Size Matters….Bit Size That Is!

Choosing the right bit size is important. If the bit is either too small or too large it can not do the job it is meant for and can actually harm your horse. Bits, at their best, always create pressure….pressure on soft tissue, on the palate, on the tongue, and even on nerves for the purpose of communication. The very best bit for your horse is the bit with the mildest action while still allowing you a communication pathway. There are many, many, many styles to choose from.

Your horse’s conformation and shape of his mouth/tongue/palate has an impact on what bit will be comfortable for their use. Not all bits fit all horses. Equine dentistry also plays a major role in bit “success” by maintaining the correct alignment and movement of the horse’s jaw. Dentition concerns such as wolf teeth, hooks and ramps, and sharp dental points all can interfere with the movement of their mouth and alter the way a bit actually sits. Finding the right bit for you and your horse may take some trials, but Advanced Equine Dentistry will be happy to assist you by measuring the actual bit seat during your routine dental visit, assessing the conformation of your horse’s tongue and palate, and maintaining their teeth in pristine condition! While we can’t be sure which “bit” you will choose, we can certainly help start your search by giving you some vital information about your horse’s mouth.

Sand Colic….Different?

Sand colic is a specific type of colic seen in horses that live in a sandy environment. It accounts for about 5% of all colics seen. Sand colic presents with symptoms similar to any generic colic, such as inappetence, pawing, rolling, looking or kicking at the stomach, distress and unease, and dehydration. One sign that is more specific for sand colic is diarrhea.  The sand likes to settle in the large colon1, where it causes irritation and pain.

Any equid can pick up sand from the environment. They get it from grazing on sandy pastures, that are often overgrazed by too many horses. Any location with sand is a risk, including if you feed in an arena. They best way to avoid or decrease the risk of your horse ingesting sand is to feed from a rubber tub on the ground for both the hay and the grain. Rubber mats are also an option. This minimizes their exposure to sand and another small particles from the ground. You can also feed from low-hanging hay nets or low mangers.

            The way to test for how much sand your horse has is his gut is simple. Take 6 fresh fecal balls that haven’t had contact with the ground and place them in a quart of water in a bucket or bag of some sort. Mix the contents and let sit for 15 minutes. If more than a teaspoon of sand accumulates, your horse is potentially ingesting a dangerous amount of sand1.

            There are not a lot of ways to remove the sand, aside from colic surgery. Psyllium is a feed additive that can help move some sand through the gut and out into the feces. If you decide to start adding psyllium, be sure to follow the label instructions for feeding, as it is also a laxative. One veterinarian recommends feeding one to two cups of psyllium per 1,000 pounds of horse daily for a week, every four to five weeks. Alternatively, psyllium can be fed one day a week, every week2. Feeding it every day does not seem to be as effective in clearing the sand from the gut.

            If you ever notice signs of colic in your horse, immediately contact your veterinarian. I recommend testing your horses to see how much sand they have in their feces, and then considering adding psyllium to their diet.

Written by: Dr. Morgan Bosch

Works Cited:



Deworming Strategies

For the last 50 years, most horse owners have been told to deworm their horses every 2 months with rotating dewormers. While this has been effective in decreasing infection from what was considered the major parasite of horses 50 years ago, S. vulgaris or the large strongyle, it is now a moot point. S. vulgaris is no longer considered a major player in the parasitic arena in correctly managed herds. Currently, small strongyles called cyanthosomes, Parascaris equorum or equine roundworms, and A. perfoliata or equine tapeworms, are considered the main parasitic threats to equine health1. Due to the extensive use of rotating dewormers, there is emerging drug resistance in many of these parasites, meaning current dewormers aren’t as effective.  If horse owners continue to deworm every 2 months, we may soon run out of effective dewormers.

            Small strongyles infect almost every horse with access to grass, so it’s important to know how heavy an individual’s parasite burden is. Each horse has some innate resistance to parasites, but it varies from horse to horse. Small strongyles only cause disease when present in large numbers in the horse’s GI tract1. This means that your horse could have a small parasite burden and be perfectly fine. It has been found that in most herds, 15-30% of the horses are responsible for up to 80% of the parasite egg burden1.  The main goal of deworming is to target these horses and get their parasite burden down to a manageable level.

            So, what should you do? The only way to determine how heavy your horse’s worm burden is is to perform a Fecal Egg Count. This is a test that quantifies how heavy your horse’s infection is, and establishes a baseline to determine treatment. Low shedders have less than 200 eggs per gram of feces. These horses don’t generally require treatment. Moderate shedders have 200-500 EPG, and high shedders have over 500 EPG. These two groups should be treated based on the type of worm present and the type of dewormer those worms are susceptible to. Ideally, the test should be performed prior to deworming, or at least 6 weeks after deworming.

            There are several other things you can do to help decrease the egg burden on your farm, such as rotating pastures, removing manure frequently from pastures (at least twice weekly), harrowing/dragging and mowing pastures to expose larvae and eggs to elements and predators, and avoiding equine overcrowding. Florida has different recommendations for deworming due to its climate. The best time to treat horses is during the winter. Below is a chart put together by AED to help aid in deworming your horse with the correct products at the correct time of year based on their Fecal Egg Count test results. If you have any questions, don’t hesitate to ask during our next visit!

