1. NSAIDS (Ibuprofen, Naproxen) -- Topping the list are the common household medications called non-steroidal anti-inflammatories (NSAIDs), which include common names such as ibuprofen and naproxen. While these medications are safe for people, even on or two pills can cause serious harm to a pet. Dogs, cats, birds and other small mammals including ferrets, gerbils and hamsters may develop serious stomach and intestinal ulcers as well as kidney failure.
2. ACETAMINOPHEN -- When it comes to pain medications, acetaminophen (Tylenol) is popular. Even though this drug is safe for children, it is not safe for pets, especially cats. One regular strength tablet of acetaminophen may cause damage to a cat's red blood cells, limiting their ability to carry oxygen. In dogs, acetaminophen leads to liver failure and, in large doses, red blood cell damage.
3. ANTIDEPRESSANTS (Effexor, Cymbalta, Prozac, Lexapro) -- While these and other antidepressant drugs are occasionally used in pets, overdoses can lead to serious neurological problems such as sedation, incoordination, tremors or seizures. Some antidepressants also have a stimulant effect leading to a dangerously elevated heart rate, blood pressure and body temperature. Pets, especially cats, seem to enjoy the taste of Effexor and often eat the entire pill. Unfortunately, just one pill can cause serious poisoning.
4. ADD AND ADHD MEDICATIONS (Concerta, Adderall, Ritalin) -- Medications used to treat Attention Deficit Disorder and Attention Deficit Hyperactivity Disorder contain potent stimulants such as amphetamines and methylphenidate. Even minimal ingestions of these medications by pets can cause life-threatening tremors, seizures, elevated body temperature and heart problems.
5. BENZODIAZEPINES AND SLEEP AIDS (Xanax, Klonopin, Ambien, Lunesta) -- These medications are designed to reduce anxiety and help people sleep better. However, in pets, they may have the opposite effect. About half of dogs that ingest sleep aids become agitated instead of sedate. In addition, these drugs may cause severe lethargy, incoordination (including walking "drunk"), and slowed breathing in pets. In cats, some forms of benzodiazepines can cause liver failure when ingested.
6. BIRTH CONTROL (Estrogen, Estradiol, Progesterone) -- Birth control pills often come in packages that dogs find irresistible. Thankfully, small ingestions of these medications typically do not cause trouble. However, large ingestions of estrogen and estradiol can cause bone marrow suppression, particularly in birds. Additionally, intact female pets are at an increased risk of side effects from estrogen poisoning.
7. ACE INHIBITORS (Zestril, Altace) -- Angiotensin-converting enzyme (ACE) inhibitors are commonly used to treat high blood pressure in people and occasionally, pets. Though overdoses can cause low blood pressure, dizziness, and weakness, this category of medication is typically safe. Pets ingesting small amounts of this medication can potentially be monitored at home, unless they have kidney failure or heart disease.
8. BETA-BLOCKERS (Tenormin, Toprol, Coreg) -- Beta-blockers are also used to treat high blood pressure but, unlike with ACE inhibitors, small ingestions of doses can cause life-threatening decreases in blood pressure and a very slow heart rate.
9. THYROID HORMONES (Armour Desiccated Thyroid, Synthroid) -- Pets - especially dogs - get underactive thyroids too. Interestingly, the dose of thyroid hormone needed to treat dogs is much higher than a person's dose. Therefore, if dogs accidentally get into thyroid hormones at home, it rarely results in problems. However, large acute overdoses in cats and dogs can cause muscle tremors, nervousness, panting, a rapid heart rate, and aggression.
10. CHOLESTROL LOWERING AGENTS (Lipitor, Zocor, Crestor) -- These popular medications, often called statins, are commonly used in the U.S.. While pets do not typically get high cholesterol, they may still get into the pill bottle. Thankfully, most statin ingestions only cause mild vomiting or diarrhea. Serious side effects from these drugs come with long-term use, not one-time ingestions.