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Rat Terrier-Chihuahua Mix: What You Should Know (Rat-Cha Breed)

Due to the often high cost and demanding upkeep associated with purebred dogs, many pet-loving people are now electing to adopt dogs of mixed breed.

One of the most popular of these mixed breed adoptees is the rat terrier-chihuahua mix, a dog that is colloquially referred to as the “Rat-Cha.”

If this sounds like an interesting choice to you, experts suggest that you first do some basic homework before pulling the adoption trigger, just to ensure that this particular type of dog is the right choice for you and your family.

In this article, we will help you complete some of this homework by first providing an in-depth description of each of these breeds, followed by some information regarding the mixed breed, specifically—the appearance, temperament, care and health of the Rat-Cha, among other characteristics.

A Bit about the Rat Terrier

Despite the unfortunate fact that the word “rat” is right in its title, the Rat Terrier is actually a very loving, attractive and intelligent dog, one that makes for a great companion and is fairly easy-going around children.

Depending on lineage and sex, the dog can vary somewhat in terms of its size, ranging from between 13 and 18 inches tall when measured from the shoulder; and weighing between 10 and 25 pounds, with the males typically larger than the females.

There are also larger (greater than 25 pounds) and smaller strains of the Rat Terrier, the latter of which is becoming increasing popular as a boutique pet.

While many dogs that are closely related to it are of European origin, the Rat Terrier is a purely American “invention.”

The breed was developed by early immigrants to America by “breeding the Fox Terrier with the Bull Terrier, Manchester Terrier, and Old English White Terrier.”

Originally bred as a hunting dog, the Rat Terrier earned its name from the productive duties it performed on early farms and ranches, specifically rodent control.

Their muzzle shape and patience makes them excellent rat and rodent killers.

Also known as a “Decker,” the Rat Terrier comes in a variety of coloring.

The classic or most popular version of the dog is usually colored black with tan piebald spotting, but they can also be found in various versions of tan, chocolate, mahogany, pearl and apricot colors.

The dogs usually have two (bi-coloring) or three (tri-coloring) different colors altogether.

The coat of the Rat Terrier, which has fairly easy and straightforward grooming requirements, is smooth to the touch (rather than wiry) and is always close cut to the skin.

Its head resembles a “smooth blunt,” widening gradually towards the base of the dog’s ears, which are V-shaped and sit nicely atop the skull.

The Rat Terrier’s eyes, usually brown or hazel in color, are wide-set and oval, emitting both an intelligent and inquisitive glow.

Finally, the tail of the Rat Terrier is merely a continuation of its spine, and while most owners tend to dock the tail at the second or third joint, when it is left alone it simply tapers in width until it reaches the end.

A Bit about the Chihuahua

Lively, spirited and alert, the chihuahua is one of the most well-loved dogs in the world, in large part thanks to its very small size.

According to the two most well-known dog associations (UKC and AKC), the chihuahua is the smallest recognized breed, with most of them never reaching 8 pounds at full maturity.

They have a reputation for being bold and sometimes stubborn, two qualities that make them difficult to train for the average owner; but their watchful and always-alert nature makes them one of the best watchdogs you can own.

Chihuahuas love their owner (s), but they can sometimes be very jealous when they are not receiving the bulk of your attention—attention for which they always believe they are deserving.

Most chihuahuas come in one of three colors: white, black or brown; and many of these sport two or more of these color palettes.

With most of these dogs, the coat, while also close cut like the Rat Terrier, is a bit more wiry and harsher to the touch, but they are still very easy to groom, even though they are often known to resist this process.

Some of them also have longer coats that are known to be even rougher.

The head of the chihuahua typically takes on a rounded or “apple” shape, but there are varieties within the breed whose heads resemble that of a young deer—the appropriately-named “deer head chihuahuas.”

Chihuahuas have round eyes that are generally dark brown to even black in color, but in rare instances the eyes can also be red or blue.

One of the things you will probably notice first about the chihuahua, aside from its tiny size, is its large ears.

Well, the ears are not very large by comparison’s sake, but proportionately they seem too large for the body of the animal, standing erect and alert atop a tiny skull.

Rat Terrier-Chihuahua Mix:  What You Need to Know

Now that you have a better idea regarding the appearance, personality and behavior of both the Rat Terrier and Chihuahua, let’s turn to what you can expect when these two pooches are bred with each other.

To accomplish this task, below we will highlight and explain several characteristics associated with this mixed breed, beginning with its general appearance.


Both the Rat Terrier and chihuahua are smaller-than-average dogs, with the latter being the smallest breed recognized by the American Kennel Club.

Therefore, you can expect that a cross between these two breeds will result in a dog that is usually smaller than your average purebred Rat Terrier, yet a bit larger than a natural chihuahua.

More specifically, most Rat-Chas stand between 10 and 16 inches in height when measured from their withers; and can weigh anywhere from 10-16 pounds.

Independently, the Rat Terrier and chihuahua have coats that can vary greatly in color.

This is also the case when you mix the two breeds.

Rat-Chas can have coloring ranging from black to white to brown to tan, and often there is a combination of two or more of these colors.

Their coats tend to be very close cut, harsher than that of a purebred Rat Terrier, but softer than that of a chihuahua.

Although chihuahuas have eyes that appear to be protruding from the skull, Rat-Chas’ eyes are more deep set like a terrier.

