This article charts the development milestones being reached by an 8 month old kitten. From how much they should weigh and how much they need to eat, to coping with disruptive adolescent behaviors.
- 8 month old kitten size
- Feeding an 8 month old kitten
- When will my cat be full grown?
- 8 month kitten behavior
- Caring for cats at 8 months
- Why does my 8 month old kitten bite me?
- Kitten development milestones at 8 months
An 8 month old kitten hasn’t got much further to go to reach adulthood. The rate at which they are growing and changing physically has slowed right down compared to the first few months after you bought them home. But emotionally they’re only just becoming ‘teenagers’, and sometimes it shows!
8 month old kitten size
An 8 month old kitten has reached roughly 90% of their adult size. If they come from a small breed, they might only achieve a few more ounces after this point. But if they’re a mighty Maine Coon or Norwegian Forest Cat, they might still gain a couple of pounds. If you know the size of your kitten’s parents, you’ll have an idea of what their predicted adult weight is, and whether their progress so far fits in with that. If you rescued your kitten and you don’t know what breed their parents were, their size now can help you estimate their final size. Either way, if you’re worried that their weight is very wide of what you expected, then it’s a good idea to get a veterinarian’s opinion.
Beside your cat’s weight in pounds and ounces, a veterinarian will also examine their overall body condition. A healthy 8 month old cat should have a visible waist when viewed from above. Their ribs shouldn’t be visible, but you should be able to feel them easily if you press flat hands gently against the sides of their torso. Sometimes a very thick coat can make these assessments easier said than done. But once your veterinarian has shown you exactly what to look for on your own kitten, it’ll be easier to judge their body condition for yourself at home too.
Feeding an 8 month old kitten
If you’re feeding your kitten a kibble diet, the recommended daily portion size on the packaging has probably been increasing every month or two so far. But as they approach their final adult size, they’re not going to need calories to fuel the growth of new bone and tissue anymore. So this might be the first month that the portion size recommended by the packaging actually goes down. Don’t worry, this isn’t a typo! But if you’re worried about it, have a chat with your veterinarian.
If your 8 month old kitten is eating a kitten-specific diet, it’s still not quite time to switch to the adult equivalent just yet. Most adult diets are formulated for cats aged 12 months and over. If you’re dissatisfied with what they’re eating at the moment for any reason, consider moving them onto an all life stages diet instead. All life stages diets are formulated to be nutritionally complete and appropriate for kittens, adult and senior cats alike.
When will my cat be full grown?
How long is it going to take for your cat to achieve that last 10% of their growth, and reach their final adult size? Well, again this can vary. Small cat breeds reach their final adult size sooner than large breeds. And within a breed, females tend to finish growing earlier than males (because they are smaller than males on average).
If you have a small to medium cat, such as a Cornish Rex, American Curl, or Siamese, they will probably be fully grown by their first birthday. But, as we’ve seen, they only have a few ounces to go, so you might not notice much visible change between now and then! The largest cat breeds (like the Maine Coon and Norwegian Forest cat mentioned earlier) can keep growing until they are 18 or even 24 months old. When you compare them on their 2nd birthday to photos you’ve taken this month, you’ll probably be able to see the difference too.
A helpful way to tell when your cat is fully grown is by keeping a kitten growth chart. Put a few treats on your bathroom scale once a month, and jot down your cat’s weight while they eat them. When they stop making gains month on month, they’re likely to be fully grown.
8 month kitten behavior
Sometime between 6 and 10 months old your kitten will start adolescence. So it’s very likely that you’re either starting to notice the first signs of it now. It might even be well under way! Adolescence is the process of maturing from a kitten into an adult cat. Just like human teenagers, adolescent kittens become more confident and independent, tend to sleep a lot, and might display some challenging behaviors which push the boundaries of what you consider acceptable!
Playing with other pets
Now they’re big enough to look after themselves, and get away from threatening situations swiftly, your 8 month old cat’s social confidence is likely to be at an all time high. If you have older pets, your kitten might start spending a lot of time trying to engage them in playing games. Bear in mind that older cats tend to be less interested in social play than kittens and younger cats. So you’ll need to be ready to step in and redirect your kitten if they’re annoying your older cat too much.
It’s a good idea to make sure your kitten has a variety of toys suitable for playing with independently, and to rotate them in and out of usage so they stay ‘fresh’ and exciting. Stock up on catnip mice, balls, feeding puzzles, tunnels, and cardboard boxes to play with, so they don’t become over reliant on other pets for entertainment.
Counter surfing and climbing
As your cat gets bigger, stronger, and more coordinated, you might notice they try to explore more places you don’t want them too – for example kitchen work surfaces, bookcases and (if they’re destined to be an indoor cat) the outside world. It’s important not to punish this behavior, as this will damage your bond and make your kitten distrustful of you. Instead, make sure your home has a variety of high up perches in cat trees, window hammocks, and on cat shelves. All cats love to look down on the world, and redirecting them to an appropriate vantage point is kinder and less stressful for you than trying to keep them on the ground.
