I really like dogs. They are the most widely abudant carnivores!
I love dogs but I've never had one! Are there many different breeds?
Well there are 337 pure bred dog breed that are recognized. 
Holy cow! That's a lot! What's a good dog breed to have as a pet?
Australian Cattle Dog
The Australian Cattle Dog (ACD), or simply Cattle Dog, is a breed of herding dog originally developed in Australia for droving cattle over long distances across rough terrain. This breed is a medium-sized, short-coated dog that occurs in two main colour forms. It has either brown or black hair distributed fairly evenly through a white coat, which gives the appearance of a "red" or "blue" dog.
As with dogs from other working breeds, the Australian Cattle Dog
that mixed-breed dogs have a health advantage over pure-bred dogs. A German study finds that "Mongrels require less veterinary treatment". Studies in Sweden have found that "Mongrel dogs are less prone to many diseases than the average purebred dog" and, referring to death rates, “Mongrels were consistently in the low risk category”. Data from Denmark also suggest that mixed breeds have higher longevity on average compared to purebreeds.
In one landmark study, the effect of breed on longevity in the pet dog