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Interesting Facts and Myths About the Runt of the Litter

Adrienne is a certified dog trainer and former veterinarian assistant who partners with some of the best veterinarians worldwide.

What makes a runt a runt? Can they survive and thrive as well as other puppies? Read on to learn the answers to these questions and more.

What makes a runt a runt? Can they survive and thrive as well as other puppies? Read on to learn the answers to these questions and more.

"Runt of the Litter" Meaning

First of all, let's get an idea of what it means to be the runt of the litter. The word "runt" means "smallest or weakest of the litter." A litter is simply a group of young animals born to the same mother all at once. The term "runt of the litter” is used to describe the smallest or the weakest of all the siblings in a dog's litter. But, while runts are often portrayed as the smallest pups in the litter, there is still no clear-cut definition of exactly what a runt is.

The Term "Runt" Doesn't Have a Universal Meaning

Is the categorization based purely on size? Or is it a matter of a puppy being weaker than the others? Are runts just small, or do they also have to act sickly to qualify as a runt? It seems like the parameters of what qualifies a puppy as a runt are blurry and subject to personal interpretation. Even among veterinarians, there doesn't seem to be a consensus as to what constitutes a runt, and the term seems to be used loosely.

"There is really no agreement among veterinarians—or anyone else for that matter—as to what constitutes a runt."

— Dr. Ron Hines, DVM/PhD

There are a few common myths about runts that, while widely believed, are not actually true.

There are a few common myths about runts that, while widely believed, are not actually true.

Common Myths About Runts

There are several inaccuracies on the web as to what causes a runt to be a runt. Two of the most common misconceptions state that runts are simply puppies that were positioned in the middle of the uterus or ones who came from the eggs that were fertilized last.

The Puppy in the Middle of the Uterus Will Be the Runt

False. The theory that the runt is positioned in the middle is based on the fact that the uterus of a dog is shaped like the letter "Y." The belief is that being in the middle positions the runt farthest away from the nutritious blood supply necessary for normal development. This theory is untrue. When puppies are in the uterus, they move around and change positions constantly.

The Puppy That's Conceived Last Will Be the Runt

False. Another theory states that whichever pup is conceived last will be the runt. This is an equally unfounded claim, considering that the mother dog's eggs are fertilized at the same time or very close to it. All pups in a litter are ultimately the same age.

So, What Makes a Runt a Runt?

A veterinary theriogenologist is a board-certified veterinarian who specializes in animal reproduction. These respected professionals have made reproduction their area of expertise. One of the most respected veterinary theriogenologists is Dr. Margaret V. Root Kustritz. So, what does she have to say about the topic?

Runts Are Pups With Comparatively Poor Implantation Sites

In her book, The Dog Breeder’s Guide to Successful Breeding and Health Management, Dr. Kustritz explains that runts are simply puppies who had poor placentation. Runts are not weak because they were conceived last or happened to be positioned in the middle of the uterus; they just had the misfortune of having a poor implantation site while the other pups had better ones.

"What accounts for runts is not being fertilized later than the other eggs, it is their placement within the uterine horn, " says Myra Savant-Harris in the book Canine Reproduction and Whelping: A Dog Breeder's Guide. She also says that runts are not premature puppies; they are simply puppies who had a "poor implantation site in the uterus." Similarly, large puppies are not large because they are born overdue; they simply had great implantation sites.

"Runt pups most likely are the same age as their littermates but had poor placentation."

— Margaret V. Root Kustritz

Common Disadvantages of "Runt" Puppies

Since runts are smaller or weaker than the rest of the squad of puppies, they do experience several disadvantages, but one of the main disadvantages is that the runt has a harder time competing for the milk that the mother dog provides her litter. The other puppies are stronger than the runt, so the runt has a hard time getting its nutrition from its mother.

They Struggle With Nursing

Getting nutrition in the first 48 hours of life is very important, as this is when a mother dog produces special milk known as colostrum, which is rich in maternal antibodies and provides maternal immunity. Failure to reap the benefits of this milk may lead to a weak immune system and vulnerability to illness. If a puppy is reluctant to nurse, caregivers should provide a commercial puppy-milk replacer that is rich in naturally occurring microbial compounds.

