Why Do Cows Not Have Top Teeth? How Do They Chew?

You may have noticed something strange if you have looked inside a cow’s mouth.

Cows, unlike people, do not have teeth on the top of their mouths!

But if they do not have top teeth, how do they eat?

Cows don’t have top teeth in the normal way we think, but they have premolars and molars at the back of their top mouth. Cows and other ruminant animals have a hard roof on their mouth known as a dental pad to help chew through tough food before passing it to the back of their mouths. 

It is a little misleading to say cows do not have top teeth.

They only have sharp incisor teeth at the front of their mouth and are missing most other mammals’ corresponding upper incisors. 

Next, we’ll cover more about how cows chew, why ruminant animals have the teeth they do (and don’t), and how a cow’s teeth change as they age. 

why cows dont have top teeth

How Do Cows Chew Their Food Without Top Teeth?

Cows are herbivores meaning they are animals who eat grass and other plants for their nutrients. 

Like many herbivores, cows do not have any canine teeth in their mouth and only have incisor teeth in the bottom of their mouths.

However, in exchange, cows have a hard mound on the roof of their mouth known as a dental pad which provides a surface for grinding in combination with their lower incisors.

The combination of these two parts and the powerful muscles in a cow’s jaws provides the necessary cutting and grinding action ideal for breaking down tough foods and cutting grass.

Cattle will also use their tongue to assist them in eating- grabbing chunks of plant materials to pull them together and then biting through the clump.

However, the back of a cow’s mouth looks more familiar- large flat teeth known as premolars and molars used to further grind up foods and serve another purpose, chewing cud.

Cows go through the digestive process of chewing cud with their back molars to break down food and maximize the nutrients processed.

Cud is food partially digested in the rumen and brought back into the cow’s mouth to be chewed again.

It allows the food to be broken down and fully extract all the nutrients from their food. 

When Do Calves Lose their Baby Teeth And Gain Their Adult Teeth?

Calves are born with two different kinds of teeth, including eight baby incisors and 12 permanent teeth in their premolars.

More scientifically, these baby teeth are called deciduous teeth, temporary teeth a calf has until they begin to grow their adult teeth.

When a calf is born, there may only be two incisors showing, known as milk teeth; however, within the first month, all eight temporary incisors will be showing.

It is not until the calf is two years old that the first pair of adult incisors begin to replace the temporary teeth, and from there, the other six incisors will be replaced.

Interestingly, calves grow a pair of adult teeth simultaneously, starting from the middle and working out to the corners.

Within the first 3 years, cattle will also grow the rest of their molars. 

They have 12 in total, bringing the number of teeth from 20 as a calf to 32 as an adult cow. 

How To Tell A Cow’s Age Based On Its Teeth

Looking at which teeth are baby or permanent, including the amount of wear on the teeth, one can gather a pretty good idea of how old a cow is. 

To start, if the cow only has baby teeth showing and no signs of adult tooth development, it is between 2-18 months.

However, once those permanent front incisors, also known as pinchers, begin to show, somewhere between 18-24 months is a good approximation.

Next to develop are the intermediate incisors, which develop between 24-36 months of age, and 36-48 months for the next set of incisors, also known as intermediate incisors.

The final pair of adult teeth in the front to develop are known as corners, and those will begin to show at about 42-48 months and fully develop by the time cattle are 5 years old.

After this point, it is more difficult to estimate the age as it is based on the wear on the teeth, which may be affected by any number of external factors.

However, as a general rule, the pinchers will show noticeable wear between 7-8 years, the intermediate incisors at 8-10 years, and the corners will show wear at 10 years.

As the animal ages, these teeth will wear down to the root and may even fall out, resulting in a “broken-mouth” animal or a “gummer” if all of the teeth have fallen out. 

Common Dental Problems To Watch Out For In Your Cattle

Early Tooth Wear

While tooth wear is a normal part of the aging process for cattle, early tooth wear is something to watch out for and prevent if possible.

Early tooth wear may result from diet, injury, or disease, such as laminitis, preventing the animal from grazing properly.

Watch for symptoms such as lesions in the mouth, irregularly shaped molars, rotten smells coming from their mouths, and any other irregularities in the mouth of the animal.

If you notice these things, disinfecting the mouth may be an appropriate first step, and veterinary help may be necessary if problems persist. 

Lumpy Jaw

Actinomycosis, also known as Lumpy Jaw, results from infection between the cheek and jaw of cattle, most commonly in beef cattle.

The bacteria may infect the cow due to injury or when the molars erupt and offer an open wound as the avenue for infection.

The symptoms, as the name suggests, present as a large lump in the animal’s jaw and may be treated temporarily with antibiotics with no permanent cure.