C15
Aging Sheep and Goats By Their Teeth

Introduction: Both sheep and goats have a total of 32 teeth. They do not have any upper incisors. The dental formula for sheep and goats is as follows:

0/4 incisors, 3/3 pre-molars, 3/3 molars. The first number in each formula represents how many sets of teeth are on the upper jaw; the second number indicates how many sets of teeth are on the lower jaw. For example, the 0/4 means that sheep/goats have no upper incisors, but have 4 sets of lower incisors (8 lower incisors in all). Most of the time the dental formula looks like this 2 (0/4 incisors, 3/3 pre-molars, 3/3 molars) = 32.

All baby sheep and goats are born with deciduous teeth (teeth that will fall out). Deciduous teeth are much smaller than permanent teeth. The deciduous teeth are replaced with permanent teeth as the animal ages. The following table outlines when the permanent teeth will appear or erupt:

Permanent Tooth Eruption in Sheep and Goats
Permanent tooth Age at Eruption
Incisor (I1) 1-1.5 years
Incisor (I2) 1.5-2 years
Incisor (I3) 2.5-3 years
Incisor (I4) 3.5-4 years
Premolars 1.5-2 years
Molar (M1) 3 months
Molar (M2) 9-12 months
Molar (M3) 1.5-2 years

 

This is a diagram of the incisors associated with the lower jaw. These incisors are the teeth that can easily be used to age an animal. In this diagram, all the incisors are permanent teeth.


Common Dentition of Sheep:

Dentition of a yearling sheep. Two incisors are permanent (black arrows).

 

Dentition of a 2 year old sheep. Four incisors are permanent (black arrows).

 

Dentition of a 4 year old sheep or "full mouth." All incisors are permanent.

 

Dentition of a 6-8 year old sheep. Notice the wide spacing between the teeth.

 

Dentition of an extremely aged sheep (from 8-12 years of age), frequently referred to as a "broken mouth." Notice how this ewe has severely worn or missing teeth, with receding gum lines.



Common Dentition of Goats:

Dentition of a goat 2 weeks of age. All the teeth are baby or deciduous teeth.

 

Dentition of a goat 10 months of age. All the teeth are still baby or deciduous teeth.

 

Dentition at 1.5-2 years of age. Four incisors are permanent (black arrows).

 

Dentition of a 3 year old goat. Six incisors are permanent (black arrows).

 

Dentition of an aged goat (about 10 years old). All the incisors are permanent and worn. The black arrow shows where this goat is missing an incisor tooth.