A 35 kg American Bully that gains 2 kg in three months without any change in activity often indicates a poorly calibrated diet. This stocky breed, with its broad chest and dense musculature, easily stores excess weight. Adjusting your American Bully’s diet is not just about choosing a brand of kibble: it requires understanding its actual energy needs, monitoring critical nutrients like calcium, and adjusting the food portion over the months.
Metabolic Weight and Energy Needs of the American Bully
Most online guides suggest rations in “cups per day” without considering the dog’s actual size. For an American Bully, this approach is risky. The European recommendations from FEDIAF calculate energy needs based on metabolic weight, not gross weight. Specifically, a formula based on body weight raised to the power of 0.75 is used to estimate daily kilocalories.
This calculation is a starting point, not a fixed value. A medium-sized Standard Bully and an XL will not have the same needs, even with comparable activity levels. Adjustments are then made according to body condition: if the ribs are no longer palpable under a slight layer of fat, the portion decreases. If the dog appears hollow behind the shoulders, we gradually increase the amount.
To find the essentials at X Anima on this topic, the logic remains the same: start with the dog’s data, not a generic chart printed on a bag of kibble.
Calcium and Phosphorus: The Limits Not to Exceed for Joints
People often talk about “strengthening the bones” of a Bully by adding calcium. In reality, an excess of calcium weakens the joints, especially during growth. The FEDIAF 2025 guidelines precisely regulate these intakes with clear nutritional ceilings.
- Early growth (up to about half of the estimated adult weight): the maximum is set at 1.60 g of calcium per 1,000 kcal of metabolizable energy.
- Late growth (beyond half of the adult weight): the ceiling rises slightly to 1.80 g, as the skeleton can better handle the intake at this stage.
- Adult maintenance: the maximum drops back to 1.60 g, except for very active dogs where it can reach 2.50 g.
- The calcium/phosphorus ratio must not exceed 2 to 1 in adults, or it risks disrupting phosphorus absorption.
For an American Bully, a heavy breed with heavily stressed joints, these ceilings are not trivial. Supplementing with calcium without controlling the calcium/phosphorus ratio creates an imbalance that can lead to osteoarticular disorders, particularly noticeable in the front limbs of rapidly growing puppies.
How to Check These Values on a Label
Look at the guaranteed nutritional analysis on the packaging. Calcium is listed as a percentage of dry matter. To convert this value to grams per 1,000 kcal, divide the percentage by the energy density of the food (indicated in kcal/kg). If the manufacturer does not provide the energy density, it’s a red flag: we cannot verify compliance with FEDIAF ceilings.
Adjusting the Ration According to the Age and Morphology of the Bully
A four-month-old American Bully does not eat like a three-year-old adult, and a Pocket does not eat like an XL. Feedback varies on this point, but it is generally observed that a Bully puppy needs divided meals (three to four times a day until six months, then twice a day) to avoid blood sugar spikes and digestive overloads.
For adults, two meals a day remain the norm. A single large daily meal increases the risk of gastric dilatation-volvulus, especially in larger sizes. Spacing out meals also allows for better monitoring of appetite: a dog that turns its nose up at the morning bowl but devours the evening one may signal morning digestive discomfort related to the food’s composition.
Animal Proteins: What Rate to Aim For
The American Bully needs quality proteins to maintain its muscle mass. A food whose primary protein source is a plant-based meal is not suitable for this breed. The identified animal protein must be the first ingredient (dehydrated chicken, lamb, fish), not a generic term like “animal by-products.”
The crude protein percentage on the label gives an indication, but not digestibility. A food with a high protein content based on tendons or cartilage will be less well absorbed than food with a slightly lower rate but made from muscle. The quality of the source matters more than the displayed percentage.
Concrete Signs of an Unbalanced Diet in the Bully
Before changing kibble or switching to BARF, observe the dog. Some signals are directly related to diet and warrant a quick response.
- Chronic soft or very large stools: often an excess of insoluble fibers or poor digestibility of the food.
- Dull coat and persistent dandruff: likely a deficiency in omega-3 or omega-6 fatty acids, common with low-quality foods.
- Weight gain without changes in activity: the energy density of the food is too high for the dog’s exercise level.
- Excessive flatulence: a sign of abnormal intestinal fermentation, indicating a poorly tolerated ingredient or too abrupt a dietary change.
A dietary change should always be gradual, over seven to ten days, by mixing the old and new food. Switching overnight from kibble to a home-cooked meal almost always causes digestive issues, even in a healthy dog.
The diet of an American Bully is based on three measurable pillars: a ration based on metabolic weight, strict calcium control during growth, and quality animal protein as the first ingredient. Everything else, brand or dietary trend, comes after these fundamentals.
