When Do Gerbils Stop Growing?

When Do Gerbils Stop Growing?

Gerbils are adorable pets with various breeds and colors, known for their lively and curious personalities. As a gerbil owner, you might be curious about when your gerbil stops growing, how big they get as adults, and how to ensure their healthy development. In this article, I’ll share insights into the stages of gerbil growth, aiming to help you better understand and care for your furry friends.

I. Understanding Characteristics of Different Gerbil Growth Stages

Gerbil growth is divided into four stages: newborn, juvenile, adolescent, and adult. Each stage exhibits unique features, identifiable through observations of their size, fur color, teeth, reproductive organs, and behavior.

  • Newborn Stage: Gerbils are born at about half an inch in length, weighing around 2 grams. They are hairless, with closed eyes and ears, unable to hear or move. Relying on their mother’s milk for survival, they need to feed every few hours. This stage lasts about 10 days, during which gerbils grow rapidly—10 times their initial weight, doubling in length, and developing visible fur.

  • Juvenile Stage: Around 10 days old, gerbils open their eyes, start exploring their surroundings, and can hear sounds. Their ears become prominent, and teeth begin to grow, requiring gnawing on hard objects like wood or stones. While they start consuming solid foods like seeds, fruits, and vegetables, they still depend on their mother’s milk for nutritional support. Lasting about 20 days, gerbils continue to grow, reaching one-third of their adult size, weighing around 30 grams, with more defined fur colors.

  • Adolescent Stage: Around 30 days old, gerbils enter adolescence, marking their fastest growth period—becoming more active and curious. Their size rapidly increases to half of their adult size, weighing about 60 grams, displaying vibrant fur colors. Reproductive organs start developing, and they may exhibit sexual behaviors, engaging in fights or mating. Their behaviors become more complex, expressing emotions and personalities, interacting with owners or companions, playing games, and displaying preferences. This stage lasts approximately 30 days, during which gerbils nearly complete their growth—reaching 90% of adult size, weighing about 80 grams, and settling into fixed fur colors.

  • Adult Stage: Around 60 days old, gerbils reach adulthood, stabilizing in size and maturity—the ideal stage for keeping them as pets. Their size stops increasing, reaching full adulthood at 80-120 grams, with no further changes in fur color. Reproductive organs fully develop, and they enter a regular breeding cycle. Behaviors become more stable, forming habits and preferences, establishing deep connections with owners or companions, and enjoying comfort and safety. This stage continues until the end of a gerbil’s lifespan, typically 2-3 years, maintaining a healthy and happy state with proper care and affection.

II. Duration of Full Gerbil Growth

The speed and duration of gerbil growth depend on their breed and individual differences. Generally, gerbils stop growing and reach full adulthood around 3-4 months. Some may mature earlier or later, which is normal as long as their size and weight fall within the normal range.

Different gerbil breeds also have varying growth cycles. Larger gerbils take longer to mature, while smaller ones have shorter growth times. For example, the giant-sized Golden Agouti gerbil may take 4-5 months to reach full size, with an adult weight of up to 150 grams. In contrast, the Dwarf gerbil, the smallest breed, might only take 2-3 months to reach an adult weight of around 60 grams. These are rough estimates, and actual growth can vary based on each gerbil’s specific circumstances.

III. Key Factors Affecting Gerbil Growth

Several external factors influence gerbil growth in addition to breed and individual differences:

  • Diet: A well-balanced diet rich in protein, vitamins, and minerals is crucial for gerbil growth. Foods like seeds, nuts, hay, fruits, and vegetables provide the necessary energy and nutrients for bone, muscle, and fur development. Avoid overfeeding or providing unsuitable foods like meat, dairy, or chocolate, as these can lead to digestion issues, obesity, or poisoning, impacting their health and growth.

  • Genetics: Genes determine adult gerbil size, with different genes resulting in distinct features like fur color, length, and ear size. Generally, offspring inherit their size traits from their parents. However, occasional mutations or skipped generations can lead to variations in size compared to their parents. As long as gerbil size and weight fall within the normal range, there’s no need for concern.

  • Exercise: Moderate exercise stimulates bone and muscle growth in gerbils, enhancing their physical fitness and immune system. Gerbils are naturally active and curious, enjoying running inside or outside their cage, exploring new things, and playing with companions or owners. These activities provide excellent exercise, contributing to both physical and mental well-being. However, ensure they don’t become overly fatigued or injured, allowing sufficient rest and recovery time to avoid unnecessary stress and harm.

  • Disease: Illnesses can impede gerbil growth, affecting their health and lifespan. Preventing and treating common diseases like colds, diarrhea, skin issues, or dental problems is essential. Symptoms such as decreased appetite, weight loss, dull fur color, and lethargy may indicate illness. Timely adjustments to their diet, maintaining a warm environment, keeping their cage clean, and using medications when necessary can prevent the worsening of health conditions. In severe cases, consult a veterinarian to ensure proper care.

In conclusion, understanding the stages of gerbil growth, the duration of their full development, and the factors influencing their growth is crucial for providing optimal care. By considering their diet, genetics, exercise, and health, you can contribute to the well-being and happiness of your gerbil companions.

