How do I calculate RER to determine proper feeding amounts?

To determine proper feeding amounts, you must first calculate your dog’s Resting Energy Requirement (RER) to establish a baseline of the calories they need at rest, and then calculate their Daily Energy Requirement (DER) to account for their specific growth stage and activity level.

Step 1: Calculate the RER. First, determine your dog’s weight in kilograms. You can calculate their RER using one of two equations:

• Standard Equation: RER = 70 × (body weight in kg)^0.75.

• Alternative Equation (for puppies weighing 2 to 30 kg): RER = (30 × body weight in kg) + 70.

Step 2: Calculate the DER. Once you have the RER, multiply it by a specific factor to determine your dog’s total Daily Energy Requirement (DER). The multiplier changes depending on your dog’s life stage:

• Weaning to 50% of adult body weight: 3 × RER.

• 50% to 80% of adult body weight: 2.5 × RER.

• 80% to 100% of adult body weight: 1.8 to 2.0 × RER.

• Neutered or spayed adults: 1.4 to 1.6 × RER (energy requirements rapidly decline after spaying/neutering, warranting a reduction in their DER by 10% or more).

Note specifically for Great Danes: They are an exception to standard growth rules; they have a 25% higher energy requirement in the first two months after weaning and may not grow properly if fed less than 2.5 times their RER during this period.

Step 3: Portion the Meals. Once you have calculated the total daily calories (DER), divide this amount and provide it over two to four meals per day. Keep in mind that any treats you provide should make up no more than a 10% allowance of this total daily caloric intake.

Because large breed puppies grow so quickly, it is recommended to frequently assess their Body Condition Score (ideally every 2 to 3 weeks) and adjust your calculations as their weight changes to ensure they maintain a lean body condition throughout their growth.