Last Updated on August 30, 2026 by Jorge Bastos
A hippo’s canine teeth can grow longer than a human leg, never stop growing throughout its life, and are made of a material valuable enough to sustain an illegal international trade. They are also, confusingly, barely used for the one thing teeth normally do: eating. Understanding hippo teeth means understanding a genuine paradox — one of the animal kingdom’s most formidable weapons, grown from a substance that has made the hippopotamus a poaching target for centuries.
Hippo Teeth: Quick Facts
| Feature | Common Hippo | Pygmy Hippo |
|---|---|---|
| Total teeth | 36 | 34 |
| Incisor pairs | 2 pairs (lower jaw) | 1 pair |
| Lower canine length | Up to 50 cm (20 in) | Up to 5 cm (2 in) |
| Upper canine length | Up to 30 cm (12 in) | Smaller |
| Longest canine recorded | 122 cm (48 in) | — |
| Jaw opening angle | 150–180 degrees | Less wide |
| Tooth material | Ivory (hypselodont) | Ivory |
| Teeth used for eating | Molars and lips only | Molars and lips |
| CITES status | Appendix II | Appendix II |
How Many Teeth Does a Hippo Have?
A common hippopotamus has 36 teeth in total:
- 8 incisors (4 upper, 4 lower)
- 4 canines (2 upper, 2 lower) — the tusks
- 12 premolars (6 upper, 6 lower)
- 12 molars (6 upper, 6 lower)
The dental formula for each side of the jaw is: 2 incisors, 1 canine, 3 premolars, 3 molars.
Some individual hippos have more than 36 teeth. Hippos can retain their deciduous (baby) teeth even after permanent teeth have erupted — an uncommon trait in mammals — which in some cases results in extra incisors or canines remaining alongside the permanent set.
The pygmy hippopotamus typically has 34 teeth: it has only one pair of lower incisors, compared to the common hippo’s two pairs, according to the San Diego Zoo Wildlife Alliance.
The Canine Teeth: Nature’s Most Formidable Tusks
The hippopotamus’s most visually striking anatomical feature is its canine teeth. These are the long, curved, ivory teeth that protrude from the lower jaw — commonly called tusks, though technically canines — and they are among the most extraordinary dental structures in the animal kingdom.
Size and Growth
The lower canines of a common hippo typically grow to 40–50 cm (16–20 inches) in length. The upper canines, which point downward, reach approximately 25–30 cm (10–12 inches).
In exceptional individuals, the lower canines grow considerably longer. Guinness World Records documents a typical maximum of around 71 cm (28 inches), and the longest single hippo canine ever recorded measured an extraordinary 122 cm (48 inches) — just over four feet.
Canines grow continuously throughout the hippo’s life. They are hypselodont — high-crowned, ever-growing teeth — meaning they are never lost to natural wear. The older the hippo, the longer the canines, which is why very large, dominant bulls carry the most impressive tusks.
Self-Sharpening
The canines sharpen themselves through natural use. As the jaw opens and closes, the upper and lower canines grind against each other in a precise alignment, honing their edges continuously. This self-sharpening mechanism means a hippo’s tusks do not become blunt with age — they remain effective weapons throughout the animal’s life.
What Are Hippo Canines Made Of?
Hippo canines are composed of ivory — the same dense, mineralised material as elephant tusks, though with a different chemical composition. According to Encyclopaedia Britannica, hippo ivory is notably denser and initially whiter than elephant ivory, and it maintains its whiteness better over time. In the historical ivory trade, hippo ivory was used extensively for items requiring especially white or hard-wearing ivory — including piano keys, dental work, and fine decorative carving — and was considered superior to elephant ivory for some applications.
Jaw Anatomy: How Wide Does a Hippo’s Mouth Open?
The hippo’s jaw can open to 150–180 degrees, compared to a human’s maximum of approximately 45 degrees. At full gape, the mouth measures approximately 90–120 cm (3–4 feet) wide from corner to corner — the widest mouth of any land mammal.
This extreme gape serves two purposes beyond simple intimidation. It maximises the leverage of the temporalis and masseter muscles that close the jaw, amplifying bite force, and it functions as a deliberate threat display — the hippo “yawn” that warns rivals and intruders before any physical contact occurs.
What Hippos Do Not Use Their Teeth For: Eating
Perhaps the most counter-intuitive fact about hippo teeth is that the most impressive ones — the enormous canines and long incisors — are never used to eat. Hippos are herbivores. Their diet consists almost entirely of grass, supplemented by some leaves, fallen fruit, and aquatic vegetation.
To eat, hippos use:
- Their lips — thick, wide, muscular lips that can grip large quantities of grass and pull it free from the ground with a sharp jerk of the head.
- Their molars — the grinding teeth at the back of the jaw. These are the teeth that do all the work of processing food.
