The Unexpected Advantages of Being a Runt Puppy

What is a Runt Puppy?

A runt is defined as the smallest or weakest puppy in a litter of newborn puppies. Runt puppies tend to weigh significantly less than their littermates and are noticeably smaller in size even at birth (Source:

The typical runt puppy weighs 25-50% less than the other puppies. They may only weigh a few ounces at birth compared to littermates that weigh over a pound. Their small size is evident immediately and they continue to be considerably smaller as they grow. (Source:

There are a few reasons a puppy may be born unusually small and become the runt. This includes the puppy not receiving adequate nutrition in the womb, having a congenital defect, or coming from a litter that is too large for the mother to properly nourish each puppy before birth. Genetics can also play a role if the parents are smaller dogs. (Source:

Common Causes of Runt Puppies

There are several common causes that can lead to a puppy being born unusually small or lagging behind its littermates in growth and development:

Poor prenatal nutrition can stunt a puppy’s growth in the womb if the mother dog suffers from illness, poor diet, or stress during pregnancy. Puppies rely entirely on the mother dog for nutrition before birth, so any disruption can negatively impact development.

Genetics also play a role, as some purebred dogs are predisposed to having smaller puppies. Certain breeds routinely produce runts, especially toy and miniature breeds. The genetics simply favor smaller body size.

some breeds like toy and mini dogs genetically tend to have runt puppies.

Birth order can also affect size, as earlier pups have longer access to nutrition before birth. Later-born puppies in large litters may not receive as much nutrition in the womb.

Finally, illness or disease like canine herpesvirus and parvovirus can attack pups in the womb, impeding proper development and causing affected pups to be born unusually small. Liver shunts and heart defects can also stunt growth.


Potential Health Issues

Runt puppies are more prone to health issues due to their small size and underdevelopment at birth. Some of the key health risks include:

Higher risk of health problems – Due to their low birth weight, runt puppies have an increased likelihood of illness and medical complications such as heart defects, liver problems, blood sugar issues, and gastrointestinal disorders.

Congenital defects – Runts can be born with congenital conditions like cleft palate, hernias, and malformed limbs due to poor prenatal nutrition and developmental issues. These defects may require surgery or long-term care.

Increased vulnerability to viruses – With an underdeveloped immune system, runts are more susceptible to viruses like canine parvovirus and distemper virus, especially in their first few months before vaccines can be administered.

Behavior and Temperament

Runt puppies often exhibit timider and more cautious behavior compared to their normal-sized littermates, especially when initially introduced to new people or environments. This is likely due to their smaller size and relative weakness as a puppy. However, with proper socialization, runt puppies become quite friendly and affectionate 1.

Since runts tend to receive additional attention and handling from their human caretakers, they are very responsive to training. Their intelligence mixed with a strong desire to please makes runts highly trainable dogs. With dedication and positive reinforcement, runts can overcome their initial shyness and become well-adjusted and obedient companions 2.

Special Care for Runts

Runt puppies require some additional care and monitoring, especially in the first few weeks of life. Here are some of the main areas breeders and new owners should focus on:

Closer monitoring by the breeder is crucial. The breeder will need to observe the runt puppy closely, watching for any potential health issues or complications. More frequent weight checks and veterinary exams may be necessary. According to this WikiHow article, runt puppies should be examined by a vet within 24 hours of birth.

runt puppies need closer monitoring by breeders for potential health issues.

Supplemental feedings are often required for runts to help them gain weight and nutrition. The runt may need to be bottle fed with a puppy milk replacer or nurser bottle every 2-3 hours initially. Slowly transitioning to wet puppy food several times a day can help the puppy gain weight in a healthy manner. Owners can also try nutritional gel supplements designed for underweight puppies if recommended by a vet.

Keeping the runt puppy warm is also very important, especially immediately after birth when their temperature regulation may be inadequate. The breeder can provide heating pads, hot water bottles, or incubators if the puppy has difficulty maintaining its body heat. Monitoring temperatures and stimulating the pup to eliminate are key.

Growth and Size

Runt puppies often remain on the smaller side even when fully grown compared to the rest of their littermates. According to, runts may reach only 75-80% of the size of their siblings. Their growth plates close later, so runts tend to take longer to reach their full adult size.

In addition, runt puppies frequently take longer to reach developmental milestones related to their growth. They may start walking later, be slower to be weaned from their mother, and take longer before they can safely go to new homes. With time, care, and proper nutrition, most runts can catch up to their littermates in terms of development.

Impact on Adoption

Runt puppies are often adopted later than their littermates. Many people initially view them as less desirable due to their smaller size and increased likelihood of health issues. However, runt puppies can make wonderful pets when given the chance.

Runts tend to get adopted last, with their brothers and sisters finding homes first. People frequently pass over runt puppies in favor of their larger, heartier littermates. There is a misconception that runts are weak or sickly. In reality, with proper care and nutrition, runt puppies can live long, healthy lives. Their small size should not be the sole factor in determining their adoptability.

While some runt puppies do face additional health hurdles, many thrive and catch up to a normal size. Runts adopted later in life can form extremely strong bonds with their owners. They can be playful, affectionate companion animals. With patience and understanding, runts often exhibit tremendous grit and determination to survive and flourish. Their fighting spirit makes them loving pets. [1]

with patience and care, runt puppies can form extremely strong bonds with owners.


There are mixed opinions on whether runt puppies have shorter lifespans than their littermates. Some people believe that runts are more likely to have health problems that could shorten their lives. However, others argue that with proper care and nutrition, runt puppies can live just as long.

According to many veterinarians, if a runt puppy survives past the first few critical weeks and receives good care, it is likely to have a normal lifespan, the same as any other puppy. Runts that thrive past the first year are expected to live full, healthy lives like any other dog.1

There are many anecdotal stories of runts living very long lives, well past the average lifespan for their breed. For example, some runt Yorkshire Terriers and Chihuahuas have lived 16-20 years. With a healthy start and attentive care, runt puppies can defy the odds and live to old age.

there are stories of runt yorkies and chihuahuas living 16-20 years despite their size.

Special Considerations

Runt puppies often require some special considerations and extra care, especially in their early weeks and months. Here are some key things to keep in mind:

May require long-term nutritional support

Since runt puppies can have trouble competing with their larger litter mates for nutrition, they may need supplemental bottle feeding over an extended period. It’s important to follow veterinarian guidelines for milk replacers and weaning to ensure the puppy gets the nutrition it needs.

According to this source, hand feeding with a nurser bottle every few hours may be required initially.

Training may need extra patience initially

The smaller size and potential developmental delays of some runts may mean housetraining takes a little longer. Using positive reinforcement training, keeping sessions brief, and showing extra patience can help the puppy learn successfully.

Vet care important

Since they can be prone to health issues, regular vet checkups are important for monitoring a runt puppy’s growth and development. Things like parasites, low blood sugar, and inadequate nutrition should be watched for.

According to this source, making sure the puppy stays warm and gets proper nursing time with the mother is also crucial.

The Outlook for Runts

While runt puppies face more health and behavior challenges early on, with love and proper care from owners, they can go on to live completely normal lives. In fact, runts often make amazing pets given their resilient spirits. Their small size and need for extra attention means they frequently bond very closely with their owners. With patient owners willing to provide extra nurturing when they are young, runt puppies can thrive and overcome any early disadvantages. While they may require more patience, runt puppies have just as much potential to have happy and fulfilling lives as their larger littermates. So while raising a runt puppy requires more effort, they are deserving of a chance too!


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