Medically Reviewed By: Medsdog Team
Last Updated: September 2026
Amantadine dosage for dogs is a prescription only medication veterinarians use to help manage chronic pain particularly osteoarthritis, nerve pain, cancer-related pain, degenerative joint disease, and disk disease. It isn’t a standalone painkiller; it’s almost always added to a dog’s existing pain-management plan when other medications aren’t fully controlling discomfort.
This guide covers exactly how much amantadine to give a dog by weight, a free dosage calculator, a printable chart, side effects, drug interactions, and answers to the questions dog owners search for most.
The standard amantadine dosage for dogs is 3–5 mg/kg by mouth, once or twice daily (q12–24h), most often prescribed alongside another pain reliever such as an NSAID or gabapentin. Always confirm the exact amount with your veterinarian before giving any dose.
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Disclaimer: All information in this guide is provided for educational purposes only and should never replace professional veterinary advice.
Amantadine Dosage Calculator for Dogs By Weight
Accurately calculate the low and high target dosage ranges based on your dog’s weight.
- Always verify calculations with your veterinarian before giving medication.
- Amantadine must be paired with other analgesics for effective relief.
- Long-term therapy requires routine blood panels to safeguard organs.
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Amantadine For Dogs Overview
- Amantadine for dogs is a prescription drug used for chronic and nerve-related pain, not sudden or acute pain.
- The typical amantadine dose for dogs is 3–5 mg/kg, given once or twice a day.
- It was originally developed as a human antiviral but is used off-label (“extra-label”) in veterinary medicine for pain.
- Most dogs tolerate amantadine well; the most common side effects are mild digestive upset.
- Full pain-relief benefits can take 1–3 weeks to become noticeable it is not a fast-acting medication.
What Is Amantadine for Dogs?
Amantadine (Symmetrel®, Gocovri®, Osmolex ER®, and Endantadine®) is an antiviral drug was initially designed to treat Influenza infections in humans, however currently it is widely used by veterinarians off label for pain management in dogs.
Amantadine is not primarily used as a pain reliever; instead, it is used in combination with other drugs like gabapentin, opioids or NSAIDs when pain persists or is no longer well-managed.
Amantadine functions by interfering with the central nervous system’s processing of pain signals, which is why it may be useful for chronic, neuropathic pain. Its use in veterinary medicine is “extra-label” and pet owners should be diligent in following their veterinarian’s dosage and monitoring guidelines.
Amantadine use in dogs and cats is considered extra-label (off-label) because it is not specifically approved by the FDA for use in animals but is used as a result of veterinary experience and evidence. No veterinary specific formulation exists and veterinarians often use human formulations, such as tablets, capsules, liquid solutions or even compounded formulations that have been adapted to an individual pet’s dose.
How Much Amantadine Can Dogs Take?
Based on a pharmacokinetic study, the recommended amantadine dosage for dogs is 3–5 mg/kg, given once daily (every 24 hours) or divided into two doses (every 12 hours), as directed by your veterinarian.
Once Daily or Twice Daily?
Most published dosing guidance lists amantadine as 3–5 mg/kg once daily, but pharmacokinetic research in dogs has found the drug clears the bloodstream fairly quickly. Because of this, some veterinary pain specialists now prefer splitting the same total dose into two smaller doses given 12 hours apart for more consistent pain control throughout the day.
This is a clinical decision your vet will make based on your dog’s specific case never change the frequency on your own.
