How to turn a label figure into an amount for your pet
Almost every reference figure is per kilogram of body weight, and almost every label is per serving. Three steps that make them comparable, and the four places it goes wrong.
The label gives you an amount per serving. The literature gives you amounts per kilogram of body weight per day. Until you put both on the same footing, no label tells you whether a product suits your animal. The finder does this arithmetic for you, but it is worth seeing once by hand.
The three steps
- Work out the servings per day. Feeding guidance is usually banded by weight. With "up to 25 kg: 1 scoop, up to 40 kg: 2 scoops", a 30 kg dog gets two scoops.
- Work out the daily amount. Amount per serving times servings per day. At 500 mg of green-lipped mussel per scoop, that is 1000 mg a day.
- Divide by body weight. 1000 mg over 30 kg is roughly 33 mg per kilogram per day. That is the figure you compare with the reference span, which for green-lipped mussel is 25 to 50 mg per kilogram.
So the product sits in the lower third of the span. Not too little, but not generous either.
The four places it goes wrong
The ingredient is not the product. "500 mg of salmon oil" is not an omega-3 figure. What matters is the EPA and DHA within it, and depending on quality that is somewhere between 15 and 30 percent. If the share is not stated, you cannot judge the serving.
The units are not the same. Biotin is in micrograms, zinc in milligrams, vitamin E in international units, probiotics in colony-forming units. One milligram is a thousand micrograms. Miss that and you read a factor of 1000 as a rounding error.
The weight band is coarse. If a band runs from 10 to 25 kg, the 11 kg dog gets more than twice as much per kilogram as the 24 kg dog. Near a band edge it is worth checking whether the neighbouring band fits better.
The composition names no amounts. "Contains green-lipped mussel, glucosamine, MSM" without figures is not information. The order in a composition list tells you what weighs most, not how much of it there is.
What a good declaration looks like
A pack you can do arithmetic with states the amount per serving in a clear unit, bands the feeding by weight, and for oils gives the share of the fatty acids. Anything else forces you to guess, and guessing is expensive here.
Supplements are not a medicine. If your animal moves or behaves differently than usual, the cause belongs with a vet first.