WHEN ARE CATS FULLY GROWN?
Many cat owners find themselves pondering about the key development stages of their pets. Feline life phases differ from human life stages, and these differences make the time we spend with our cats so precious. We are here to answer all your questions about when a kitten officially reaches adulthood. For example, when do kittens stop growing? It can be confusing figuring out when your cats are fully grown. It’s important to remember that kittens experience a period of rapid growth before they are a year old and that all cats can grow at different rates. However, there are several important kitten growth stages to be aware of : the neonatal stage, transitional stage, socialisation stage, juvenile stage, and the adolescent stage. In this article, we will explore the key stages that you need to know about, as well as what generally signals maturity in your cat. Being well informed regarding when cats are fully grown helps you make important decisions regarding their care and development, which enables you to support their unique needs at every stage, from nutritional care to training and beyond.
Stages of kitten growth
1. Neonatal Stage (0–2 weeks)
The first two weeks of your kitten's life is called the neonatal stage, during this period your kitten is completely dependent on their mother for food, comfort, temperature regulation and stimulated elimination of urine and faeces. Kittens are born with their eyes closed and their ears folded down, which makes them particularly vulnerable and reliant on you and their mother for protection during this stage. A kitten’s eyes will begin to open around 7-14 days old, this is a gradual process. During the neonatal stage, a warm environment is paramount, kittens rely on their mother for temperature regulation during this time as their bodies cannot regulate their own body heat yet. Kittens also require regular feeding from their mother, their movement is limited and they will crawl to their mother’s belly seeking milk, guided only by her scent. Ideally kittens should be kept with their mother until 12 weeks, however if tragedy strikes they can also be bottle fed during this time. Curious about how to take care of unweaned kittens? We have all the support you need.
2. Transitional Stage (2–4 weeks)
The next stage of a kitten's life is referred to as the transitional stage, this begins at 2 weeks and carries on until 4 weeks of age. This is a significant period for the sensory development of kittens as they begin to understand the world around them more. As mentioned previously, this is when a kitten will begin to open their eyes fully and start to take in their surroundings through sight and sound. Their ears will also begin to unfold. Their movements may still be shaky, but their motor skills are developing quickly and they will become more adventurous. Kittens should be walking at around 3 weeks old. This is also a key stage for the socialisation of your kittens, which is why keeping them with their mother and littermates is so important while they are still learning how to play, interact with the world around them and interpret social cues. They will also become better acquainted with their litter box and may begin to use it independently. Kittens typically begin weaning at 3-4 weeks and will start to show interest in solid food.
3. Socialization Stage (4–12 weeks)
The socialisation stage is a crucial period to be aware of to ensure your kittens are well adjusted felines, this is the time when they are learning the most about the world around them and they are very impressionable. Ideally it is best to keep kittens with their mother until week 12, as this ensures they will grow into a well adjusted cat. Positive interactions are key to reinforce good behaviour, this can be achieved through praise and treats. Negative experiences during this time may have a lasting impact, reinforcing fearful or anxious behaviour that could continue into adulthood. Early socialisation during this stage will help kittens adapt to new people and animals that enter their lives. Their first vet visit is due during this time, their first round of vaccinations should be undertaken between 6 and 8 weeks to ensure good health. The weaning process continues during this stage of development and is usually completed by 8 weeks, which means they should be exclusively eating solid food by this time.
3. Juvenile Stage (3-6 Months)
Kittens continue to learn from their mother and littermates during the juvenile stage. They are experiencing some major life changes and will soon be ready for adoption as well as neutering. You will notice they are extremely energetic and are growing in confidence. They will also experience rapid growth during this time, becoming more curious, playful and agile. Kittens also begin to reach sexual maturity during this stage, which is why neutering is so important to avoid unwanted litters. Kittens are generally ready to be spayed or neutered at around 6 months of age, however some vets may recommend this happens at 8 weeks, if they are the right weight. This is why booking them in for their first vet visit during the socialisation stage is so important. At 3 months kittens generally still have their gorgeously soft baby coats, their adult coats will come in by 6 months and you will have to consider their grooming needs. By 7 months all their adult teeth should have come through too, so make sure they have lots of toys to bite and play with.