Amantadine Dosage Chart for Dogs by Weight
| Dog Weight | Weight (kg) | Low Dose (3 mg/kg) | High Dose (5 mg/kg) | Daily Dose Range |
|---|---|---|---|---|
| 5 lb | 2.3 kg | 6.9 mg | 11.5 mg | 6.9–11.5 mg |
| 10 lb | 4.5 kg | 13.5 mg | 22.5 mg | 13.5–22.5 mg |
| 15 lb | 6.8 kg | 20.4 mg | 34 mg | 20.4–34 mg |
| 20 lb | 9.1 kg | 27.3 mg | 45.5 mg | 27.3–45.5 mg |
| 30 lb | 13.6 kg | 40.8 mg | 68 mg | 40.8–68 mg |
| 40 lb | 18.1 kg | 54.3 mg | 90.5 mg | 54.3–90.5 mg |
| 50 lb | 22.7 kg | 68.1 mg | 113.5 mg | 68.1–113.5 mg |
| 60 lb | 27.2 kg | 81.6 mg | 136 mg | 81.6–136 mg |
| 70 lb | 31.8 kg | 95.4 mg | 159 mg | 95.4–159 mg |
| 80 lb | 36.3 kg | 108.9 mg | 181.5 mg | 108.9–181.5 mg |
| 90 lb | 40.8 kg | 122.4 mg | 204 mg | 122.4–204 mg |
| 100 lb | 45.4 kg | 136.2 mg | 227 mg | 136.2–227 mg |
| 110 lb | 49.9 kg | 149.7 mg | 249.5 mg | 149.7–249.5 mg |
| 120 lb | 54.4 kg | 163.2 mg | 272 mg | 163.2–272 mg |
Amantadine 100 mg for Dogs Dosage Chart
| Dog Weight | Weight (kg) | Number of 100 mg Capsules |
|---|---|---|
| 45 lb | 20.4 kg | 1 capsule |
| 50 lb | 22.7 kg | 1 capsule |
| 55 lb | 24.9 kg | 1 capsule |
| 60 lb | 27.2 kg | 1 capsule |
| 65 lb | 29.5 kg | 1 capsule |
| 70 lb | 31.8 kg | 1 capsule |
| 75 lb | 34.0 kg | 1 capsule |
| 80 lb | 36.3 kg | 1 capsule |
| 90 lb | 40.8 kg | 1 capsule |
| 100 lb | 45.4 kg | 1 capsule |
Important: Standard human capsules come in a fixed 100 mg size and cannot be safely split into fractional doses. For dogs under roughly 40 lbs, vets typically prescribe a compounded liquid.
Amantadine 50 mg /5ml (10 mg/ml) Dosage Chart for Dogs by Weight
| Dog Weight | Weight (kg) | Low Dose (3 mg/kg) | High Dose (5 mg/kg) | Volume per Dose (3–5 mg/kg) |
|---|---|---|---|---|
| 5 lb | 2.3 kg | 6.9 mg | 11.5 mg | 0.69–1.15 mL |
| 10 lb | 4.5 kg | 13.5 mg | 22.5 mg | 1.35–2.25 mL |
| 15 lb | 6.8 kg | 20.4 mg | 34 mg | 2.04–3.40 mL |
| 20 lb | 9.1 kg | 27.3 mg | 45.5 mg | 2.73–4.55 mL |
| 30 lb | 13.6 kg | 40.8 mg | 68 mg | 4.08–6.80 mL |
| 40 lb | 18.1 kg | 54.3 mg | 90.5 mg | 5.43–9.05 mL |
| 50 lb | 22.7 kg | 68.1 mg | 113.5 mg | 6.81–11.35 mL |
What Is Amantadine Used for in Dogs?
Amantadine for pets is mostly used to manage chronic and neuropathic (nerve-related) pain in a dog when other pain medications are no longer effective. It does this by dampening pain sensitization in the nervous system, making it especially effective for those dogs that are suffering from chronic or escalating pain.
Amantadine is used for the following conditions in dogs:
- Osteoarthritis and other degenerative diseases of the joints
- Pain due to cancer, especially osteosarcoma (bone cancer)
- Intervertebral Disc Disease (IVDD).
- Any kind of pain or nerve related conditions that affect the nervous system.
- Chronic pain syndromes
- Post-operative pain management
How Amantadine Helps
Amantadine is recommended when a dog’s nervous system gets “wound up,” or “central sensitization” occurs, meaning that the nervous system is overly sensitive to pain. The drug’s action on this process may help to better manage pain and encourage dogs to be more comfortable and active.
Common Combination Medications
Amantadine is rarely used alone. It’s typically layered onto an existing multimodal pain protocol that may include:
- NSAIDs for dogs already on an anti-inflammatory, understanding how meloxicam dosing works for arthritis pain in dogs helps explain why amantadine is often added rather than substituted
- Gabapentin or pregabalin dosing guidelines for nerve-related pain in dogs
- Opioids such as tramadol dosage charts for dogs in chronic pain protocols
Clinical research has found that dogs with arthritis who receive amantadine alongside an NSAID often show better mobility than dogs treated with an NSAID alone which is why vets frequently combine it with carprofen dosage protocols for canine osteoarthritis or with newer options like grapiprant as an NSAID alternative for long-term joint pain.
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Important Considerations
- The treatment plan is customized to meet the needs of the dog.
- Amantadine is to be used with caution in dogs with kidney disease, liver disease, or heart failure.
- Most of the time it is not recommended for pregnant or nursing dogs.
- It can take 10 days or longer to see all the benefits of the medication.
- For the best and safest results, always follow your veterinarian’s directions for dosing and administration.
What Are the Benefits of Amantadine for Pets?
The use of Amantadine drugs for dogs can provide a number of benefits for pets, especially if they are suffering from chronic or persistent pain that is hard to manage with other pain relief options. It is typically used when other pain-relieving drugs on their own have failed to ease the pain and is generally combined with other pain-management strategies.
