Greater Swiss Mountain Dog nutrition: bloat and growth

For a Greater Swiss Mountain Dog, the feeding decision with the most at stake is how meals are given, because gastric dilatation-volvulus (GDV, or bloat) is an emergency of large, deep-chested dogs, and speed of eating and bowl height both change the risk. Growth, joints and seizures come next, and each has a food question attached.

Bloat and how meals are given

In GDV the stomach fills with gas and then twists, cutting off its own blood supply. VCA Animal Hospitals calls it one of the most serious non-traumatic conditions in dogs, needing veterinary attention within minutes to a few hours. Large, deep-chested dogs are most at risk, and VCA gives the lifetime risk for dogs over 100 pounds (45 kg) as about 20%. We found no published bloat rate for the Swissy itself.

The best evidence on everyday risk factors comes from a prospective study of 1,637 large and giant breed dogs followed over time. The Swissy was not among the eleven breeds, but the findings are the best guide available for dogs of its build. Risk rose with age, with having a parent, sibling or offspring that had bloated, with faster eating and with a raised food bowl. The authors attributed roughly half of the GDV cases in the giant breeds to raised bowls, the opposite of the old advice to lift the bowl. VCA adds feeding only one meal a day and an anxious or fearful temperament to the list.

What that means in practice:

• Split the daily food into at least two meals. Many owners of giant dogs use three.
• Feed from a bowl on the floor, not a raised stand.
• Slow a fast eater with a slow-feed bowl or by scattering kibble on a mat.
• Feed dogs apart if they compete over food, which speeds eating and raises tension.
• Keep the time after meals quiet. VCA notes that exercise after a large meal or a large drink may increase risk. The evidence for any exact rest period is weak, but an hour or so of calm costs nothing.

Prophylactic gastropexy

Gastropexy stitches the stomach to the inside of the body wall. According to VCA it is the most effective means of prevention, and some vets recommend doing it at the same time as spaying or neutering in high-risk breeds. It does not stop the stomach filling with gas, but in most cases it prevents the twist. Ask about it before the spay or neuter appointment.

Before any planned surgery, Swissy owners should know about one breed-specific bleeding problem. A mutation in the P2Y12 platelet receptor gene was found across five generations of one family of Greater Swiss Mountain Dogs, after a dog bled heavily following a routine spay. The dog's standard clotting tests were normal. The authors note that affected dogs show little or no spontaneous bleeding but can bleed heavily after routine surgery or injury, so tell the surgeon about any bleeding problems in the dog's family.

A twisted spleen (splenic torsion) can happen with GDV or on its own, and it causes overlapping signs: pain, a swollen belly, weakness and pale gums. It needs the same emergency visit and is diagnosed with imaging and surgery.

Calories by body weight

The standard starting point for any dog is the calculation in the Merck Veterinary Manual. Resting energy requirement (RER), in kcal per day, is 70 multiplied by body weight in kilograms raised to the power 0.75. A neutered adult needs about 1.6 times RER, an intact adult 1.8 times, and a dog that gains weight easily 1.4 times. Rounded to the nearest 5 kcal:

Merck notes that dogs of the same weight can need up to 30% more or less than the formula gives, and that breed alone changes needs: its example is that Newfoundlands appear to need fewer calories than Great Danes. The short coat makes body condition easy to judge. Ribs should be easy to feel under a thin layer of fat, with a visible waist behind them. Weigh the dog monthly, on a vet clinic scale if needed, and change portions by about a tenth at a time.

Growing a large puppy slowly

Large puppies are sensitive to how they are fed while their skeleton develops, and the Swissy's shoulders are a known weak point. Switzerland includes the shoulders in its official radiographic screening of breeding dogs, and a review of those X-rays from 1993 to 2013 found osteochondrosis of the head of the humerus, the ball of the shoulder joint, in 14% of Greater Swiss Mountain Dogs screened.

