Rat Terrier – little dogs on a big mission

President Theodore Roosevelt is said to have given this little breed its name not for its size, but because of its swift removal of the White House’s rat problem. This little guy, also known as the Rattie or RT, is up to any challenge you throw at him—provided you can get around his stubborn nature first.


  • Comes in two sizes: miniature and standard
  • High energy and requires plenty of exercise
  • Intelligent but stubborn
  • High prey drive, and successful escape artists


The rat terrier was bred in America to work originally as a farm dog. A rat infestation could be the difference between thriving and starvation on a farm, and so farmers began to breed these terriers to hunt rats and other small vermin that could get into food stores.

The breed’s popularity increased, and by the 1890s, other breeds like whippets and beagles were bred in to create both a faster dog, and a more pack-focused dog.

While these dogs were the size of what we consider standard rat terriers today, by the 1920s they began to be bred with toy fox terriers that were too large to breed with each other. This introduced the miniature rat terrier.

Although Theodore Roosevelt is said to have given this breed its name, there is some debate as to whether this is true. The dog that Theodore Roosevelt owned is believed to have been a different breed, and the AKC recognizes the Teddy Roosevelt terrier as a separate breed.

Appearance and Vital Stats

Rat Terrier Appearance and Vital Stats

General Appearance

Though the rat terrier’s appearance can vary by strain, there are general standards for their appearance. They are classified as small to medium-sized dogs, and come in to size varieties: standard and miniature.

The rat terrier has generally sharp, pointed features. The miniature variety is bred to be small enough to crawl and reach into places where vermin may hide.

Rat Terrier General Appearance

Dog Breed Group

The rat terrier is part of the terrier group. Terriers are dogs that have been bred to hunt and guard the family farm from intruders both two-legged and otherwise. The rat terrier is no exception to this.


The miniature rat terrier stands at 13 inches or less, while the standard’s height is 13 to 18. They range in weight from 10 to 25 pounds, depending on the strain.

In the 1970s, breeder Milton Decker created a new strain of rat terrier nicknamed the Decker. They are recognizable for their larger size, frequently upwards of 25 pounds. However, the Decker is considered a variant of the standard rat terrier strain. The National Rat Terrier Registry is the only registry that maintains records on the Decker.

Life Span

As smaller dogs, the rat terrier’s lifespan tends to be longer than its larger cousins. A healthy rat terrier can expect a life span of about 12 to 18 years.

Coat and Colors

Rat Terrier Coat and Colors

The rat terrier’s coloring varies greatly, and usually comes in pied colors. You’ll find these dogs ranging from black tan to blue to pale gold to black. You will always find the rat terrier with piebald spotting.

Though some rat terriers are brindle, this particular coloring is not considered breed-standard. There is movement within rat terrier circles to have brindle recognized as part of breed standard, this has yet to be achieved.

You may also find some merle colored rat terriers, though this too is unacceptable by breed standards. This coloring is usually thought to come from recent outcrossing, and so makes it ineligible to be part of the breed standard.

The rat terrier sheds seasonally. As the breed has shorter fur, shedding season is usually easy to manage.


Docked Rat Terrier

The rat terrier’s tail is traditionally docked, though undocked is also acceptable as part of the breed standard and many owners and breeders choose to leave the tail undocked. A docked tail is normally about 2-3 inches long. Many rat terriers also carry the bobtail gene, which means that its tail is naturally short or nonexistent.


Rat terriers’ ears are usually naturally upright. Some rat terriers, however, have semi-erect ears, or buttoned ears, where the ear folds over and covers part of the ear opening. All of these are considered acceptable for the breed standard.


High intelligence and energy levels mean either a wonderful companion to play and hike with, or a tiny menace in your home. The rat terrier requires lots of mental and physical stimulation, so get ready to start upping your daily activity levels!

Bred to guard the farm, rat terriers can be wary of strangers. They’ll warm up quickly, though, and visitors to your home will find themselves with a wonderful new friend. Just make sure they are socialized properly early on, so as not to develop any aggression problems.

As for the rat terrier’s owners, they’ll have a loyal, affectionate companion for life. Though they can be obstinate, they love to please, and would follow you to the end of the earth. Their high levels of intelligence make them incredibly intuitive, and they’ll recognize and react to your moods.

The rat terrier’s intelligence means that they are highly trainable, though a little persistence may be necessary on their human’s end because of their natural stubbornness. Praise and positive reinforcement are the best methods for training this little breed.

Watch out for the rat terrier’s innate instinct to dig. These little escape artists can and will dig holes in your yard, and can easily dig one under your fence easy for them to slip under. It might be a good idea to section off a part of your yard for them to dig in—away from any fences, of course.

Rat terriers are loving, playful, and loyal companions that are generally quiet and don’t bark too much. As long as you make sure to give them enough physical and mental stimulation, they’ll be a wonderful companion.

Rat Terrier Personality

Apartment Living

While it’s best to have a yard for your rat terrier to run around and play in, they do adapt surprisingly well to apartment life. As long as you can give your rat terrier about 40 minutes of exercise a day, he should be calm and well-suited to living in an apartment.