Some of the main advantages of Amantadine for pets are:
- Supports chronic pain and neuropathic (nerve) pain.
- May enhance the comfort and quality of life of pets suffering from chronic painful disease.
- Typical uses are post surgery healing and treatment of arthritis and osteosarcoma.
- Helps to reduce pain along with other analgesics.
- May help pets with pain not responding to other pain medication.
- May be part of some treatment protocol for its antiviral properties.
- Veterinarians prescribe for dogs and cats as part of a treatment plan tailored to a specific animal.
Amantadine may also be used in combination with other pain control drugs to relieve pain in a more effective and all-encompassing manner in pets suffering from chronic and persistent pain.
What Are the Common Side Effects of Amantadine in Dogs?
Most dogs will have few or no significant side effects from Amantadine, and the drug is thought to be safe for dogs. If side effects do happen, they are generally mild and short-lived, and may get better as the dog’s body becomes accustomed to the drug. Amantadine should be taken with food to help prevent stomach problems.
Common Side Effects
Common side effects are:
- Poor or loose stools
- Vomiting
- Flatulence (gas)
- Decreased appetite
- Sleepiness or drowsiness
- Some fatigue or sluggishness
- Restlessness or agitation
Less common side effects may include:
Some dogs may experience less common side effects, such as:
- And incoordination or difficulty in walking (ataxia).
- Lightheadedness
- Excessive drooling
- Increased thirst
- Dry mouth
- Dysuria or retention of urine
- Alterations in urination habits.
- Increased heart rate
- Constipation
- Dry eyes
Very uncommon but serious side effects.
More serious reactions are rare but may happen and do need immediate veterinary care:
- Severe agitation or aggressive behaviour
- Tremors
- Anxiety
- Seizures
- Limb swelling
- Confusion or behaviour like a hallucination, especially at high doses, or in combination with some medicines that affect the nervous system
Important Safety Notes
- Most gastrointestinal side effects are mild, such as diarrhea, gas or vomiting, and tend to improve over the first few days of treatment without intervention.
- More prolonged effects may be seen in dogs with kidney or liver disease as the medication may remain in the body longer.
- If the side effects continue or get worse or your dog appears to be having a serious reaction or possible overdose, contact your veterinarian immediately.
- Always adjust or discontinue meds for your dog only with a veterinarian’s advice.
In general, most dogs tolerate amantadine well and when used correctly under veterinary supervision, it can be extremely helpful for pain relief.
What Are the Most Serious Risks of Amantadine for Dogs?
Amantadine dosage for dogs is generally safe for most dogs, but in rare cases serious side effects may occur. Owners should be mindful of these potential risks and if any concerning signs appear during treatments, veterinary attention should be sought immediately.
Severe Side Effects to be Alert to
Side effects that are very rare but can be serious in amantadine are:
- Seizures
- Severe restlessness, agitation
- Lack of co-ordination (balance)
- Walking problems or unusual walking pattern
- Swelling of the limbs especially in dogs with heart disease.
If your dog shows signs of any of these problems, call your vet or emergency veterinarian right away.
Dogs at Higher Risk
Dogs with some health conditions should not take Amantadine or should take it with caution such as:
- Kidney disease
- Liver disease
- Heart failure or heart disease
- Seizure disorders
- Behavioral disorders
- Untreated glaucoma
- Eczematoid dermatitis
- History of allergies or sensitivity to amantadine.
Use in Pregnancy and During Lactation
Amantadine should be used with caution in pregnant or nursing dogs because it has not been sufficiently proven to be safe in these animals.
Potential Drug Interactions
Some drugs may interfere with the way amantadine works and may be more likely to cause side effects. Let your veterinarian know if your dog is on any other medications or supplements, particularly:
- Thiazide diuretics
- Trimethoprim-sulfa antibiotics
- Heart medications, such as quinidine
With careful veterinary monitoring and proper dosing, however, there is the potential for dogs to receive amantadine’s pain-management benefits while reducing risks.
Does Amantadine Interact With Other Dog Medications?
Amantadine is compatible with many veterinary drugs and only has a few significant drug interactions. However, some medications may interact with amantadine, either increase the amount of amantadine in the blood or increase the risk of side effects.
Therefore, dog owners should always let their veterinarian know of any prescription or over the counter drugs, vitamins, supplements or herbal treatments that their dog is on.
Medications that may interact with Amantadine.
Amantadine should be used with caution in combination with:
- Amitriptyline
- Antihistamines like diphenhydramine (Benadryl®)
- Atropine
- Selegiline (Anipryl®)
- Quinidine
- Quinine
- Trimethoprim/sulfa (Bactrim®)
- Thiazide diuretics (e.g., hydrochlorothiazide)
- Triamterene
- Other anticholinergic medications
- Stimulants that act on the central nervous system (CNS stimulants)
- Medications that affect the pH of the urine; urinary acidifiers
The possibility of drug interactions and what they may be.
