From German Shepherds to Rottweilers, man's best friend looked a lot different a century ago.

From German Shepherds to Rottweilers, man’s best friend looked a lot different a century ago. Some dogs had leaner faces, while others were taller. The dogs of today might be much cuter and certainly bigger, but they have one underlying issue. They’re much less healthy.

Due to selective breeding over decades, some of today’s dogs have more health problems than ever before. Especially dogs that have been bred in certain ways to highlight specific features. Let’s get into how and why these 10 dog breeds have changed completely.

10. German Shepherds
Believe it or not, German shepherds used to be a medium-sized dog. Today, they weigh in at around 40 kg (88lbs), which is 16 more kg (35 lbs) than they weighed back in 1915. This weight gain has led to joint problems such as hip dysplasia among other health issues.

9. Pugs
The Pug’s short skull has been bred to be exaggerated over the years. This has led to many health problems, including high blood pressure, heart problems, and breathing issues.

Oh, and their signature curly tail? That’s been bred into the dogs as well. It’s actually a genetic defect that can result in paralysis.

8. Bull Terriers
These dogs are famous for their egg-shaped heads, but they didn’t always look like this. The transformation from their much more “normal” shaped skull was a result of breeding with many different types of dogs; both for looks, and for dogfighting.

The shape of their head is almost like a football, and can lead to deafness for the dogs.

7. Chow Chows
The chow chow is one of the oldest dog breeds. Guarding their owners in ancient China, these dogs used to have much smaller heads and bodies. Now, the dogs are much bigger with thicker coats.

6. English Bulldogs
English bulldogs used to be agile animals known for bull-baiting. A type of bullfighting using dogs. Over time, their muscular and lean figures have slowly morphed into wrinkles and fat.

5. Dachshunds
This breed, with its small, nimble body was once helpful in hunting badgers. But now, that simply wouldn’t be possible; thanks to their tiny legs and awkwardly shaped bodies. These physical characteristics also make them the breed most likely to have spine and joint issues.

4. Boxers
Over the years, boxers’ faces have only gotten shorter and more smooshed. Unfortunately, this has given them a lot of trouble with their breathing and with regulating their body temperature.

3. Saint Bernards
What used to be a breed of highly skilled worker dogs doesn’t do much of anything these days. That’s because they’re now prone to eyelid abnormalities, bleeding disorders and overheating.

2. Doberman Pinschers
This breed has actually gotten healthier over the years. These dogs were once massive, but are a now a more appropriate size. They’ve also gotten much less aggressive over the years thanks to selective breeding.

1. White Terriers
Although these dogs look mostly the same as they always have, their differences are mainly beneath the surface.
The white terrier used to be a very athletic dog who had great instincts. That dog is no more. Although they do make a great house pet, they’re not quite as smart as they used to be.

All these dog breeds may be much cuter and fluffier than ever before, but is it really worth it if we’re slowly hurting their bodies?

Maybe selective breeding isn’t the best idea for dogs. It might be better for humans to let nature run its course.