Children and Other Pets

The rat terrier is a great dog for kids. As a loyal and playful breed, your children will enjoy hours of affection and fun every day with your rat terrier. The important thing is to teach your children early how to interact with dogs. Show them that pulling tails and ears is not good behavior, and that they shouldn’t bother the dog while he’s eating. Socialize your rat terrier around children as early as you can, too. As long as these steps are followed, your children will find themselves with a loyal, affectionate best friend for the rest of your dog’s life.

Rat terrier tend to do well around other dogs, as long as they are properly socialized. Rat terriers are energetic, and love to play. Having a fellow dog companion for them might keep them from getting bored. It’s best, however, to choose a companion that is around the same size as your rat terrier. The rat terrier may not understand how small he is, and could try to bite off more than he can chew with a large dog.

Because these dogs were bred to chase and kill small animals like rats, they would do best in a home with only larger animals.



Feed your rat terrier high quality dog food, and keep track of your dog’s caloric intake to prevent obesity. A rat terrier that is between 10 to 15 pounds should eat ? cup to 1 cup of dry dog food per day. A rat terrier between 15 to 25 pounds should be eating ? of a cup to 1 ? cups per day.

It’s best to feed your dog half his daily food in the morning and half in the evening to prevent him from eating too quickly, and keep him feeling satisfied throughout the day.


Rat terriers have short coats, so you won’t have to visit the groomer for trimming. You should brush your rat terrier’s coat about once a week to keep it healthy, along with a monthly bath. While the rat terrier is in his seasonal shed, using a rubber curry mitt or brush will help remove the loose hairs.

Brush your dog’s teeth at least a few times a week, ideally daily if your schedule allows. Also check their ears for excess wax and dirt. Trim your dog’s nails so are kept short. Having nails that are too long can be painful for dogs to walk with.


Although calmer than their cousin the Russel terrier, the rat terrier still requires a decent amount of exercise per day. Aim for about forty minutes or more every day to keep them tired and happy. A good walk, fetch, or even some vigorous indoor playtime if you’re in a pinch should do the trick.

The rat terrier’s high level of intelligence requires a decent amount of mental stimulation on top of the physical. Spend some time teaching him new tricks, put some treats in a Kong toy, or use a snuffle matt to exercise his mind.

You might also consider enrolling your rat terrier in dog sports like agility to burn off that excess energy and keep them entertained.


Patellar Luxation

Although this breed has been regularly outcrossed, which means bred with dissimilar breeds, it can still encounter health problems specific to the breed. Once such is patellar luxation, which is also called a “trick knee.” The knee in this case dislocates or moves from a normal position. As active dogs, the rat terrier can be prone to developing a trick knee.

Legg-Calve-Perthes disease

This ailment is when the head or ball of the femur begins to spontaneously degenerate. The exact cause of this disease isn’t known, but it is generally agreed it likely comes from disrupted blood flow to the hips. As the disease progresses, the hip will collapse and arthritis may become an issue. Small dogs like the rat terrier are especially at risk.

Watch for signs of your dog limping, and for sudden pain around the joint. If you believe your dog may have Legg-Calve-Perthes disease, call your vet immediately.

Hip dysplasia

The standard rat terrier especially can be prone to hip dysplasia, as it normally affects medium to large sized dogs more than it does smaller dogs. Hip dysplasia is a genetic condition that can be exacerbated by a dog’s weight, activity levels, and hormones.

Watch for pain in your dog’s back legs, as well as weakness. The dog may have difficulty getting up from sitting or lying down. He may also limp while walking. If your dog begins showing signs of hip dysplasia, call your vet to discuss getting a diagnosis and treatment options.

Similar Breeds

Teddy Roosevelt Terrier

Teddy Roosevelt Terrier

The Teddy Roosevelt terrier, or “Teddy,” was originally a variety of the rat terrier. The two were eventually distinguished as separate breeds by the AKC.

Though the rat terrier and the Teddy share the same colorings, the Teddy can be identified by its shorter, more compact body.

Toy Fox Terrier

Toy Fox Terrier

The rat terrier, especially of the miniature strain, can sometimes be confused with the toy fox terrier. Although they have similar coloring, the toy fox terrier is generally a few inches shorter, standing at 8.5 to 11 inches.

Russel Terrier

Russel Terrier

The Russel terrier is another similar breed. These dogs tend to be much more active and energetic than the rat terrier. They generally have a stockier build, and while the rat terrier’s coat must be short and smooth to fit within the breed standards, the Russel terrier’s coat may be smooth, rough or broken.

Smooth Fox Terrier

Smooth Fox Terrier

You may also find the rat terrier compared to the smooth fox terrier. Also bred for hunting purposes, the smooth fox terrier is slightly larger at about 15 inches tall. They do, however, share the same length of fur, and require the same level of grooming. The smooth fox terrier’s size, as well as its v-shaped head, are what truly set it apart. It does also tend to have different coloring.