Learn why exact drug doses for dogs and cats must be prescribed by a veterinarian, and get a checklist of questions to ask instead of guessing.
Giving pets the wrong medication or wrong dose is one of the most common causes of pet poisoning. Unlike humans, dogs and cats process medications very differently—and what's safe for one species can be deadly for another.
This safety guide explains why online dosage calculators are dangerous and provides questions to ask your veterinarian instead.
Pet medication dosing is far more complex than simple weight-based math:
Dogs and cats metabolize drugs differently. A medication safe for dogs may be fatal to cats (and vice versa). For example, dogs can tolerate certain NSAIDs that would kill a cat, while cats can handle medications that would harm dogs.
Even within the same species, factors affect how medications work:
The same drug comes in different:
These errors send thousands of pets to emergency vets each year:
Many human OTC drugs are toxic to pets. Never assume a drug is safe just because you can buy it without a prescription.
A medication prescribed for one pet may be dangerous for another, even if they're the same species and weight.
Misreading labels, using wrong measuring tools, or calculating incorrectly can result in overdose or underdose.
Some medications are designed for slow release and become dangerous when crushed. Others taste bitter and pets won't take them.
Stopping antibiotics early can create resistant bacteria. Missing doses can make treatment ineffective.
Before giving any medication to your pet, ask:
If your pet has ingested medication accidentally:
Follow these guidelines for safer medication administration:
Generally, no—not without calling a veterinarian or poison control first. Many common human medications are toxic to pets. Even "safe" medications require specific dosing. Call your vet or an emergency clinic before giving anything.
Pet metabolism differs significantly from humans. Cats lack certain liver enzymes that process common drugs, making medications toxic that are safe for humans. Dogs process some drugs faster or slower than we do. Dosing must account for species-specific pharmacology, not just weight.
Aspirin can be used in dogs under veterinary guidance, but it's not as simple as "safe" or "unsafe." The dose is different from humans, it can cause stomach ulcers, it interacts with other medications, and some dogs shouldn't take it at all. Never give aspirin without vet approval.
Cats lack the liver enzyme (glucuronyl transferase) needed to metabolize acetaminophen. Even a small dose can cause fatal red blood cell damage and liver failure in cats. Never give any acetaminophen product to cats.
No. Medications are prescribed for a specific pet based on their individual health status, weight, and diagnosis. Using another pet's medication could result in wrong dosing, wrong drug, or dangerous interactions. Expired medications may also be ineffective or harmful.
Call your vet or pet poison control immediately. Don't wait for symptoms. Have the medication container ready with information about what was given and how much. Quick action can prevent serious harm.
Some medications can be used in pets with veterinary guidance—like certain antihistamines or stomach medications. However, "safe" depends on the specific product, dose, your pet's health, and other factors. Always confirm with your vet first, even for medications you've heard are safe.
Options include: hiding pills in treats or pill pockets, asking for flavored compounding, liquid formulations, transdermal gels (absorbed through skin), or learning proper pilling technique from your vet. Never crush medications unless your vet confirms it's safe.