1. Importance of Age

2. Introduction Young horses are referred to by age Foal – Until weaned
Female – Filly until 3 yrs
Then referred to as a mare
Male – Colt until 3 yrs
Then referred to as a stallion/gelding
Yearlings – 1-2 yrs
Prime age is 7 – 9 yrs
Can be active into the 20s

3. Competitions Foal’s birthday is January 1st Regardless of actual month
Ex: Foal born April 1, 1996 will be 10 yrs on January 1, 2006
People who race or show horses try to have foals born as close to January 1st as possible
This gives the horse the advantage of more growth than those born later

4. Number and Type of Teeth
Tooth
Age at Eruption
Temporary
(Baby, Milk, or Deciduous)
1st Incisor (Centrals)
Birth/1st Week
2nd Incisor
(Intermediates)
4 – 6 Weeks
3rd Incisor (Corners)
6 – 9 Months
Canine (Bridle)
Birth to 1st 2 weeks for all premolars
1st Premolar
2nd Premolar
3rd Premolar

5. Number and Type of Teeth
Tooth
Age at Eruption
Permanent
1st Incisor (Centrals)
2.5 yrs
2nd Incisor (Intermediates)
3.5 yrs
3rd Incisor (Corners)
4.5 yrs
Canine (Bridle)
4 – 5 yrs
1st Premolar (Wolf Tooth)
5 – 6 yrs
2nd Premolar
3rd Premolar
3 yrs
4th Premolar
4 yrs
1st Molar
9 – 12 mo
2nd Molar
2 yrs
3rd Molar
3.5 – 4 yrs

6. Occurrence of Permanent Teeth
Two sets of teeth
Temporary
Deciduous, Baby, Milk Teeth
Permanent
Well grown 2 yr old may be mistaken for an older horse unless permanent teeth can be accurately identified
4 center permanent teeth appear (2 above and 2 below) as they reach 3, the intermediates at 4, and corners at 5
Full mouth

7. Using Changes in Teeth to Determine Age
Young horses is easy to be accurate
Become harder after 10 to 14 yrs
Management can affect changes in teeth
Stabled animals tent to appear young
Grazing in sandy areas appear older because of the wear of teeth
Age estimation is made by inspection of the 12 front teeth, called incisors
The 2 central pairs (above and below) called centrals, pincers, or nippers
4 adjacent are called intermediates
Outer 4 teeth are corners
Canine or “tusks” appear ~4 – 5 yrs
Common in geldings and stallions, seldom appear in mares
Adults have 24 molar teeth
Key changes
Disappearance of cups
Angle of incidence
Shape of the surface of the teeth

8. Disappearance of Cups
Young permanent teeth have deep indentures in the center
Called cups
Cups are commonly used as reference points
Upper teeth are deeper than below
Do not wear evenly at equal periods of time
Cups become smooth in this order
Lower centers
Intermediates
Corners
Upper centers
At the following ages
6, 7, 8, 9, 10, and 11 yrs
A smooth mouth appears at 11 yrs

9. Angle of Incidence
Angle formed by the meeting of the upper and lower incisor teeth
Changes approx 160 – 180 degrees in young horses, to < a right angle with aging
As the slant increases, the surfaces of the lower teeth do not wear clear to the back margin of the uppers
Dovetail, notch or hook is formed on the upper corners at 7 yrs
Condition varies between horses

10. Shape of the Surface of the Teeth
Appear broad and flat in young horses
Reverses when they reach or pass 20 years
8 – 12 yrs the back surfaces become oval, then triangular at ~ 15 yrs
21 yr old change to rectangular and be twice as deep from front to rear as they are wide

11. Changes with Age

12. Five Years Permanent dentition is complete Incisors are in wear
Canines have erupted completely
Dental surfaces of centrals and intermediates are wide and show wear
Cups are readily visible and completely encircled by the central enamel
Corners are starting to wear on the border to the tooth closest to the gums

13. Changes with Age Due to Wear
Type of Wear
Year
1st Incisor
2nd Incisor
3rd Incisor
Smooth (Cups gone) 6 7 8
Stars 9 10
Round 11
Triangular 16 17
17-18
Rectangular
18-20+ -

14. 6 to 7 Years
Dental surface of lower corner incisor is narrower in profile than that of the upper
Leads to 7 yr notch
Dental surface of lower central and intermediate incisors are smooth
Cups no longer present
Lower corners retain their cups

15. 8 Years Lower dental surfaces are smooth and all cups are gone
Dental star appears in the lower central incisors
First appears as a dark yellow or yellow brown line

16. 10 Years Angle becomes more oblique
Dental star is more distinct and near center of tooth
“Smooth Mouth”

17. 15 Years
Galvayne’s groove extends ½ way down the outer surface of the upper incisors
Dental surfaces appear triangular
Intermediates are round to triangular and all lower incisors show a dark, distinct star

18. 20 Years Galvayne’s groove extends the entire length of incisor
Dental table of the lower incisors may be worn almost to gum

19. Floating Teeth To care for horse’s teeth
Vet will mildly sedate and insert a speculum into the horse’s mouth to keep it open
Tools called floats are used to file down the sharp areas and any other abnormalities
If a tooth abscesses it may have to be pulled
Molars should be checked regularly by vets

20. Floating Teeth (cont.)
As horses age, the quality and quantity of teeth diminish to the point where floating cannot help
Finding wads of feed around feeding areas may indicate a horse cannot break down food enough to swallow
Causing a horse to drop weight
Hay pellets or cubes soaked in water can help

21. Abnormal Conditions of Teeth
Parrot Mouth
Upper and lower incisors do not meet b/c the lower jaw is too short
Interfere with grazing
Monkey Mouth
Opposite of parrot mouth
Seldom seen in horses
Cribbing
Habit common in stabled horses
Damages incisors by chipping or breaking them
Bishoping
Tampering with cups to make a horse appear younger than it is

22. Other Age Indicators Sides of face become depressed with age
Poll is more prominent
Hollows above eyes are deeper
Backbone more prominent and starts to sag
Joints appear more angular
White hairs will appear around temples, eyes, nostrils