You think of your dog as a member of the family, but until you consider the similarities, you may not realize how close humans and dogs really are. Dogs share many characteristics with humans including emotions, brain and digestive systems, dietary needs and five senses. There are even some diseases that affect both humans and dogs. Comparing all the ways humans and dogs are alike, it's no wonder they're considered man's best friend.
Digestive Systems and Dietary Requirements
Both humans and dogs have monogastric digestive systems. That means that they each have only one stomach that secretes acid and breaks down the food they eat. The entire digestive system of both humans and dogs includes:
- Salivary glands
- Esophagus and stomach
- Small and large intestines
- Gall bladder
The nutrients those digestive systems process are similar, too. Dogs and humans both need protein, fat, carbohydrates, vitamins, minerals and plenty of water in their diets to remain healthy.
Emotions and Behaviors
Anyone who lives with a dog knows that they experience emotions. In his article for Psychology Today, University of British Columbia professor of psychology Stanley Coren, Ph.D., says that dogs do, indeed, experience emotions like humans do. However, the depth to which they experience them is more like a 2-year-old child rather than an adult. Still, that means that dogs feel emotions such as love and affection, shyness, joy, anger, fear, jealousy, disgust, contentment, distress and excitement. Dogs will even laugh and feel grief over a loss, such as when a human or animal companion dies.
Similarities of the Brains
It could be that dogs behave in similar ways to humans and share some of the same emotions because their brains have essentially the same structures. Not only do human and dog brains produce oxytocin, a hormone that encourages affection and bonding, but they also have similar neurological regions that produce like responses in both. A 2014 study published in Current Biology revealed that, through these voice-sensitive areas in their brains, humans and dogs process the voices of others and the emotions attached to them in the same way.
All Five Senses
Humans and dogs share the same five senses of taste, touch, hearing, sight and smell. They both use those senses to experience the world however, dogs primarily rely on their senses of hearing and smell, using their other three senses as "backup." Humans, on the other hand, rely on vision as their primary sense, but in her article for Scientific American, science journalist Lena Groegner reveals that, most of the time, the senses team up and work together to affect the way humans perceive things.
Infections, Viruses and Parasites
Though you might enjoy sharing your life with your dog, you don't want to share a disease with him. Unfortunately, there are viruses, infections and parasites that dogs and humans can share and sometimes transmit to each other. These include streptococcus, staphylococcus, ringworm, rabies, leptospirosis and gastrointestinal infections such as salmonella. Additionally, because of the influenza virus's ability to mutate, it's even possible for your dog to catch the flu from you.
- Washington State University College of Veterinary Medicine: Digestive System of the Dog
- American Society for the Prevention of Cruelty to Animals: Nutrients Your Dog Needs
- Central Community School District 4: Types of Animal Digestive Systems
- Psychology Today: Which Emotions Do Dogs Actually Experience?
- Cesar's Way: The Science of Canine Emotions: What's Behind a Dog's Feelings?
- Scientific American: Feeling Simpatico with Your Dog? It May Be Based on Similar Human–Canine Brain Structures
- Current Biology: Voice-Sensitive Regions in the Dog and Human Brain Are Revealed by Comparative fMRI
- Doindogs Kennel: Your Dog's Senses Are More Powerful Than You Know - Find Out Why
- Brainline.org: Vision is Our Dominant Sense
- Scientific American: Making Sense of the World, Several Senses at a Time
- Cornell University Center for Animal Resources and Education: Potential Zoonoses Associated With Dogs
- Oregon State University: Can You Really Give Your Dog or Cat the Flu?
- Psychology Today: What is Oxytocin?