How much should I feed a 4kg dog?

The resting energy for a 4kg dog works out to around 198 kcal, and a typical active neutered pet needs close to 1.6 times that, around 315 kcal a day. At 350 to 400 kcal per 100g of dry food, that lands near 80 to 90g.

That baseline assumes an averagely active pet dog. A small terrier that spends hours digging, chasing, or patrolling the garden can need meaningfully more, sometimes 20 percent above this figure.

Breeds bred for work, such as small terriers, often carry more lean muscle for their size than a similarly sized lapdog breed, and muscle burns more calories at rest than fat does.

If your 4kg dog is constantly active and starts looking ribby on the baseline amount, increase the daily total by 10g at a time rather than jumping straight to a much larger portion.

Feel along the ribs weekly for the first month on a new amount. You want to feel them easily under a thin covering, not see them and not have to press through fat.

Keep a simple note of the weight every two weeks so you can catch a drift in either direction before it becomes a bigger adjustment. Once you have three or four checks showing a stable trend, monthly weighing is usually frequent enough to keep going.