Rat Terriers are small, scrappy, and honestly, they act like they're immortal. If you’ve ever seen one fly across a yard chasing a squirrel or leap four feet into the air just because they’re excited you’re home, you know exactly what I mean. They have this "tough guy" energy that makes it hard to imagine them ever slowing down. But eventually, time catches up. Owners often find themselves wondering what do rat terriers die from when that puppy energy starts to fade into gray muzzles and longer naps.
The good news? They are one of the hardiest breeds out there. It’s not uncommon to hear about "Ratties" hitting 16, 17, or even 19 years old. However, being hardy doesn't mean they're bulletproof. Like any breed, they have a "genetic script" that usually determines how their final chapters play out.
The Big C: Why Cancer is the Leading Cause
If you look at the data from the University of Georgia’s Veterinary Medical Database, cancer is a massive player in canine mortality across the board. Rat Terriers aren't exempt. While they aren't as prone to certain bone cancers as Giant breeds, they often face "old dog" cancers.
Lymphoma and mammary tumors are things you’ve gotta watch for. Honestly, the mammary tumor risk is a big reason why vets push for spaying. If a female Rat Terrier is spayed before her first heat, the risk drops to almost zero. If you wait? It climbs. Then there are the skin issues. Because many Rat Terriers have short, thin coats—and sometimes patches of white skin—they can be prone to squamous cell carcinoma if they spend too much time sunbathing.
Think about your dog's belly. If they love flipping over in the grass to soak up the rays, that thin hair on their stomach isn't doing much to block UV rays. Over a decade, that adds up.
Heart Failure and the "Mitral Valve" Problem
Small dogs and leaky heart valves go together like peanut butter and jelly, unfortunately. As Rat Terriers age, the mitral valve—which is basically a one-way gate in the heart—starts to wear out. It gets "lumpy" and doesn't close all the way.
Blood starts leaking backward.
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This is called Mitral Valve Disease (MVD). You’ll usually hear a vet mention a "heart murmur" during a routine check-up long before the dog feels sick. If it progresses, it leads to congestive heart failure. This is often what ends up being the final cause of death for older Ratties. They might start coughing, especially at night, or getting tired after just a short walk. It’s manageable for a long time with meds like Pimobendan, but it’s a progressive downhill slide.
Kidney Disease: The Silent Decline
Kidneys are the filters. When they stop working, toxins build up in the blood. In Rat Terriers, chronic kidney disease is a common "old age" culprit. It’s sneaky. You might notice your dog is drinking a ton of water. Like, way more than usual. You’re filling the bowl three times a day and they’re asking to go out at 3:00 AM.
By the time a dog shows physical signs of kidney failure, like vomiting or weight loss, a huge chunk of kidney function is already gone. It's one of those things that usually gets them in the end because the body just can't keep itself clean anymore.
The Accidents That Nobody Likes to Talk About
We have to be real here: Rat Terriers are "high-drive" dogs. They were bred to hunt. They have zero "stranger danger" when it comes to cars or bigger animals.
Because they are so fast and so focused on prey, trauma is a significant cause of death, especially in younger and middle-aged dogs. They bolt. They see a rabbit, they hit a "flow state," and they don't hear you calling. They don't see the truck.
It’s heartbreaking.
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I’ve talked to many owners who lost their dogs not to disease, but to a split-second decision to chase a squirrel across a busy road. This is why a "solid" recall is more than just a trick; it’s literally life-saving equipment for this breed.
Patellar Luxation and the "Slippery" Slope of Mobility
While a "slipped kneecap" (patellar luxation) won't kill a dog directly, it’s often the beginning of the end for their quality of life. Rat Terriers are prone to this. The kneecap pops out of place, they limp for a second, then it pops back in.
Over years, this causes severe arthritis.
When a 15-year-old Rat Terrier can no longer stand up to go to the bathroom because their knees and hips are shot, owners often have to make the hard choice of euthanasia. Mobility is life for a terrier. When they can’t move, their spirit often breaks. Keeping them lean is the best way to prevent this. A fat Rat Terrier is a dog on a fast track to joint failure.
Legg-Calvé-Perthes Disease
This is a weird one. It’s a condition where the head of the femur (the "ball" of the hip joint) starts to die off because of poor blood supply. It usually shows up when they are young, but if it isn't treated surgically, it leads to a lifetime of pain and eventual immobility. It’s a genetic quirk in many small breeds, including the Rattie.
Epilepsy and Neurological Issues
It’s not the most common thing, but idiopathic epilepsy does pop up in the breed. Seizures are terrifying to watch. While many dogs live full lives on phenobarbital or other meds, severe clusters of seizures can be fatal or lead to brain damage.
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Most owners find that seizures start between ages two and five. If your dog makes it to seven without a seizure, they’re usually in the clear for the "genetic" version of the disorder. In older dogs, a sudden onset of seizures usually points toward a brain tumor, which—as we discussed earlier—is a common end-of-life reality for seniors.
Diabetes and Metabolic Struggles
Rat Terriers love to eat. They are master manipulators when it comes to getting a piece of your cheese. But obesity leads to pancreatitis and diabetes.
Diabetes in dogs is a full-time job for the owner. It requires twice-daily insulin shots and a very strict diet. If the blood sugar swings too wildly, it can lead to ketoacidosis or hypoglycemic shock. While not a "death sentence" today, complications from poorly managed diabetes frequently shorten their lifespan.
How to Actually Extend Their Life
You can't change genetics. You can't stop the clock. But you can definitely influence what do rat terriers die from by being proactive.
First: Dental health is not optional. Small dogs have crowded mouths. Bacteria from rotting teeth and infected gums don't stay in the mouth. They enter the bloodstream and attach themselves to the heart valves and kidneys. You want to avoid that heart failure we talked about? Brush their teeth. It sounds annoying, but it adds years.
Second: Weight management. Every extra pound on a 15-pound dog is like a human carrying an extra 30 pounds. It kills their joints and taxes their heart. If you can't feel your dog's ribs easily, they are too heavy.
Third: Annual bloodwork. Starting around age seven, get the "Senior Screen." This catches kidney and liver issues before the dog actually feels sick. It's the difference between changing a diet now and facing organ failure in six months.
Practical Steps for Owners
- Feel for lumps: Once a month, give your Rat Terrier a "massage." Feel for any new bumps under the skin. Early detection of cancer is the only way to beat it.
- Watch the eyes: Cloudiness can be cataracts, but it can also be a sign of systemic issues like diabetes.
- Listen to the breath: If they are panting more than usual while resting, get their heart checked.
- Secure the perimeter: Ensure fences are dig-proof. Rat Terriers are notorious escape artists when a scent catches their nose.
Rat Terriers usually die from the "wear and tear" of a long, high-energy life—most often heart failure, cancer, or kidney disease. By keeping them lean, keeping their teeth clean, and staying on top of regular vet visits, you aren't just giving them more years; you're giving them more "terrier" in those years. They deserve to go out with their tail wagging and that signature spark still in their eyes.