The old saying "what to eat" is no exception to our pig friends.

Although pigs are mainly depicted as round and plump, this may not be the healthiest way of life for them.

Dr. Evelyn MacKay, a clinical assistant professor in the College of Veterinary and Biomedical Sciences at Texas A&M University, provided some guidance on healthy pig weight, how to maintain weight, and the consequences of not doing so.

According to MacKay, the appearance of a healthy weight may vary, depending on the breed of pig.

Although many breeds, such as Vietnamese pot-bellied pigs, have a round belly, viewed from above, all pigs should have a "waist circumference".

Many veterinarians turn to the Body Condition Score (BCS), which allows veterinarians to visually assess an animal based on its size and fat mass and classify it as ideal, overweight, or underweight.

"When assessed on a BCS scale of 1 to 9, a healthy pig will have a BCS of 4 to 6," MacKay said.

Fat deposits are a clear sign of excessive weight gain. Fat deposits around the eyes of obese pigs; the formation of these deposits can lead to so-called "fat blindness", which occurs when the pig's upper eyelid/eyebrows cover the eyes.

"A pig should not have so much fat that it will block the pig's sight, cause its belly to drag on the ground, or roll on its face or neck," McKay said. "Healthy pigs are active, vocal, and interact with their environment." 

Pigs that gain too much weight become less active and more sedentary.

When overweight, pigs are more likely to limp and unwilling to get up. This change in behavior and lifestyle will quickly lead to a series of unnecessary health problems.

"The extra weight puts more pressure on their joints and may cause them to be less active," McKay said. "This creates a vicious circle of weight gain and reduced activity."

In addition, pigs, especially pot-bellied pigs, are naturally susceptible to arthritis as they age due to their structure, including calf and large size.

In terms of healthy eating, the stereotype of pigs eating "feces" or garbage is wrong.

Pigs should be fed a balanced diet that meets their specific nutritional needs, such as commercial pellets formulated for small pigs. Avoid eating or feeding very limited starch or sugary foods, such as oatmeal or sweet fruits.

For low-calorie foods, pet owners can try to feed their pigs watermelon, celery, green leafy vegetables and carrots.

For pig nutrition guidance and addressing the needs of overweight pigs, MacKay encourages pet owners to consult their veterinarian.

"Weight loss should be gradual and should not exceed 0.5-1% of body weight every week," she said.

Combining daily activities with pigs’ daily activities can better help pet owners balance their weight.

This can take the form of teaching pig tricks; use their food to puzzle; give them a small mud pool or children's pool for them to play; or train them to walk on safety belts.

"Preventing inappropriate weight gain is always easier than letting obese pigs lose weight," McKay said. "Regular health checks with veterinarians and discussions about the appropriate number of pet pigs fed from a young age will help prevent obesity and ensure that pet pigs can maintain a healthy weight and enjoy the highest quality of life."

It is important for pet owners to understand the needs of animals and work hard to maintain them. Through a balanced diet and regular activities, owners can help their pigs live a long, active and healthy life.

Pet Talk is a service of the College of Veterinary and Biomedical Sciences at Texas A&M University. The story can be viewed on the vetmed.tamu.edu/news/pet-talk website. Suggestions for future topics can be sent to editor@cvm.tamu.edu.