Written by: Morgan Bosch, DVM


1. AAEP Internal Parasite Control Guidelines.

Tis the Season…Be Careful!

The definition of liability is “the state of being responsible for something, especially by law”. Sadly, the holiday season can bring out both the best and worst in folks leaving some horse owners subject to losses they weren’t expecting. Lately, we’ve heard numerous stories from clients who have hired “equine” contractors or services only to find they had no avenue for restitution when things went awry. The one question we always ask them is “was your service provider insured” and often find our clients don’t know or didn’t ask. Bottom line…..anyone completing work on your horses or your property should have liability insurance to protect YOU. Be sure to ask….and bypass some of the holiday scrooges!

Horses Get Cavities Too!

Horse’s teeth have the same composition as human teeth and just like humans, they can get cavities. As the life expectancy of horses has increased, our ability to treat dental caries has a huge impact….the cost of placing a composite filling into an equine cavity can preserve the integrity of the tooth and may prevent the need for a complete extraction later on.

Source: British Equine Veterinary Association

Because horse’s teeth normally have ridges and variations in coloring, cavities are not always easily detected. And, just like in humans, the point at which they must be treated depends on their depth and location. Once your equine dentist finds a cavity and decides on a composite filling for your horse, the process is much like your own fillings: the decay is removed, the surface prepared for the placement of the composite, the composite is used to fill the opening, and a light cure assures it is hardened and secure. An equine dental filling, when done correctly, is just as strong as the tooth it protects and can last their entire lifetime.

The photo above shows a recent patient of Advanced Equine Dentistry who now has two composite fillings in his premolars to correct decay that was identified during a routine dental exam. We’d be happy to teach you more about dental caries in horses and check your own equine partner at our visit!

Creeping Indigo

Creeping Indigo (CI) is a non-native flowering ground cover plant that was introduced to Florida in the mid-1900’s. Ironically, it was brought in by universities to see if it could be used as livestock forage. This didn’t work out, as animals began to show signs of toxicity and death when fed a diet of Indigofera over a period of a few weeks. There are over 750 different species of Indigofera; the toxic species in Florida is I. hendecaphylla. There are two toxins that affect livestock: 3-nitropropionic acid (3-NPA) and Indospicine. 3-NPA causes a majority of the neurologic effects seen in animals, while Indospicine mainly effects the eyes and mucous membranes. Only Indospicine can be found in the serum of affected animals.

            So, what does this plant look like? Creeping Indigo leaves are similar to clover. It runs low to the ground, with branched runners fanning out in all directions from the center. The root is a white, slender, tapering taproot that is hard to pull up and can reach almost 3 feet underground. The stems are pale-green to yellow, tough, and thickly set with alternating, pinnate, clover-like leaflets that are 1-5 cm long. The slender, tubular flowers are brick-red to pink to white. The most characteristic and identifiable feature are the needle-like, stiff, sharp-tipped seed pods, 1-3 cm long, that are found under the leaves in dense, downward-pointing clusters (see Orange arrow below).  These seeds disperse when you mow the yard or field, and can hitch a ride on the mower to new areas. The plant is killed back in winter in central and north-central Florida but sprouts from the root in the spring.1

            How much does a horse have to eat to start showing signs of toxicity? Based on current research, an average-sized horse only needs to consume 10 pounds daily for 2 weeks to become symptomatic. Foals can also show signs from drinking contaminated milk from their mother. A majority of horses show neurologic signs. This can range from a change in demeanor (more calm or less energetic) in the early stages, progressing to low head-carriage and episodes of standing narcolepsy, head-pressing into corners, or compulsive walking around the inside of a stall or paddock.1 Some affected horses show signs of vestibular disease, such as tilting their heads to one side and their necks and bodies twisted in the same direction. These signs may be accompanied by rhythmic blinking and jerking eye movements (nystagmus). The blink response to hand gestures toward the eyes (menace response) is frequently absent or reduced, although constriction of the pupils to bright light is usually unchanged.1 There can be flaccid (drooping) paralysis of the muzzle and lips. In retrospect, owners note an abnormal gait that has been developing over the preceding several days, characterized by incoordination and weakness in all limbs, with unpredictable crossing of pairs of limbs, interference between hooves, buckling of joints during weight-bearing, a “crab-like” gait and abnormal posturing at rest1. Some affected horses develop a bizarre “goose-stepping” gait in their front legs. If the horse continues to eat CI, they eventually become recumbent and unable to rise. Once the horse is down, they either become unconscious or develop convulsions, which can become generalized and severe before death or euthanasia. This can all progress in a matter of days once a toxic level is reached.

            There are also non-neurologic signs of CI toxicity. These can include weight loss, inappetence, high heart rate/respiratory rate, labored breathing, excessive salivation or foaming at the mouth, dehydration, pale mucous membranes, bad breath, dropping hay balls (quidding) due to paralysis, and ulceration of the tongue and gums. The toxins can also affect the eyes, causing excessive tearing, corneal opacity or ulceration, and squinting.