Hunting and predatory behaviors
An important part of going through adolescence and reaching maturity is learning to fend for oneself. So you’re likely to notice your kitten practicing their hunting skills more than ever now. If they’re allowed outside, they might even start bringing in small birds and mammals they’ve managed to catch. If they’re an indoor cat, they might pounce at your feet and ankles with every opportunity they get. My mom’s cat (who would not survive five minutes in the wild) started ‘hunting’ the camelia bush in their backyard, and triumphantly carrying the flowers she snapped off back indoors.
To stop normal predatory behaviors becoming nuisance behaviors, make time to play interactive games with your kitten every day. Feathers and teaser toys on a long rod are ideal for this, because you can animate them like prey, but keep yourself safely out of reach.
Finally, adolescent cats usually start to perform an increasing number of territorial behaviors around 8 months old. This can include scratching, and urine marking. Set up scratching posts next to key doorways and thoroughfares in your home. The scratch marks and pheromones they leave behind from their paws are important ways that cats communicate their presence in places which are important to them. So tucking a scratching post in an out of sight corner won’t work – and they’re likely to ignore it!
Male and female cats are both territorial to an extent. But males will roam more widely to secure a wider territory, fight trespassers (which can result in injuries and transmission of infectious diseases), and spray urine against inside walls to mark ‘his’ space. Neutering is a very effective way to prevent these behaviors, so if you haven’t planned for this yet, discuss all the pros and cons with your veterinarian now
Caring for cats at 8 months
As we’ve seen, monitoring your cat’s growth, adapting to their changing behavior, and meeting their need for physical and mental enrichment is probably already keeping you pretty busy this month. But there are some other practical elements of kitty care to keep in mind too:
- Grooming. Now your kitten’s adult coat has totally come through, make time to brush it through regularly. Long haired cats need the help avoiding knots and tangles. But even short haired cats will benefit from the attention. Grooming is the perfect opportunity to spot things like ticks, abscesses and cuts, and deal with them promptly.
- Teething. Your kitten’s adult teeth should finish erupting this month. They may have had a bit of bad breath whilst they were teething, which is normal. But persistent 8 month old kitten bad breath may be a sign that something is more seriously wrong. Check their mouth for retained baby teeth, which can cause painful and smelly infections, and seek immediate veterinary attention if you find any.
- Tooth brushing. Still on the theme of dental hygiene, if you haven’t introduced a routine for keeping your kitten’s teeth clean yet, do it now. You can choose from toothpastes, gels, and specially designed chews.
Why does my 8 month old kitten bite me?
8 month old cats tend to be a bit less cuddly and lovey dovey than younger kittens. This is because they are reaching a threshold in their life when they would achieve independence from their mom in the wild. They might also bite and nip you more frequently. This is because they are programmed to practice hunting, in order to succeed at being independent adults. But the combination of these things in a pet cat can feel like a personal insult. Why have they suddenly started being so aloof and mean?!
It’s not personal! Your cat is hardwired to practice these behaviors now, or they wouldn’t have survived in the wild. Playing with teaser toys is a great way to divert your kitten from biting you, and also maintain a bond where they see you as a fun source of mental enrichment. If you haven’t already done so, this is a great time to try simple clicker training with your cat too. Finding enough to eat is a top priority for a newly independent adolescent cat, so they will be very motivated to gain access any good training treats you use. Why not teach your cat to come to their name, sit on cue at meal times, and give you a paw?
Kitten development milestones at 8 months
An 8 month old kitten has transformed before your very eyes from sweet and sleepy baby to rambunctious teenager. Here’s a summary of the key development stages:
- They’ve reached about 90% of their adult weight.
- They’re getting more active, and more physically and social confident – provide a variety toys to occupy them, and make time to play with them every day.
- Their adult teeth have fully erupted, and all their baby teeth should have fallen out.
- Try training – start with something simple and build it up in stages.
Your 8 month old kitten
We’d love to hear how your 8 month old kitten is getting on! Let us know in the comments box down below!
Also in this series
- 12 Week Old Kitten – A Complete Guide From The Happy Cat Site
- 4 Month Old Kitten – Growing And Changing Fast
- 5 Month Old Kitten
- 6 Month Old Kitten – Complete Guide To Caring For Your Cat
- 7 Month Old Kitten
- When Do Cats Stop Growing? A Complete Guide To Kitten Growth
Langley-Hobbs et al. Retained and persistent deciduous teeth in cats. Veterinary Record. 2015.
Rodan & Heath. Feline Behavioral Health & Welfare. Elsevier Health Sciences. 2015.
Seksel. Preventing Behavior Problems in Puppies and Kittens. Veterinary Clinics of North America: Small Animal Practice. 2008.
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