Cerenia vs Ondansetron

Pet owners and veterinarians alike often encounter the issue of canine vomiting, which can be distressing for both the dog and the owner. Two commonly prescribed medications to address this issue are Cerenia (maropitant citrate) and Ondansetron. But what distinguishes one from the other? And when might one be chosen over the other?

Contents hide

1. Understanding the Basics

Cerenia (Maropitant Citrate)

Class: Neurokinin-1 Receptor Antagonist

Use: Broad-spectrum antiemetic, effective for various causes of vomiting, including motion sickness.

Mode of Action: Blocks the action of substance P—a key neurotransmitter involved in vomiting reflex.


Class: Serotonin 5-HT3 Receptor Antagonist

Use: Primarily used for chemotherapy-induced vomiting and acute vomiting.

Mode of Action: Prevents nausea and vomiting by blocking serotonin receptors in both the central nervous system and the gut.

2. Clinical Applications


Motion Sickness: Recognized as an excellent choice for controlling motion sickness in dogs.

Chemotherapy-Induced Emesis: Shows efficacy in preventing and treating cisplatin-induced emesis.


Chemotherapy-Induced Emesis: Commonly administered as a slow IV injection for this purpose.

Acute Vomiting: Useful for short-term and acute instances of vomiting.

3. Cerenia & Ondansetron: A Comparative Glance

Efficiency: While both drugs are effective antiemetics, their efficiency might vary based on the cause of vomiting. For instance, Cerenia often stands out as the first choice for motion sickness.

Administration: Both drugs can be given via injection, but there are oral forms available too.

Side Effects: As with any medication, side effects are possible. Ondansetron may cause headaches or constipation, while Cerenia can cause drooling, lethargy, or occasional diarrhea. Always consult with your vet regarding potential side effects.

4. Co-Administration: Can They be Used Together?

In cases of severe or persistent vomiting, veterinarians might consider using both medications concurrently. Their different modes of action can provide complementary benefits. However, it’s crucial to monitor for any adverse reactions or interactions.

5. When to Choose One Over the Other

Cerenia: Particularly beneficial for motion sickness or when a broad-spectrum antiemetic is needed.

Ondansetron: More suited for chemotherapy-induced vomiting and instances of acute vomiting.

6. Key Takeaways

  • Both Cerenia and Ondansetron are efficient in managing canine vomiting but serve slightly different clinical needs.
  • It’s essential to understand the cause of the vomiting to select the most suitable treatment.
  • In some cases, co-administration might be beneficial, but always under veterinary supervision.

FAQs: Cerenia vs Ondansetron

Q1: What are the primary side effects of Cerenia and Ondansetron?

Cerenia: Some potential side effects include drooling, lethargy, lack of appetite, or occasional diarrhea.

Ondansetron: Dogs may experience headaches, local reactions at the injection site, constipation, or, in rare cases, an allergic reaction.

Q2: Can cats be given Cerenia or Ondansetron?

Cerenia: Yes, Cerenia has been used for cats, especially for vomiting control.

Ondansetron: It’s also a viable option for feline patients, particularly for cases of acute vomiting or after chemotherapy.

Q3: Are there contraindications to using these antiemetics?

Cerenia: It shouldn’t be used in puppies under eight weeks old. Additionally, dogs with liver issues should be monitored closely when on this medication.

Ondansetron: Dogs with liver problems might not process the drug as efficiently. Also, it’s not recommended for puppies younger than four weeks.

Q4: How quickly can one expect to see results after administration?

Cerenia: Effects can be noticeable within a couple of hours post-administration, especially when given intravenously.

Ondansetron: Usually takes effect within 30 minutes to an hour after administration, depending on the dog’s condition and the method of administration.

Q5: How are these drugs metabolized, and are there any concerns for dogs with liver or kidney issues?

Cerenia: Primarily metabolized in the liver. If a dog has liver issues, dosing might need adjustments, and they should be closely monitored.

Ondansetron: Also metabolized in the liver, so similar precautions apply. Kidney function doesn’t significantly impact the drug’s metabolism, but always best to consult with a vet.

Q6: Can these medications be given with food?

Cerenia: It is often recommended to administer Cerenia tablets an hour before feeding. However, the injectable form isn’t as dependent on meal timings.