They Are Often Ignored by Their Mothers

Another disadvantage is that sometimes the runt is ignored by the mother dog because she detects that the puppy is small or weak and naturally tends to focus on the healthier pups. This is a form of natural selection; in other words, it is survival of the fittest.

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They Are Prone to Ailments

On top of struggling to nurse, runts often also struggle with health ailments which can range from mild to severe to life-threatening.

Runts have long gotten a bad rap, but with a little TLC, they can thrive just as well any other puppy.

Runts have long gotten a bad rap, but with a little TLC, they can thrive just as well any other puppy.

With Tender Loving Care, Runts Can Thrive

Runts have a hard time surviving in the wild because they are weak and small, generally failing to survive past their infancy. In a domestic setting, however, things are quite different. When given proper care, runts may not only survive, but they will likely thrive and live happy lives just like the other non-runt puppies. Many caretakers confess that helping these little fellows out and watching them grow bigger and stronger is a very rewarding experience!

Many runts need help from the get-go, but just what kind of help do they need? Because runts are small and weak, their mothers might ignore them. Mother dogs may be reluctant to nurse them or may just simply reject them right when they are born. This means that human intervention may be necessary in order to help the puppy survive.

After creating a plan with a veterinarian, puppy owners may have to roll up their sleeves to free the runt from the amniotic sac, massage their teeny bodies to increase circulation, clear their airways of fluid and sever the umbilical cord. Puppy owners may also need to provide assistance to help the runt stay warm, clean, and well-fed.

Monitoring new pups—especially runts—for health issues is critical.

Monitoring new pups—especially runts—for health issues is critical.

Special Precautions to Take With Runt Puppies

Upon being born, runts should be monitored carefully and checked out by a vet to determine whether there may be some underlying congenital abnormality or other health problem that is preventing them from blooming like the other pups. Breeders should take a daily weight of all of the puppies in a litter to keep track of growth, paying particular attention to the runt.

Upon being adopted in a new home, all new puppy owners are advised to have their puppy undergo a health check by a veterinarian, but this is even more imperative when bringing a runt puppy home. Arrangements should have been put in place in advance with the breeder as to who pays for these veterinary services and what shall be reimbursed should the pup be found to have a health ailment.

Possible causes that may prevent a pup from flourishing may include the presence of a liver shunt, a heavy parasite load, a heart defect, or a cleft palate, just to name a few.

"The runts of the litter can have heart defects and other congenital problems including umbilical hernias that the breeder might not disclose to you so it's a good idea to have your veterinarian do a complete examination of the puppy before you agree to buy the pup (or have a refund if there is a congenital problem)."

— Dr. Jan

Beware of breeders who label runts as "teacup" or "micro" puppies and sell them for a premium.

Beware of breeders who label runts as "teacup" or "micro" puppies and sell them for a premium.

Runts Shouldn't Sell for a Higher or Lower Price

Oftentimes, prospective puppy owners expect to pay a lower price for runts because they are slower to develop compared to other pups; however, as long as the pup is healthy, there should really be no reason to pay less.

Besides, many runts catch up quickly, and it's not unheard of for some to even outgrow their siblings! This is part of why breeders are often unwilling to lower their prices for runts unless there is something wrong in the health department.

Beware of Shady Breeders

I'd like to offer a word of caution about breeders of so-called "teacup" puppies or "micro" puppies who try to sell runts for a premium, making them appear valuable and highly in demand. A breeder would normally sell runts at the same price as the other pups, knowing that they are not more valuable nor less valuable than any other pup in a litter.

"The small size does not necessarily mean that the runt of the litter will not be a good pet if all other health issues are within expected limits."

— Dr. Robert L. Ridgway

Famous Runts in Pop Culture

Pop culture is stocked with an abundance of characters who were runts of the litter. Clearly, this figure has inspired authors and moviemakers worldwide. For instance, Wilbur, the protagonist pig of Charlotte's Web, was a runt of the litter destined for slaughter. Remarkably, he not only survives but manages to become famous, all thanks to a spider who works tirelessly to save him.