Calcium is the nutrient to watch. Merck explains that growing large and giant breed puppies, from weaning to a year old, are more sensitive to excess calcium than small dogs. In rapidly growing large breed puppies, diets with more than 3% calcium on a dry matter basis produced more severe osteochondrosis and poorer bone remodeling than diets with 1% to 3%. Puppies fed a complete growth food do not need calcium supplements, and adding them, or bone meal, pushes intake in the wrong direction.

• Choose a food labeled complete and balanced for growth of large-size dogs. With an "all life stages" food, check that the label includes growth of large-size dogs.
• Measure every meal. Free feeding makes it hard to control the rate of growth.
• Feed to body condition, not to the growth chart. A lean, slightly lanky adolescent is the aim. Check ribs and waist every couple of weeks and cut back if the puppy is getting round.
• See a vet for lameness in a growing puppy, especially a front-leg limp that comes and goes.

Joints in the adult dog

Keeping a large dog lean is the part of joint care with the strongest support. Every extra kilogram loads the hips, elbows and shoulders on every stride, and weight gain is easy to miss on a dog this size. Glucosamine, chondroitin and fish oil are often suggested. Doses for a dog of 50 kg vary widely between products, fish oil adds calories, and the evidence that they protect joints is limited. Discuss a specific product and dose with the vet, particularly for a dog already on medication.

Epilepsy and diet

Idiopathic epilepsy, recurrent seizures with no underlying brain lesion, is suspected to run in the breed. In a German study of 94 Swissies with idiopathic epilepsy, the average age at the first seizure was about two and a half years, and males were affected more often than females. Nearly half of the dogs had cluster seizures and more than a third had status epilepticus, a prolonged seizure or a run of seizures without recovery in between. Both are emergencies.

That study found that seizures often began with vomiting, retching or drooling. In a Swissy, retching and drooling are also signs of bloat. If a dog is retching without producing anything and its belly is swelling, treat it as possible GDV and go to the emergency vet.

Diet cannot replace anti-seizure medication, but one addition has trial evidence. In a randomized, double-blind crossover trial in 28 dogs with idiopathic epilepsy, adding medium-chain triglyceride (MCT) oil to the usual diet lowered seizure frequency compared with a control oil. The reduction was modest overall, though two dogs had no seizures while taking the supplement. MCT oil is a concentrated source of calories, so it has to come out of the daily energy budget, and it should be added with the vet who manages the medication. Other diet claims for epilepsy, such as avoiding rosemary extract or giving liver-support supplements, have little evidence behind them.

Changes to food for an epileptic dog should be gradual. Discuss any change of food with the vet first, since the dog's medication levels may need checking afterwards.

Urine leaking in spayed females

Urinary incontinence in spayed females is often mentioned as a Swissy problem, but we found no published figure for how common it is in the breed. It usually shows up as a wet patch where the dog has been lying. A vet will check for a urinary infection and other causes, and the common hormonal form usually responds to medication. Do not restrict water to reduce leaking, since less water means more concentrated urine and no treatment of the cause. Keeping the dog lean is sensible, but no food or supplement, cranberry included, has been shown to treat incontinence.

Sources

1. Gastric Dilatation and Volvulus in Dogs. VCA Animal Hospitals.
2. Non-dietary risk factors for gastric dilatation-volvulus in large and giant breed dogs. Journal of the American Veterinary Medical Association, 2000.
3. P2Y12 receptor gene mutation associated with postoperative hemorrhage in a Greater Swiss Mountain dog. Veterinary Clinical Pathology, 2011.
4. Nutritional Requirements of Small Animals. Merck Veterinary Manual, 2023.
5. Prevalence of humeral head osteochondrosis in the Greater Swiss Mountain dog and the Border Collie in Switzerland. Schweizer Archiv für Tierheilkunde, 2016.
6. Phenotype of idiopathic epilepsy in Great Swiss Mountain Dogs in Germany: a retrospective study. Frontiers in Veterinary Science, 2022.
7. A multicenter randomized controlled trial of medium-chain triglyceride dietary supplementation on epilepsy in dogs. Journal of Veterinary Internal Medicine, 2020.