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.
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 (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.
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. https://veterinaryrecord.bmj.com/content/185/23/730
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”!
Whenever we check a new horse, especially a younger one, we look for the presence of wolf teeth. Wolf teeth are typically present just in front of the first cheek tooth, and can be present on both the top (more common) and the bottom jaw. They are numbered 105/205/305/405 and are present in around 70% of horses1. Wolf teeth are remnants from the original horse “Eohippus,” who was a browser and ate more twigs and branches in the forests millions of years ago. As horses evolved and became grazers, their diet changed to mostly grass. Their teeth also changed, and they had less use for these wolf teeth2. They are now what we call “vestigial,” meaning they no longer have a use but still continue to grow.
Wolf teeth normal erupt between 5-12 months of age. Horses can have anywhere from 1 to 4 wolf teeth, and they can occasionally be blind (meaning they don’t emerge from the gumline but are still present). They generally have a single root, but can be varying lengths and sizes. They sit in the same area as the bit, so we remove them before they cause any training issues. There are varying schools of though on whether or not they should be removed, but we only leave them if the horse is never going to have a bit it their mouth (i.e. broodmares, pasture ornaments, ect). Even though they’re small, they can still fracture or become mobile as the cheek teeth come in and cause issues2. Removing them at a young age is the simplest solution, as they can become fused to the jaw bone with age.
Removal is usually quite simple, needing only sedation and local lidocaine. The gum and ligaments around the tooth are loosened with a tool called an elevator, allowing the tooth to be removed with forceps. There are some photos from a recent extraction of bilateral wolf teeth at the end of this post. There are very few complications with a complete removal. Occasionally, the root can fracture off, causing a more complicated extraction. It is never acceptable to just break off the crown of the tooth and leave the root. This leaves exposed roots and pulp chambers, which leads to pain and possible infection. It is always good to have your horse up to date on their tetanus vaccine prior to the procedure. Tetanus bacteria live in the dirt and on rusted objects, so horses can pick it up just about anywhere. Infection is almost always fatal.
Some people confuse wolf teeth with their horse’s canine teeth. The canines are the teeth in front of where the wolf teeth come in. Canines erupt from the gum between 4.5-5.5 years of age, so much later than wolf teeth. They are also much larger than wolf teeth, and very challenging to remove. They are more common in males than females, and can also be blind.
_____________________________________________________Extraction of actual Wolf Teeth performed by AED
At Advanced Equine Dentistry, we are keenly aware of our role in helping our clients provide preventative care for their equine partners. We specialize in dentistry but we also offer the routine veterinary services that allow you to keep them healthy….and bring it right to your barn door! After talking with many of you, we’ve developed these bundles as a way to reduce your costs and still be sure to meet those needs. We are proud to be the practice you choose to help care for your horses!
After reading our article on Body Condition Scoring, you may be wondering if you are feeding your horse properly. Clients often ask us for nutritional advise based on what they have noticed with their horse. Sometimes, this is their first horse and they just feed what they were told by the old owner. Choosing the correct feeding regimen for your horse’s activity level, age, dentition, and other factors should begin with choosing the correct type of hay. Grain can be added as a supplement, if needed. Many horses do well with only access to hay and pasture, plus or minus a ration balancer.
The first thing to consider is your horse’s energy requirement. Are they mainly pasture ornaments that go out for occasional pleasure rides? Are they weekend warriors that truck it out on trails? Or do you have a competition horse in training, broodmare, or growing foal that needs a lot of energy? Different types of hay have different nutritional content. They only way to truly be sure of what you’re feeding is to have an analysis done of the hay. This involves taking a core sample of the hay bale and submitting it to a lab for analysis. Some labs do group samples if you have an entire shipment you want analyzed. Below is a chart from the University of Florida Equine Department you can use as basic guidelines when choosing a hay for your horse. Donkeys have lower energy requirements than horses based on where they originated from (the mountains of South America). They don’t need grain and do well on lower quality hays, like Tifton or even straw. You also have to monitor their pasture time, or they will get overweight. This predisposes them to a number of health problems, such as hyperlipema and Equine Metabolic Syndrome.
Now, on to the different types of hay. Going to the feed store can be a bit overwhelming for new horse owners and veterans alike. There are three main types of hay you can feed: legume, grass, or mixed.
Legumes- Includes alfalfa and perennial peanut. Generally better quality than grass hay, as they have less fiber, higher calorie content, and more potassium and calcium. More palatable for most horses1. Peanut hay tends to lose a lot of leaves as it gets moved around, causing it to lose important nutrients. A good option for horses needing more energy or those that are hard keepers.
Grasses- Includes orchard, timothy, fescue, rye, Costal Bermuda and other Bermudagrass varieties, and Tifton. All types have generally the same nutrition content. Variation will depend on growing conditions, weed content, and fertilization. We don’t generally recommend feeding Tifton unless you have a donkey or overweight horse.
Mixed hays- Contain a certain percentage of both legume and grass hay. Nutritional content varies based on what hays are used and in what ratio. Suitable for most riding horses that are not in hard work. Examples include orchard/alfalfa (O&A) and timothy/alfalfa (T&A).
Below is another chart from the University of Florida that has a basic analysis of several hay types.
