Why wobbliness changes the picture for your 4 kg cat
Seeing your cat stumble after eating the melatonin means the drug has already entered their system. At 5 mg, that's over ten times the typical feline dose used in veterinary medicine, which explains the pronounced effects. The wobbliness suggests neurological impact, which could progress to full sedation or, paradoxically, agitation as their small body processes the overload.
Unlike dogs, cats lack certain liver enzymes to efficiently break down melatonin, so effects last longer. What might cause mild sleepiness in a human can overwhelm a cat's system for 12-24 hours. The gummy form doesn't increase toxicity but may have allowed faster absorption than a tablet would, explaining why signs appeared quickly.
Gummy versus tablet: what really differs for cats
The 5 mg dose is the main concern, but gummies pose unique risks. Their chewy texture and sweet flavor make them more enticing to cats, who might ignore a plain tablet. A gummy also sticks to teeth and palate, prolonging contact with oral membranes and potentially increasing absorption rate compared to a swallowed tablet.
Tablets often crumble when chewed, which could reduce absorption if fragments aren't swallowed. A gummy's cohesive texture means your cat likely ingested the full 5 mg at once. Neither form is 'safer' at this dose, but future prevention requires different strategies—childproof containers for gummies versus high cabinets for tablets.
The next 8 hours with a dosed cat
Your cat's wobbliness indicates they're mid-reaction, not at peak effect yet. Over the next few hours, monitor for progression to inability to stand, exaggerated startle responses, or unusual vocalization. These would signal deepening neurological impact requiring immediate support. Keep them in a dim, quiet room with floor-level bedding to prevent falls.
Hydration matters because sedated cats often forget to drink. Offer water in a shallow dish they can access while lying down. Don't try to make them eat—nausea is common with melatonin overdose. If their wobbliness hasn't improved in six hours or worsens before then, their body isn't metabolizing the dose effectively.
Why weight makes this emergency-level for cats
A 4 kg cat receiving 5 mg melatonin gets 1.25 mg/kg—a dose that would sedate a 70 kg human for days. Feline sensitivity isn't just about size; their neurochemistry reacts strongly to hormonal supplements. Even if your cat seems to recover, secondary effects like disrupted sleep cycles or appetite changes may linger for 48 hours.
Small bodies also risk hypothermia during sedation. Feel their ears and paws—if cool to the touch, wrap them in a blanket (not heated pads). Cats under melatonin's influence can't regulate body temperature normally. One episode of overdose increases future sensitivity too, meaning next time could be worse with less.
The step-by-step response, from the first minute to the vet visit, is in our Sleep Aids (Melatonin, Zolpidem, Valerian) emergency guide.