Feeding by breed and weight / Terrier group
Feeding · Terrier group
How much to feed a Fox Terrier
A neutered adult Fox Terrier at 18 lb needs about 541 kcal a day, which is 1½ cups of a 369 kcal/cup food. That is the maintenance figure before treats, from the resting energy requirement formula and the Merck Veterinary Manual's factor of 1.6 for a neutered adult.
- 1Adult weight about 18 lb
- 2At 18 lb 541 kcal a day
- 3Cups 1½ cups at 369 kcal/cup
Fox Terrier feeding table by weight and life stage
Each row is a Fox Terrier at that weight. Columns are the Merck factors: a neutered adult (×1.6), an intact adult (×1.8) and a dog that is inactive or gains weight easily (×1.4). Cups assume 369 kcal per cup, the label figure for Purina Pro Plan Complete Essentials Shredded Blend Chicken & Rice (adult dry); change it to your bag's number on the sizer.
| Weight | RER | Neutered adult | Cups | Intact adult | Cups | Inactive / weight-prone | Cups |
|---|---|---|---|---|---|---|---|
| 18 lb (8.2 kg) | 338 | 541 kcal | 1½ | 609 kcal | 1¾ | 473 kcal | 1¼ |
| 18 lb (8.2 kg) | 338 | 541 kcal | 1½ | 609 kcal | 1¾ | 473 kcal | 1¼ |
RER = 70 × kg0.75; factors from the Merck Veterinary Manual. Calorie density from the Purina product page (3790 kcal/kg, 369 kcal per 8 oz cup, about 96 g). Checked 2026-10-20.
Why the number is lower than the bag says
Bag feeding guides are written for an active, intact adult and often run above the neutered-maintenance figure; for a 18 lb Fox Terrier the gap between the intact and neutered columns is 68 kcal a day, roughly 0.2 cups. A dog that is already carrying extra weight should start from the inactive column (473 kcal at 18 lb) and be weighed every two weeks. Treats and chews count: a single dental chew can be 70–100 kcal, a sizeable share of a small dog's day.
Formulas get a healthy adult into the right range; body condition keeps it there. Ribs should be easy to feel under a thin layer of fat, and the dog should have a visible waist from above. If that is not the case after four weeks, adjust by about 10% and re-check — and ask your vet before changing a dog with a medical condition, a pregnant or nursing female, or a working dog in season.
Grams and meals
At 18 lb and 541 kcal, 1½ cups is about 144 g a day of a 96 g/cup kibble — a kitchen scale is more repeatable than a scoop. Split into two meals for an adult. Puppies eat more per pound and more often: see the Fox Terrier puppy feeding chart.
How the Fox Terrier compares
Calories per pound fall as dogs get bigger, because RER scales with weight to the 0.75 power rather than linearly. A 18 lb Fox Terrier needs 30 kcal per pound; a 20 lb West Highland White Terrier needs 585 kcal (29 per lb), a 25 lb Rat Terrier needs 692 kcal (28 per lb), a 20 lb Shetland Sheepdog needs 585 kcal (29 per lb). The breed ranks 35 of 132 by weight on this site. Females of the breed top out around 16 lb, which is 495 kcal a day neutered.
Adult weight from AKC breed standard (PDF), checked 2026-10-21. Figures are maintenance starting points for a healthy adult; they are not veterinary advice.