It is sometimes easy for pet lovers considering a small mammal to get their rodents confused. Guinea pigs, however, are more than just a small mammal -- they are cavies, and cavy bodies are built differently than regular rodents like rats and squirrels. Most notably, guinea pigs do not have tails.
Guinea pig bodies have 258 bones, including the skull, ribs and breastbone. Their spinal cord contains between 32 and 36 bones, with the coccygeal vertebrae making up the tailbone. The number of bones in their front and back legs vary. A guinea pig's front legs contain 43 bones, and the back legs contain 36. While this may seem like a large number, these bones do not make guinea pigs very agile at jumping and landing from a fall, separating them from other small mammals like squirrels and even rabbits. While guinea pigs do not usually enjoy climbing, burrowing or jumping, they are active creatures and do use these bones for activities like running and foraging for food.
Seven of the bones in a guinea pig's body are actually tailbones, but it is extremely uncommon for any of these bones to protrude on a normal, healthy guinea pig, and thus an actual "tail" will not be visible. Rather than having a long, trailing tail such as a rat, you could think of guinea pig tails being similar to those of a human's -- close together and tucked beneath the pelvis.
Sometimes, rough-coated guinea pigs, especially Peruvians with their long flowing hair, can appear to have a tail on the outside of their body that resembles a horse's. This is due to cowlicks in the guinea pig's coat and is not connected to the spinal cord or any other bones in your pet's body. If you don't want your guinea pig to appear to have a tail, rough-coated guinea pig hair can often be tamed with regular brushing.
Caring For Your Guinea Pig's Body
In order for your guinea pig to make the most of his skeletal structure, routine veterinary checkups, along with exercise and grooming are necessary. Not only does grooming a guinea pig allow you to tame an unwanted appearance of a tail, but it also helps you get to know your pet's body. Even if your short-haired guinea pig does not appear to need brushing, all guinea pigs need their nails clipped for health and comfort purposes. Exercising your guinea pig in a safe, indoor pen or through training is not only helpful to his health, but also provides a great way to interact with your pet.
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Jillian Bliss is a University of Texas alumnae who wrote for several different publications during her undergraduate career. She majored in journalism, a passion rivaled only by her love of horses. Jillian has ridden English since age six and currently owns two miniature horses, Ollie and Dare.