Pain management in dogs has become increasingly prominent in recent years. Not only are pain medications important for managing acute, post-operative pain in our beloved companions, but it has become even more so when managing pain due to conditions such as arthritis. And, since many pets are living longer and longer, the likelihood that you, as a pet parent, will have to manage a chronic condition in your pet becomes increasingly likely.

Because humans regularly use aspirin to manage pain, you might think it is perfectly safe for your dog. While aspirin is one of the options for over-the-counter pain relief that you CAN give your dog, it can have severe side effects if given at the incorrect dose and with certain other medications. 

What Is Aspirin?

Aspirin, or acetylsalicylic acid (ASA), belongs to a class of pain medications called non-steroidal anti-inflammatories (NSAIDs). This class also includes the drugs ibuprofen, naproxen, meloxicam, and a long list of other NSAIDs that are typically geared toward human use.

Aspirin works by reducing pain and inflammation, inhibiting an enzyme called cyclooxygenase, or COX. The COX-1 and COX-2 enzymes are responsible for producing prostaglandins in your dog’s body. While these prostaglandins, or hormone-like chemicals, have many beneficial roles within your canine companion’s body, they also result in pain, inflammation, and fever. 

So, if aspirin “blocks” the activity of the COX enzymes, it can also prevent pain, inflammation, and fever.

Aspirin is a very commonly used pain reliever for humans, but it should be used with extreme caution in dogs due to the often severe and potentially life-threatening side effects that could occur. It is strongly recommended that you consult with your veterinarian before giving your dog aspirin. 

There are much safer and more effective pain management alternatives that can be recommended for your beloved companion.

Can Dogs Have Aspirin?

Aspirin can be prescribed for your dog, but should only be done under the direct supervision of your veterinarian. Not only are there several potentially severe side effects, adverse reactions, risk factors, and drug interactions that should be carefully considered—but overdoses of aspirin can be fatal in dogs.

That said, veterinarians generally prescribe aspirin to treat mild pain, inflammation, or fevers.  Short-term use of aspirin is most common for conditions such as osteoarthritis and musculoskeletal inflammation.  

And, because of its anticoagulant properties, aspirin has also been prescribed to prevent blood clot formation due to certain medical conditions in dogs.

Now, because the correct dosage of aspirin for your dog depends on several factors, such as your dog’s size, weight, and overall health, it remains extremely important to seek input from your veterinarian before giving aspirin or any other medications, whether they are considered “over-the-counter” or not. 

Even over-the-counter products labeled as “baby aspirin” (generally a low-dose aspirin meant for children) or “enteric coated” (a.k.a. buffered) should be discussed with your veterinarian before choosing to medicate, as certain medical conditions may require a significant dosage adjustment.

Potential Benefits of Aspirin for Dogs

While giving your dog aspirin for pain management can have several potential side effects, it also has a few potential benefits.  

Popular uses of aspirin in dogs:

• Osteoarthritis
• Dental disease
• Forelimb sprain
• Hindlimb sprain
• Broken toenails
• Fever
• Blood clots

It should be noted that even though aspirin for dogs has positive effects, it should ideally only be used short-term. This is due to the differences in metabolization of medications compared to humans. Dogs may be more prone to developing side effects of aspirin. 

If your dog’s condition could benefit from long-term NSAID use, it is best to discuss the numerous options with your veterinarian for those that are specifically formulated for dogs that are safer and will be less likely to cause severe side effects.

Dangers, Risks and Side Effects of Aspirin in Dogs

Now that we have discussed the potential benefits of aspirin in dogs, let’s take a closer look at the most common side effects that can occur:

Gastrointestinal Issues

Damage to the gastrointestinal tract is one of the most commonly experienced side effects when giving dogs aspirin. 

As stated previously, aspirin “works” by blocking the COX enzymes. While some COX enzymes are responsible for causing inflammation, other COX enzymes are helpful and are responsible for regulating blood flow, clotting, and mucus production within the gastrointestinal tract and other major organs. 

Aspirin is non-selective (i.e., it blocks both “good” and “bad” COX enzymes), it reduces the inhibition of normal platelet activity and clotting, which results in bleeding ulcers within the gastrointestinal tract.  

The most common side effects:

• Stomach upset
• Vomiting
• Blood in the vomitus
• Diarrhea
• Dark, tarry stools (digested blood from bleeding in the upper gastrointestinal tract) 
• Frank blood (bright red blood visible, which indicates undigested blood from the large intestine) 

Toxicity and Overdose

Aspirin poisoning or toxicity often occurs when your pet accidentally gets into this medication and ingests a dose that is much too high. The chance of toxicity also increases in dogs with certain pre-existing medical conditions or when aspirin interacts with certain other medications that your dog is already taking. 

Because aspirin is broken down and eliminated by the liver and then partially by the kidneys, overdoses of aspirin can significantly reduce the normal flow of blood to these organs by blocking the ‘good’ COX enzymes. This can result in liver and kidney failure and even death if the dose is high enough or if that same dose is given repeatedly. If your furry friend has pre-existing liver or kidney issues, they could be even more sensitive to toxicity and overdose.

Blood Clotting Issues

Aspirin can interfere with the normal clotting mechanisms in your dog’s body. This occurs when aspirin blocks the previously mentioned COX-1 enzyme, decreasing the production of thromboxane. 

