Do you know my age Horses teeth are

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: l Validate advertised age when buying l Confirming age when racing or showing l Feeding for proper nutrition at various life stages

Aging by Teeth l l l l 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 The horse is anisognathic, which means the upper and lower jaws are different widths, ". The maxilla (the upper jaw or cheek) is about 30% wider than the mandible (the lower jaw), and the maxillary teeth are slightly wider than the mandibular teeth

l l Deciduous- ID 3/3 CD 0/0 PD 3/3 MD 0 Permanent-I 3/3 C 0 -1/0 -1 P 3 -4/3 M 3/3

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 l l Hypsodonts Two times l l l 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 l l l Milk teeth 12 incisors 12 premolars

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. l The “caps” are usually present at birth or by 1 to 2 weeks of age. l Rule of 3 eights: I 1 - 8 days, I 2 - 8 weeks, and I 3 - 8 months -charts may show these as Di 1, Di 2, Di 3 l The number of permanent teeth may vary, depending on if the horse has wolf teeth or canines. l

Aging - Incisors l l Deciduous eruption pattern: Central @ 6 -8 days Middle @ 6 -8 weeks Corner @ 6 -8 months l Premolar eruption l l l pattern: PM 2 @ 2 years 8 months PM 3 @ 2 years 10 months PM 4 @ 3 years 8 months l l l l Permanent eruption pattern: Central @ 2. 5 years Middle @ 3. 5 years Corner @ 4. 5 years Molar eruption pattern: M 1 @ 1 year M 2 @ 2 years M 3 @ 3 - 4 years

Cups, stars and spots: l 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.

l 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 – 8 -10 days Temporary intermediates: 4 – 8 weeks Temporary corners: 6– 8 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 l A typically small maxillary wolf tooth (premolar [PM] 1) is present just rostral to PM 2.

l l l First premolar (PM 1): 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 l Disappears at 8 years, returns at 11 l Length with age “long in the tooth”

I 1 I 2 I 3 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 8 years 9 years 10 years Galvayne’s groove 10 -30 years Seven year notch 7 years, and 11 years l l 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 l Reserve crown Elliptical mastication pattern Wear pattern: l Results in sharp l enamel points. l Buccal aspect (upper) l Lingual aspect (lower)

Triadan Numbering System l l 100’s = Right maxilla 200’s = Left maxilla 300’s = Left mandible 400’s = Right mandible l l l Incisors = 1, 2, 3 Canines = 4 Wolf teeth = 5 Premolars = 6, 7, 8 Molars = 9, 10, 11

Dental Examination Visually inspect: l Prior to rinsing mouth l After rinsing mouth Digitally palpate: l Individual teeth l Gingiva l Palate l Tongue Record findings on a standard form

Historical Clues to Dental Problems Performance habits l Head tilt l Head tossing l Refusing the bit Eating habits l Quidding l Slow, deliberate mastication l Exaggerated tongue movement

Change in fecal character l l 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 l Incisors l l Check occlusion Inspect eruption pattern Canines erupting at this age. Premolars: l Look for wolf tooth. Inspect for caps. Periodontal disease l Molars l Inspect eruption pattern. l Exam frequency: semiannual l l

Age: 7 - 15 years Incisors l Inspect for l Injury or damage l Supernumerary teeth l Missing incisors l Misalignment l Wear pattern

Age: 7 – 15 years Canine teeth l Check for sharp points l Check for tartar

Age: 7 – 15 years Premolar and molar teeth: Enamel points (odontophytes) Occlusion abnormalities l Hooks and ramps l Unopposed teeth l 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 l Wearing of infundibular enamel Dental caries Tooth root abscess Tooth loss Exam Frequency Semiannual

Dental Equipment l Chemical restraint l Xylazine Detomidine Butorphanol l l Dental halter Speculum Full-mouth Wedge Light source Floats/Motorized instruments Elevators/Extractors Perineural anesthesia

Dental Equipment l l l l Dental floats Extractors Wolf tooth Premolars (cap) Molars Periosteal elevator Forceps Electric dremmel

Halter and Speculum

MOTORIZED EQUIPMENT

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!

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.