Lettuce

An occasional hydrating nibble with almost no calories, though many cats just bat it around.

1-2 small pieces per serving without reducing main-diet intake.

Rinse and tear into small pieces, serve at room temperature, and add no seasoning.

Dressings, vinaigrette and anything containing onion or garlic must not be used, so contact a vet if eaten; cats do not need vegetables.

About 95% water and only around 15 kcal per 100 g, so it is little more than a crunchy snack for a dog on a diet.

1-2 leaves per serving (half a leaf for a small dog), within roughly 10% of daily energy intake.

Rinse and tear into small pieces, as long whole leaves can choke, and serve raw or lightly steamed with no dressing, oil or salt.

Salad dressing is oily, salty and often contains onion or garlic, which is toxic, so contact a vet if it is eaten; any lettuce variety is fine if washed thoroughly.