6-Week Kitten Checklist: 400-600 g and First Deworming

Six weeks is the first age where a kitten's numbers are worth writing down. The weight band is 400 to 600 g, three checks decide whether the kitten is on track, and the first deworming happens now on a vet's prescription rather than from a shelf.

What 400 to 600 g actually means

From week 2 to week 16, weight tracks close to 100 g per week of age, so a 6-week-old sits near 600 g and a small female at 420 g is still inside the band. The spread starts at birth: 90 to 110 g on day 1 becomes 400 to 600 g by day 42 at a gain of 10 to 15 g a day. That daily figure is the one to watch, because a weekly total hides 3 bad days inside 4 good ones.

Use a kitchen scale with 1 g resolution, same hour each morning, before the first meal. Three readings 7 days apart beat one perfect number. Two weigh-ins in a row with no gain, or any loss of 10 g or more, earns a vet visit in the same week.

Three checks, done once, properly

Body condition. Ribs under a thin fat layer, spine not visible, 4 or 5 on a 9-point scale. A 6-week-old with a round belly and a visible spine is not chubby; that is a worm burden or a feeding problem.

Head. Eyes clear with no discharge, ears pale pink inside with no dark wax, gums pink and moist. All 26 baby teeth are through by week 6, and the mouth should close without an overbite you can hook a finger under.

Skin and umbilicus. The umbilical scar flat and dry, no scab, no swelling; no flea dirt in the groin; no bald patches. Temperature runs 38.0 to 39.2 C, heart 200 to 260 beats a minute, breathing 30 to 40 at rest.

Item	Normal range	Recheck	What to do
Weight	400-600 g	7 days	Same scale, same hour, before food
Daily gain	10-15 g	3 days	Log 3 mornings and average them
Temperature	38.0-39.2 C	48 hours	Rectal, 1 minute, only if the kitten seems off
Heart rate	200-260 bpm	14 days	Count 15 seconds, multiply by 4
Deworming	Day 0 and day 14	14 days	Vet-measured dose, by weight

First deworming is a prescription, not a purchase

Week 6 is the standard start. The vet weighs the kitten and sets the dose: at 400 to 600 g a kitten needs a measured fraction of an adult dose, and splitting a tablet by eye at this size is how kittens end up underdosed. Several shelf products are labelled for cats over 1 kg, which is 2 to 3 weeks away at this weight.

The common pattern is 2 doses 14 days apart, then monthly to 6 months, then 3 to 4 times a year for an indoor cat. A stool sample of 2 to 3 g, about a walnut, tells the vet whether roundworm, tapeworm or coccidia is present, and coccidia needs a different drug entirely, so dosing blind wastes the trip.

Treat the queen and every littermate on the same day. Eggs survive in bedding, and a kitten treated alone is reinfected within 2 to 3 weeks. Wash bedding at 60 C, scoop the box twice a day, and wear gloves for 48 hours after dosing.

Feeding a 500 g kitten

Four meals a day, 60 to 90 kcal in total, which is roughly 80 to 110 g of wet kitten food or 25 to 35 g of dry. Weaning gruel is 1 part warm water to 1 part kitten food in a shallow 2 cm dish, and the water drops out by week 8.

Kittens this small do not regulate blood sugar well. More than 8 hours without food is too long, so the last meal lands at 22:00 and the first at 06:00. A kitten that drools, wobbles or goes quiet before a meal needs food on the gums and a phone call, not a nap.

Room, litter, and heat

The nest stays at 24 to 26 C in week 6 and drops 1 to 2 C a week after that. Litter goes in a tray with sides under 5 cm, 3 to 4 cm deep, unscented, 1 to 2 m from the food bowl in a quiet corner. Two kittens want 2 trays plus 1 spare, and both are scooped twice a day.

The 2-week recheck lands at week 8

Book day 14 in the same phone call as the deworming. By then the weight should be 700 to 900 g, the second dose is due, and the first FVRCP vaccine goes in if the kitten has been well for 7 days. Bring the weight log and a fresh stool sample; the visit runs 20 to 30 minutes and the injection is the easy part.

A kitten at 640 g on day 14 instead of 700 g has not failed. It is a reason to reweigh in 7 days and check for worms, coccidia, and whether it is eating or still nursing. The next checkpoint, 1.2 to 1.6 kg at 12 weeks, is where a slow start turns into a visible gap.

Call the vet the same day for

• No gain across 2 weigh-ins, or a drop of 10 g or more
• Temperature under 37.5 C or over 39.5 C
• Diarrhea past 24 hours, or any blood in it
• Refusing 2 meals in a row, or 12 hours with no food
• Eyes glued shut, or breathing with the mouth open

Six things to do this week

1. Weigh 3 mornings running and write the numbers down.
2. Book the deworming visit and the day-14 recheck in one call.
3. Collect a 2 to 3 g stool sample in a clean jar.
4. Count 4 meals a day and stop leaving dry food down.
5. Set the room to 24 to 26 C and move the tray away from the bowl.
6. Handle the kitten 3 to 5 minutes a day and put it down the moment it struggles.

Week 6 is mostly measurement: 400 to 600 g, three checks, one prescription, one appointment 14 days out. Get those four right and week 8 becomes a formality. The full sequence is in the week-by-week milestones, the handling that starts now feeds into the socialization checklist, and the breed quiz is a 2-minute detour if the breed is still open.

Terms mentioned in this article

FVRCP

Frequently asked

Related guides

• 12-Week Kitten Checklist: 1.2-1.6 kg, 2-3 Shots, 3 Rooms
• 8-Week Kitten Checklist: First Vaccine at 700-900 g
• Kitten Milestones Week by Week, 0 to 16
• 30-Item Kitten Socialization Plan for 8-16 Weeks
• First Vet Visit: 8 Checks in 30 Minutes
• Bringing a Kitten Home: What to Do in the First Week