These interactions may:
- Blood levels of amantadine can be increased by giving it as a bolus followed by a continuous infusion.
- Cause side effects to occur more easily
- Raise the level of activity, excitement or agitation of the nervous system
- Worsen anticholinergic side effects such as:
- Dry mouth
- Dry eyes
- Constipation
- Difficulty urinating
- Increased heart rate
- Blurred vision
- Slow down the clearance of amantadine from the body
Important Safety Advice
Amantadine dosage for dogs per pound is relatively safe and may be administered with other veterinary drugs, however, drug interactions may occur. Always ask your vet before adding, removing or mixing medicines, to make sure of the safest and best treatment for your dog.
How Much Does Amantadine Cost for Dogs?
Amantadine is inexpensive relative to many chronic pain medications. Because it’s a human generic drug, a 30-tablet supply typically runs in the range of roughly $15–$60 depending on pharmacy, dose strength, and whether a compounded liquid formulation is needed.
Compounded versions for small dogs are usually priced higher due to custom preparation. Your veterinarian or a veterinary compounding pharmacy can give you an exact quote for your dog’s prescribed dose.
Storage Guidelines
- Store at controlled room temperature, 68°F–77°F (20°C–25°C); brief excursions to 59°F–86°F (15°C–30°C) are acceptable.
- Keep in a tightly closed container, away from moisture and light.
- Compounded liquid formulations should follow the compounding pharmacy’s specific storage instructions — most should not be frozen unless directed.
- Keep out of reach of children and other pets.
FAQs
What is amantadine used for in dogs?
Amantadine is used to manage chronic and nerve-related pain in dogs, typically as an add-on to another pain medication when arthritis, cancer pain, IVDD, or post-surgical pain isn’t fully controlled on its own.
How much amantadine can a dog have?
The standard amantadine dose for dogs is 3–5 mg/kg by mouth, once or twice daily. The exact amount depends on your dog’s weight, health status, and other medications use the calculator above as a reference, then confirm with your vet.
If my dog misses a dose of amantadine, what should I do?
Give the missed dose as soon as you remember. If it’s almost time for the next scheduled dose, skip the missed one and resume the normal schedule. Never double up doses.
When does amantadine start working in dogs?
Most dogs show noticeable improvement within 1–3 weeks. Because amantadine addresses nervous-system pain sensitization rather than providing immediate relief, it needs to be given consistently for several weeks before judging its effectiveness.
How long do the effects of amantadine last in a dog?
Effects generally last about 24 hours, though some vets prescribe twice-daily dosing for more consistent pain control.
Can amantadine be used by itself?
It can be, but it’s most effective when combined with another pain medication such as an NSAID, gabapentin, or tramadol, since amantadine alone is a weaker analgesic.
Is gabapentin the same as amantadine?
No. They belong to different drug classes and relieve pain through different mechanisms, which is why they’re often prescribed together rather than as substitutes for each other.
What should I do if I think my dog overdosed on amantadine?
Signs of overdose include extreme drowsiness, tremors, vomiting, restlessness, trouble breathing, excessive drooling, and loss of coordination. Contact your veterinarian or an animal poison control center immediately.
Where can I get amantadine for my dog?
Amantadine is prescription-only. It can be filled at a human pharmacy with a veterinary prescription or obtained as a compounded formulation through a veterinary compounding pharmacy.
Final Thoughts
Amantadine dosage for dogs generally falls between 3–5 mg/kg, given once or twice daily, and works best as part of a broader multimodal pain-management plan rather than as a standalone treatment. Most dogs tolerate it well, with mild digestive upset being the most common side effect and serious reactions being rare. Because full benefits can take one to three weeks to appear, consistency matters more than speed with this medication.
Always confirm your dog’s exact dose, frequency, and any medication combinations with your veterinarian the calculator and chart on this page are educational tools, not a substitute for professional veterinary guidance.
References
- British Small Animal Veterinary Association. Amantadine fact sheet.
- Grubb, T. (2018). Gabapentin and Amantadine for Chronic Pain: Is Your Dose Right? Today’s Veterinary Practice.
- Gruen, M.E., et al. (2022). AAHA Pain Management Guidelines for Dogs and Cats. Journal of the American Animal Hospital Association.
- Lascelles, B.D., et al. (2008). Amantadine in combination with meloxicam for canine osteoarthritis pain placebo-controlled trial.
- Cornell Riney Canine Health Center. Intervertebral Disc Disease overview.
