The dog is an animal very present in our lives. Because they have high doses of companionship, joy and confidence, dogs are considered man's best friends and members of the families they pass through. So, if you have already had a furry friend in your life, you certainly believe you know everything about the canine universe. After all, it is common to do a brief research before receiving the new member of the family.But the truth is that dogs never tire of surprising us every day, and make us learn more and more about their particularities. With that in mind, Patas da Casa has separated 40 curiosities about dogs to help you understand some of your friend's attitudes.

• Many people wonder how many teeth a dog has: canine teeth start to develop at around 2 to 3 weeks of age. At around two months, the dog already has 28 temporary teeth. After the change, he has 42 permanent teeth;
• Dogs are champions in variety of sizes, breeds and shapes;
• The average puppy pregnancy can produce 6 puppies at a time, but in the case of large breeds, the number can reach 15;
• Puppies are born deaf, blind and toothless, but by less than three weeks old, they are beginning to acquire their senses.
• Dogs' sense of smell is 1 million times better than humans';
• Want to know how many years a dog lives? Between 10 to 13 years, depending on breed and size, but there are reports of dogs that have lived much longer;
• A dog's muzzle print is as unique as our fingerprint and can even be used to effectively identify the animal;
• Dogs lick their noses to put the scent they smell into their mouths;
• Puppies sweat through their paws;
• The dog's tail is an extension of its spine;
• Why do dogs howl? This is a way of communicating at a distance with other dogs. The frequency and timbre of the howls can be heard from far away;
• Dog neutering can help prevent some types of cancer, such as breast cancer and prostate cancer;
• In 6 years, a female can give birth to about 66 puppies, so castration is essential!
• Dogs poop in alignment with the Earth's magnetic field. This is because dogs are sensitive to small variations in the field. They poop with their bodies aligned with the north-south axis when there are few variations in magnetism;
• The way dogs see is not the same as humans. They see colors on a scale of blue and yellow;
• Puppies can run up to 30 km/hour;
• A dog's normal temperature is between 38º and 39ºC. Different temperatures can mean some illness;
• Dogs can be as smart as a 2-year-old child;
• How to calculate the age of the dog is not difficult: for example, 2 years of a small, medium and large dog are equivalent to 25, 21 and 18 years of a human respectively;
• Dogs curl up into a ball when they sleep to stay warm and also to protect themselves from predators;
• Dogs only sleep on their bellies in places they feel safe;

Did you know that dogs are able to smile at their owners?

• Dogs smile in an attempt to get their owners to give them affection - clever, right?!

• When dogs sniff each other's bottoms, it's a sign of greeting. It's like the human handshake;
• The dog has a third eyelid, called the nictitating membrane, which helps clear debris and mucus from its eyeballs and produce tears;
• The Basenji is the only breed of dog that cannot bark. Its long, high-pitched howl is its main form of communication;
• The Norwegian Lundehund is the only dog to have six toes on each paw. They serve to give more stability to the dog, whose main function in the past was to hunt the sea kite;
• Learning how to train a dog is not difficult, it just takes constant training. In addition to teaching how to paw or sit, for example, dogs can be trained to identify changes in the human body, such as illness;
• The Bloodhound breed is capable of sniffing out odors over 300 hours old;
• The "digging" with the hind legs after peeing is a kind of territory demarcation common among adult males;
• Dogs sometimes pretend to be sick to get attention from their owner;
• Border Collie is the smartest dog breed in the world;
• Despite being only a few centimeters in size, the Pinscher is one of the bravest breeds in the canine world;
• The title of laziest dog in the world goes to the English Bulldog;
• The gestation of the female can last up to 60 days;
• Dogs are omnivores, so they should not eat only meat;
• Dogs often express their facial reactions by the movement of their ears;
• Some canine diseases are similar to those of humans, such as depression and anxiety;
• The same hormone (oxytocin) that makes your dog love you, is also capable of making him fall in love with other dogs;
• The sound of rain bothers dogs' acute hearing;
• Canine obesity is the most common disease among dogs.