Ageing

Ageing

It is possible to estimate the age of a horse based on the wear of his incisor teeth, but the accuracy of this estimate declines considerably with age.

Foals develop temporary (“milk”) teeth that fall out and are replaced by permanent teeth as they grow older, just like humans. Their teeth erupt at the approximate times shown in the table below and incisor teeth come into wear (meet the opposing tooth) about six months later.
  

TOOTH	DECIDUOUS	PERMANENT
Central incisor	0-1 week	2 ½ years
Lateral incisor	2-4 weeks	3 ½ years
Corner incisor	7-9 months	4 ½ years
Canine (tush)	None	3-4 years
Premolar 2	2-8 weeks	2 ½ years
Premolar 3	2-8 weeks	3 years
Premolar 4	2-8 weeks	4 years
Molar 1	None	1 year
Molar 2	None	2 years
Molar 3	None	3 ½ years

Once all incisors are present and in wear, ageing is based on the angle of the teeth (decreases with age) and the wear pattern on the tables (biting surface).
Horses wear their incisors differently according to breed and individual variation. Accuracies of ageing vary considerably with age as can be seen from the table below.
 

AGE (YRS)	ACCURACY	AGE(YRS)	ACCURACY
1	6 Months	8	3 Year
3	1 Year	9	3 Year
4	1 Year	10	3 Year
5	1 Year	13	4 Year
6	2 Year	15	6 Year
7	2 Year	>20	10 Year

Remember that an estimate of age is just that ' an estimate!