Suspect poisoning? US: ASPCA Poison Control (888) 426-4435 · UK: 01202 509 000 · Severe symptoms → nearest emergency vet now.

My 5 kg cat licked a Baclofen tablet that was left out on a damp windowsill overnight — does moisture make it more dangerous?

Cats · Emergency guide

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Short answer

Yes, moisture can make it more dangerous by dissolving the coating and releasing the drug faster. Baclofen is highly toxic to cats, and a single 10 mg tablet is a massive dose for a 5 kg animal. Signs like wobbliness, deep sedation, and slow breathing can appear within 30 minutes to two hours. The damp tablet might also crumble, making it harder to estimate how much was ingested. This is an emergency. Call the ASPCA poison line at 888-426-4435 or your vet immediately. Keep your cat calm and contained in a carrier on the way—a sedated pet can slump and block its own airway.

Why is this dangerous?

Baclofen is a central muscle relaxant used for back spasm and MS. In dogs it causes deep sedation, loss of coordination, tremors and, in severe cases, respiratory depression and death.

Human tablets are 10–20 mg, which is enormous for a pet — reports describe severe poisoning in dogs from one or two tablets.

Why speed matters

Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.

Signs to watch for

  • Deep sedation, difficulty waking
  • Wobbliness, unable to stand
  • Head tremors, twitching, rigidity
  • Vomiting, drooling
  • Slow shallow breathing, coma (emergency)

What to do right now

  1. Treat any baclofen ingestion as an emergency and go to the vet now.
  2. Bring the bottle so the exact dose can be calculated.
  3. Support the head so the airway stays open if the pet is sedated.
  4. Do not induce vomiting in a drowsy pet.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.

The step-by-step response, from the first minute to the vet visit, is in our Muscle Relaxants (Baclofen, Cyclobenzaprine) emergency guide.

Open the full emergency guide: Muscle Relaxants (Baclofen, Cyclobenzaprine) →