One of the most common questions veterinarians get is, ‘What can I give my dog to relieve pain?’ While there are many prescription painkiller options for dogs, what pet owners usually want to ask about are the over-the-counter painkillers they have in the cupboard to give their dog in case of an emergency.
For a long time, the most effective and safest pain reliever for humans and dogs was aspirin, but if you ask your vet this question today, they’ll likely tell you that there are no over-the-counter pain relievers that are safe for dogs. Why?
Aspirin poses a high risk of toxicity to dogs and there are many safer alternatives available, so aspirin is rarely recommended for any purpose.
What is Aspirin?
Aspirin, also known as acetylsalicylic acid (try saying that five times quickly), is a painkiller that belongs to the NSAID family (nonsteroidal anti-inflammatory drugs).
NSAIDs are used to:
- Pain control
- Reduces inflammation
- Decreased clotting
- Antipyretics
Aspirin gets its long name because it’s one of several salicylates, chemicals found in a variety of products.
Some examples are given below:
- Pepto-Bismol (Bismuth Subsalicylate)
- Pain relieving cream (Bengay, Icy Hot)
- Foundation and concealer
- Topical acne medications
- Wintergreen Oil
Although all of these salicylates are NSAIDs, they have varying levels of toxicity to dogs.
How does aspirin work?
Aspirin, as an NSAID, works by blocking an enzyme called cyclooxygenase from forming compounds called prostaglandins. Prostaglandins have many functions in the body, including inducing fever, causing inflammation and pain, and helping platelets clot at the site of a cut. So aspirin inhibits this, lowering fever, treating pain and inflammation, and reducing the body’s ability to clot.
Why is aspirin unsafe for dogs?
There are many different types of prostaglandins in the body, each with a different function. Ideally, aspirin would only inhibit the production of the prostaglandins that cause pain, inflammation, and fever, without causing any other side effects. Drugs like aspirin that inhibit all of them in this way are called nonselective COX inhibitors.
Aspirin has been replaced by many other NSAIDs or NSAID alternatives that more selectively inhibit the production of the prostaglandins you want to inhibit and have a lower risk of unwanted side effects.
The most common problem with aspirin, and what makes it worse than other NSAIDs, is that it causes insufficient blood flow to stomach cells, leading to cell death and the formation of stomach ulcers. Not only can it cause life-threatening gastrointestinal bleeding, but insufficient blood flow to the kidneys can cause kidney damage and other organs can be affected as well. Combine the risk of bleeding and the risk of not clotting as side effects of the drug and you can imagine how dangerous it can be.
Pregnant female dogs are at even higher risk of aspirin poisoning, as high levels of aspirin can accumulate in the fetus and cause death or bleeding in the mother.
Aspirin can be toxic to dogs, whether given once or repeatedly. It is very dangerous and does not provide better pain relief than other painkillers, so it is unsafe to give to dogs.
One of aspirin’s long-standing uses was as an anticoagulant, a drug to prevent blood clotting. This has been largely replaced by more effective and safer drugs, making aspirin’s use in dogs almost obsolete.
Signs of Aspirin Poisoning
- Vomiting, especially bloody vomiting
- diarrhea
- Black, tarry or bloody stools
- Apathy
- Pale or yellow gums
- abdominal pain
- Rapid breathing
- Seizures
- Poor clotting
- Weaknesses
- Hyperthermia
- Increased drinking and urination
- Sudden collapse
If your dog is showing these signs, it is best to consult a veterinarian.
How is aspirin poisoning in dogs diagnosed?
The first step in diagnosing aspirin poisoning in dogs is to determine, if possible, whether a dog showing the signs above may have been exposed to aspirin or a similar salicylate. Unfortunately, salicylate drug tests are not readily available for bedside testing in dogs and the turnaround time for results is too long for emergency cases.
If aspirin poisoning is suspected or confirmed, your dog’s blood will need to be tested to check his organs, red blood cell count (to check for anemia), and electrolytes. Aspirin does not affect platelets, as it prevents them from combining and forming clots, rather than decreasing their production.
Treating Aspirin Poisoning in Dogs
Treatment for aspirin poisoning depends on how soon your dog is taken to the vet after ingesting it.
If your dog has taken the aspirin within the last few hours, your veterinarian can induce vomiting to cause the aspirin to be regurgitated before it is fully absorbed.
After inducing vomiting, or if exposed several hours prior, your vet can give your dog activated charcoal, which will bind with the aspirin in your dog’s intestines and prevent it from being absorbed into the body, helping to limit the drug’s potential toxicity if given in time.
In some cases, the aspirin has already been completely digested and it is too late to intervene to stop or limit the absorption of the drug. In these cases, all we have left is supportive care. In mild cases with few or no symptoms, your veterinarian will perform blood tests, administer gastroprotectants to prevent stomach ulcers, and provide hydration support. More severe cases may require hospitalization, blood transfusions, oxygen therapy, anti-seizure medications, and intravenous fluids.
Aspirin Alternatives for Dogs
Aspirin is meant to treat pain associated with inflammation, which in dogs usually means arthritis pain.
Alternative treatments for arthritis include the following:
- Joint supplements – glucosamine, fish oil (omega-3 fatty acids), MSM, green lipped mussel extract, Adequan injections
- Other NSAIDs – Carprofen, Meloxicam, Etodolac, Deracoxib, Robenacoxib, Firocoxib
- Alternative painkillers to NSAIDs – Grapiprant, Gabapentin, Amantadine
- CBD
Historically, the other main use of aspirin in dogs was as an anticoagulant. Aspirin has been largely replaced by clopidogrel, a safer anticoagulant with far fewer side effects.
While humans would turn to aspirin to bring down a fever, in dogs we focus on the fact that fever is meant to help the body fight off infection and do not intervene unless the condition is severe, in which case we treat it differently in hospital.
Most of the things on this list are prescription drugs, but joint supplements and CBD are available over the counter and can be used for arthritis pain, but not acute pain. However, aspirin is also not suitable for acute pain.
Aspirin Drug Interactions
Aspirin can interact with several other medications, potentially changing how well they work or how well they are absorbed. Examples of medications that should never be given to dogs taking aspirin include those that increase the risk of side effects or change how other medications work.
- Other NSAIDs
- Corticosteroids (such as prednisone)
- Lasix (Furosemide)
- Digoxin
- Spironolactone
- Phenobarbital
- Tetracycline – Buffered Aspirin only
summary
Aspirin is effective as a pain reliever and blood thinner, but there are now many safer and more effective alternatives to reduce pain and inflammation in dogs, as well as better blood thinners. Aspirin toxicity can occur after even a single dose of the drug, and while it was previously thought that the dosage range was relatively wide, new research suggests that the safe dosage range may be significantly narrower than previously thought, making giving the drug too risky.
If your pet needs pain medication, it’s best to take them to the vet as soon as possible so they can receive treatment safely.
Featured image credit: Irin Fierce, Shutterstock
