How These Common Human Medications Pose a Risk to Dogs

It’s a running joke in my family that if you're ill, the way to get any sympathy is to have a leathery nose and a tail. Indeed, I’m more likely to have an animal medicationon hand than a human one. Take the infamous time my son had a madly itchy flea bite -- all I could find to ease the itch was a half-used tube of dog ointment.

Turning things on their head, if the pet is ill, it may be tempting to try a home remedy with something from the bathroom cabinet. However, what works well for people is often disastrous for animals and could give the pet a whole new set of health problems more serious than the first.

With over 50% of all pet poisoningsbeing the result of human medications being given to pets, let’s look inside the bathroom cabinet to see what dangers lurk there for our dogs.

Pain Relief

Never give your dog pain relief from the bathroom cabinet without first speaking to your vet. Here's why:

• The doses of human meds are huge when compared to the size of the dog. Even if a drug is safe in principle, it’s all too easy to give an accidental overdose purely because of the size difference between people and dogs.
• Dogs metabolize drugs differently than people do, so what is safe for us could cause liver or kidney failure in the dog.
• Many drugs don’t combine well with other medications, so if your pet is taking meds or has an existing health problem then adding in a painkiller could cause complications.
• Certain painkillers are particularly harmful:
• Acetaminophen (Tylenol): This has a low safety margin in dogs and overdose is easy, of which the classic complication is liver damage.
• Ibuprofen (Advil) and Naproxen (Aleve): Dogs are very sensitive to these NSAIDs (non-steroidal anti-inflammatories), and even small amounts can cause stomach ulcers or kidney failure.
• Tramadol: Yes, this is sometimes prescribed by vets -- but at a safe dose. This painkiller is also easy to overdose, leading to vomiting, disorientation and possibly seizures.
• Acetylsalicylic acid (Aspirin): The biggest danger with aspirin is an adult 300mg tablet being given a small dog, leading to overdose. Serious complications include gastric ulceration and kidney failure.

Cold and Flu Remedies

Most cold and flu remedies are a cocktail of different pharmaceuticals to tackle cough, fever, sore throat and blocked sinuses. Many of the drugs are not safe for dogs -- even down to things like low-sugar formulations containing xylitol.

Never even consider giving a dog a cough medicine containing acetaminophen, alcohol, caffeine, pseudoephedrine, or xylitol. Indeed, for dogs on other medications, even cough medicines generally regarded as safe, like dextromethorphan (Benylin, Robitussin), should be avoided due to drug interactions. (The FDA does not recognize dextromethorphan as suitable for dogs, but it's useful in some cases of bronchitis.)

Sleeping Tablets

Sleeping tablets pose a special risk to dogs because people often take them out of the cabinet and put them by the bed to remember to take them. Then a curious dog comes and wolfs down the pack.

The effects of human sleeping tablets can be dramatic in dogs and cause a dangerous drop in blood pressure. Ironically, they sometimes have the opposite effect and make the dog hyper-excitable, with an equally dangerous spike in blood pressure or possibly even seizures.

• Benzodiazepines (Valium): These are sometimes prescribed to dogs but at small doses. Overdose is a real risk here and could cause profound sedation and coma.
• Alprazolam (Xanax): A small dose is unlikely to be problematic, but a dog taking a human dose could cause profoundly low blood pressure.
• Zolpidem (Ambien): This is likely to cause over-excitement, agitation and possibly seizures.

Antihistamines

We tend to think of antihistamines as harmless medications that help combat itchiness. However, some human antihistamines contain additives that are not safe for dogs.

The well-known antihistamine Zyrtec contains cetirizine and is widely considered safe at the appropriate dosage (although not licensed as such by the FDA and therefore given at the person's own risk). However, a similar product, Zyrtec-D, contains a decongestant agent, pseudoephedrine. The latter is toxic to dogsand causes dangerously high blood pressure, so it should not be given.

The moral? Safety first and convenience last. Remember -- when thinking of dosing your dog with something from the bathroom cabinet, always read the drug's label thoroughly and double-check its safety with your vet.

This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Feb. 17, 2017.