One record, three facts on the same line
Weight alone tells you a number moved; it cannot tell you why. Keep a single running record where each entry holds three facts together: the weight taken that day, a body condition note from feeling the ribs and looking at the waist from above and the side, and the exact amount of food being fed at that moment, including regular treats and chews. When the three sit on one line, a later reader can see that the weight rose during the weeks the evening chew doubled, rather than guessing months afterwards.
Weigh and assess the same way each time
Use the same scales, at a similar time of day, and write the body condition note in your own plain words alongside a score if your vet uses one. Note anything that distorts a single reading, such as a recent big drink, a thick winter coat or a weigh-in straight after a meal, instead of treating every figure as equally clean. Consistency matters more than frequency: a careful entry every few weeks builds a trend you can trust, while hurried daily numbers taken five different ways mostly build noise. If you weigh after a growth spurt, a heavy moult or a course of treatment, write that beside the entry too, because those weeks explain a reading that would otherwise look like a simple feeding mistake.
Change one thing, then write the change down
When you adjust the diet, alter a single element — the main food amount, the treat habit or the food itself — and record the date of the change, what changed and what you left alone. Then hold everything steady long enough for the next two or three entries to show an effect before changing anything else. Owners who tweak three things in one week can never say which tweak worked, and the record exists precisely to answer that question when a vet asks how the current weight was reached.
Read the trend, not the single weigh-in
Look back over several entries before reacting. A slow drift across a season, a sudden drop between two close entries and a stable weight with a worsening body condition note each call for a different response, and only the joined-up record separates them. A rapid unexplained loss, a gain paired with a pot-bellied shape, or appetite changes alongside the weight shift are reasons to book a veterinary appointment promptly and take the record with you, because a vet can do far more with a dated trail than with a memory of roughly what the dog weighed last spring.
Keep the record where the rest of the history lives
Store this sheet with your dog's vaccination and health paperwork rather than on a kitchen note that gets thrown away at the next tidy-up. When a new food is tried, a family member takes over feeding, or a boarder needs the current amount, the same page answers everyone identically. Keeping weight, condition and food amounts joined in your dog's Pet Passport on KinsLe means the reasoning behind every diet change travels with the rest of his records, ready for any vet visit or handover.