Introduction
Miniature pigs typically weigh between 32-68 kg (70-150 lb). Half of adult body weight is achieved by approximately 1 year of age and mini pigs will continue to grow until 3-4 years of age, when growth plates completely fuse.
Pigs easily gain weight and obesity is a very common problem in pet pigs, particularly when animals are inactive and fed free-choice. Obesity contributes to a host of serious health concerns, including arthritis, impaired hearing, poor vision, and even complete blindness.
Body condition scoring is based on careful visual observation of the pig, paired with palpation of fat over bony prominences, like the hips or ribs (Table 1). The scoring system described below ranges from a scale of 1 to 5, with 1 representing emaciation and 5 indicating obesity.
These two pigs have the same size and frame, but the pig on the left is in excellent body condition (BCS 3), while the pig on the right is obese (BCS 5). Photo credit: Dr. Kristie Mozzachio. Click image to enlarge.
Ideal body condition
The objective of proper pet care is to feed pigs to an ideal body condition (BCS) of 3. A pig with good body condition lacks bulging jowls. There should be no skin folds over the eyes or on the forehead. Can eye color be identified? Even deep-set eyes should be clearly visible. Most miniature pig breeds also have upright ears and a true neck. The shoulders should also be wider than the head and each individual rib should be easy to feel (but not see) beneath the skin. The rump is nicely rounded. A hint of hip bones are just barely visible and the bones can be slightly felt with firm pressure. Belly shape can vary with breed conformation, but a potbellied pig in excellent shape will have no bulge of the abdomen or a slight “potbelly”. When viewed from above, a true waist is visible.
A Vietnamese potbellied pig with an ideal body condition. Photo credit: Dr. Kristie Mozzachio. Click image to enlarge.
Obesity
Pigs easily gain weight, and obesity (BCS 5) is a common problem in pet pigs. The condition is often associated with free choice feeding or overfeeding of inappropriate food items and lack of exercise.
The obese pig possesses deep skin folds on the cheeks, creating the appearance of hanging jowls or “chipmunk cheeks”. The eyes are obscured by fat-filled folds of skin on the brow, preventing the pig from seeing well or even leading to “fat blindness”. Prominent skin folds on the brow also push the ears to a more horizontal position, which can impair hearing. A large belly extends beneath the knees, often near to or dragging on the ground. When viewed from above, there is no visible waist. The tail base is dimpled and buried within protruding fat. In sows, folds of fat also block the vulva from view.
Shown here, an obese potbellied pig. Photo credit: Animal Rescue League of Boston LowellSun via Flickr Creative Commons. Click image to enlarge.
Obesity is a common cause of health problems, including arthritis and associated lameness and entropion, or an inward rolling of the eyelid, which often leads to irritation or even corneal ulceration. Overweight pigs can have difficulty lying down, rising, walking around, and even breathing. Prevention of obesity in pet pigs relies on exercise and proper diet, as well as regular weighing and careful monitoring of body condition score.
Emaciation
With the advent of so-called “teacup” and “micro” pigs, emaciation (BCS 1) is becoming a more common finding in miniature pigs. Some breeders erroneously instruct owners to feed a tiny amount of food in the unrealistic effort to keep adult pigs unnaturally small. Of course, the result is emaciation and malnutrition.
Prominent spinal vertebrae and hip bones in an emaciated miniature pig. Photo credit: Dr. Kristie Mozzachio. Click image to enlarge.
Emaciated pigs possess sunken or hollow eyes, and the head and ears may appear disproportionally large for the body. Due to a lack of soft tissue, a gap may be palpable beneath the chin. The ribs, spine, hip bones, and tail base are all prominent. Without supporting musculature, the spine tends to curve up creating a hunched posture. The legs tend to bow out. The skin tends to be dull and dry and the hair coat is often thin and coarse. The hairs may not lie flat. Emaciated pigs are often weak or lethargic. Affected animals may be unable to stand normally, often displaying a staggered or unsteady gait and a glazed look in the eyes.
Table 1
| Body condition scoring the pet pig | |||
|---|---|---|---|
| Obesity | Ideal Body Condition | Emaciation | |
| Eyes | Eyes are hidden by skin folds on the brow | Eyes are clearly visible | Sunken, hollow eyes |
| Ears | Fat pushes ears to a more horizontal position | Upright ears in most breeds | Ears appear out of proportion to the body |
| Face | Bulging jowls or “chipmunk cheeks” Skin folds over the eyes or on the forehead | No bulging jowls or skin folds over the brow | The head appears too large for the body and a gap can be felt beneath the chin |
| Neck | Most breeds have a true neck | ||
| Shoulder | The shoulders should be wider than the face. | ||
| Ribs | Thick fat cover | Each individual rib is easy to feel (but not see) beneath the skin. | Individual ribs are very prominent |
| Belly | A large belly hangs below the knees, possibly touching or even dragging on the ground. Exception: pregnancy | No bulge of the abdomen or a slight “potbelly” can be present | |
| Vertebrae | Midline appears as a slight hollow between rolls of fat | Visible over the shoulder; some cover further back | Prominent and sharp spinal vertebrae |
| Waist | No waist is visible from above | A true waist is visible from above. | |
| Pelvis | Hip bones cannot be seen or palpated. | A hint of hip bone should be visible. | Hip bones are prominent. |
| Tail | The tail base is “dimpled” and the tail head is buried within folds of fat | Prominent tail base | |