Transcript Do you know my age4a

Do you know my age??
Horses' teeth are often used to estimate the animal's age,
hence the sayings "long in the tooth" and "Don't look a gift
horse in the mouth".
The Importance of Determining
the Age of Horses
Uses:
 Validate advertised age when buying
 Confirming age when racing or showing
 Feeding for proper nutrition at various life
stages
Aging by Teeth








Not foolproof
An art that requires skill and
experience
Very old method of aging horses
Error increases with horse’s age
Becomes an educated guess after
horse is older than 14 years
Stabled horses tend to appear
younger (less tooth wear)
Pastured horses tend to appear
older (more tooth wear)
Bishoping- altering teeth to hide age
Equine Tooth Structure
Maxilla
Wolf Tooth
(when present)
Canines
Incisors
Mandible
Molars
Premolars
Horses have 24 temporary teeth and up to 42 permanent teeth


Deciduous- ID3/3 CD0/0 PD3/3 MD0
Permanent-I 3/3 C 0-1/0-1 P 3-4/3 M3/3
How many teeth does a horse have?
A typical adult male horse has 42 permanent teeth,
while a typical mare may have 36 teeth, because
mares are less likely to have canine (bridle) teeth.
A horse’s permanent teeth are about four inches long.
Dentition


Hypsodonts
Two times






Incisors 3/3
Canines 1/1
Premolars 3 or 4/3
Molars 3/3
Male total of 40 or 42; female total 36 to 40
Young horse has 24 deciduous teeth



Milk teeth
12 incisors
12 molars
Do horses have “baby” teeth?
Like humans, horses have two sets of teeth in
their lifetimes.
The baby teeth, called deciduous teeth, are
temporary.
The first deciduous incisors may erupt before
the foal is born.
The last deciduous teeth come in when the
horse is about eight months of age.
These “baby” teeth will begin to be replaced by
adult teeth around the age of 2 ½, and by age
5-6, most horses have all of their permanent
teeth.
Estimating age using tooth eruption
There are 24 deciduous teeth (“caps”).
These come out in pairs, and are pushed
out later by the permanent teeth.
 The “caps” are usually present at birth or
by 1 to 2 weeks of age.
 Rule of 3 eights: I1- 8 days, I2- 8 weeks,
and I3- 8 months
-charts may show these as Di1, Di2, Di3
 The number of permanent teeth may vary,
depending on if the horse has wolf teeth or
canines.

Aging - Incisors








Deciduous eruption
pattern:
Central @ 6-8 days
Middle @ 6-8 weeks
Corner @ 6-8 months

Premolar eruption
pattern:
PM 2 @ 2 years 8
months
PM 3 @ 2 years 10
months
PM 4 @ 3 years 8
months







Permanent eruption
pattern:
Central @ 2 .5 years
Middle @ 3.5 years
Corner @ 4.5 years
Molar eruption pattern:
M1 @ 1 year
M2 @ 2 years
M3 @ 3 - 4 years
Cups, stars and spots:

The cup is the center of the
infundibulum. Wear of the occlusal
surface causes the cup to get
smaller and eventually disappear
from all lower incisors at about 6-8
years of age leaving the enamel
spot in its place. The enamel spot
is the deepest part of the
infundibulum. The dental star
corresponds with the pulp cavity
and appears at 8 years of age in
the first incisor. It appears as a line
and then changes to a large, round
spot as the occlusal surface is
worn further.

