Dentition in Sheep and Goat - Dental Formula of Animals

Introduction:

Type and number of teeth in a species. Different kinds of teeth have different functions; a grass-eating animal will have large molars for grinding its food, whereas a meat-eater will need powerful canines for catching and killing its prey. The teeth that are less useful to an animal's lifestyle may be reduced in size or missing altogether. An animal's dentition is represented diagrammatically by a dental formula.

Facts:
1- All domestic animals have two successive sets of teeth; Deciduous teeth, or milk teeth, are the first set of teeth in young animals.These are replaced by a permanent set of teeth as animals age.  In an anatomic tooth- identification system, permanent teeth are designated as incisor (I), canine (C), premolar (P) and molar (M) ; deciduous teeth are designated as Di, Dc, and Dp. The canine tooth of domestic ruminants has commonly been counted as a fourth incisor.

2- The number of each type of tooth varies from one species to another and the conventional way of describing them is a "dental formula". The type of teeth are indicated by the first letter, and the number of teeth on one side of the upper jaw is indicated over the number of the same type of teeth on the lower jaw. Because the formula is on one side of the mouth, the total number of teeth is the total in the formula x 2.

3- Goat Deciduous Teeth Dental Formula: 2(Di 0/4; Dc 0/0; Dp 3/3) = 2(10)=20 Goat Permanent Teeth Dental Formula: 2(I0/4; C0/0; P3/3; M3/3)= 2(16)=32 The dental formula for different species are as follows where I = incisors, C = canines, P = premolars and M = molars

4- Old animals with worn teeth and broken mouths will not eat as well as younger animals and will lose condition. How to check the teeth Baby teeth (milk teeth): under 1 year of age 2 tooth: 1 to 1½ years 4 tooth: 2 years 6 tooth: 2½ years Full mouth: 2½ to 3 years Worn to broken mouth: over 3 years of age Gummy: aged.

5- 2 tooth: 1 to 1½ years 4 tooth: 2 years 6 tooth: 2½ years Full mouth: 2½ to 3 years.

6- Worn to broken mouth: over 3 years of age Gummy: aged.

7- The teeth of a sheep are divided into two distinct sections namely, eight permanent incisors in the lower front jaw and twenty-four molars, the latter being divided into six on each side of the upper and lower jaw. Sheep have no teeth in the front part of the upper jaw which consists of a dense, hard, fibrous pad. Sheep dentition.

8- 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 68-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."

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

10- Dentition of a 4-year-old sheep or "full mouth." All incisors are permanent. Dentition of a 68-year-old sheep. Notice the wide spacing between the teeth.

11- Dentition of an extremely aged sheep (from 812 years of age), frequently referred to as a "broken mouth."     

 The morphology of mammalian teeth correlates closely with the animal’s alimentation. This explains the large variety in dental morphology between different species of animals. All domestic animals, however, have a diphyodont dentition. The dental formulas are listed in the following formulas:

 Horse:

Deciduous:

  Permanent:

Cow, Sheep, and Goat:

Deciduous:

 

Permanent:

In an anatomic tooth identification system, permanent teeth are designated as incisor (I), canine (C), premolar (P), and molar (M); deciduous teeth are designated as Di, Dc, and Dp.

Some Examples:

Sheep less than 1 year:

Sheep (1-1.5 years):

Sheep (1.5- 2 years):

Sheep (2.5 - 3 years):

Sheep (3.5 - 4years):

Extremely aged Sheep ( more than 6 years):

Note: there is a wide space between the teeth