Babe, another piglet runt of the litter, also risks becoming Christmas dinner. He is miraculously turned into a hero and is even entered into a sheep-herding competition.

Clifford the Big Red Dog is a runt who not only survives but thrives so much that he grows to be 25 feet tall, though sometimes he gets into trouble because of his size.

Other examples of famous runts who have inspired the imagination of novelists, cartoonists and filmmakers include:

  • Shade the bat from Silverwing,
  • Fiver from Watership Down,
  • Goliath II from Disney's movie of the same name,
  • Ruth from Anne McCaffrey's novel The White Dragon,
  • Jock from the real story Jock of the Bushveld by Sir James Percy FitzPatrick,
  • Cadpig in Dodie Smith's novel The Hundred and One Dalmatians,
  • and many more!

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Questions & Answers

Question: Can a female runt of the litter have puppies?

Answer: Technically yes, runts can have puppies, however, there are some things to keep in mind.1) runts don't always remain "runts." In other words, although they have a slow start in life, once they are nursed and weaned, many of them catch up and grow as normal puppies. 2) while some unethical breeders purposely breed their runt with another runt in hopes of producing whole litters of smaller than average dogs, this practice is not recommended due to failing to breed dogs in the name of health and therefore failing in perfecting the breed.

© 2016 Adrienne Farricelli


Ruth on August 16, 2020:

I got my tiny fox terrier from a kind woman who had rescued her from a breeder

With full knowledge I adopted her knowing that she had a stage 4 heart murmur.She is so wonderful and gutsy,and gives my male foxy a runfor his money.So happy to have her.Please consider adopting a dog that needs a chance in life.You will be rewarded many times over.

Doris May on June 10, 2020:

Thank you so much for making this information available, sincerely !!!!!

Dylan on March 14, 2020:

Thank you for the articles! It really gives me more confidence and faith in raising my tiny little one (he is 1/3 the size compared to the biggest one among the siblings). He is a 7 week Border Collie weighing 1.82 pound, healthy and started to show interest in his food (canned food) since yesterday. I thought i almost lost him as he wasnt eating and drinking much.

Sandra on March 01, 2020:

I adopted a Border Collie 8 yrs ago from a rescue group. He was one of two left to be homed from the litter. The entire group was still there but the only two left available were pointed out to me. Henry was off to himself in a bed. I now realize the lady tried to steer me to the other dog but when I picked Henry up and he wrapped his legs around my arm I was hooked. He is the smartest dog I have ever known but I will say he can be a handful at times. He has never bitten anyone but does not like to be around most other people and growls at everyone. He even growls at us when we pet him. He even shows his teeth at the same time he is wagging his tail. He growls over his food in a very protective manner. From time to time he seems to have digestive issues. We love him but tend to keep him away from everyone. I consider him typical of many things I have heard about runts. Be prepared to deal with challenges if you decide to home a runt.

Kevin B Conniff on January 14, 2020:

We have a six year old Dachshund named Scrappy. Black and Tan his ears are short, nose short, body short with little paws. His Mom and Dad were full blooded Dachshunds normal in every visual attribute you would expect of a Dachshund. We also adopted a female Dachshund a couple years after we got Scrappy. We love them both. I must say that Scrappy has exhibited by far the most intelligence of any dog we have had. The volume of words he understands has far exceeded what we believed a dog could learn. Yes he was the runt of the litter when my S.O. picked him out but it in no has turned out to be a handicap nor impairment. We love him...and Coco also. Thank you for letting me share

Angel on December 03, 2019:

I just bought an Argentino Dogo at 7weeks and she is extremely small for a Dogo. She weighs only 6 pounds and has worms we just found out. What can we do to fatten her up and have her looking like the Dogo she’s suppose to be?

