How Safe Are Human OTC Medications for Dogs?

Only a few over the counter (OTC) medications are safe for dogs. While some prescription medications are used both in humans and canines for specific conditions, this does imply that all medications formulated for humans are equally safe in dogs. Canine physiology differs from human physiology, and certain OTCs are fatal when used on dogs.


Acetaminophen is commonly marketed under the trade name Tylenol. However, it is often an ingredient in other pain and cold medications. It is available through many discount pharmacy chains under their own brand name. Acetaminophen should not be administered to dogs, as it is highly toxic.

Results of acetaminophen toxicity are:

  • Liver damage or complete failure
  • Inability of red blood cells to carry oxygen (hemoglobin)
  • Mutation of red blood cells

Signs of toxicity include:

  • Vomiting
  • Discoloration of gums
  • Breathing becomes difficult
  • Generalized swelling of the body or face
  • Convulsions


Ibuprofen is commonly used to alleviate symptoms of pain or headache in humans. Common trade names include Motrin, Advil and Nuprin. It is also available under many other brand names. Ibuprofen should not be administered to canines. Depending upon the dosage, death could occur within hours or days.

Damage caused by ibuprofen toxicity: 

  • Kidney damage or renal failure
  • Bleeding ulcerations of the stomach lining 

Symptoms of toxicity include: 

  • Abdominal and stomach pain
  • Vomit containing blood
  • Dark or discolored stools
  • Lack of appetite
  • Listlessness


Aspirin is a form of acetylsalicylic acid. It is commonly available under the trade names Bayer, Bufferin and Ecotrin. It is also available under many independent brand names. Some pet supply stores stock a specially formulated canine version of aspirin. 

Given in small doses, aspirin is generally safe for dogs. It is often used to alleviate the pain and discomfort of arthritis. Dogs with preexisting conditions should never be given aspirin, unless directed by your veterinarian. 

Precautions when administering aspirin:

  • Never administer aspirin on an empty stomach, as it can easily upset the stomach
  • Never give to dogs receiving blood thinners
  • In some canines, aspirin may cause stomach pain
  • May cause ulcerations of the stomach lining
  • May interact with other medication
  • Never give to pregnant females 

Possible side-effects include:

  • Vomiting
  • Diarrhea 


Diphenhydramine HCI is an antihistamine most commonly available under the brand name Benadryl. It is also available at discount pharmacies under different brand names. Benadryl is used to alleviate symptoms of allergies, allergic reactions and itching. The most common side-effect is drowsiness. 

Benadryl should not be given to dogs suffering from the following conditions: 

  • Heart disease
  • Pulmonary disease
  • Hyperthyroidism
  • Taking other medications 


Dimenhydrinate is most often available under the trade name Dramamine, but it is also marketed as Driminate, Gravol and Gravamin. It is also available under names affiliated with particular pharmacies. This medication is an antihistamine generally used to treat motion sickness. Dramamine is similar to a low dose of Benadryl, but it is longer acting and with fewer side-effects. The most common side-effect is drowsiness.


If your pet is suffering from cough or congestion, you may use Robitussin. This product is also available under various names. The active ingredients in Robitussin are guaifenesin and dextromethorphan.

  • Quaifenesin is an expectorant that will assist in expelling mucus
  • Dextromethorphan is a cough suppressant 

Only products containing guaifenesin or dextromethorphan should be used. Do not use products containing additional pain or cold medications. The most common side-effect is drowsiness.

Always consult with your veterinarian before administering OTC medications to your pet.