Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) is a progressive dental disease that causes painful breakdown of tooth structure in horses, primarily affecting the incisors and canine teeth. If left unmanaged, EOTRH can significantly impact a horse's comfort, appetite and overall wellbeing.
What is EOTRH in Horses?
| EOTRH (Equine Odontoclastic Tooth Resorption and Hypercementosis) is a condition in which a horse's tooth structure gradually breaks down while abnormal calcified tissue (cementum) builds up around the tooth roots in an attempt to keep them stable. The disease most commonly affects the incisors and canine teeth, though the premolars can also be involved. |
EOTRH is progressive, meaning it worsens over time. Horses in the early stages may show no obvious signs, which makes routine dental examinations by a veterinarian essential for early detection. When your veterinarian diagnoses EOTRH, they will stage it from 0 (no disease) to 3 (most severe) using dental radiographs of the incisors and canine teeth.
What Are the Symptoms of EOTRH in Horses?
The symptoms of EOTRH often appear gradually and can be easy to overlook in the early stages. Many older horses show no outward signs until the condition has progressed.
Watch for these signs:
- Inflamed or receding gums: Cementum buildup around the tooth roots can cause swollen, bulb-like areas around the gumline (hypercementosis). You may also notice reddened, pimple-like lesions or gum recession.
- Behavioral changes: Increased head shaking, irritability when bridled or ridden, or resistance to bit contact can all indicate oral discomfort associated with more advanced disease.
- Difficulty eating: Oral pain may discourage your horse from grazing, lead to weight loss or cause them to dunk hay in water before eating. Reluctance to bite down on firm foods such as apples or carrots is another common sign.
- Bad breath: A persistent foul odor can signal bacterial infection in the affected areas of the mouth.
- Visible tooth changes: Looseness, fractures or discoloration of the incisors are signs of significant disease progression.
Because symptoms become more evident as EOTRH advances, regular veterinary dental exams are the most reliable way to detect it early.
What Causes EOTRH in Horses?
The exact causes of EOTRH are not yet fully understood. However, research suggests that several factors, individually or in combination, may contribute to its development.
Possible risk factors include:
- Age: Older horses are disproportionately affected. Approximately half of reported EOTRH cases occur in thoroughbreds and warmbloods aged 15 years or older, suggesting a strong age-related component.
- Diet and environment: A horse's feed type or limited access to grazing may contribute to dental problems over time.
- Oral bacteria: Certain microorganisms present in the mouth may increase a horse's susceptibility to the condition.
- Genetics: Some horses may carry a predisposition to dental disease.
- Medical history: Prior dental trauma, periodontal disease or other systemic conditions, including pituitary pars intermedia dysfunction (PPID), may be contributing factors.
More research is needed to identify definitive causes. Your veterinarian can help you evaluate your horse's individual risk profile and develop a monitoring plan.
How Is EOTRH Diagnosed?
Your veterinarian will typically begin with a thorough dental examination and a review of your horse's medical history. Radiographs (X-rays) of the incisors and canine teeth are used to confirm the diagnosis and stage the disease from 0 to 3 based on severity.
Because EOTRH symptoms can be subtle in early stages, annual or biannual dental exams (including radiographic evaluation in horses over 15) are the most effective way to catch the disease before it becomes severe.
EOTRH Treatment Options
There is no cure for EOTRH, but treatment options may address pain, infection and disease progression, and your veterinarian will develop a plan based on the stage of disease. Your veterinarian will develop a treatment plan based on the stage of the disease, which may include surgical extractions combined with medications to manage infection and inflammation.
As a full-service equine pharmacy, Mixlab provides a range of branded, generic and compounded medications to support your veterinarian's treatment plan, including the options below. All medications require a veterinarian's prescription.
Antibiotics for EOTRH
Antibiotics are used to address bacterial infections that can accompany EOTRH-related dental damage.