IV. Determining if a Gerbil is Fully Grown

Whether a gerbil is fully grown depends not only on their age but also on changes in their body size, reproductive organs, and behavior. Several methods can help determine if a gerbil is fully grown:

  • Observing the cessation of changes in body size: During the growth process, gerbils continuously increase in body size and weight, evident signs of their development. Measuring a gerbil’s length and weight or comparing it to other gerbils helps assess their growth status. Typically, adult gerbils have a length between 4-6 inches and a weight ranging from 80-120 grams. If a gerbil’s size and weight are within or close to this range without significant changes over some time, they can be considered fully grown.

  • Examining the full development of reproductive organs: The maturity of a gerbil’s reproductive organs serves as a crucial indicator of sexual maturity. By observing the appearance and functionality of these organs, one can determine if a gerbil has reached full maturity. For instance, in males, testicles descend during adolescence and become more visible in adulthood, while females exhibit pronounced nipples, and both genders display regular mating behavior. If a gerbil’s reproductive organs show these features without noticeable changes over time, they can be considered fully grown.

  • Assessing the stability of mature behavior patterns: The behavioral patterns of gerbils reflect their psychological maturity. Observing habits, preferences, and social interactions helps judge if they are fully grown. Typically, adult gerbils exhibit stable behavior patterns, establishing routines in activities like sleep, eating, excretion, and play. They also express distinct personalities and emotions, forming bonds with owners or companions. If a gerbil’s behavior displays these characteristics consistently without significant changes, they can be deemed fully grown.

V: Reasons for Continued Growth in Adult Gerbils

While gerbils generally cease growing after reaching adulthood, some may continue to grow for various reasons:

  • Obesity: Overeating and insufficient exercise are common causes of gerbil obesity. If a gerbil consumes excessive or oily food without adequate physical activity to burn excess calories, it can lead to fat accumulation, resulting in increased weight and size. This poses health risks such as heart disease and diabetes. To prevent obesity, provide a balanced diet, avoiding excessive or inappropriate foods like meat, dairy, or chocolate, and ensure sufficient exercise space and toys for an active and happy lifestyle.

  • Tumors: Abdominal tumors can make a gerbil appear larger. Tumors can cause the abdomen to swell as they grow, increasing body size and weight. Detecting such tumors is crucial, as they can adversely affect the gerbil’s health, impacting normal physiological functions and causing discomfort. Regular health checks and prompt veterinary attention are essential to identify and treat potential tumors.

  • Pregnancy: Pregnancy is a natural reason for an adult female gerbil to continue growing. If a female shares a habitat with a male and mating occurs, pregnancy is likely. As the uterus expands with fetal development, the abdomen enlarges, contributing to increased body size and weight. Pregnancy enhances a female gerbil’s maternal and protective instincts, bringing happiness and fulfillment. Provide a nutritious diet, a warm and quiet environment, and minimize disturbances to facilitate a smooth pregnancy and delivery.

VI: Ensuring the Healthy Growth of Gerbils

Facilitating the healthy growth of gerbils requires understanding their developmental characteristics and providing appropriate care and affection in a comfortable and safe environment. To ensure the well-being of gerbils:

  • Offer a sufficiently spacious cage and toys: Gerbils thrive on ample space for activity, exploration, and play. A cage should allow them to stand and stretch freely, and an array of toys like wheels, tunnels, swings, and wooden houses provides entertainment and mental stimulation, satisfying their curiosity and energy.

  • Provide adequate and balanced nutrition: Gerbils require a diet rich in protein, vitamins, and minerals, including seeds, nuts, hay, fruits, and vegetables. Regular and moderate feeding, along with access to clean water, supports their growth in terms of bone structure, muscle development, and fur quality. Avoid overfeeding or offering unsuitable foods, such as meat, dairy, or chocolate, to prevent digestive issues, obesity, or poisoning.

  • Conduct regular health checks: Gerbils are prone to illnesses, exhibiting symptoms like reduced appetite, weight loss, dull fur, and behavioral changes. Regular health checks involving observations of body size, weight, coat color, eyes, ears, nose, mouth, and anus help identify abnormalities. Monitor their appetite, spirits, excretion, and breathing. If any discomfort is noticed, provide appropriate treatment, adjust their diet, maintain a warm and clean cage, and use medication if necessary. Prompt veterinary attention is essential to avoid worsening conditions.

  • Seek immediate medical treatment: Gerbils are sensitive creatures susceptible to injuries or poisoning from accidents or external factors like bites, sharp objects, or toxic foods. Timely medical attention involving disinfection, bandaging, fluid therapy, injections, and professional diagnosis and treatment is crucial to prevent infection, bleeding, alleviate pain, and promote wound healing and recovery. In cases of severe injuries or deep poisoning, quickly consult a veterinarian to avoid delaying life-saving interventions.


Gerbils, with their diverse breeds and colors, possess lively and curious personalities, enjoying interactions with companions. Their growth spans four stages: newborn, juvenile, adolescent, and adult, each characterized by unique features. The pace and duration of gerbil growth depend on factors like breed, genetics, exercise, diet, and health, with most gerbils ceasing growth around 3-4 months, reaching full adulthood. External influences like diet, genetics, exercise, and illness impact gerbil size, health, and lifespan.

To ensure the healthy growth of gerbils, attentive care and affection are crucial. Providing a spacious cage with engaging toys, a balanced and nutritious diet, regular health checks, and prompt medical attention when needed creates an environment for gerbils to grow healthily and happily.

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