Canine's Canines:
A dog’s dental anatomy offers valuable insight into what they are biologically designed to eat. One of the most telling features is the structure and function of the carnassial teeth—the large, shearing teeth located towards the back of the mouth. These teeth evolved specifically for processing animal tissue, not plant matter or dry, heavily processed food.
Anatomy and Function of Carnassial Teeth
The carnassial teeth consist of the upper fourth premolar and the lower first molar. These teeth align in a scissor-like fashion and are adapted for cutting through flesh, skin, sinew, and other soft tissues during the consumption of prey. Unlike herbivores or omnivores, which have flat molars designed for grinding, the canine jaw moves primarily in a vertical chopping motion, not laterally. This reflects their evolutionary adaptation to a predominantly carnivorous diet.
These sharp, pyramidal teeth are used in combination with the front teeth—incisors and canines—for capturing and holding food, while the carnassials perform the mechanical breakdown necessary for swallowing and digestion.
Dry & Processed Foods
Modern dry dog foods, often referred to as kibble, typically contain significant proportions of carbohydrates such as corn, rice, wheat, peas, or legumes—sometimes exceeding 50% of the total formula. These ingredients are not part of the ancestral canine diet and are included primarily for cost, shelf stability, and manufacturing convenience.
The mechanical act of eating kibble does not require the slicing motion that engages the carnassials. Many dogs swallow these small pellets with minimal chewing, bypassing the intended function of their dental structure. Additionally, these extruded foods are cooked at high temperatures, which can alter protein structures and reduce nutrient availability.
Kibble and Dental Health
It is frequently claimed that dry food helps clean a dog’s teeth. However, research and clinical experience suggest this is largely ineffective. The abrasive action of kibble is minimal, especially for dogs that do not chew thoroughly. Consequently, periodontal disease remains one of the most common conditions affecting companion dogs, regardless of kibble consumption.
In contrast, feeding raw meaty bones or other natural, fibrous whole foods does stimulate chewing, supports jaw strength, and helps mechanically clean the teeth. This form of dental engagement more closely mirrors what dogs experience when consuming natural prey.
Digestive and Metabolic Considerations
Dogs are facultative carnivores. While they have some ability to digest starches, their digestive systems are better adapted to high-protein, high-fat diets with minimal carbohydrate content. Excessive carbohydrate intake can disrupt gut health, contribute to systemic inflammation, and may affect long-term metabolic balance.
Feeding in alignment with the dog’s physiology—emphasizing raw or lightly cooked meat, bone, and organ tissue, alongside essential micronutrients—supports not only oral health but also gastrointestinal function, immune regulation, and overall wellbeing.
Conclusion
The form and function of a dog’s carnassial teeth offer clear evidence of their evolutionary dietary needs. These shearing teeth are not designed to process small, hard pellets composed largely of plant-based starches. Feeding practices that respect a dog’s anatomical and physiological design are more likely to support long-term health outcomes, particularly when it comes to dental integrity and digestive resilience.
References and Further Reading
Veterinary Practice News (USA, 2015)
“What Are Carnassial Teeth and Why Do Dogs Need Them?”
https://www.veterinarypracticenews.com/what-are-carnassial-teeth-and-why-do-dogs-need-them/Watson ADJ (Australia, 1994)
Diet and periodontal disease in dogs and cats
Australian Veterinary Journal
Abstract: https://pubmed.ncbi.nlm.nih.gov/8063477/Buckley C, Colyer A, Skrzywanek M, Jodkowska K, Kurski G, Shaw S (UK, 2011)
The effects of diet on periodontal disease in dogs
Journal of Veterinary Dentistry
Abstract: https://journals.sagepub.com/doi/10.1177/089875641104800402