The anatomic relationships between incisor anatomy and the
cups and stars seen on the occlusal surface as they wear are
depicted in the images and diagrams immediately above. The
image on the right is shows an incisor of a young horse cut
longitudinally while still in the jaw.
Equine Tooth Structure
Central Incisors
(also pincers or nippers)
Intermediate
Incisors
Corner Incisors
Age is determined using the 12 front teeth (incisors)
Mouthing a Horse for Age
In Real Life: Hold the tongue out and to the side with your hand. This
restraint provides an unobstructed view and is not painful to the
horse.
Tooth Emergence
Temporary Teeth (Baby Teeth)
Temporary pincers: Birth - 10 days
Temporary intermediates: 4 – 6 weeks
Temporary corners: 6– 10 months
Tooth Emergence
Permanent Teeth
6 years old
Canine teeth
appear: 4-5
years
Permanent
corners: 4
½ years
Permanent pincers:
2 ½ years
Permanent
intermediates:
3 ½ years
Tooth Wear
As horses age, “caps” disappear from incisors
6 years old
15 years old
As horses age, teeth become more triangular-shaped
What are wolf teeth?
Wolf teeth are the remnants of the first
premolars that have now become obsolete
with the evolution of the horse.
The most common first premolars seen in the
horse are the uppers and they are shaped
similar to small canine teeth.
This is why they are often described as wolf
teeth. These sharp teeth, if present, are in the
area of the mouth where the bit fits.
Wolf teeth may cause the horse some
discomfort when pressure is placed on the
bit. Therefore, these teeth are usually
removed in young riding horses.
Wolf tooth

A typically small
maxillary wolf tooth
(premolar [PM] 1) is
present just rostral
to PM2.






First premolar (PM1):
Wolf tooth
Erupts @ 6 months
Deciduous premolars:
Present at birth.
Shedding teeth or
caps.
Galvayne’s Groove
A mark on the upper corner incisors that appears and
disappears in a predictable pattern as horses age
Usually appears around the
age of 10 years.
Galvayne’s Groove
A mark on the upper corner incisors that appears and
disappears in a predictable pattern as horses age
Groove is usually half way
down at age 15
Galvayne’s Groove
A mark on the upper corner incisors that appears and
disappears in a predictable pattern as horses age
By age 20 the groove usually
extends the full length of the
tooth
Galvayne’s Groove
A mark on the upper corner incisors that appears and
disappears in a predictable pattern as horses age
Groove begins to recede
around age 21
Galvayne’s Groove
A mark on the upper corner incisors that appears and
disappears in a predictable pattern as horses age
Groove is halfway gone by age
25 and disappears completely
around age 30.
7 year notch
 Disappears at 8 years,
returns at 11

Length with age
“long in the tooth”
I1
I2
I3
Baby erupt
8 days
8 weeks
8 months
Permanents erupt
2 1/2
3 1/2
4½
Cups gone
6 years
7 years
8 years
Dental Star
8years
9 years
10 years
Galvayne’s
groove
10-30 years
Seven year notch
7years, and 11
years




