What Is the Runt of the Litter?

What is it that attracts us to the smallest player on the field, the underdog in the match, the weaker opponent? What about the runt of the litter? We all love a good comeback story, especially if it’s covered in hair and smells like a puppy. We can’t help but fall for the runt of the litter, but what exactly does that mean?

Let’s dive into what a runt is, what makes one puppy smaller and seemingly weaker than the rest, and how to care for them.

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What is a runt?

Your vet may call them small for gestational age or say they have a low birth weight, but you likely just know them as runts of the litter. These pups are the smallest of a group of puppies born at the same time. They may or may not be smaller than the average birth weight for puppies of their breed.

Characteristics of the runt

Sometimes the size difference is very noticeable, sometimes it’s so slight you’ll only be able to tell it by weighing the puppies. Either way, there’s always a puppy that’s smaller than the rest to some degree.

Runts are not only smaller; they may also be weaker at birth and require some special attention to keep up with their siblings.

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Health considerations for the runt

Littermates aren’t concerned about the survival of their siblings, especially in the early weeks. They just want their share of the resources — body heat, food, and maternal care — and they’ll crawl over their smaller, weaker siblings in order to get it.

Because of this, runts may be more prone to many different health issues. Keep in mind that this isn’t always the case, some runts do just fine on their own, but generally, the more proportionately smaller a runt is, the more likely they will have issues with:

• Hypothermia: Neonatal puppies have no regulation over their own body temperature. This means that for the first three to four weeks of life, they need to be near their mother and littermates to stay warm. Smaller, weaker puppies may be more easily pushed to the side and left out of the warm doggie pile where hypothermia may quickly prevail.

• Feeding difficulties: Newborn puppies require near constant nutrition. If they don’t eat frequently or get enough per feeding, they can develop hypoglycemia (low blood sugar), further weakness, weight loss and ultimately die. Weaker, smaller puppies can more easily be forced out at feeding time, preventing them from getting much needed nutrition.

• Increased mortality: If runts aren’t given a little extra attention to make sure they’re getting proper nutrition and kept warm, they can more easily become sick and dehydrated, both of which can cause mortality.

Care and management needs

A mother dog has a lot going on after the birth of her puppies. She has many new little bodies to look after, and it can be pretty easy for the smallest one to slip beneath her radar. In order to give the runt the best chance for survival, intervention may be necessary.

Keep a close eye on the little pup providing supplemental heat and food as needed, and weigh the pup frequently to make sure they are gaining weight. Speak to your veterinarian to determine your runt’s particular needs.

What causes runtiness?

Runts are smaller at birth usually due to placental issues. The placenta is what provides puppies with nutrients while in utero. It’s how a mother feeds her babies before they are born. It’s an amazing organ, but it’s not uniform in its abilities. Some puppies are going to get more while others are going to get less. The runt of the litter simply receives fewer nutrients than their littermates, and therefore, doesn’t grow as large before birth.

Infections during pregnancy may be another reason that some puppies don’t grow as much as their littermates.

Behavioral differences in the runt

With proper care and attention, a runt can develop into a normal, healthy adult dog. After a few weeks of a little intervention, most runts can catch up to their littermates and never look back. Personality wise, runts typically aren’t any different, but increased handling in the early weeks after birth may make runts more comfortable with humans and better socialized.

It can also make them spoiled and disrespectful of boundaries if firm ones aren’t set. Training a runt puppy is similar to training any other puppy — use positive reinforcement, set boundaries, and stay consistent to keep them from walking all over you.

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Should I pick the runt of the litter?

As the runt of the litter grows, they often become indistinguishable from their heavier littermates, especially if they’ve received the care they need in the early days of life. As long as they are active and healthy, size doesn’t matter.

Consider having a runt puppy checked out by a veterinarian before agreeing to take them home to make sure everything is good to go.

Bottom line

The runt is the smallest puppy born in a litter. They may be significantly and obviously smaller and weaker or the difference may only be detectable by weight. These smaller pups often need extra attention to ensure they get the nutrients and warmth that they need and may otherwise miss out on in order to prevent hypothermia, hypoglycemia, and death. If properly cared for, most runts grow into healthy, active adults that make great pets given proper training.

FAQs

Are runts always the smallest animals in the litter?

By definition, the runt is the smallest puppy of the litter. The difference in size may vary as well as the runt’s strength and vitality. Runts don’t necessarily stay the smallest. Given proper care, they may grow to the same size or even exceed the adult size of their littermates.

Can runts develop health problems as they grow?

The first three to four weeks of their lives are the most crucial for runts. During this time they are unable to regulate their body heat and require nutrition every couple of hours. If they don’t get what they need, they are more likely to develop healthy problems or even die.

How can I care for a runt to ensure it thrives?

For runts that are significantly smaller and weaker than their littermates, you may need to intervene by supplementally feeding them and keeping them warm. Closely monitor their weight to ensure they are gaining and provide a safe heat source if needed. Speak to your veterinarian for further advice on your little runt’s specific needs.