Cat Scratching All Night: 5 Checks, 1 Threshold

A cat that scratches hard enough to wake you at 2 a.m. is usually reacting to 1 of 3 things: fleas, an allergy, or ear mites. The useful first move is not a cream but a count: how many scratching bouts in 10 minutes, and where on the body. Under 1 bout per 10 minutes is normal grooming. At 5 or more, or any scratching that draws blood, the cat is itchy enough to need a plan tonight rather than a wait-and-see week.

Why the Scratching Peaks After Dark

Three things stack up at night. Fleas are most active in the hours a host is resting, and a cat asleep in one warm spot is an easy target. The house is quiet, so a 2-second scratch that you never notice at noon is the loudest sound in the room at 3 a.m. And a cat that has been holding an itch all day stops self-restraining once the household is still. Owners typically notice 3 to 4 times more scratching at night, which is why the bedroom is where the diagnosis gets made.

Fleas: The 24-Hour Cycle

An adult flea that lands on a cat starts feeding within 24 hours, and mating and egg-laying follow within 24 to 48 hours. Eggs drop off the cat, hatch in 2 to 6 days, and larvae hide in carpet and bedding for 5 to 11 days before pupating for 7 to 14 days. That adds up to 3 to 5 weeks from egg to adult, and the pupae can sit dormant for months. This is why 1 flea treatment is not enough: treat every 30 days for at least 90 days, treat every animal in the house on the same day, and vacuum daily for 14 days, emptying the canister outside each time. Wash bedding at 60 C.

Allergy: Three Different Problems

Flea allergy dermatitis needs only 1 or 2 bites to set off 24 to 48 hours of intense scratching at the base of the tail and the back of the thighs. Food allergy shows up as itching on the face, ears and neck, often with 2 or more episodes of vomiting a week, and it needs an 8-week hydrolyzed or novel-protein trial with no other food, no flavored medication and no table scraps. Environmental allergy is usually seasonal at first and then year-round after 2 to 3 years, and it responds to wiping the cat down with a damp cloth once a day, washing bedding weekly, and keeping indoor humidity at 40 to 50 percent.

Ear Mites: 3 Weeks to Clear

Ear mites live 2 to 3 weeks and spend their whole life on the cat, so the treatment window is 3 to 4 weeks, both ears, every cat and dog in the house. The classic sign is dark coffee-ground debris in the ear canal, plus scratching at the ear and head shaking 5 or more times an hour. Do not use cotton swabs down the canal: wipe the visible folds with a gauze pad and let the prescribed product do the work. A mite that survives 1 dose because it was still an egg will restart the cycle in 21 days.

Five Home Checks, 15 Minutes

• 1. Flea comb the base of the tail and belly for 5 minutes over white paper; more than 5 dark specks that turn red-brown on a damp tissue means flea dirt.
• 2. Map the scabs: 4 x 4 cm patches at the tail base and thigh mean fleas, patches on the neck and face mean allergy or mites.
• 3. Look into both ears with a phone light for 0.5 cm of dark debris or a red canal; compare left and right.
• 4. Check the skin along the spine for 3 or more small crusts, and part the fur to look for broken hairs and redness.
• 5. Count bouts with a 10-minute timer at the same time each night for 3 nights, and note whether the cat also vomits, sneezes or has runny eyes.

The Itch Threshold

Numbers beat impressions. Normal grooming is 5 to 10 minutes spread over a waking day and rarely wakes the cat. Count scratching, biting and licking as one behaviour. A cat at 3 to 4 bouts per 10 minutes is borderline; 5 or more per 10 minutes, or 2 or more hours of scratching in a night, is over threshold and needs treatment started tonight. Also count lesions: 3 or more new scabs in 48 hours, or hair loss over 5 percent of the body, moves the cat from home care to a clinic visit. Track the count for 3 nights, because a single bad night is often just a flea that got in.

What the Signs Point To

What you see	Most likely cause	Count threshold	Act within
Scabs at tail base, flea dirt	flea allergy	1 to 2 bites is enough	24 hours
Face and neck itching, vomiting	food allergy	8 week diet trial	7 days
Dark debris in one or both ears	ear mites	5 head shakes per hour	48 hours
Itching every autumn, no scabs	environmental allergy	2 seasons in a row	2 weeks
Bald patches spreading fast	ringworm or mites	3 new patches in 48 hours	48 hours

When to See a Vet, by the Hour

Go now, within 1 hour, for facial or eyelid swelling, noisy or open-mouth breathing, or a wound that keeps bleeding after 10 minutes of firm pressure. Go within 6 hours if the cat is screaming and cannot settle at all, or if a claw is torn and catching on fabric. Go within 24 hours for 5 or more bouts per 10 minutes that continue after a flea treatment, 2 consecutive nights with under 4 hours of sleep, a hot swollen ear that the cat guards, or any kitten under 8 weeks with visible fleas. Go within 48 hours for spreading bald patches, 3 or more new scabs, or ear discharge with a head tilt. A cat that stops eating for 24 hours alongside the itching goes in the same day, regardless of the skin.

Tonight, Then the Next 30 Days

Tonight: flea-comb for 5 minutes, note the count, wipe the ears with gauze, and if the cat allows it, put an Elizabethan collar on to break the scratch-scab cycle. Days 1 to 3: start a flea product labeled for the cat's weight, treat every pet, and vacuum daily. Days 4 to 30: repeat the 10-minute count on nights 4, 7 and 14; if it is not falling by half, book the visit. If you suspect a toxin instead, check the toxic plant and product list before assuming allergy, since a single exposure can cause face rubbing that looks like itching. For wounds the cat has already opened, see wounds that are not healing, and for any wheeze or cough that comes with the scratching, see cat wheezing.

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