Shape of teeth
Round 9-11 years
Triangular 14-17 years
Biangular 18-21 years
Aging Using Teeth
Determine the most likely age for the following horse
1. 7 years
2. 14 years
3. 21 years
4. 28 years
Wear – No
Cups
Aging Using Teeth
Determine the most likely age for the following horse
1. 1 year
2. 8 years
3. 17 years
Oval Shaped
Teeth
No Canines
4. 26 years
Aging Using Teeth
Which horse is older?
A
B
Common ages for tooth eruption
(page 248 LACP)
Type of tooth
Number
Deciduous
Permanent
Incisor
First (central)
birth to 8 days
2.5 yrs
Incisor
Second (intermediate)
4.5-6 weeks
3.5-4 yrs
Incisor
Third (corner)
6-9 months
4.5-5 yrs
Absent
3.5-5 yrs, some around
6 yrs (if ever)
Canine
Premolar
First (wolf)
Absent
6 months to 3 years (if ever)
Premolar
Second
birth to 2 weeks
2-3 yrs
Premolar
Third
birth to 2 weeks
2.5-3 yrs
Premolar
Fourth
birth to 2 weeks
3-4 yrs
Molar
First
Absent
9-12 months
Molar
Second
Absent
2 yrs
Molar
Third
Absent
3-4 yrs
How do diet, pasture management
and stabling impact dental wear?
Mother Nature designed horses to be pasture grazing animals.
Horses in the wild normally spend 16 hours a day with their
heads down, grazing grass.
For a horse to properly process 20-30 pounds of wet-grass
forage a day, it uses a wide, crushing chewing pattern.
This allows the incisor teeth and cheek teeth to wear at a
normal and even rate.
Under artificial conditions, horses are fed an abnormal diet
(grain and hay) for shorter intervals during the day, with an
abnormal head posture (feed tub or hay rack).
All of these conditions alter the chewing pattern and adversely
affect the way teeth are worn over time.
What is cribbing and how does it affect
dental care?
Cribbing is a stereotypic behavior, or vice, that
some horses develop.
The horse exhibits cribbing by grabbing onto an
inanimate object (fence posts, buckets, stall walls,
etc.) with its incisor teeth, pulling the object and
often making a sucking sound.
Because these horses spend the majority of their
time during the day preoccupied with this behavior
rather than grazing or eating, they quite often have
dental wear problems.
The upper incisor teeth (front teeth) are often worn
excessively from hours of abnormal attrition. These
horses are referred to as "stump suckers.”
What does it mean to “float” a horse’s
teeth?
Routine maintenance of a horse’s
mouth has been historically referred
to as “floating.”
Floating removes the sharp enamel
points.
Occlusal equilibration is the term now
used to describe smoothing enamel
points, correcting malocclusion (faulty
meeting of the upper and lower teeth),
balancing the dental arcades and
correcting other dental problems.
Equine Dentistry: General Principles
Hypsodont
 Reserve crown
Elliptical mastication pattern
Wear pattern:
 Results in sharp
 enamel points.
 Buccal aspect (upper)

Lingual aspect (lower)
Triadan Numbering System




100’s = Right maxilla
200’s = Left maxilla
300’s = Left mandible
400’s = Right
mandible





Incisors = 1,2,3
Canines = 4
Wolf teeth = 5
Premolars = 6, 7, 8
Molars = 9, 10, 11

Upper R Cheek

Lower R Cheek
Upper incisors
Lower Incisors
Upper L Cheek
Lower L Cheek
Dental Examination
Visually inspect:
 Prior to rinsing mouth
 After rinsing mouth
Digitally palpate:
 Individual teeth
 Gingiva
 Palate
 Tongue
Record findings on a
standard form
Historical Clues to Dental
Problems
Performance habits
 Head tilt
 Head tossing
 Refusing the bit
Eating habits
 Quidding
 Slow, deliberate
mastication
 Exaggerated tongue
movement
Change in fecal
character


Increase in fiber length
Whole grain in feces
Weight loss
Poor body condition
Facial asymmetry
Unilateral nasal
discharge
Halitosis
Dental Examination: Juvenile
Age: 6 months to 7 years
 Incisors




Check occlusion
Inspect eruption pattern
Canines erupting at this
age.
Premolars:

Look for wolf tooth.
Inspect for caps.
Periodontal disease

Molars

Inspect eruption pattern.

Exam frequency:
semiannual


Age: 7 - 15 years
Incisors
 Inspect for
 Injury or damage
 Supernumerary teeth
 Missing incisors
 Misalignment
 Wear pattern
Age: 7 – 15 years
Canine teeth
 Check for sharp
points
 Check for tartar
Age: 7 – 15 years
Premolar and molar teeth:
Enamel points (odontophytes)
Occlusion abnormalities
 Hooks and ramps
 Unopposed teeth
 Wave/Shear mouth
Exam frequency - Annually
Dental Examination: Geriatric
Age: 15 years and older
Premolar and molar teeth:
Periodontal disease
o Most common condition
affecting horse > 15 years of age
o Gingival recession
o Diastema formation
Molar cupping

Wearing of infundibular
enamel
Dental caries
Tooth root abscess
Tooth loss
Exam Frequency Semiannual
Dental Equipment

Chemical restraint

Xylazine
Detomidine
Butorphanol










Dental halter
Speculum
Full-mouth
Wedge
Light source
Floats/Motorized
instruments
Elevators/Extractors
Perineural anesthesia