This does not mean that the eyes are not prominent on the dog’s face; they are.

However, they do not present with the same bug-eyed appearance that is so common in chihuahuas.

The head of the Rat-Cha can vary in size, but the triangular-shaped ears always sit well-spaced and erect on top of its skull.

Personality and Temperament

First off, the Rat-Cha is a very friendly dog that can also be extremely lively and vibrant when it chooses to be.

The mixed breed is very intelligent, but in order for that intelligence to transfer into training it takes an assertive owner that does not allow the stubborn and willful side of the dog to take over.

Rat-Chas are notorious cuddlers, and will stay in your lap all day garnering attention if they are allowed to do so.

Fortunately, they are also very alert and watchful, much like the purebred chihuahua, so there is little chance that a stranger could ever enter—or even get close to—your home without a chorus of barking from your dog.

Although the Rat-Cha is friendly and great with children, it can be prone to fits of anxiety and separation anxiety.

This condition can bring about a host of unwanted behaviors, including excessive barking, chewing, and urinating in the home when they feel stressed or scared.

Health and Care Requirements

Finally, if you are looking for a dog with a long lifespan, the mixed breed Rat-Terrier-Chihuahua is definitely a great choice.

According to experts, the dog can live anywhere from 12 to 18 years—a lifespan that is longer than a purebred Rat Terrier and about the same as that of a chihuahua.

Because of their closely-cropped coats, Rat-Chas do not require the same arduous grooming as some other small dogs (like Pomeranians and Poodles).

And although they do not enjoy taking baths, owners should try to bathe their pets at least every 2-4 weeks and brush them out quickly with a comb designed for their fur length.

The Rat-Cha can be a very active dog with a faster-than-average metabolism.

This rapid metabolism and hyperactive behavior makes them very susceptible to hypoglycemia or low blood sugar, a condition that can cause shaking, anxiety and any number of physical symptoms.

Because of this, you may need to feed your Rat-Cha on a different schedule than you would another dog.

Rather than feeding your pet one or two larger meals each day, try to spread their calorie requirements over 3-4 smaller meals to maintain sugar stability.

Choose smaller kibble brands to accommodate their small mouths and nutritional requirements, and try adding a drop or two of sugar into their water bowl if they begin to exhibit any signs of low blood sugar.

image: Reddit

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13 thoughts on “Rat Terrier-Chihuahua Mix: What You Should Know (Rat-Cha Breed)”

  1. Just got a rescue dog through a friend. Looked like chihuahua but different. Told friend: “Billy is doing well.” Shared some stories. Friend says, “Reminds me of rat terrier we used to have on our farm.” Looked up rat terrier descriptions saw rat-cha descriptions. Saw Billy. Understood much more about Billy. Your info greatly appreciated by me and Billy.

  2. We are getting ready to adopt a 4 year old Rat-cha. Seems to be rather shy when we had our meet and greet. Came across as very gentle and attentive. We are wnating to adopt him as a companion for our 14 year old long hair chihuahua as a replacement for the hole in our hearts when his companion of 10 years passed away. Do you think this will be a good move?

    • I can tell you that my Rat Cha has been a very loving companion to 2 of my senior dogs, especially as they were dying (one at a time) from congestive heart failure. Give your Rat Cha plenty of 1-on-1 snuggle time, to calm any anxiety, and they will be a wonderful companion to your senior dog as well as to you. Mine stayed with each of them, more often, almost like velcro, to comfort them right to the end.

  3. I am so glad I came across this article. It is spot on. Miss Bean looks like one of your picture except her legs seem to be a little longer. Her temperament is exactly like you describe and OMG she is definitely a velcro dog. Love her to pieces.

  4. my 3-4 year old sophie, is a rat-cha. she used to be overweight and is now in the proper range but declining fast and im beginning to wonder if she hasnt eaten something that has blocked her digestive tract. she is vomiting water because that seems to be just about all she is ingesting and shes not pooing like she was and size has decreased. im really concerned and would have already taken her to the vet if the finacial wasnt such an issue. I tried giving her like a third of the dollar tree gentle laxative earlier and am really hoping that will help. are there any suggestions out there? I desperately need help with her!!!!!!!!!!

    • Our Valentino (Tino) is probably the best dog we have had in 50 years.
      Very loving & funny he is devoted to us. Friendly & energetic (I walk him 5-7 miles a day).
      He was a rescue from Chula Vista Animal Rescue…
      Highly recommend the breed (Rat Terrier Chihuahua mix) as long as U have time & stamina to walk/entertain them.

    • I’ve found that instead of giving laxatives its best to give them a tsp of yogurt. The probiotics in yogurt can help them digest their food better as well as eliminate (poop) better. My little dog has a serious sweet tooth and like to get into any kind of candy she can find

    • You really need to find a vet who is willing to work with what you can afford. If this is a blockage your dog will need surgery to survive. Please find a vet. Store bought laxatives meant for humans could have very adverse effects on your dog. Please don’t give human remedies without checking it with a vet first. Good luck!


  6. One year ago, my Rat Terrier had a litter of 5 Rat-Chas. I sold 2 in
    my neighborhood. The rest I sold in no time at all. Rat-Chas are the perfect size small dogs. They have a good temperament, but still make excellent watchdogs.


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