effects in cats on doxorubicin chemotherapy. Veterinary journal (London, England : 1997), 2024.