The Labrador answer: appetite is the whole problem
A Labrador Retriever should not eat food made for other kinds of pets, because his relationship with food removes the safety margin other dogs have. Many Labradors carry a genuine, breed-typical drive to keep eating long past fullness, and food made for other species exploits it perfectly. Cat food is richer, more aromatic, and more calorie-dense than his own diet, designed to tempt a finicky carnivore; to a Labrador it is irresistible, and he will eat the cat's portion, the spare bowl, and the contents of any bag he can open. A single taste is rarely a crisis, but access turns into a daily habit faster with this breed than with almost any other.
What steady raiding does to a Labrador's body
Weight is the headline issue, because a Labrador gains readily and extra pounds load his elbows, hips, and shoulders every time he launches himself into water or up a bank. Owners often trace a puzzling weight climb back to the cat's feeding station once they start watching closely. His stomach pays a second price: rich cat food in Labrador quantities commonly produces loose stool, urgency, and occasional vomiting, usually blamed on something he found on a walk. There is also the displacement effect, where a Labrador full of stolen food still eats his own dinner, because fullness barely registers, so nothing about his behaviour warns you the calories doubled.
Comparing the foods a Labrador will find
Wet cat food is the richest and his top target, and he can eat a cat's entire day of it in one visit. Dry cat kibble follows, small and easy to swallow in huge mouthfuls from a torn bag. Ferret food is more concentrated than either and should never be within his reach. Rabbit pellets and hay are less rewarding but still eaten, passing through as bulk that can leave him constipated or passing very large stools, while bird seed contributes oily calories and husks. Even another dog's food causes trouble in a Labrador home when it is a puppy formula or a diet for a different condition, because his portions stop being the ones you planned.
Labrador-proofing the feeding arrangements
Assume a Labrador will test every barrier, and choose ones that do not depend on his cooperation. Feed the cat behind a closed door or a gate with an opening too small for a Labrador's head, and lift the bowl the moment the cat walks away. Keep all pet food in bins with latching lids inside cupboards, never in bags on the floor, because he will open a bag silently and eat until interrupted. Feed small pets inside their enclosure, sweep spills immediately, and give the Labrador his own meal in a separate space at the same time, ideally in a slow-feeding bowl that stretches his mealtime past the cat's.
When to call the veterinarian about a Labrador's raid
Call your veterinarian if a Labrador who raided another pet's food vomits repeatedly, has diarrhoea that is not improving after a day, seems sore around the belly, or goes off his own food, which for this breed is a notable change. Seek urgent help if he retches without producing anything, paces and cannot settle, or his abdomen looks swollen, and call sooner for a puppy or an older Labrador. Report what he ate and your best estimate of the amount, acknowledging honestly if access has been ongoing, because the clinic's advice differs for a one-off feast versus weeks of rich extras. A household record in KinsLe Care Teams, with each of his meals assigned and ticked off, shows that history at a glance.