Product details
Zonisamide is an anticonvulsant (anti-seizure) medication used to treat and control seizures in animals.
This product is a capsule formulation.
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Can be used as a single agent, though it is often used in combination with other medications (e.g., phenobarbital) for seizure control in cats and dogs.
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Do not discontinue this medication abruptly; request refills ahead of time to prevent treatment interruption.
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Do not administer to breeding or pregnant animals. Pregnant individuals should avoid handling this medication if possible; if handling is necessary, wear gloves and exercise extreme caution.
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May be prescribed for other animal species; please consult your veterinarian.
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While this drug does not have an FDA-approved indication for all animal uses, it is commonly accepted for veterinarians to prescribe this medication for use in animals.
*Please note: This is a generic medication. Product packaging and appearance, including size, color, and shape, may differ from the description or images provided and are subject to manufacturer availability.
Product sourced directly from the manufacturer or their approved distributor. Guaranteed genuine product backed by the manufacturer.
For
Dogs and Cats
Active ingredient(s)
Zonisamide
Common brand names
Zonegran
Drug class
Anticonvulsant
Product strength & size
Zonisamide capsules may be available in multiple strengths and/or sizes. Please ensure the selected product and package size are appropriate for your pet, as recommended by your veterinarian.
For current availability, please refer to the product selection above.
Usage
Zonisamide Capsules should be given orally as directed by your veterinarian.
Do not discontinue this medication abruptly. Please consult your veterinarian before making any changes or discontinuing the prescribed dosing schedule.
This medication can be given with or without food. If your pet vomits or appears unwell after receiving a dose on an empty stomach, give future doses with food or a small treat. If vomiting continues, contact your veterinarian.
If you are pregnant, breastfeeding, or planning to become pregnant: avoid handling this medication if possible. If handling is necessary, wear gloves and exercise extreme caution during handling and administration. All pet owners should wash their hands thoroughly with soap and water after handling (even if gloves are worn).
Missed doses
Administer the dose as soon as possible. If it is almost time for the next dose, skip the missed dose and continue with the regular schedule. Do not give two doses at once.
Storage
Store in a cool, dry place at a controlled room temperature (68 to 77°F, excursions permitted between 59 and 86°F). Keep in a tight, light-resistant container and out of the reach of children and pets. Store away from heat and direct sunlight. Do not store in the bathroom, near the kitchen sink, or in damp places. The medicine may break down if exposed to heat or moisture.
Side effects
The most common side effects of this medication are drowsiness/sedation, lowered energy level, loss of balance/coordination, vomiting, diarrhea, and decreased appetite.
In rare cases, urinary stones and kidney or liver issues have been reported in some animals.
Contact your veterinarian immediately if you notice your pet has any extreme behavioral changes (e.g., aggression), complete loss of appetite, appears excessively tired, or if you notice yellowing of the skin, whites of the eyes, and/or gums.
Notify your veterinarian if your pet experiences any of the effects described above, or if you notice any other side effects that are persistent or troublesome.
If you notice anything unusual, please consult your veterinarian.
Precautions
Do NOT discontinue this medication abruptly. Please consult your veterinarian before making any changes to the prescribed dosing schedule, and request refills ahead of time to prevent treatment interruptions.
Do NOT administer to breeding or pregnant animals and use with caution in nursing animals. Significant risks, including birth defects, have been documented.
Pregnant individuals should avoid handling this medication if possible; if handling is necessary, wear gloves and exercise extreme caution.
Use with caution in animals with significant kidney impairment, preexisting liver disease, or keratoconjunctivitis sicca (a dry eye syndrome).
Do not administer to animals with a known history or suspected allergy/hypersensitivity to any sulfonamide drug, including this medication and any of its ingredients. Allergic reactions to medications may occur. Be sure to inform Vetsource and your veterinarian if your pet has any known drug sensitivities or allergies.
If your pet displays symptoms of an allergic reaction, discontinue therapy and call your veterinarian immediately or seek emergency veterinary attention. Symptoms may include (but are not limited to): swollen lips, tongue, face, or airways; difficulty breathing; agitation; profuse salivation; and widespread hives or itching.
Human exposure warning
This medication is classified as hazardous due to potential risks to individuals who are actively trying to conceive, as well as to women who are pregnant, breastfeeding, and those who may become pregnant.
If handling is necessary for pregnant, planning, or breastfeeding women: wear gloves while handling or administering this medication. All pet owners should wash their hands thoroughly with soap and water after handling the medication or if contact is made with the bodily fluids (e.g., vomit) of a treated animal, even if gloves are worn.
Unopened, intact capsules may not pose the same degree of risk as injectable drugs, which usually require extensive preparation. Opening, crushing, or otherwise manipulating capsules may increase the risk of exposure.
Drug and food interactions
The following drugs* may have potential interactions with this medication: amantadine, benzodiazepines (e.g., alprazolam, diazepam), carbonic anhydrase inhibitors (oral or ophthalmic, e.g., dorzolamide), CNS depressant drugs (e.g., dexmedetomidine, gabapentin, hydroxyzine, opioids), dexamethasone, ketoconazole, phenobarbital, phenothiazines (e.g., acepromazine, trimeprazine), salicylates (e.g., aspirin, bismuth subsalicylate), tramadol, trazodone, and tricyclic antidepressants (e.g., amitriptyline, clomipramine).
*NOTE: this may not be a comprehensive list. Contact your veterinarian if your pet experiences any unusual reactions when different medications are given together.
Please ensure your veterinarian is aware of all medications and supplements that your pet is currently receiving. Your veterinarian may prescribe multiple medications, even if a potential drug interaction may occur. In these instances, your veterinarian may adjust the dosages or monitor your pet more closely.
Adverse reactions
If you are concerned that your pet has experienced an adverse reaction to this medication, please contact Vetsource Pet Owner Care at 877-738-4443.
Overdose
If you have any reason to suspect an overdose, call your doctor/veterinarian or the appropriate poison control resource immediately.
For humans:
The national toll-free Poison Help line, 1-800-222-1222, will connect you to your local poison center in case of emergency. This service is available nationwide and in most U.S. territories.
For animals:
The ASPCA Animal Poison Control Center is available 24 hours a day, 365 days a year at 888-426-4435.
Pet Poison Helpline® also provides a 24/7 animal poison control service at 855-764-7661.
*Please note: this information is for third-party services and is provided for convenience in case of potential poison-related emergencies. There may be consultation fee for these services.
Disclaimer
The content provided on this page is NOT medical advice.
All content, including the images and product description above, is intended for general informational purposes only and should not be considered a substitute for professional veterinary consultation, diagnosis, or treatment.
Consult your veterinarian for complete information about this product and how it fits into your pet's individual treatment plan.
Last revised: 7/14/2025