            There is no treatment for CI toxicity. If you catch the signs of toxicity early enough and remove the horse from the contaminated pasture, some of the effects are reversible. However, the gait abnormalities can persist. Management of affected horses should include removal from the source, confinement to prevent any injuries, and non-specific supportive therapy.1 The University of Florida specifies only two herbicides containing aminopyralid that kill CI: Milestone (Dow AgroChemicals) at 5 fl oz per acre or GrazonNext HL(Dow AgroChemical) at 24 fl oz per acre.1  You will have to stay of top of it and likely retreat the next year. Dead plants retain toxicity and must be removed and disposed of. Grass clippings and manure from animals that graze herbicide-treated pastures should not be composted.1 The plant thrives in just about any environment, but overgrazed pastures are especially at risk.

Written by: Morgan Bosch, DVM

Source: Creeping Indigo Toxicity by: Rob MacKay (UF-LAH)

Equine Odontoclastic Tooth Resorption and Hypercementosis…..EOTRH for Short!

Equine odontoclastic tooth resorption and hypercementosis. A long name for a complicated disease. Thankfully, we shorten the name to EOTRH (or “E-roth” as we say). EOTRH is a degenerative disease that affects the incisors and canines, in most cases. There have been a few select reports of it also involving the first premolars, but it is rare. Horses aged 12 years and older are affected, and it can be seen in any breed. However, it has been more commonly reported in Thoroughbreds and Warmbloods1.

First, a short course in the structure of a tooth. Teeth are made up of cementin, dentin, and enamel, with a pulp cavity(or cavities) in the middle to supply nutrients. There is also a ligament that holds the tooth in the socket.  EOTRH is characterized by resorption of tooth structures, often with simultaneous excessive production of cementin on the surface of the tooth root. Once the process begins, it continues until the tooth breaks or is completely resorbed. This process is EXTREMELY painful. Horses with EOTRH often resent the pressure caused by the speculum we use to open their mouth, and need more sedation as a result. EOTRH can involve anywhere from one tooth, to the entirety of both the upper and lower incisors and canines. It has been noted that the disease seems to start with the outer 03 incisors and work towards the middle1. Due to the painful nature of the disease, the only current treatment is to remove all affected teeth. Although it seems barbaric, owners have noted a complete change in their horses’ demeanor after removing the teeth. The horses are much more comfortable and happier once the extractions have healed.

A normal tooth on X-ray (2nd from left) and a tooth showing advanced resorption and hypercementosis (2nd from right)

So, what are some signs to look for? Each horse has a different way of displaying the pain associated with EOTRH. Some horses will continue on like nothing is wrong, despite having advanced disease. Others will stop eating or start resisting the bridle, or just start acting cranky. A common test is what we call “the carrot test.” Offer your horse a carrot to bite. If he bites through it with no problem, it’s all good. But, if he starts to hesitate or can’t bite through it, this is a sign that his teeth hurt and he may have EOTRH. Some owners notice pustules forming on the gums and/or gingival recession. This is due to infection surrounding the tooth. The gums can also look bumpy or swollen if there is hypercementosis associated with the disease. Sometimes, we don’t know they have it until they break a tooth and we take an X-ray. 

A pustule above an affected tooth, with concurrent gingival recession  

Unfortunately, no distinct cause has been identified at this time. There is ongoing research to determine if EOTRH has a singular cause or is the result of many factors over the life of the horse. It is suspected that inflammation of the periodontal ligament surrounding the tooth plays a roll in initiating the disease1. This can lead to secondary infection by different bacteria, which help progress the resorption of the tooth structures and cause visible infection around the tooth. The hypercementosis is suspected to be the body trying to repair the resorption; it just goes out of control1. Not every case has hypercementosis associated with it. As stated earlier, the only treatment is to remove the affected teeth. This is done with the horse sedated and standing, and can take up to 4 hours. Nerve blocks with lidocaine or carbocaine help to numb the entire affected area, and we also numb around each tooth with lidocaine. The disease is progressive and painful, and if left alone, causes profound discomfort and stress to the horse. Regular dental check ups can help to identify suspicious lesions and track the progression of the disease, if previously identified. The best way to determine the extent of disease is to take an X-ray of both the upper and lower incisors and canines. We have documented numerous cases of EOTRH within our practice, and regularly remove affected teeth. If you suspect your horse may have something wrong, don’t hesitate to give us a call. X-rays are a quick and easy way to determine if your horse is suffering from EOTRH.

Written by: Dr. Morgan Bosch, DVM


1. Vahideh Rahmani, Lotta Häyrinen, Ilona Kareinen and Mirja Ruohoniemi. History, clinical findings and outcome of horses with radiographical signs of equine odontoclastic tooth resorption and hypercementosis.

AED is Proud to Sponsor PHA’s Annual “Equines for K9’s” Benefit

Please come join Advanced Equine Dentistry as we support the Pasco County Horseman’s Association and the Pasco County Sheriffs Canine Team on November 8th, 2020! Great organizations and lots of equine fun and prizes! Don’t miss the K9 Demonstration! Stop by the AED trailer and say “Hi”!