Expects Share 18 Reasons Why Your Maine Coon Is Small

Maine Coons are known for their impressive size and are often referred to as the “gentle giants” of the cat world. Typically, male Maine Coons weigh between 18–22 lbs (8–10 kg), while females weigh around 12–15 lbs (5–7 kg).
However, despite their reputation for being large, not all Maine Coons reach these substantial sizes. Instead, some remain small due to various genetic, environmental, and health-related factors.
Why Your Maine Coon Is Small
If your Maine Coon appears smaller than expected, it could be due to several factors, ranging from genetics to health conditions.
Here’s a detailed look at the possible reasons why a Maine Coon is small:
1. Genetics
Genetics play a crucial role in determining a Maine Coon’s size. If a kitten inherits genes from smaller ancestors, it’ll likely remain small regardless of proper care and nutrition.
Some Maine Coons come from lineages where breeders prioritize traits such as temperament or coat quality over size, leading to smaller cats.
Additionally, if your cat is not a purebred Maine Coon but rather a mix, it may inherit size traits from the non-Maine Coon parent.
2. Late Growth Rate
Maine Coons are slow-growing cats that take 3 to 5 years to reach full maturity. While other breeds finish growing in about a year, your Maine Coon might just not have finished growing!
A young Maine Coon that looks small may simply be in the early stages of development, with plenty of time left to grow. Owners often worry prematurely, not realizing that their cat is just a late bloomer.
3. Malnutrition
A nutrient-rich diet is essential for large, muscular cats like Maine Coons.
Poor-quality cat food often lacks essential nutrients such as protein, taurine, vitamins, and minerals which can lead to stunted growth and an underdeveloped body.
Malnourished kittens may never fully catch up in size, even if their diet improves later.
Ensuring that your Maine Coon receives a balanced, high-protein diet is key to supporting healthy growth.
4. Parasites
Internal parasites such as roundworms, hookworms, and tapeworms can severely impact a Maine Coon’s growth by stealing essential nutrients.
A cat infested with parasites may:
- Appear underweight
- Have a poor coat condition
- Remain smaller than average
Regular deworming and veterinary check-ups are essential to ensure parasites are not the cause of a cat’s small size.
5. Early Neutering Or Spaying
Neutering or spaying a Maine Coon too early may affect its growth.
Some studies suggest early neutering (before 6 months) may cause cats to grow taller but leaner due to the delayed closure of growth plates. Conversely, some cats may develop less muscle mass, leading to a smaller, less robust appearance.
However, this is not universally true, and many neutered Maine Coons grow to full size.
6. Health Conditions
Underlying health issues can significantly impact a Maine Coon’s size.
Conditions such as Hypertrophic Cardiomyopathy (HCM), a heart disease common in the breed, can limit a cat’s energy and overall muscle development.
Other diseases like Feline Leukemia Virus (FeLV) and Feline Infectious Peritonitis (FIP) can weaken the immune system, stunting growth.
Regular veterinary check-ups are essential to identify and manage these health conditions early.
7. Thyroid Disorders
Hyperthyroidism and hypothyroidism can affect a Maine Coon’s metabolism and growth rate.
Hypothyroidism, in particular, slows down the metabolism, preventing the cat from properly building muscle and body mass. A cat with an overactive or underactive thyroid may appear thin, lethargic, or underdeveloped.
8. Exercise And Muscle Development
Maine Coons are naturally active and muscular cats. If a cat does not receive enough physical stimulation, it may fail to build the muscle mass typically associated with the breed.
Cats that live a sedentary indoor lifestyle without access to climbing towers, toys, or playtime may remain smaller and less robust than active Maine Coons.
Encouraging exercise can support better muscle tone and overall size.
9. Breeder Practices
Not all breeders prioritize size when breeding Maine Coons. Backyard breeders, in particular, may focus on profit rather than maintaining breed standards.
Inbreeding or poor breeding practices can lead to:
- Genetic weaknesses
- Poor health
- Smaller cats
Reputable breeders carefully select healthy, large Maine Coons to maintain the breed’s characteristic size.
10. Illness During Kittenhood
Kittens that experience illness or trauma during early development may struggle to grow properly.
Infections, poor appetite, or prolonged periods of weakness can cause stunted growth. Even with recovery, some Maine Coons may never fully regain their growth potential if the illness occurs during a critical growth phase.
11. Mixed Maine Coon
Maine Coons mixed with other breeds may inherit smaller physical traits, preventing them from reaching the size of a purebred Maine Coon.
Genetic diversity can reduce bone structure, muscle mass, and overall growth potential.
12. Undereating
Cats that do not consume enough calories to meet their energy requirements will lose weight or fail to grow to their genetic potential.
Maine Coons need more food than smaller breeds due to their larger body size and high energy levels.
13. Dwarfism
Genetic dwarfism is a rare but possible condition where the cat’s growth is significantly stunted due to abnormal bone development. These cats may have disproportionately short limbs or other skeletal abnormalities.
14. Runt Of The Litter
The smallest kitten in a litter often struggles to compete for food and maternal attention. This early nutritional deficit can lead to smaller adult size, even if the cat later receives adequate care.
15. Premature Removal From Mother
Kittens separated from their mother too early miss out on crucial nutrients and antibodies found in mother’s milk. This can lead to weakened immunity and slower growth rates.
16. Enzyme Deficiency
Certain enzyme deficiencies impair a cat’s ability to digest and absorb nutrients properly. Without sufficient nutrients, growth is slowed, and overall size may be compromised.
17. Cancer
Certain cancers can cause weight loss and muscle wasting, leading to a smaller and weaker appearance. Tumors may interfere with organ function and nutrient absorption.
18. Portosystemic Shunt
This rare liver condition prevents toxins from being filtered properly, leading to poor growth, lethargy, and a small size. Without treatment, affected cats often fail to thrive.