4. Adolescent Stage (6-12 Months)
When are cats fully grown? This will happen at the end of the adolescent stage, when they reach 12 months (one year) old. This is the stage when a kitten officially becomes a cat. Kittens also begin to reach sexual maturity during this stage, which is why neutering is so important to avoid unwanted litters. You will notice some behavioural changes too, such as territoriality and marking/spaying. This means kittens will start spraying urine vertically to mark their territory, neutering before sexual maturity can reduce this natural behaviour. It is generally more prevalent in males. At 6 months a kitten could be considered a "teenager", this comparison can help you empathise and understand their behaviour! They may begin testing your patience and boundaries, but make sure to be tolerant and empathetic, as scolding them may only encourage bad habits. They will probably start scratching furniture, make sure their environment is enriched with scratching posts to avoid damage. By 7 months all their adult teeth should have come through too, so make sure they have lots of toys to bite and play with.
Factors that impact the growth of kittens
Breed
When are kittens fully grown depending on their breed? It is important to remember that a kitten’s breed has a huge influence on their overall development! Larger breeds such as Maine Coons develop at a slower pace and could continue growing for up to 5 years. In comparison, smaller breeds, like the Siamese, experience more rapid growth and generally reach their full size by 12 months. However it is important to remember that many other factors influence your pet’s overall growth, including your kitten’s diet, health and sex. Females tend to be smaller than males.
How do genetics influence when a cat is fully grown? Your pet’s genetics influence many factors, this includes their breed (larger or smaller), their sex, bone structure, muscle mass, leg length, coat colour, overall size and build! Knowing more about your kitten’s breed as well as viewing their mother can give you better insight into these areas.
Health
When does a kitten become a cat based on their overall health? Healthy kittens grow at a normal pace, factors that influence this include a complete and well balanced diet catered to their changing needs. Underfeeding can cause stunted growth in kittens and overfeeding can also cause health issues. Their overall health impacts growth too, this is why vaccinations are so important. Illness including diarrhoea and upper respiratory infections can impact growth.
Spaying/Neutering
Why does spaying and neutering impact when a cat is fully grown? The timing of neutering and spaying may slightly affect growth and composition. Male cats that are neutered after sexual maturity may end up heavier. Making sure you monitor how much you are feeding your pet and ensuring they are getting adequate exercise is key to maintaining a healthy weight before and after spaying or neutering.
Socialisation
Does socialisation impact when kittens stop growing? Socialisation does not typically impact when kittens become fully grown physically, however it can have a huge impact on their emotional growth, which is another area owners need to be keenly aware of. For example, poorly socialised cats could be aggressive, fearful, anxious or destructive, well into their adult years. Unfamiliar people and places could be a huge trigger for them, which is why socialisation is so important to ensuring happy, well adjusted and friendly cats.
Environment
How does the environment around them impact when kittens stop growing? The environment they are raised in can also have a huge impact on a kitten’s mental and physical development. Providing an enriching environment is key, this includes ensuring they have adequate access to clean water and food. Inadequate nutrition can be very detrimental to their growth and overall health. Areas also need to be clean, spacious enough, safe and comfortable so that your kitten feels secure. Kittens can be triggered by loud noises and extreme temperatures, they also need hiding spaces, scratching posts, toys and a consistent routine.
Nutrition
Overall nutrition has a huge impact on when your cats are fully grown. Kittens require a complete and well balanced diet to ensure healthy development overall as they need more energy and protein than adult cats. Kittens need to get enough calories, protein, vitamins, minerals, and water to keep up with their rapid growth. Poor nutrition can have a huge impact on a kitten’s overall growth and health, from their immune system strength to body composition. It also impacts their muscles, organs, tissues, skin and coat health. Kittens should always be given food that is specifically formulated for their growth stage, they cannot be fed adult cat food. Kittens and adult cats must always have access to clean fresh water to drink.
Feeding Kittens at different stages of life
A kitten's feeding needs change as they grow. Understanding their nutritional requirements at different life stages is key. Frequency of feeding starts high but this will need to taper off as a kitten grows older.
Nutritional requirements and lifestages
Up to six months, your kitten is growing at a very fast rate. From six months onward, their growth rate will slow down considerably. When do kittens stop growing? At 12 months old, your inquisitive cat probably still looks like a kitten to you and they are still more than likely to be getting into their fair share of mischief. However, by 9 to 12 months, many kittens have nearly reached their full grown size. At one year old, your kitten is generally considered to be an adult (even if you think they are still not acting like one!).
