Bernese Mountain Dog nutrition: growth, joints and bloat

Bernese Mountain Dogs are big and comparatively short-lived. The American Kennel Club gives 80 to 115 pounds (36 to 52 kg) for males, 70 to 95 pounds (32 to 43 kg) for females, and a life expectancy of 7 to 10 years. Cancer, especially histiocytic sarcoma, is a major risk in the breed, and no diet has been shown to change that. Feeding does matter for the other big risks: how fast a puppy grows, how much weight the hips and elbows carry, and how bloat risk is managed at meal times.

Growth in the first two years

Berners grow for a long time, and giant-breed puppies are sensitive to excess calcium. The Merck Veterinary Manual explains that puppies from weaning to about 6 months old may not be able to regulate how much calcium they absorb when the diet contains too much. Rapidly growing large-breed puppies fed diets supplemented above 3% calcium on a dry matter basis showed more severe osteochondrosis and poorer bone remodeling than puppies fed 1% to 3%. Lameness and pain have not been reported in small or more slowly growing breeds fed the same amounts.

In practice that means three things:

• Feed a complete growth food formulated for large or giant breeds, and follow its feeding guide as a starting point.
• Add no calcium, bone meal or calcium-rich extras. A complete puppy food already contains what the puppy needs, and a supplement on top pushes intake up.
• Feed measured meals and keep the puppy lean. A plump puppy is growing faster than its skeleton needs. Weigh every couple of weeks, check that the ribs are easy to feel, and reduce the portion if the puppy is filling out.

Breed standards and growth charts vary, so there is no single target weight gain per month that suits every Berner. The vet can plot the puppy's weight at each visit and advise when to switch to adult food, which in giant breeds is usually later than in small dogs.

Calories for adults

Merck's formula for resting energy requirement is 70 multiplied by body weight in kilograms to the power 0.75. That result is multiplied by 1.6 for a neutered adult, 1.8 for an intact adult and 1.4 for an adult prone to weight gain.

Dogs of the same weight can differ by up to 30% in what they need, so these are starting points. The AKC suggests at least half an hour of moderate exercise a day for the breed; a Berner that gets little more than that will usually need a figure toward the lower end. The AKC also notes that some are prone to weight gain. The thick double coat hides fat well. Feel for the ribs every couple of weeks, check for a waist from above, and weigh the dog monthly.

Cancer and histiocytic sarcoma

Cancer risk is high in the breed. An analysis of cancer deaths across 85 breeds compared each breed's cancer mortality with what its size and lifespan would predict. The Bernese Mountain Dog was one of four breeds with a risk more than 50% above expected.

One cancer stands out in the breed: histiocytic sarcoma, an aggressive cancer of immune cells called histiocytes. A study of 365 affected Berners and 289 Flat-Coated Retrievers, two of the breeds most often affected, found that most Berners (61%) had the disseminated form, spread through several organs, rather than a single localized tumor. Signs vary with where the tumor is. Lethargy, poor appetite, weight loss, lameness, coughing, pale gums or a swollen belly in a middle-aged Berner all justify a prompt vet visit rather than waiting to see.

Diet claims for cancer prevention in this breed are common and unsupported. There is no published evidence that antioxidant-rich ingredients, low-carbohydrate diets, particular preservatives or fish oil doses prevent histiocytic sarcoma or delay its onset in Berners. When choosing a puppy, it is reasonable to ask the breeder what the dogs in the pedigree died of, and at what age.

For a dog already diagnosed, the oncologist will advise on diet, which often centers on keeping the dog eating and holding its weight during treatment.

Hips, elbows and body weight

Breeders screen Berners for hip and elbow dysplasia, and a heavy frame puts large loads on both joints. Genetics set the risk. Body weight changes how much the joints carry. In a lifelong feeding study of 48 Labrador Retrievers, dogs fed 25% less than their pair-mates were leaner, had a longer median lifespan and developed signs of chronic disease later. The study was not in Berners, but it supports keeping a large dog lean from puppyhood.

Joint supplements containing glucosamine, chondroitin or green-lipped mussel are widely sold. Evidence that they prevent dysplasia in young dogs is lacking. For a dog with stiffness or lameness, a vet examination comes first, then a plan that may include weight loss, pain relief, controlled exercise and, where appropriate, a joint diet or omega-3 supplement at a dose the vet sets.

Bloat (gastric dilatation-volvulus)

In gastric dilatation-volvulus (GDV) the stomach fills with gas and food and can twist, cutting off its own blood supply. It progresses fast and needs emergency treatment, and the AKC notes that all large breeds are susceptible.

Much of what is known about feeding and GDV comes from a five-year study of large and giant breeds recruited at dog shows. Berners were not among the breeds studied, but the American College of Veterinary Surgeons (ACVS) lists similar associations for deep-chested dogs in general:

• Avoid raised food bowls. A raised bowl was linked to higher risk, and about 52% of GDV cases in the giant-breed dogs were attributed to it. Fast eating, older age and having a first-degree relative (parent, sibling or offspring) with GDV also raised risk.
• Split the daily ration. Dogs fed a larger volume of food per meal had higher risk, and risk was highest in those fed a large volume once a day. Two or three meals keep each one smaller.
• Slow down fast eaters with a slow-feeder bowl or by scattering kibble.
• Keep meals and hard exercise apart. Evidence for a specific waiting time is limited, but a quiet hour after eating is a common precaution.

Signs to act on immediately include an anxious look, looking at the belly, standing and stretching, drooling, a swelling abdomen and retching without bringing anything up. Later the dog may pant, weaken and collapse. Go straight to the nearest emergency clinic. ACVS notes that many veterinary surgeons now recommend a preventive gastropexy, which fixes the stomach to the body wall so it cannot twist, for at-risk breeds. It can often be done at the same time as spaying or neutering, and it is worth discussing with the vet while the dog is young.

Sources

1. Bernese Mountain Dog Dog Breed Information. American Kennel Club.
2. Nutritional Requirements of Small Animals. Merck Veterinary Manual.
3. The effect of body size and inbreeding on cancer mortality in breeds of the domestic dog: a test of the multi-stage model of carcinogenesis. Royal Society Open Science, 2024.
4. Comparison of the Clinical Characteristics of Histiocytic Sarcoma in Bernese Mountain Dogs and Flat-Coated Retrievers. Veterinary Sciences, 2022.
5. Effects of diet restriction on life span and age-related changes in dogs. Journal of the American Veterinary Medical Association, 2002.
6. Gastric Dilatation-Volvulus. American College of Veterinary Surgeons.
7. Non-dietary risk factors for gastric dilatation-volvulus in large and giant breed dogs. Journal of the American Veterinary Medical Association, 2000.
8. Diet-related risk factors for gastric dilatation-volvulus in dogs of high-risk breeds. Journal of the American Animal Hospital Association, 2004.