Adrienne Farricelli (author) on November 30, 2019:

Maureen, It is always great to hear stories of runts of the litter blooming into great dogs!

maureem on November 21, 2019:

i have two runts from my boston terrier Wiki . there was a total of 7 pups 4 females 3 males . the two smallest were boys no bigger than you thumb . the others would bulldoze them from the titties . had to have mom lay on the bed to feed them . plus i would feed milk replacer and wash rag them every two hours. hubby would do the same while i was at work. i had them sleep with me all swaddled and bundled beside me . they couldnt be with those big fat hog siblings of thiers. they are now two yrs old couldnt ask for better boys. they are half the size of their siblings which are living is really good homes being loved. Doc and Dillon ( named after Gunsmoke)are smart and have their own funny ways.. they love thier mommie which is me.

Kailin on May 23, 2019:

I got my dog the day after she was born i was working for a breeder and got pick of the litter there were 6 puppies altogether but only 3 made it the mother wouldnt take care of the 2 smaller ones so we put then on a schedule with milk replacer and they went everywhere with us because we couldnt leave them there seeing the schedule was feeding every hour and we were gone hours on end the 2 smallest ones almost died but they are now 1 year old and mine is pregnant being the runt the breeder thought she was dead when born but i kept up hope and she started breathing am wiggled into my hand she is my baby

Janet K. Billingsley on November 15, 2018:

I have a 3 year old male Standard Poodle and I am interested in the purchase of a female that the owner discloses is the runt of the liter. Are there specific issues to breeding with a former runt female?

CoSmO on March 20, 2018:

I put a $200 deposit down on a American bulldog litter pick of the litter female. When the puppies were born there were four males and one female... The female is gorgeous red color but she is the smallest of the letter at Two weeks old. The breeder said I could have the deposit back. The mothers 107 pounds fathers hundred 120 pounds. I want 100 pound dog at least. What should I do? Please comment if you have and opinion.

Adrienne Farricelli (author) on December 31, 2017:

Talk with the breeder. This pup should still stay with mom and pups for another 3 weeks at a minimum if this is happening at 5 weeks. By then, the health issue may have cleared up.

Jessica on December 23, 2017:

I had a runt puppy that I adopted from a rescue centre after someone left it on the street to die with two others it was in a very bad condition unlike the other two the vets told us it was the runt and that it needed more care than the other two so we got the other adopted by our friend and we took the runt after a couple years the pups did grow up together and the runt ended up even more active than the other he is the same height so just because they are the runt doesn't mean they might have problems as they get older.

Nicjj on December 12, 2017:

we have picked the smallest bitch from a litter of miniature schnauzer, at 5 weeks she is being hand fed as she wasn't getting to her mother, after a check at the vets she is on anti biotics as a precaution as her stomach is bloated, otherwise bright & alert should this put me off buying her??

Shae on July 13, 2017:

I had a raunt 3 weeks old he was a lot smaller and weaker I didn't know to keep him from the others liter mates they pushed him over and he died I read everything about a raunt but not to separate one I thought they need to stay together

Susan Robinson on July 13, 2017:

We had a litter of 7 border collie pups, the tiny runt girl had a dreadful battle to survive. At 5 weeks we were told she had a heart murmur, then at 7 weeks it was slightly worse and we had a cardiologist do a Scan. Poor Rosie has pulmonary stenosis, she is staying home with her Mum and Dad and at the moment seems well, just a little wheezy at times. She has just going over 7 pounds in weight whereas her siblings will no doubt now be 14 pounds. She is such a beautiful little character who loves playing with her Mum Lottie

Adrienne Farricelli (author) on July 09, 2017:

Patrick, gotta love those runts. And don't be surprised if that pup catches up a little later, it does happen sometimes!

Patrick on July 08, 2017:

very informative article. We are actually about to adopt a blue nose pitbull runt and the vet already says he can tell by the size of her head she won't ever be as big as her siblings or Mom or Dad

Adrienne Farricelli (author) on December 03, 2016:

Suhail, glad you found this article on puppy runts informative, kind regards!

Suhail and my dog K2 on December 03, 2016:

Hi Adrienne,

I would have never thought about runts so much except for this article.

Very informative indeed!



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