Nutritional requirements and lifestyle factors
As your kitten transitions into adulthood, it is important to keep up with their changing needs. In addition to their slower growth rate, their nutritional requirements depend on certain lifestyle factors. Among others, these may include decreased physical activity depending on whether your cat has access to the outdoors or not, whether they are neutered, and if they rule the roost or has to share their home with another cat or dog, which tends to keep them more stimulated than if they are on their own. For instance, as one might expect, a young adult cat with access to the outdoors and who sometimes plays with another household pet is likely to have higher calorie requirements than that of a lone indoor cat with a more sedentary lifestyle.
Understanding your kitten’s nutritional needs
Perhaps the first step to lifelong wellbeing for your cat is to grasp how and why your kitten’s needs differ from an adult cat’s requirements. How much should you feed a kitten? With their small stomach capacity, your hungry kitten requires multiple daily food portions, sometimes up to 18 feeding occasions per day and night to get their fill. Complete and balanced kitten food contains all of the nutrients they need in just the right amounts, it's high in protein, fat and balanced in minerals in order to meet their energy requirements. After all, reaching your adult size takes some eating!
In addition, as you well know, kittens have a lot of energy! With all that intense playing, roughhousing and growing going on, it is especially important for your feline friend to get high quality, nutritionally complete and balanced food. This will provide a healthy foundation for the rest of their life. Consequently, it is generally recommended to give your companion specially formulated kitten food until they are considered an adult at a year old.
Moving into adulthood: your cat’s changing nutritional needs
When your kitten has reached the age of 6 months, with sexual maturity fast approaching, this is sometimes considered the best time to consider neutering. For health reasons, many veterinarians often recommend early neutering when your kitten is between 4 and 6 months old. It is important to be aware that neutering will have certain consequences on your cat’s appetite and metabolism. For example, a neutered cat’s ability to burn calories is modified and weight gain could increase up to 20% quickly . There is a chance they may also be more inclined to beg for food in an attempt to satisfy their new found hunger. Hence, it is crucial to pay close attention to their body weight throughout this potentially tricky 18 week period following neutering and to closely monitor their food intake.
Transitioning from kitten food to adult food
So, when are cats fully grown? Adult cats need less food due to decreased activity (yes, your apparently hyperactive ball of fur will one day slow down), the fact that they are growing much less quickly, and a less active metabolism in case of neutering. Switching cat food is key. Consequently, generally speaking at age one, it is best to switch your kitten to adult food, which is lower in protein and fat. However, in case of neutering, it may be better for your kitten to transition to adult food earlier, from six months to a year, depending on your vet’s advice, and when all the signs that their body growth is complete have been identified. It all depends on the nutritional contents of the food formula chosen (ex. recipe for kitten or for sterile kitten from 6 to 12 months).
The art of the smooth transition
Switching your cat from kitten food to adult cat food should be done gradually and requires a little organization. Transitioning too rapidly may lead to digestive issues for your cat. A gradual shift over the course of 5-8 days is best to allow them to get used to their new diet. Start by mixing a small amount, say 10%, of adult food with the kitten food. Every two days increase the percentage of adult food. Normally, by day seven or eight your kitten will have successfully made the switch. If you have not already done so, it is often recommended to begin to steadily introduce different flavours and textures of food, including both dry and wet food. This will help ensure that your cat does not become a picky eater. In addition, certain cats naturally love variety.
Monitoring your young adult cat’s weight
As your cat grows older and transitions to adult food it is especially important to monitor their body weight. In order to help your cat maintain a healthy bodyweight, you could try adding wet food to your cat's dry food diet. Wet food is far less calorie dense than dry food and also has the advantage of much higher water content, which is always good for your cat. You can also try out puzzle feeding toys that stimulate them mentally. Finally, you can also help your cat maintain a healthy bodyweight by regularly engaging in games they love using cat toys to encourage physical exercise.
The underweight cat
While most of us tend to worry about our cat becoming overweight, it is also equally important to ensure that they are not underweight. If your young adult cat is looking a bit thin or suddenly refusing to eat, we advise consulting your cat’s veterinarian. Losing weight can be a sign of health issues or that your cat’s dietary needs are not being met properly. Your vet can advise you on any dietary changes that need to be made. In particular, it is recommended to worm your kitten regularly. Consult your vet regarding the frequency of deworming.