Perhaps you've learned your zoning laws allow for potbellied pigs, or perhaps you've moved to a larger plot of land and are exploring fun and exciting new pets to add to your menagerie. Or maybe you just watched “Babe” for the first time in years and absolutely need to own a pig. Whatever the reason, pigs are fascinating creatures and excellent animals to share time with -- but compatibility issues with dogs may present problems.
Predator and Prey
Your dog is a predator. Any domestic dog's lineage traces back to wolves. from the biggest mastiff to the tiniest teacup Chihuahua. This is important to note, as it's the basis for any proposed relationship between pigs and dogs. In the wild, wolves hunt boar, and this primal, predator-prey staging can happen in the living room or backyard as well. Domestication makes it less likely, but it's possible. Sadly, it happens all the time.
It can happen to any meal: A steaming ham's pulled from the oven and plated on the table to cool, only to be pounced upon and devoured by the family dog the minute he's left alone in the kitchen. The best-trained dog will never not want a delicious ham, and a savvy owner knows that eliminating temptation is, at least in the case of saving that ham, the best way to keep dinner safe. Your pet pig may be more friend than food, but the dog may always see his companion as a walking ham. Don't leave the pig alone with your dog.
To dog owners unfamiliar with porcine ways, it's easy to lump four-legged friends together and expect similar behaviors from pigs and dogs, but it's important to remember they're completely different animals. In a home with two or more dogs, canines will establish and respect a social order; pigs have no such concept. This difference spells trouble when a dog decides he wants something the pig has, usually food, and the pig doesn't back off like a subordinate dog would. Instinct could cause a dog to attack, and the pig will suffer the consequences of the species difference -- this is especially gruesome when dogs unite as a pack against a pig.
A pig can really get on a dog's nerves. A playful pig will never understand a dog's cues to leave him alone, and this is a sure-fire invitation to attack. In particular, a pig's high-pitched squeal is a primal wake-up call to a dog's predatory instinct. Numerous accounts exist of perfectly docile dogs transforming into beasts when they hear the sound.