Sulfadiazine Sodium with Trimethoprim: This antibiotic combination (sulfadiazine sodium 416 mg/mL with trimethoprim 83 mg/mL, 30 mL) is available as an oral paste through Mixlab. It is an antibiotic combination commonly prescribed in the context of dental infections.
Doxycycline: A broad-spectrum tetracycline antibiotic that may be considered for bacterial infections associated with EOTRH. Available through Mixlab in multiple formulations:
- Oral powder (5 g/scoop in 20, 30 or 60 scoops)
- Oral paste (5 g/15 mL in 60 mL)
- Suspension
NSAIDs for EOTRH Pain Management
Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to manage the pain and inflammation associated with EOTRH.
Phenylbutazone: Phenylbutazone is a commonly prescribed NSAID that veterinarians may select for horses with EOTRH-related pain and inflammation. Mixlab offers it in several formulations:
Oral powder formulations:
- Phenylbutazone 1 gm/scoop and cimetidine 500 mg/scoop, 120 scoops
- Phenylbutazone 1 gm/scoop and cimetidine 500 mg/scoop, 60 scoops
- Smart Bute: phenylbutazone 2 gm/scoop and omeprazole 1 gm/scoop, 30 scoops
Oral paste formulation:
- Phenylbutazone 200 mg/mL and cimetidine 100 mg/mL, 60 mL syringe
Firocoxib (Equioxx): Available as 57 mg tablets in counts of 60 or 180, firocoxib is one of the most rigorously tested NSAIDs for safety in horses and is commercially available through Mixlab.
Flunixin: Flunixin is an NSAID that veterinarians may prescribe for pain management in horses with EOTRH, and is available through Mixlab in multiple forms, including the branded version, Banamine.
Available formulations:
- Flunixin Meglumine 50 mg/mL + Cimetidine 100 mg/mL, oral paste, 30 mL or 60 mL syringe
- Flunixin Meglumine 500 mg/scoop, oral powder, 120 scoops
- Banamine in 100 mL or 250 mL vials for injection
Frequently Asked Questions About EOTRH in Horses
What does EOTRH stand for?
EOTRH stands for Equine Odontoclastic Tooth Resorption and Hypercementosis, a progressive dental disease in horses involving breakdown of tooth structure and abnormal buildup of cementum around the tooth roots.
Which horses are most at risk for EOTRH?
Older horses are at greatest risk. Research indicates that roughly half of all reported EOTRH cases occur in thoroughbreds and warmbloods aged 15 and older. Horses with prior dental trauma, periodontal disease or PPID may also have elevated risk.
Can EOTRH be cured?
There is currently no cure for EOTRH. Treatment focuses on managing pain, controlling infection and, in more advanced cases, extracting affected teeth. With appropriate veterinary care, many horses go on to live comfortably after treatment.
How is EOTRH diagnosed in horses?
A veterinarian diagnoses EOTRH through a dental examination and dental radiographs (X-rays). The disease is staged from 0 to 3 based on severity. Early-stage EOTRH often has no visible symptoms, which is why routine dental exams with radiographic evaluation are recommended for horses over 15.
What happens if EOTRH goes untreated?
Untreated EOTRH causes progressive tooth deterioration, increasing pain and difficulty eating. As the disease advances, horses may experience significant weight loss, behavioral changes and systemic infection. Early detection and treatment are important for preserving your horse's quality of life.
Can a horse eat normally after EOTRH tooth extractions?
Many horses adapt well following extraction of affected teeth. Your veterinarian will advise on dietary adjustments during recovery. Horses that have undergone incisor extractions often return to normal grazing behavior, though this varies by individual.
Support Your Horse's Dental Health with Mixlab
Mixlab is a full-service equine pharmacy offering branded, generic and compounded medications for horses, including antibiotics and NSAIDs used in EOTRH management, along with vitamins and supplements to support overall health and performance. We offer convenient two-day delivery and accept prescription requests online.
Order online and we'll contact your veterinarian for their prescription, or reach out to your veterinarian directly to learn more about treatment options for your horse.
