Like all cats, the domestic cat you know and love is a carnivore, meaning they are primarily a meat eater and are well adapted to a hunting lifestyle. (Although some cats certainly like to pretend they aren’t able to do anything but get pampered by their human). Cats have become dependent on a meat protein diet and actually cannot survive without it in their diet. This means that cats are obligate carnivores; they need meat in their diet for their body to function correctly. There are some essential nutrients found in meat that cats cannot synthesise or ‘make’ themselves.

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What can’t they make?

Cats lack the ability to synthesise (make) a number of important nutrients due to a complete deletion or severe limitation of the enzyme or pathway that makes each nutrient. Important examples include taurine, arginine, and Vitamin A, but there are others.

Protein

Proteins are large complex molecules consisting of chains of smaller ‘building blocks’, these are called amino acids. These are essential for the cat for many different biological processes.

However, while humans and dogs can adapt to diets that have a relatively low protein content, for example plant-based diets, cats have a much higher protein requirement in their diet that would typically only be met by feeding a meat-based diet, because they have come to rely on protein as an energy source.

In addition to requiring a much higher level of protein in the diet, cats also require a number of specific amino acids to be present:

  • Taurine
  • Arginine
  • Methionine
  • Cysteine

Why is meat important then?

This inability to make specific amino acids makes meat important in a cat’s diet. These amino acids may not be found in plants, or the cat cannot use the plants to ‘make’ them.

Many animals (including dogs and humans) can convert and use other amino acids derived from plants for at least some of these, but cats have lost the ability to synthesise these amino acids. As mentioned above the pathways have been lost or depleted because their natural diet (animal flesh and meat) contains these amino acids in abundance. Without these amino acids in the diet, cats become very sick and ultimately it can be fatal.

I have heard of Taurine being important? Why?

Dogs and cats exclusively use taurine to conjugate bile acids which have a number of important functions. Dogs can make at least some of their own taurine to meet their needs, if their food contains adequate amounts of sulphur-containing amino acids.

In cats, the ability to synthesise taurine is limited and insufficient to compensate for the natural losses in the gastrointestinal tract. Therefore, taurine is an essential nutrient for cats.

Taurine deficiency can lead to:

  • Feline central retinal degeneration
  • Dilated cardiomyopathy
  • Reproductive failure
  • And more…

How does this relate to meat and cat food?

Taurine is not degraded by enzymes in the cats’ body; but is excreted in the urine or via the gastrointestinal tract. However, some studies have indicated that taurine can be degraded by the intestinal microflora.

So, taurine is important, but the level of it can differ between foods and still be safe. The composition of the cat food, as well as the type of production process influence this intestinal degradation. Heat-processed cat foods resulted in lower taurine plasma levels and greater losses compared to frozen-preserved. For this reason, the recommendation for taurine in canned cat food is higher than that for dry food or purified diets.

Individual companies can have different levels of taurine in their products as long as they ensure that the products maintain adequate blood value in the cat’s body. They can ensure this through feeding trials.

What other components are important in meats?

Fats

Fat in the diet is a good source of energy. But it can help in a number of other ways by:

  • Supplying fat-soluble vitamins (A, D and E)
  • Enhancing the palatability of food
  • Providing a source of essential fatty acids

These essential fatty acids (EFAs) play key roles in maintaining the health of animals, being vital in many metabolic pathways and for the integrity of the skin. Many animals like dogs and humans can convert EFAs found in plants into the EFAs that are needed in the body; but again cats require a source of animal fat, as they cannot meet their needs from plant sources.

So, are Carbohydrates bad if they need high meat content?

Although obligate carnivores, cats can digest and use carbohydrates. However, cats have a slightly reduced ability to digest and utilise carbohydrates, as a carnivorous diet is naturally relatively low in carbohydrates.

In contrast to many other animals, cats will derive most of their blood sugar, and therefore their energy, from the breakdown of protein in the diet rather than carbohydrates. 

So, are carbs bad?

The cat’s “native” diet is inherently low in carbohydrates, consisting mainly of whatever is found in the gut contents of their prey such as rodents. As such, even very low carbohydrate diets can be safely fed to many cats of all life stages. However, this does not mean that cats cannot use carbohydrates or that they should not be present in the diet.

What should I look for on an ingredients list?

So, this is where it may get confusing, because what you see on an ingredients list, and what you think about that, might not be a good reflection on nutritional ‘completeness’ or appropriability to your cat.

More meat does not necessarily mean better, and high meat content is not synonymous with ‘complete pet food’.

Yes, it is critical to have high quality ingredients and to have a company that has the expertise to put them together in a way that meets all your pet’s nutritional needs. Sometimes, however, the companies that do this, and do it well – the ones that conduct feeding trials, and the ones that have research behind them, the ones who have board certified veterinary nutritionists or animal nutrition PhD holders on board and formulate to FEDIAF standards – don’t have the most ‘aesthetically pleasing’ ingredient list.

It is hard to determine diet quality from the label or the ingredient list. While we may feel better about feeding a diet full of great-sounding ingredients, these diets are usually similar or even potentially less nutritious than diets containing ingredients that are less appealing to people.

Ultimately, cats need nutrients not just ingredients!

The best thing you can do is go for companies that:

  • Have conducted Association of American Feed Control Officials (AAFCO) feeding trials. If AAFCO feeding trials are not conducted, the manufacturer should at least ensure their diets meet AAFCO nutrient profiles through analysis of the finished product (rather than by predicting they meet the profiles based only on the recipe).  
  • Employ at least one full-time qualified nutritionist. At the level of a PhD in animal nutrition or board-certification.
  • Conduct strict quality-control measures to ensure safe, consistent, and nutritious food for your pet
  • More important questions can be found here.

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