Equine Dentistry: How to Look a Good Horse in the Mouth
By: Ann Pearson-Wegner DVM, MS
JUVENILE DENTISTRY
Foals can be checked soon after birth and as weanlings to check for abnormalities. Exams should be done at the latest by the second year and definitely before the bit is used. Teeth are softer when young; thereby, forming points faster. It is recommended to treat the young horse every 4-6 months until 5-6 years. Asynchronous eruption of permanent teeth can cause bite abnormalities.
ERUPTION TIMES
Deciduous incisors: The central incisors generally erupt the first week of life. The middle incisors emerge at approximately 4-6 wks and the corner incisors erupt between the sixth and the ninth month of life.
Permanent incisors: In general, deciduous incisors are shed at 2.5, 3.5 and 4.5 years, for the central, middle and corner incisors, respectively.
Permanent premolars: The 2nd, 3rd and 4th permanent premolars erupt at 2 yrs-8 mos., 2 yrs-10 mos. and 3 yrs-8 mos., respectively. The deciduous premolars (baby teeth) will then form caps. Look for bumps along the lower mandible of the jaw.
Molars: The first molars erupt at 1 yr, 2nd molars, 2 yrs and 3rd molars at 3-4 years.
Caps should be removed if loose or line of demarcation between permanent teeth is present. This can save a horse from days to weeks of discomfort.
TOOTH NUMBER DESIGNATION
The teeth are numbered as follows: the central incisor on the upper right is the first tooth (101) the tooth at the far back of the mouth (caudal) on the upper right is tooth number 111. The sequence for designating the tooth number runs in a clockwise fashion. The 200 series is the upper left arcade, the 300 series is the lower left arcade and the 400 series is the lower right arcade.
EQUINE CHEEK TEETH DENTISTRY
Power equipment should be considered for efficiency and safety. The thorough oral exam is the key to effective dentistry and sedation is often necessary. A full mouth speculum is used for a complete oral exam. During the exam, your veterinarian will check for cheek and tongue lesions. The third molars are 10-14 inches caudal to (behind) the incisors. The most common cause of mouth pain is sharp enamel points due to uneven tooth wear. Points form on the outer edge of the upper premolars and molars and the inner edge of the lower premolars and molars. The size of the enamel points on the cheek side of the upper teeth can be related to the size of the grooves on the sides of the teeth. (cingulae)
MATURE HORSE DENTISTRY
Hooks or overgrowths of the first (06) or last cheek teeth (11) occur when the upper and lower teeth are not aligned properly. Hooks may result in soft tissue and bone destruction. The hooks usually occur at teeth #106, 206, 311 and 411. Steps occur when one tooth higher than another and can involve one or more teeth. Hooks and steps restrict rostral to caudal movement (front to back.) The practitioner may want to do reductions in stages to prevent damaging the tooth. Taking steps, hooks and waves down will reduce grinding efficiency for a short period of time.
BIT SEATS
Involve rounding of the upper 2nd premolars in front (rostral) and on the cheek (buccal) side, as well as on the lower 2nd premolars on the lingual side(tongue) and front. Bit seats allow for placement of the bit to limit damage to soft tissue such as the cheeks, lips and tongue.
WOLF TEETH
Wolf teeth are designated as #105, 205, 305 and 405. They should be removed before using a bit. Removal is performed with sedation and local anesthesia.
OLDER HORSE DENTISTRY
The goal is to allow your horse to chew comfortably and with optimal grinding efficiency. It is possible that the practitioner will not be able to resolve all abnormalities completely, because of decreased grinding ability resulting from excessive leveling after the teeth no longer erupt. Squeaky teeth indicate that teeth have, or soon will expire and it is possible that feeding soaked pellets will become necessary. The squeaky teeth may feel smooth and are completely worn down to gum level. Older horses may need to be checked frequently because of lost or broken teeth or gum disease. Periodontal diseases such as hay pockets and gingivitis may indicate a systemic infection. It is always wise to consult with your veterinarian if you have any questions.
INTERESTING FACTS
Horse teeth are called hypsodont – meaning they continue to erupt
Horses secrete 50 mls/min of saliva from the parotid salivary glands. Saliva is produced when the horse is chewing and is necessary for normal mastication and degradation of feedstuffs. Therefore, make sure your horse can chew normally and is pain free for ideal absorption of feed.
