Unlike the term "teacup" which is used to describe miniature versions of some dog breeds, the term "jug" has nothing to do with the size of a jug puppy. Yours will certainly not fit inside a jug. The jug is a cross of a Jack Russell terrier and a pug.
While the American Kennel Club doesn't recognize this breed, the American Canine Hybrid Club does. As you might expect with a cross breed, there are variations in the appearance of a jug depending on his genetic makeup. In general, most jugs tend to have the pug face and curly tail, but with the wiry terrier body. Some jugs have the sleeker pug coat, whereas others have the rougher Jack Russell coat. A jug grows to between 10 and 14 inches in height and weighs between 10 and 18 pounds. If you're considering getting a jug, it's worth reading up on both the pug and Jack Russell breeds so you'll have an idea of what to expect.
Jack Russell terriers are traditionally rat catchers, so they have the hunting instinct to sniff, dig and chase. They also tend to be rather vocal, as originally the dog used his voice to intimidate his prey and to alert his owner to his location. They tend to have a big dog attitude and often have no idea that they are actually a fairly small dog. As a result, this terrier is known for his courage. He likes a lot of physical activity and he isn't the type of dog that can be left alone for hours as he gets bored. A bored Jack Russell may resort to barking as a way of entertaining himself, but your neighbors may not like it. His reputation for being highly intelligent is a product of his ability when hunting to resolve problems for himself rather than wait on instructions.
Unlikely the Jack Russell, the pug was definitely not bred to be a working dog. The pug's ancestors were worshipped by Chinese emperors and were considered a prized possession. As a result a pug could expect to have the best of everything, including servants to look after him. The pug loves being a lap dog, and unlike the Jack Russell you are unlikely to find him getting himself dirty by digging up the garden. He much prefers being cuddled up with you in the warmth. He is known for his charm and his love of entertaining his owners. Also, unlike the Jack Russell, he has a stocky body and with his love of food and dislike of exercise he can pile on the pounds with ease.
One of the reasons breeders are attracted to cross breeding Jack Russells with pugs is that they hope to get the best of both breeds: a puppy that is less hyper than a Jack Russell, but more active than the comfort-loving pug. Jug pups are considered intelligent, but be aware that the terrier's hunting gene does seem to be dominant in jug pups and he's likely to engage in some yard digging activity. He may also have the Jack Russell's aggressive attitude toward larger dogs, but with the presence of those laid-back pug genes, this type of behavior is usually easy to correct.
Based in London, Eleanor McKenzie has been writing lifestyle-related books and articles since 1998. Her articles have appeared in the "Palm Beach Times" and she is the author of numerous books published by Hamlyn U.K., including "Healing Reiki" and "Pilates System." She holds a Master of Arts in informational studies from London University.