May 4, 2026 - Ondansetron treats severe nausea and vomiting in cats. The standard dose of ondansetron for cats is 0.5 mg per kg of body weight. Side effects like constipation may occur.

Serious but rare adverse reactions may occur. If any of the following signs develop, stop giving ondansetron and contact your veterinarian immediately:

April 8, 2026 - Other conditions requiring cautious ... electrolyte imbalances, particularly low potassium or magnesium levels, may have increased cardiac risks when receiving medications that affect cardiac conduction....

Side effects are uncommon but may include constipation, sleepiness, or head shaking; rare serious reactions include abnormal heart rhythms, fainting/collapse, or low blood pressure.

July 23, 2025 - Signs of an overdose of ondansetron may include constipation, diarrhea, grogginess, and head shaking. Ondansetron overdose can also cause elevated liver levels, abnormal heart rhythm, and abnormally low blood pressure.

6 days ago - Cats with diabetes have so many times of experiencing low potassium, influenced by polyuria and insulin administration. I think of how low potassium contributes to the weakness cats feel then, and it makes me want them to have relief. ... I'm seeing info that problems can occur if potassium levels are too low when giving Ondansetron, too.

Checking your browser before accessing pubmed.ncbi.nlm.nih.gov · Click here if you are not automatically redirected after 5 seconds

While it can be beneficial, there are potential side effects to consider before administering it to your cat. Possible side effects include changes in behavior such as agitation or changes in mood. Ondansetron is generally well-tolerated, but some cats may experience constipation or diarrhea.

March 16, 2021 - Veterinarian's Assistant: What’s the cat’s name? Customer: Buddy. Veterinarian's Assistant: Is there anything else the vet should know about Buddy? Customer: We give him subcutaneous fluids every day, along with aluminum hydroxide, maropitant (I know I’m spelling things wrong), and potassium alongside the ondansetron. He has been responding very negatively just to the ondansetron and maropitant (which we now administer through

Checking your browser before accessing pmc.ncbi.nlm.nih.gov · Click here if you are not automatically redirected after 5 seconds

When pets experience persistent nausea or vomiting, especially in complex situations like chemotherapy or toxin exposure, veterinarians often turn to Ondansetron, a powerful antiemetic originally developed for humans and marketed under the brand name Zofran®. Though not officially approved by the FDA for animal use, it remains a trusted treatment in veterinary medicine through legal extra-label prescribing. This guide explores how this antiemetic helps manage nausea, sleep disorders, and opioid-induced itching in dogs and cats, along with key dosage details and safety information.

August 4, 2024 - I would find a different vet, where I work we use Cerenia all the time for cats along with other anti-nausea meds. Don't use anything that has not been specifically prescribed for your pet. ... Ondansetron is fine when Cerenia doesn't work well enough in rough situations.

December 26, 2025 - 2025 Vet Guide Summary: Ondansetron for Dogs & Cats – Use, Dosage, Safety & Side Effects 🐾 Ondansetron (Zofran®) is an effective anti-nausea medication used in veterinary care to treat vomiting in dogs and cats. Dr. Duncan Houston BVSc explains its uses, dosage recommendations, potential side effects, and how it compares to other treatments like Maropitant (Cerenia®). Tools like Ask A Vet, Woopf 🐾, and Purrz 🐶 help ensure safe and effective administration for your pet's comfort.

Checking your browser before accessing pmc.ncbi.nlm.nih.gov · Click here if you are not automatically redirected after 5 seconds

Heart rhythm problems or low blood pressure (both are rare).

August 20, 2021 - What are Ondansetron Tablets for Dogs and Cats? Ondansetron is a prescription medication used to treat nausea and vomiting.It has the benefit of fast onset and can sometimes help your pet within 15 minutes.Ondansetron is the generic drug in the brand…

Ondansetron is generally safe for cats when prescribed by a vet.

USE: Ondansetron is used to treat or prevent severe vomiting.

A pharmacokinetic study in dogs revealed that the oral bioavailability of ondansetron was very poor (<10%), indicating this may not be an appropriate route of administration.4 Ondansetron is also not appropriate as a transdermal medication, as a recent abstract assessing transdermal absorption in cats demonstrated no detectable blood levels after administration.