The large incisors in the front of the jaw actually prevent side-to-side grinding: because upper and lower incisors interlock tightly when the jaw closes, the lower jaw can only move vertically, not laterally. This restricts the hippo’s chewing efficiency considerably compared to a true grazer like a cow.
This means that despite carrying one of the most powerful weapons of any land mammal, the hippo’s extraordinary jaw is essentially a fighting tool that happens to accommodate some molars for eating. The teeth drive social order, not dinner.
Pygmy Hippo Teeth: Key Differences
The pygmy hippopotamus (Choeropsis liberiensis) has a notably different dental anatomy, reflecting its solitary, forest-dwelling lifestyle rather than the highly territorial existence of the common hippo:
- 34 teeth (vs. 36 in common hippos)
- One pair of incisors (vs. two in common hippos)
- Much smaller canines: upper and lower canines reach only about 2–5 cm, compared to 30–50 cm in common hippos
- Jaw structure allows for some side-to-side movement, giving it slightly better grinding capacity
The reduced canine size in the pygmy hippo reflects its very different social structure: pygmy hippos are solitary rather than pod-living, and have much less frequent intraspecific combat than common hippos. Our full pygmy hippo guide covers these differences further.
The Ivory Crisis: Why Hippo Teeth Are a Conservation Problem
Hippo ivory has been traded for centuries, but the trade has intensified in recent decades in a way directly tied to the fate of a different species. Following the 1989 international ban on the elephant ivory trade, demand shifted meaningfully toward alternative ivory sources — and hippo teeth, with their comparable density and whiteness, became a significant substitute.
The common hippopotamus has been listed on CITES Appendix II since 1989, meaning international trade in hippo products, including teeth, is regulated but — unlike elephant ivory — not outright banned. Pre-existing stock and licensed exports can move legally between countries, and this regulatory gap creates real enforcement challenges: it can be difficult to distinguish freshly poached ivory from older, legally acquired stock once it enters the trade.
The scale of the discrepancy is significant. One detailed analysis comparing Uganda’s official hippo tooth export permits against import records in destination countries between 1995 and 2016 found over 14,200 kg of hippo ivory unaccounted for — equivalent to roughly 2% of the entire continental hippo population, according to the African Wildlife Foundation. In 2022, ten African range states proposed uplisting hippos to CITES Appendix I — the strictest protection level, matching elephants — but the proposal was rejected, in part due to insufficient population data across the species’ range.
This dual-value proposition — meat that can feed a family, and teeth that can be sold internationally — makes hippos among the most economically attractive targets for bushmeat poachers in Central Africa. We cover the connection between hippo hunting, meat consumption, and the ivory trade in detail in our guide to eating hippo meat.
Frequently Asked Questions About Hippo Teeth
- How big are hippo teeth? The lower canine teeth (tusks) of a common hippo typically grow to 40–50 cm (16–20 inches). In exceptional individuals they can reach 71 cm (28 inches), and the longest ever recorded was 122 cm (48 inches). The incisors reach up to 40 cm.
- Are hippo teeth ivory? Yes. Hippo canine teeth and incisors are composed of ivory — a dense form of dentine. Hippo ivory is denser and whiter than elephant ivory and was widely traded historically for items requiring especially hard, white ivory. Trade in hippo ivory is regulated but not banned under CITES Appendix II.
- Do hippos use their teeth for eating? No. The large canines and incisors are weapons for fighting and threat display, not for processing food. Hippos eat using their wide muscular lips to grip grass, and their molars to chew it. The incisors actually prevent lateral jaw movement, making the hippo a less efficient chewer than many other grazers.
- Do hippo teeth grow back? Hippo canines grow continuously throughout the animal’s life — they are hypselodont, meaning they never stop growing, with wear continuously compensated by new growth. They do not regrow from scratch if removed. Some individuals retain their deciduous (baby) teeth alongside the permanent set, an unusual trait among mammals.
- Why is hippo ivory a conservation issue? Since the elephant ivory trade was restricted internationally in 1989, demand has shifted in part toward hippo ivory as a substitute. Hippo products remain under the more permissive CITES Appendix II rather than the outright trade ban that covers elephants, creating a regulatory gap that poachers exploit. Studies have found significant volumes of unaccounted hippo ivory moving through international trade routes.
- Is it legal to own hippo teeth? It depends on the country and the item’s provenance. Antique hippo ivory items can often be legally owned or sold under specific exemptions, but new international trade requires CITES permits, and importing undocumented hippo ivory is illegal in most countries, including the United States, the UK, and the EU.
Explore more on Hippoworlds: hippo bite force — how strong is a hippo’s bite? · can you eat hippo meat? · hippo blood sweat · pygmy hippo guide
I’ve been writing and running HippoWorlds’ content since 2019. I lived in Angola and was lucky enough to see hippos in the wild in Botswana and South Africa — I’m not a scientist, but a curious enthusiast dedicated to making this site a serious reference on the species.