Why cat treats are safe, but not suitable
Cat treats are manufactured to food-safety standards, and their ingredients — meats, fish, fats, and flavourings — are not toxic to dogs, so a dog who has just crunched one has not been poisoned. The mismatch is nutritional design. Cats need a denser, more protein- and fat-rich diet than dogs, and their treats reflect that: they are small, intense, calorie-packed morsels seasoned to be irresistible, which is exactly why your dog hunts them. Fed occasionally by accident they are harmless; handed out regularly they quietly unbalance a dog's diet, add weight, and deliver none of what a dog treat is portioned to give.
The real incident is the whole pouch
One treat is a non-event; the pouch is where the trouble lives, and your question describes a dog who has already found it more than once. A dog who tears into an unattended pouch can eat a week's worth of the cat's treats in a minute — a sudden load of rich, fatty, highly flavoured food that commonly ends in vomiting, diarrhoea, and an evening of restless stomach. Worse is the packaging itself: torn foil and plastic pouches can be swallowed in the excitement, and a dog who has learned the cupboard location will work harder next time, including counter-surfing and raiding bags. Read the situation as a storage problem to solve, not a dog to punish after the fact — he is doing exactly what the smell invites him to do.
What to do right after a raid
If he has just eaten a treat or two, do nothing beyond moving the pouch; no preparation or portion question arises, because these were never meant to be served to him. If he has emptied the pouch, note roughly how much was in it, offer water, keep his next meal plain and modest, and watch for vomiting, loose stools, or signs of belly discomfort over the following day. Call your vet if he ate packaging as well as treats, if vomiting or diarrhoea persists, or if he becomes hunched, drooling, or off his food — those details, and the approximate quantity, are what the vet will ask first.
Storage and routines that end the stealing
Move the cat's treats into a latched cupboard, a closed drawer, or a sealed tub on a high shelf — anywhere that is not the counter, the low treat drawer he already knows, or a hook his nose can reach when the house is busy. Keep the cat's treat time and the pouch's location connected to the cat's own safe spaces, ideally where she is fed away from the dog anyway, such as a room he cannot enter or a raised feeding spot. Give him a parallel ritual instead: when the cat gets her treat, he gets one of his own dog treats in his own place, so the sound of a pouch opening stops meaning a robbery opportunity and starts meaning his turn is coming too.
Why swapping treats between pets is a habit worth breaking generally
Households with several pets drift easily into one shared treat supply, and the cat-treat pouch is usually just the first example. A dog on a controlled diet for weight, allergies, or a health condition can have that diet quietly undone by rich cat treats nobody counted. Keeping each pet's treats separate, labelled, and stored where only the intended animal's routine reaches them protects the cat's supply, the dog's waistline, and any feeding plan the vet has set.
Putting the pouch rule where the whole household sees it
This problem is almost never one person's fault — it is whoever last fed the cat and set the pouch down in a hurry. Writing the storage spot and the parallel-treat ritual into his KinsLe Care Teams duties means the person on feeding duty that day follows the same pouch rule, and the timestamped tasks show whether his own treat actually arrived when the cat got hers.