chronic inflammation in dogs

When free radicals are released from cells undergoing oxidative stress, the result is chronic inflammation and a variety of health problems in dogs and cats.

In the first part of this article, we’ll look at the connection between chronic inflammation and obesity, and how keeping your dog or cat at a healthy weight can reduce inflammation in his body.

Chronic inflammation in a dog or cat’s body can lead to a range of health conditions, including infections, arthritis, diabetes and cancer. But did you know that obesity is one of those conditions? Obesity has several causes, of course, including diet and lifestyle, but many people don’t realize that a state of chronic cellular inflammation in a pet’s body can also contribute to obesity and its associated illnesses.

What causes chronic inflammation? 

Chronic cellular inflammation results from the increased release of free radicals from cells in a state of oxidative stress, leading to a wide variety of diseases. It occurs when tissues receive signals that cause them to respond as though the “trigger” or causative agent was still present. Rather than repairing themselves, the cells remain in an ongoing state of inflammation that can wax and wane for an entire lifetime.

As a result, tissues become deficient in antioxidant mediators, such as malonedialdehyde, glutathione, cysteine, ascorbic acid and other antioxidant vitamins. This is associated with poor clinical outcomes — including obesity and susceptibility to infections and even cancers. In fact, more than 200 diseases have been linked to oxidative stress, and research on the topic is mounting.

The obesity epidemic

Pet obesity is a national epidemic. A 2012 survey conducted by the Association for Pet Obesity Prevention revealed that 52.5% of dogs and 58.3% of cats are overweight or obese.  Banfield Pet Hospital’s State of Pet Health Report 2012 provided startling insight into the link between obesity and illness. The report analyzed data from more than two million dogs and 430,000 cats and found that:

  • 42% of dogs and 40% of cats with diabetes are overweight.
  • 40% of dogs and 37% of cats with arthritis are overweight.
  • More than 40% of dogs with high blood pressure are overweight.
  • 61% of hypothyroid dogs are overweight.

Banfield’s separate survey of pet caretakers found that 76% of dog guardians and 69% of cat guardians believed their pets were at a healthy weight, when in fact they were not.

Essentially, obesity is a state of chronic inflammation, which leads to a host of chronic inflammatory diseases. Overweight dogs are at increased risk for numerous diseases such as cardiorespiratory, endocrine, metabolic, orthopedic and urogenital disorders, body dysfunction, and neoplasia (cancer), and live an average of two years less than their ideal weight counterparts.

Dietary factors that lead to inflammation and obesity

  • Poor diet: Feeding more highly processed and energy dense convenience foods rather than fresh wholesome foods contributes to obesity and inflammation. Studies show that a poor diet doesn’t just lead to health problems by creating fat in the body; it actually changes the expression of obesity-related genes. Feeding your dog foods that suppress the genomic expression for obesity may not only result in a loss of weight, but also reduce the risk of obesity-related diseases. Once the body becomes “programmed” for fat, it’s a never-ending cycle because fat cells lead to more fat cells. The more fat cells there are in the body, the more these cells secrete pro-inflammatory mediators and the more chronic systemic inflammation there is. The fat-regulating hormones are known as adiponectin and leptin.
  • Food sensitivities: Food intolerances/sensitivities are a major cause of cellular inflammation, which creates small fissures between the cells lining the intestines, allowing foreign invaders such as bacteria and partially digested food molecules to cross from the gastrointestinal tract into the bloodstream, creating a further reaction from the immune system. Food intolerances/sensitivities can lead to weight gain because food sensitivities lead to inflammation, and obesity is an inflammatory condition.
  • Feeding “recommended” amounts: Manufacturers’ feeding recommendations can result in overfeeding, weight gain and inflammation. This is because they don’t take the specific age, health, lifestyle, activity level or other individual factors of the pet into account. They also tend to overestimate the amount of daily calories the pet needs to consume.

Fat-fighting functional foods

Since inflammation generates obesity, a key step in helping a pet lose weight is to feed him lots of fat-fighting anti-inflammatory foods, while also removing pro-inflammatory foods.

