Dogs inhabit part of every continent except Antarctica, although dogs were brought there. Dogs are carnivores even though they can ingest some fruits and vegetables. Carnivores should be fed a diet consisting primarily of fatty meat (not lean meat). They can eat a reasonable amount of fruits, vegetables, and grains. Feeding dogs too many plants will make them sickly and too much grain could give them diabetes. Undoubtedly, dogs come in almost every size and shape imaginable. Varying from the tiny Chihuahua, the hulking Bull Mastiff, to the towering Russian Wolfhound. Every dog has at least a small amount of fur ranging in color from black to white, with a few exceptions of course. Interestingly, dogs can either have single or double layered fur. Dogs with single layer fur do not shed as much, some examples being the Poodle or Chinese crested. Whereas dogs with double layer fur shed more but are also less susceptible to cold and water (with a water resistant top coat) like Labradors and Saint Bernards. Some of the benefits of owning a dog are enhanced physical health and psychological wellbeing. If you own a dog, you are more likely to go for walks, and dogs seem to have a calming effect on humans.
There are also some unbeneficiary acts that we have to take into consideration. About 4.7 million people were bitten by dogs in the United States last year. It is undeniable that stray and poorly trained dogs can be quite aggressive no matter what size or breed. Another unbeneficiary act that a dog can commit is the spread of Toxocara Canis. Toxocara Canis eggs in dog feces can lead to toxocariasis in humans. Which, left untreated, can lead to retinal damage and decreased vision. Around 10,000 cases of Toxocara infections were reported in humans last year and almost 14% of the United States population is infected. In Great Britan, 24% of soil samples taken from public parks contained T. Canis eggs. Although uncommon, stray dogs and dogs that are poorly cared for have a lot higher risk of having Toxocara Canis worms and any other parasite or disease. So to sum up, with the right diet, training, care, and depending on the breed you could have a healthy, good loving friend for up to 20 years or more.
This is a video of a well trained dog (my dog, Osa), we raised her from a puppy and she has great manners and is also very healthy (she is naturally stocky). http://youtu.be/mBFlmRLqCKw