Cats are highly adapted hunting machines. Nearly every part of their body serves to improve their ability to hunt for their food, from their sensitive whiskers, to their razor-sharp claws and teeth, to their digestive system.
Cats are obligate carnivores
Humans are often encouraged to eat a balanced diet of protein, fruits, and vegetables. However, this doesn’t apply to cats. Cats are obligate carnivores, meaning their biology requires a diet primarily composed of meat.
It’s recommended that cat food contain 30% protein for growing and pregnant cats, and 27% for adult cats. The diet of a cat should contain less than 10% carbohydrates. Cats, in fact, require 2-3 times more protein than dogs.
Cats are hypercarnivore
Cats, along with minks, are classified as hypercarnivores, meaning they require a diet consisting of more than 70% animal-based protein. This distinguishes cats from other domestic animals, as their protein requirements are significantly higher.
Unlike omnivorous pets like dogs, whose diets can include a mix of plant and animal matter, hypercarnivores are adapted to derive most of their energy from meat. The digestive systems of cats and minks are specifically designed to break down animal proteins and fats efficiently, making plant-based diets inadequate to meet their nutritional needs. This higher protein demand is vital for their growth, muscle maintenance, and overall health.
Why cats need a high protein diet
Meat contains incredibly important factors like taurine and arginine. Both taurine and arginine are only found in animal flesh. Cats can’t make taurine from other amino acids, unlike most other mammals. Not enough taurine in a cat’s diet can cause vision problems, trouble having kittens, and heart disease.
In black cats, a lack of tyrosine will turn the cat’s fur red. Tyrosine is an amino acid that plays a critical role in the production of melanin in cats. It is produced in the body from another amino acid known as phenylalanine. Since phenylalanine is an essential amino acid, it cannot be synthesized within the body and must be obtained through dietary intake.
Common sources of phenylalanine in the feline diet include protein-rich foods such as meat, fish, eggs, and dairy products, all of which are frequently found in cat food. Most commercial cat food formulations are carefully crafted to ensure a balanced provision of essential amino acids, including phenylalanine. This helps meet the nutritional requirements of cats, ensuring that they receive the necessary components to produce tyrosine, and subsequently, melanin.
Cats also lack the ability to make their own arginine, an amino acid in animal protein. Arginine is responsible for helping to remove excess ammonia from the body. A cat with an arginine deficiency could experience some unpleasant symptoms leading to neurological impairment and even death.
Humans and even dogs can make vitamin A from beta-carotene. However, cats need to obtain vitamin A in its pre-formed state. Cats are also able to meet their blood glucose requirements from gluconeogenesis using protein, whereas humans meet it through the breakdown of carbohydrates.
Taurine, arachidonic acid, vitamin A, and vitamin B12 can’t be obtained in sufficient amounts from plants. Without these key ingredients that cats get from meat, they can suffer from heart and liver problems as well as hearing loss and a slew of other health problems.
Cats have a short gastrointestinal tract
Cats have the shortest gastrointestinal tract comparable to their body size than any other mammal.
Animals with longer gastrointestinal tracts are better suited to digestive carbohydrates and plant matter as they have the length needed and the digestive bacteria within their systems to properly break down plant matter. Since raw meat is quite simple to digest and easier to break down than carbohydrates, cats don’t have a need for a longer gastrointestinal tract.
Conclusion
Most people wouldn’t expect to see an eagle or a hawk stealing an ear of corn from a field and eating that, right? In much the same way, cats simply can’t be expected to eat foods they aren’t biologically able to digest.
However, it is important to note that not all cat food is good food. Some cat foods out there contain less than ideal filler ingredients and don’t focus on the nutrients essential to cats’ well-being.
When considering what to feed your cats, one thing to look for is a statement on the can or bag stating that the food is formulated to comply with the Association of American Feed Control Officials nutrition profiles and guidelines.
References
Eisert, R. (2011). Hypercarnivory and the brain: protein requirements of cats reconsidered. Journal of Comparative Physiology B, 181(1), 1-17. DOI: 10.1007/s00360-010-0528-0
Verbrugghe, A., & Hesta, M. (2017). Cats and carbohydrates: the carnivore fantasy?. Veterinary sciences, 4(4), 55. DOI: 10.3390/vetsci4040055
Zaghini, G., & Biagi, G. (2005). Nutritional peculiarities and diet palatability in the cat. Veterinary research communications, 29(2), 39-44. DOI: 10.1007/s11259-005-0009-1
