Topamax for dogs: Usage, dosage, and safety

In this article:

• Uses
• Safety
• Dosage
• Alternatives

In this article

• Uses
• Safety
• Dosage
• Alternatives

Although veterinarians don’t use brand-name Topamax, they sometimes use the generic version topiramate as an add-on drug to prevent seizures in dogs. Topiramate is safe to give to dogs. It’s just not used very often in veterinary medicine. One reason is that it has a very short half-life in dogs, so it may not be as effective as another drug. Veterinarians usually try other antiepileptic drugs before considering topiramate. 

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What is Topamax used for in dogs?

Veterinarians use topiramate, the generic version of Topamax, to control seizures in dogs. It is only used with other anti-seizure drugs, usually after many other anti-seizure drugs have been tried and failed. There are no established guidelines for which kinds of seizures are best treated by topiramate. However, there is general agreement that it’s a viable alternative for treating seizures that don’t have an identifiable cause (canine idiopathic epilepsy) or seizures that are not being effectively treated by other drugs (refractory epilepsy). 

Seizure disorders

Seizures are a short-lived set of symptoms caused by excessive or simultaneous nerve overactivity in the brain. Epilepsy or seizure disorder is diagnosed when seizures happen at least twice in a six-month period. The American Kennel Club estimates that about 0.75% of dogs have epilepsy. 

Veterinarians treat active seizures with anticonvulsants. Some dogs may be put on daily anticonvulsants to prevent future seizures, called maintenance treatment. For many one-time seizures with an identifiable cause, maintenance treatment may not be necessary. 

A veterinarian may choose to start maintenance treatment based on seizure frequency and severity. Veterinary guidelines call for maintenance drug therapy in a dog that has:

• Had two or more seizures in a six-month period
• Had one very severe or prolonged seizure (status epilepticus)
• Experienced more than one seizure in a single day (cluster seizures)
• Increasing numbers of seizures
• Increasing lengths of seizures
• Increasing severity of seizures
• Long recovery periods after a seizure

Veterinarians rarely use brand-name human drugs like Topamax. Their price is high relative to generic or veterinary versions of the drug. 

All anti-seizure medications work by slowing nerve signals and making the nervous system less excitable. Topiramate is no exception, but its mechanism of action is poorly understood. At the right serum concentrations, it slows down nerve signals in several ways such as increasing the activity of the inhibitory neurotransmitter GABA at GABA receptors.

Topiramate is not the veterinarian’s first choice as an anti-seizure medication. It’s more likely to be somewhere near the last choice. 

The goal of drug therapy is to control canine seizures by using just one drug. A veterinarian’s first choices for seizure prevention in a dog are phenobarbital and potassium bromide. Some veterinarians may start with the anticonvulsants zonisamide or levetiracetam. 

Sometimes, that one drug is not enough to control seizures. At that point, a veterinarian may add another anti-seizure drug to the treatment regimen. Adding drugs to a primary drug treatment is called adjunctive drug therapy. 

Again, the top choices for adjunct treatment of canine epilepsy do not include topiramate. One reason is that it’s not as well-studied as other anticonvulsants, so veterinarians aren’t entirely confident in the pharmacology of topiramate. Furthermore, it has very different pharmacokinetics in dogs than in humans, so it may not work as well in dogs. In people, the half-life of topiramate is 21 hours. In dogs, the half-life of topiramate is two to four hours. That’s so short a time that it’s difficult to get topiramate plasma concentrations to a steady state even with doses given three times daily. The other downside is its twice-daily dosing. It’s easy to miss or forget doses.

Is Topamax safe for dogs?

Topamax and its generic version, topiramate, are safe for dogs. The most commonly reported side effects are gastrointestinal issues, loss of appetite, sedation, and irritability. 

Topiramate is not safe for every dog. Dogs that have had an allergic reaction to topiramate should not be given topiramate. Veterinarians may be cautious about giving topiramate to a dog with kidney or hepatic dysfunction. In those cases, they may use a low dose to prevent side effects.