Ondansetron: It can be administered with or without food. If a dog seems to have an upset stomach after taking it, trying to give it with a small meal can help.

Q7: Are there natural alternatives to these medications?

While natural remedies like ginger or peppermint can sometimes aid in nausea relief, they’re not replacements for pharmaceutical antiemetics. Before trying any alternative treatments, always consult with your veterinarian to ensure safety and efficacy.

Q8: Can long-term use of these drugs lead to resistance or decreased effectiveness?

Currently, there’s no strong evidence to suggest that dogs develop resistance to either Cerenia or Ondansetron. However, it’s always best to use medications as prescribed and to monitor your pet for any changes in response.

Q9: How should leftover medication be stored or disposed of?

Both Cerenia and Ondansetron should be stored at room temperature, away from direct sunlight and moisture. If you need to dispose of expired or unused medication, consult with your veterinary clinic or local pharmacy about safe disposal methods to ensure environmental safety.

Q10: Are there any known drug interactions with Cerenia and Ondansetron?

While these drugs can be used in conjunction with many other medications, it’s essential to inform the veterinarian of all medications and supplements your dog is currently taking to avoid any potential interactions.

Q11: How do these medications actually work in the body?

Cerenia: This operates as a neurokinin-1 (NK-1) receptor antagonist, essentially blocking certain chemical signals in the brain responsible for inducing vomiting.

Ondansetron: This belongs to a class known as serotonin 5-HT3 receptor antagonists. It blocks the action of serotonin, a chemical in the brain, which can trigger nausea and vomiting.

Q12: Are there specific breeds that might have sensitivities or reactions to these drugs?

While no breed-specific sensitivities have been conclusively identified, individual dogs, regardless of breed, may experience unique reactions. It’s essential to monitor any dog when introducing a new medication.

Q13: What should owners do if they miss giving a dose?

For both Cerenia and Ondansetron, if a dose is missed, it’s typically recommended to give the medication as soon as remembered, but not to double up on doses. If it’s close to the next dosing time, skip the missed dose and continue with the regular schedule. Always confirm with your veterinarian in such scenarios.

Q14: Can pregnant or lactating dogs take these medications?

Cerenia: Safety in pregnant or lactating dogs has not been thoroughly studied. It’s always best to consult with a veterinarian before administering it to a pregnant or nursing dog.

Ondansetron: While this drug is sometimes used in pregnant women, its safety for pregnant or lactating dogs hasn’t been conclusively established. Again, veterinarian guidance is paramount.

Q15: Are there instances where dose adjustments are necessary?

Yes, for both medications, adjustments might be necessary based on the dog’s weight, age, overall health, and presence of other medical conditions. Regular check-ins with the veterinarian can help ensure optimal dosing.

Q16: Do these drugs have any impact on a dog’s appetite?

Cerenia: While it is used to control vomiting, some dogs might experience a decrease in appetite. If this persists, a vet consultation is advised.

Ondansetron: It’s primarily an antiemetic, so it’s not expected to significantly affect appetite. However, individual reactions can vary.

Q17: How long can a dog stay on these medications?

Both drugs are generally prescribed for short-term use. Long-term usage would depend on the dog’s specific medical condition and would need close veterinary monitoring to ensure no adverse effects develop over time.

Q18: Are there any signs or symptoms indicating that the medication isn’t working?

Continuous or severe vomiting, even after medication, is a clear sign. Additionally, if the dog appears more lethargic, uncomfortable, or displays any other unusual behaviors, it may be worth re-evaluating the treatment plan with a veterinarian.

Q19: Can these medications be used alongside other treatments, like fluid therapy or dietary changes?

Yes, both Cerenia and Ondansetron can be part of a broader treatment plan, which might include fluid therapy, dietary modifications, or other medications. Always ensure each treatment component is vet-approved to avoid any potential negative interactions.

Q20: If a dog displays an adverse reaction, how long does it typically take for the effects of the drug to wear off?

The duration can vary based on the medication’s metabolism and the specific adverse effect. Generally, for both drugs, most symptoms should dissipate within 24 hours. If concerning symptoms persist, immediate veterinary care is advised.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to Top