Aspirin is a type of blood thinner that prevents blood cells from “sticking” or “clumping” together to form a clot. This decreased ability to form blood clots occurs rapidly (within an hour) after aspirin administration. And, return to normal platelet function can take anywhere from 4-10 days. This side effect could make your four-legged friend much more prone to bruising or excessive bleeding. Therefore, the potential risks should be carefully weighed against the potential benefits before aspirin administration.

Interaction with Other Medications

It is strongly recommended that you avoid giving your dog other NSAIDs or corticosteroids while they are taking aspirin. Concurrently giving these medications significantly increases the risk of severe side effects.  

You should always inform your veterinarian of any other medications your pet is on before any aspirin is administered. 

Some additional common medications that may interact with aspirin and result in negative side effects include ACE inhibitors like benazepril or enalapril, diuretics such as furosemide, anticoagulant heparin, and the anti-seizure medication phenobarbital.

A “wash-out” period of 10-14 days is generally recommended between the last dose of aspirin and starting a new treatment regimen to reduce the risk of potentially fatal side effects.

Signs of Aspirin Toxicity in Dogs

When aspirin is used at appropriate doses in dogs, it can have very beneficial effects. However, if you give your dog the wrong dosage or an accidental overdose ingestion occurs, aspirin can result in severe poisoning.  

Here are some of the common signs of aspirin toxicity that you should watch for:

• Vomiting
• Diarrhea
• Bloody vomit
• Black-tarry stool (due to digested blood from the upper gastrointestinal tract)
• Respiratory changes (generally an increased rate and depth of respiration)
• Hyperthermia (significantly increased body temperature)
• Weakness
• Change in thirst or urination (typically increased due to secondary kidney failure)
• Collapse
• Weakness
• Tremors (involuntary muscle movements that look like shaking, shivering, or trembling)
• Seizures
• Death

If you notice any of the above signs in your dog, contact your veterinarian or Pet Poison Helpline!

Safe Alternatives to Aspirin for Dogs

Although aspirin is often readily available in most households, many other dog-specific pain relief options are much safer than aspirin.  

Let’s take a closer look at some of these available options.

Prescription Medications  

Veterinary-approved, dog-specific NSAIDs are generally recommended over aspirin for pain management of both acute and chronic conditions. 

These NSAIDs tend to be more COX-specific than aspirin, i.e. they will block the “bad,” inflammation-causing COX enzymes while allowing the “good” COX enzymes to continue their positive functions in your dog’s body.  

Some of the more commonly prescribed dog-specific NSAIDs in veterinary medicine are carprofen, meloxicam, deracoxib, firocoxib, and grapiprant.

Holistic Alternatives

Physical therapy, veterinary medical acupuncture and massage, and veterinary chiropractic care are great options for pain relief that often work synergistically with traditional Western veterinary medicine treatment regimens, such as NSAIDs. These options are particularly useful for managing chronic pain in dogs.

Warm Compresses and Rest

If the pain is mild, apply a warm compress to the painful area for approximately 10 minutes. Encourage them to rest (i.e., restrict their activity), which may be beneficial and will give you time to schedule an appointment with your veterinarian.

Monoclonal Antibody Therapy

Bedinvetmab is the first and only monthly injectable monoclonal antibody therapy indicated for managing the pain of chronic arthritis in dogs. It works by binding to and preventing cell signaling in the nerve cells responsible for transmitting pain. 

As always, it is paramount to consult with your veterinarian before administering any pain medications to your dog. By doing so, you can avoid causing complications or harm to your beloved companion.

What to Do If You’ve Already Given Your Dog Aspirin

As with all cases of poisoning, early intervention is the key to successful treatment and a positive outcome. 

If your dog has been given aspirin without first consulting a veterinarian or has accidentally ingested an overdose of aspirin, it is always best to contact your veterinarian immediately for advice on how to proceed.  

Your veterinarian may induce vomiting in your dog. This is to prevent absorption into the bloodstream if the time of ingestion is known and is less than 2 hours. For most cases, your veterinarian will likely recommend stomach protectants and a bland diet for several days after ingestion. More severe cases of aspirin poisoning may require administration of activated charcoal, hospitalization with intravenous fluid therapy and medications to treat vomiting, etc., and multiple bloodwork rechecks to evaluate for kidney and liver damage, even after being discharged.

Final Thoughts on Aspirin for Dogs

While aspirin may be beneficial in some cases of pain management in dogs, it should only be used under your veterinarian’s direct supervision while consistently monitoring for the development of side effects.  

In addition, if your four-legged friend has a chronic, painful medical condition such as arthritis that would benefit from long-term and frequent use of NSAIDs, then discussing dog-specific NSAID options with your veterinarian is advised since they are considered to be much safer overall with significantly less chance of developing severe side effects. That way, you can ensure you and your dog will have many more happy and pain-free years together.

Sources

https://total.vet/aspirin-for-dogs

https://vcahospitals.com/know-your-pet/aspirin

Aspirin for Dogs: Uses, Side Effects, and Alternatives

https://nutri-vet.com/blogs/news/aspirin-pain-relief-for-dogs

https://www.petcarerx.com/article/can-you-use-aspirin-for-dogs/1473?srsltid=AfmBOor_am6sfdWpz7akz_jrAnEjoHEoxGusPbSxyipJgmrYoVVM9zqj

https://vcahospitals.com/know-your-pet/aspirin-poisoning-in-dogs

https://pmc.ncbi.nlm.nih.gov/articles/PMC6766539

Aspirin