Side effects of Topamax in dogs

The most common side effects of topiramate in dogs are:

• Gastrointestinal distress
• Reduced appetite
• Sleepiness
• Irritability
• Coordination problems (ataxia)
• Weight loss

In dogs, the most serious side effects of topiramate are severe allergic reactions, though these are rare. Immediately contact a veterinarian or veterinary hospital if a dog taking topiramate experiences symptoms such as:

• Swelling around the face or mouth
• Problems breathing
• Skin rash
• Fever

Otherwise, there isn’t much documentation in veterinary medicine about topiramate’s serious side effects in dogs. In human clinical trials, some participants experienced serious side effects such as:

• Vision problems
• Metabolic acidosis
• Neurological problems
• Kidney stones
• Pancreas inflammation (pancreatitis)

Interactions of Topamax with other pet meds

In people, topiramate has some drug interactions that may cause problems. Veterinarians don’t know if dogs have the same problems, but they assume topiramate can cause problems with:

• Drugs that make a dog sleepy like narcotic pain relievers or benzodiazepines
• The anti-seizure drugs phenytoin, lamotrigine, or valproic acid
• Glaucoma treatments called carbonic anhydrase inhibitors 

Topamax dosage for dogs

The standard topiramate dosage for dogs is 5–10 milligrams per kilogram of body weight given twice daily. Today’s Veterinary Practice recommends a dosage of 5–10 mg/kg given two to three times daily. Plumb’s Veterinary Drug Manual includes a recommended dose of 2.5–5 mg/kg given three times per day as an alternative. 

At these dosages, it is possible to give human versions of topiramate to a dog. Topamax and generic topiramate are sold as capsules and tablets at dosage strengths as low as 15 mg to as high as 200 mg. 

The veterinarian may prescribe a veterinary formulation of topiramate tablets, which come in dosage strengths ranging from 15 mg to 100 mg.

People can take an extended-release version of topiramate that requires only a single dose daily, but the veterinary literature does not specify dosages for small animals. People can also take a liquid formulation of topiramate (Eprontia), but cost may be an issue.

Can dogs overdose on Topamax?

Dogs can overdose on Topamax or its generic version, topiramate. Although topiramate is not often used in dogs, the ASPCA Animal Poison Control Center (APCC) records over a hundred reports of topiramate exposure every year. 

If a dog is given too much topiramate or ingests a person’s prescription topiramate, call the ASPCA Animal Poison Control Center or a veterinarian. The most common clinical signs of a topiramate overdose in people are sedation, low energy, lethargy, blurred vision, loss of coordination, stupor, abdominal pain, and agitation.

In dogs, the highest recommended dose is 10 mg/kg given three times per day.

Can I give my dog Topamax every day?

Topiramate is a long-term treatment to prevent canine seizures. Regular daily doses are considered safe in dogs.

How to give your dog Topamax

To work, topiramate must be given to a dog twice daily:

• Follow all the instructions given by the veterinarian.
• Do not give more than prescribed or give topiramate more often than prescribed.
• Topiramate tablets and capsules can be given to a dog with or without food.
• It’s safer to handle topiramate tablets while wearing nonpermeable gloves.
• If you do not know how to give a tablet or capsule to a dog, have a veterinary professional show you the best procedure.
• Give a missed dose when remembered unless it’s almost time for the next dose. In that case, skip the missed dose and give the next dose as scheduled. Do not give two doses to make up for a missed dose.
• The veterinarian will require follow-up visits and lab tests to monitor the effectiveness of treatment. Please keep all appointments.
• Keep topiramate tablets or capsules securely out of the reach of children and other people.

Topamax alternatives for dogs

Veterinarians only use topiramate as an add-on drug in dogs when other anti-seizure drugs aren’t successful. 

For refractory seizures—those that can’t be controlled with monotherapy—a veterinarian has a long list of possible drugs to choose from, including topiramate. Alternatives to topiramate include:

• Gabapentin
• Clonazepam
• Valproic acid
• Clorazepate
• Felbamate
• Mephenytoin
• Pregabalin
• Imepitoin
• Diazepam (no longer considered effective for preventing canine seizures)

The veterinarian will probably have tried many of these drugs before suggesting topiramate as an adjunct treatment.

Summary

In veterinary medicine, topiramate is used to control canine seizures, but it’s not the first choice for epileptic dogs. Instead, topiramate is added to the treatment regimen when other drugs are not completely successful at seizure control. Although it’s not a front-line antiepileptic drug, topiramate is effective in dogs. It’s also safe and causes few adverse effects. The downside is that it requires frequent doses, making it easier to forget or miss doses.