Some of the most important anti-inflammatory foods include:

1. High quality, bioavailable novel proteins

  • Coconut oil (virgin, expeller-pressed, preferably organic) – a medium-chain saturated fat, also known as a medium-chain triglyceride (MCT), that’s packed with health benefits ranging from immune-boosting to heart-protective properties. Coconut oil also digests differently than other fats, creating a higher thermogenic effect that boosts metabolic rate.
  • Omega-3 fatty acids – another powerful canine functional superfood, Omega-3s exert a strong anti-inflammatory effect and thus play an important role in weight loss.
  • L-Carnitine – an amino acid synthesized in the liver and kidneys, this nutrient improves protein nitrogen retention, which increases body lean mass and reduces body fat mass.
  • White kidney bean extract (Phaseolus vulgaris) – this extract has been shown to act as a starch blocker that blocks the activity of amylase – a digestive enzyme found in the pancreas of all mammals and in the saliva of humans but not dogs and cats – that breaks down starch.

2. Antiangiogenic foods

These foods interfere with or destroy the blood vessels needed for tumor growth and metastasis. Foods that prevent angiogenesis, the creation of new blood vessels, can actually shrink fat cells by cutting off their blood supply. They include:

  • Apples
  • Artichokes
  • Berries (blackberries, blueberries, raspberries)
  • Bok choy
  • Cherries
  • Curcumin (turmeric)
  • Ginseng
  • Kale
  • Lavender
  • Maitake mushrooms
  • Olive oil
  • Parsley
  • Pumpkin
  • Sea cucumber

Keep in mind that commercial weight-loss foods may not be the best choice. These products are typically high in unhealthy carbohydrates, contain pro-inflammatory ingredients, and often don’t contain enough high quality animal protein. Opt instead for fresh, wholesome ingredients that promote healthy expression of genes, minimize inflammation, and maintain a lean body mass and overall optimum health.

In Part 2 of this article (AW volume 19, issue 5), we’ll look at the link between chronic inflammation and cancer.

Other causes of obesity

  • Decreased exercise: Even though there are so-called “obesity genes”, lifestyle remains a determining factor in obesity. Lack of exercise is a primary cause in both people and pets. One study of 200,000 people who carried a specific gene predisposing them to obesity found that physically active adults who carried this gene were nearly one-third less likely to become overweight or obese than those who didn’t exercise.
  • Genetic predisposition: Certain breeds of dog have been identified as genetically predisposed to obesity, including Basset hounds, beagles, boxers, Cairn terriers, Cavalier King Charles spaniels, cocker spaniels, dachshunds, Doberman pinschers, golden retrievers, Labrador retrievers, Scottish terriers, Shetland sheepdogs and West highland white terriers. In contrast, sighthounds appear to be less susceptible, and German shepherds have the lowest incidence of obesity.
  • Spaying/neutering: A recent study found that dogs who had undergone gonadectomy (gonad removal) were significantly more likely to become overweight within two years, as compared with sexually intact dogs. There was no difference between males and females, and the increased risk was not influenced by each dog’s age at the time of the procedures.

Glossary of terms

Antioxidant – substance that reduces damage due to oxygen, such as caused by free radicals.

Free radical – highly reactive, short-lived molecules that damage cells, proteins and DNA.

Genomic – adjective referring to the complete set of genes in the body.

Mediator – inflammatory substance released from cells after an antigen-antibody reaction.

Oxidative stress – process in which reactive oxygen molecules disrupt cell metabolism and damage cells and DNA.

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Dr. Jean Dodds received her veterinary degree in 1964 from the Ontario Veterinary College. In 1986, she established Hemopet, the first non-profit national blood bank program for animals. Today, Hemopet also runs Hemolife, an international veterinary specialty diagnostics service. Dr. Dodds has been a member of many committees on hematology, animal models of human disease and veterinary medicine. She received the Holistic Veterinarian of the Year Award from the AHVMA in 1994, has served two terms on the AHVMA’s Board of Directors, chairs their Communications Committee, and currently serves on the Board of the AHVMF, as well as its Research Grant and Editorial Committees.