do you know my age??. horses' teeth are often used to estimate the animal's age, hence the...
TRANSCRIPT
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
Horses have 24 temporary teeth and up to 42 permanent teeth
Canines
Incisors
Wolf Tooth (when present)
Mandible PremolarsMolars
Maxilla
Deciduous
Permanents
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
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.
Permanent Incisors will erupt I1- at 2 ½ years I2- at 3 ½ years I3- at 4 ½ years
Horses will have a “full” mouth at 5 years of age
Estimating age using tooth eruption cont…..
Between zero to four wolf teeth, which are vestigial premolars and not canines as the name may suggest. About 13-32% of all horses also are born with wolf teeth, with most of those having only one or two. They are equally common in male and female horses and much more likely to be on the upper jaw
Most mares have 36, and most male horses have 42.
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
Age is determined using the 12 front teeth (incisors)
Central Incisors
(also pincers or nippers)Intermediate
IncisorsCorner 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 EmergenceTemporary Teeth (Baby Teeth)
Temporary pincers: Birth - 10 days
Temporary intermediates: 4 – 6 weeks
Temporary corners: 6– 10 months
Tooth EmergencePermanent Teeth
6 years old
Canine teeth appear: 4-5 years
Permanent corners: 4 ½ years Permanent
intermediates: 3 ½ years
Permanent pincers: 2 ½ years
Tooth Wear
As horses age, “caps” disappear from incisors
As horses age, teeth become more triangular-shaped
15 years old6 years old
Wolf tooth
A typically small maxillary wolf tooth (premolar [PM] 1) is present just rostral to PM2.
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 Length with age Disappears at 8 years,
returns at 11
“long in the tooth”
I1 I2 I3
Baby erupt 8 days 8 weeks 8 months
Permanents erupt 2 1/2 3 1/2 4 ½
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
4. 26 yearsOval Shaped
Teeth
No Canines
Aging Using TeethWhich 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
Canine Absent 3.5-5 yrs, some around 6 yrs (if ever)
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
Dental Care Routine dental exams
-young foals, yearlings, 18months to 2 years (first bitted), and every 6 months to annually
Floating teeth- rasping sharp edges off the cheek teeth (premolars and molars)
Abnormalities Overshot/Undershot jaw Lack/Excessive incisor wear Offset bite Curvatures or slants- Hooks- Wave mouth- teeth in arcade become different heights Missing teeth- allows opposite tooth to overgrow Sheared Molars- enamel overgrowth
Signs of a problem: Abnormal bitting or head carriage Headshaking Quidding or dropping food Excessive salivation Weight loss, general poor health Swelling or discharge in mandible maxilla or nasal discharge
A.A.E.P 1996. The official Guide for Determining the Age of the Horse. American Association of Equine Practitioners. Golden, Colorado.
Blackwell. 2009. Equine Manual for Veterinary Technicians. Blackwell Publishing. Ames, Iowa
Equine Dental Care
Why is it important for my horse to have regular dental examinations?
An oral examination should be an essential part of an annual physical examination by a veterinarian.
Regular examinations also help identify dental problems while they are still in the early stage, which decreases the chances that the dental problem can lead to other serious health issues for the horse.
How often should a horse receive a dental exam?
At the minimum, all horses should receive a yearly dental exam.
Horses aged 2 to 5 years may require more frequent dental exams than older horses, as there is an extraordinary amount of dental maturation during this period.
Senior horses (20 years old or older) are at increased risk for developing periodontal disease and face the additional challenges of advancing age.
Twice-a-year examinations are often required to keep their teeth functioning properly into their third and fourth decades of life.
How will I know if my horse has a dental problem?
Horses with dental problems may show obvious signs such as pain or irritation, or they may show no noticeable signs at all.
By the time the average owner notices a problem, such as loss of feed from the mouth while eating, fighting the bit or foul odor from the mouth or nostrils, the abnormalities inside the mouth are likely to be severe.
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.
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.
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.
What is the difference between traditional floating and power floating?
Traditionally, horses have had their sharp enamel points and dental crown elongations reduced with hand-held rasps (floats).
These manual dental instruments have improved in quality over the past 20 years but still require a reasonable amount of manual dexterity, physical strength and "elbow grease.”
High quality dental tools powered by electricity or compressed air have become readily available and affordable over the past 10 years. These instruments reduce the physical effort that is required, and with expertise and caution, allow for more complete and efficient dental care.
Will my horse need to be sedated during a dental exam?
Some horses find the process of having their mouth opened and instruments placed in the oral cavity to be stressful.
For a complete oral examination and good quality corrective care, most horses benefit from a mild sedative to relieve any stress or unnecessary movement on the patient's part.
When the horse is sedated, it allows us to do a better job in a safer way
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.
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.”
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.
Do donkeys and mules require different
dental care than do horses?
All equine species have the same type dentition.
We see the same types of pathology and wear patterns in donkeys, mules, zebras and horses.
Under current domestication practices, all require regular dental care.
Clean and Sanitary
All dental instruments, the speculum (device that holds the horse’s mouth open), buckets, etc are all cleaned and washed with an antimicrobial disinfectant (Nolvasan) between each and every horse. No exceptions!
Equipped to do the job
Equine dentist should be well equipped with good instrumentation, both motorized and non-motorized.
Examination noting pathology and record keeping
A complete examination with the use of surgical grade lighting, a dental mirror, and other appropriate instruments should be done.
A record indicating all teeth in your horse’s mouth, noting location and significance of all abnormalities, what work needs to be done, and time of follow up examinations should also be included.
Diagnostic Imaging
Dentist should have access to diagnostic imaging equipment such as x-rays, preferably digital x-rays.
This allows us to uncover and manage a host of equine dental abnormalities.
