During WWI communication was tough for soldiers in the trenches.

Rather than trying to rely on big, bulky vehicles that could break down or human runners who were easily captured or killed by the enemy, soldiers came to rely on messenger dogs to get their messages to and from their leaders.

Another use of dogs during the first World War was as medical supply runners.

The dogs would be loaded up with bandages and other medical supplies and then let loose to run through the battlefield, delivering life-saving supplies to wounded soldiers.

Possibly one of the most famous dogs from the WWI era was Sgt. Stubby. He was a part of the 102nd Infantry Regiment and assigned to the 26th (Yankee) Division.

Sgt. Stubby was celebrated for saving troops from mustard gas attacks, comforting and finding wounded soldiers, and he allegedly once caught a German soldier by biting into his backside and holding onto him until American troops arrived!

Of course, dogs can be trained to do almost anything. This pup here was strapped up with a spool of electrical line and sent in the direction that the new lines needed to be laid on the Western Front.

Let’s hope he got a big treat after all his hard work.

Humans weren’t the only ones who were susceptible to poisonous gassed during WWI.

Dogs were fitted with gas masks so they could continue on with their duties in gassed-out areas.

President Abraham Lincoln’s family dog was named Fido. When Lincoln became the president, Fido earned the honorary title of Presidential Pet.

However, he did remain in Springfield at Lincoln’s childhood home rather than move to live with him in the White House.

Getting around in the snow without motorized equipment is tough to do. Luckily, dogs love to both be outside and to run.

This worked out perfectly when people finally realized how efficient a team of dogs pulling a sled could be.

The agility and speed of dogs were some of the main reasons they were used so much during WWI.

Here we see a perfect example of that. In total, there were tens of thousands of dogs being employed during the First World War.

Although dogs do tend to be loyal to their masters, sometimes it can be hard for a dog to know which side they are fighting for.

This Belgian dog was captured by the Germans and used to do their own bidding.

Dogs have been considered man’s best friend for a long time and for so many reasons. One of the reasons, I suppose, is that they were willing to go to war and fight and die alongside their masters.

This is a picture of a team of Belgian war dogs in action.

Horses tend to be expensive, and this was true even in the 1800s. Cheaper than a horse, though, was a dog.

Although it was an act later banned in Britain around the beginning of the 1900s, this couple decided to strap a cart to their three dogs and make them earn their daily helping of free food.

Soldiers began to rely on their dog counterparts so much during WWI that they even started dressing them in uniform.

Okay, this picture is clearly for a laugh, but I wouldn’t be surprised if the dog felt right at home in this outfit.

Owney was a regular at the post office in Albany, New York in the late 1800s. He was one of the mail clerk’s dogs and began to ride around on the rail cars of the Railway Post Office (RPO), eventually traveling all the way across the country by train.

The RPO clerks would hang medals on Owney to signify all the places that he had been.

Once again we see the advantage to using dogs for transportation in the snow. It was so efficient, that the US Postal Service started implementing dog sled mail delivery into their practices.

Here’s a team of postal delivery dogs in Alaska sometime around 1910.

Frank Stanton & Prince of Princeton is a famous photo of a couple of airplane pilots from 1915.

Of course, one of the pilots (I’m assuming Prince of Princeton) couldn’t actually fly the plane. However, I bet he was the world’s most adorable co-pilot.