Fat in dog food: does your dog need it, and how much?

With our Nami, you can see it in her coat – since salmon oil started going into her bowl regularly, it's noticeably shinier.

Yes, dogs need fat: it provides energy, transports vitamins A, D, E and K and contains essential fatty acids. According to FEDIAF, dog food should contain at least 5.5% fat in the dry matter, and 8.5% for puppies. Fat becomes dangerous mainly in large amounts at once – for example from leftover roast, which can trigger inflammation of the pancreas.

You're standing in the kitchen searing a steak, and your dog is sitting next to you with eyes like saucers. A slurp of frying fat for your four-legged friend? Please don't. But feeding completely fat-free? Also wrong.

Fat is one of the most misunderstood topics in dog nutrition. In our community, there are two camps: some swear by “as lean as possible”, while others pour in salmon oil every day as if it were water. Both are wide of the mark. Let's sort the whole thing out honestly.

Fat isn't just a source of energy. It transports the fat-soluble vitamins A, D, E and K – without fat, these vitamins simply don't get into the body. Your dog could drink litres of carrot juice (for the vitamin A) and it would achieve nothing if there were no fat with it.

Fat also provides more than twice as much energy per gram as protein or carbohydrates. 1 g of fat = 9 kcal. For an active Border Collie herding sheep all day long, it's the main source of energy.

And then there's the coat. If your dog has a dull, brittle coat, lots of dandruff or dry skin – the first thing to adjust is almost always the fat. More precisely: the fatty acids.

This is where it gets interesting. There are two important families of polyunsaturated fatty acids: omega-3 and omega-6. You need both. But the ratio makes the difference.

In modern commercial food, omega-6 dominates (it comes from poultry fat, sunflower oil, maize). Omega-6 tends to promote inflammation. Omega-3 (from fish, linseed, algae) has an anti-inflammatory effect. There's no scientifically established ideal figure for the ratio. However, many experts recommend adding omega-3 in a targeted way – especially for skin or joint problems.

What you can do about it:

• Salmon oil (e.g. from Pets Deli, AniForte or Grau): provides EPA and DHA directly, which dogs can make best use of. 1 tsp per 10 kg of dog daily.
• Hemp oil: naturally has a good ratio (3:1) and tastes nutty. A good alternative for dogs that dislike the taste of fish.

Linseed oil is often recommended, but dogs convert the plant-based ALA into EPA/DHA only poorly (to a limited extent). As the sole source of omega-3, it's not enough.

Concrete figures for everyday use:

The FEDIAF guidelines give a minimum of 5.5% fat in the dry matter for adult dogs and 8.5% for puppies; most complete foods are well above this. A worked example: a neutered, normally active 20 kg dog needs around 1,060 kcal a day, so about 295 g of dry food at 360 kcal per 100 g. If the pack says 12% crude fat, that's around 35 g of fat a day. The food amount calculator works out the amount for your food.

If you cook yourself: very lean recipes, for example made only with chicken breast, can provide too little fat and energy. In that case, slightly fattier types of meat or oil can help – how much depends on the recipe. You'll find a fully calculated basic recipe in the beginner's guide to home cooking.

Very active working and sporting dogs are often given foods richer in energy and fat. Overweight dogs and dogs with a history of pancreatitis, on the other hand, tend to need lower-fat rations – how far to reduce is decided by the vet practice. More on weight loss in helping your dog lose weight.

Oh, and this is important: too much fat in one go can trigger pancreatitis. That's an acute inflammation of the pancreas – painful and sometimes fatal. Breeds at risk include Yorkshire Terriers, Schnauzers (especially Miniature Schnauzers) and Cocker Spaniels.

The classic scenario: the family is enjoying a cosy raclette evening, and the dog gets cheese rind, bacon scraps and sausage ends. The next morning, the dog is lying there listless, vomiting and in severe abdominal pain. That's an emergency. Please go straight to the vet – don't wait and see.

Food that's very high in fat over the long term isn't ideal either: it provides a lot of energy in a small volume and quickly leads to excess weight.

Too little fat is just as much of a problem. Signs:

A dull, scruffy coat. Dry, flaky skin. Itching with no allergy behind it. Poor wound healing. In puppies, growth problems.

If you see this and haven't changed anything about the food: check the label. “Crude fat” is a mandatory declaration. Convert the value to dry matter (with dry food, little changes; with wet food, a lot does) and compare it with the FEDIAF minimum values of 5.5% for adult dogs and 8.5% for puppies. If the problems persist, have your dog examined by a vet – skin problems have many possible causes.

Fat isn't the enemy. It's essential. But as with everything in nutrition: the dose makes the poison. Look at the fat content of your food, supplement with a good oil if necessary, and avoid fatty leftovers from the table.

If you cook yourself and don't know whether your ration contains enough fat – and above all the right omega ratio – the DoggoMeal app will help. You enter your ingredients, and the app automatically works out the fat content, the omega-3/6 ratio and the vitamin A supply. No calculator, no spreadsheet. Get the app