Now that you know which type of hay you want, there are some other things to consider once you lay eyes on it at the store. The outer color isn’t always indicative of quality. Yellowing can be caused by sun bleaching and rain damage. The sun bleaching doesn’t have much affect on nutritional value, as long as its just the outside of the bale. Rain damage, however, can be dangerous due to mold. It’s important to look inside the flakes and be sure they are a nice green color. The intensity of the green color can vary based on several things, such as where the hay was grown (Western hays are a more intense green than Florida-grown hays) and the type of hay (Alfalfa is a very intense, deep green compared to most other hays)1. Black, gray, or excessively brown hays should be avoided, as they can contain contaminants, mold, and have minimal nutritional value. You can usually smell and see mold when you open the bale. You will notice a musty smell and can sometimes see the mold spores take to the air as dust. There can be black or gray mold spots within the flakes, as well. If you notice any of these things, throw that bale out! Mold can be toxic! Good hay should smell sweet, like fresh cut grass1.
Another big thing to consider is the maturity of the hay. Mature hay has less nutritional value and is generally less palatable to horses. Grass hays with large seed heads are more mature and are lower quality. For legume hays, the more flowers (purple or yellow) they have, the more mature they are. Thick stems are another sign of maturity. The thicker the stems, the more fiber and less calories the hay has. It is also less digestible. Most of the nutritional value of hay is in the leaves, so the more leaves, the better1. It is worth considering mature hays if you have donkeys or overweight horses, or if you just need to supplement a thin pasture. “Easy-keepers” could also benefit from more mature hay.
Go ahead and feel the softness of the hay. Legume hays are less soft than grass hays. Mature hay with more stems will also feel coarser. Weeds contamination can be prickly and decrease palatability of the hay, in addition to decreasing the nutritional quality and potentially being toxic to the horse. Orchard is a very soft grass, and is often a good choice for older horses and those with dental issues. It is generally very palatable and easy to digest. Some horses won’t eat certain types of hay, so if you have a picky horse, try changing it up! Try a different type of hay or get it from a different supplier. Some horses like to have their hay soaked, but be careful as this removes lot of the nutrients. This could be a good idea for insulin-resistant horses or those with Equine Metabolic Syndrome, as well as horses that need to lose weight but have a higher quality hay. Be sure to discard the water and consider feeding a ration balancer to ensure the horse is getting everything they need if you choose this route.
A quick note about hay rolls. These can be a good option to supplement a thin pasture, or to try and save some grass if you have too many horses in a small area. In our area, the rolls are usually Tifton, meaning they are generally lower quality hay. So, it is a good idea to get smaller bales of higher quality hay and toss a few flakes out per horse once or twice a day, depending on the amount of grass available and the time of year. There is also a higher risk of dead animals being rolled into the bale and you not noticing. As the animal decays, it releases Botulism toxin. The horse(s) can ingest this toxin and acquire Botulism toxicity. Infection causes neurologic signs and flaccid paralysis. You will notice facial drooping and a floppy lip, difficulty chewing and swallowing, and the horse may go down and not be able to rise. If you notice any of these symptoms, call your vet immediately.
PSA- DO NOT FEED HAY BLOCKS WITH THE WIRES ON!!! Hay blocks are a recent creation made with good intentions, but with unintended consequences. Leaving the wires on is not only dangerous because of the risk of the horse getting his foot or jaw stuck (we have seen broken jaws and leg wounds from block wires), but it also ruins the horse’s gums. We often see gingival recession and gingivitis in horses that have access to hay blocks. This weakens the attachment of the incisors and can lead to the need to remove the tooth/teeth in the long run. Hay blocks can be acceptable (though not preferred) if the wires are removed and the bale is opened up. The horse shouldn’t have to spend more energy getting the food then what they are getting out of it.
*If you are interested in doing a hay analysis, the University of Florida Equine Science program has a nice chart explaining the different values and what they mean. The link is in the references at the bottom of the article.
Advanced Equine Dentistry has created “Wellness Packages” designed to save our horse owners money on the dental and wellness services you routinely use! The packages bundle common wellness services with discounts attached to each level. You choose the services you need and a discount is automatically applied based on what your horse requires during the visit. Ask us at your next visit!
Most horse owners are familiar with some of the common signs that their horse may need a dental exam, such as difficulty chewing, loss of body condition, excessive salivation, and head turning while eating. “Dropping feed” isn’t necessarily a sign your horse is having issues chewing, unless they’re dropping hay. Horses mouths aren’t designed to eat the small processed feeds we often give them, and so they tend to drop grain out the sides of their mouths. This is acceptable as long as they clean up the pieces they drop. Wetting the grain and feeding from a bucket on the ground can help them chew and digest grain more easily. However, if they are spitting out clumps of partially chewed hay, this is called “quidding” and it is an indication they aren’t chewing properly. Below is an example of what a quid looks like. They are generally oval or ball-shaped, and can be hard to notice in the pasture.
Other less noticeable signs that your horse may need a dental exam include large, undigested feed particles in their manure. This indicates that they aren’t able to properly chew their hay or grain, and are therefore unable to utilize all the nutrients you are feeding them. You will notice whole pieces of grain/corn and long stems of hay, as opposed to nicely digested small pieces. Your horse may also be trying to tell you something is bothering them while riding. Head tilting/tossing, bit chewing/resisting the bit, tongue lolling, inadequate stopping, and even bucking/rearing can be signs your horse is uncomfortable with his mouth. We have had numerous clients whose horses had behavioral issues that resolved after their dental was taken care of. Some horses are extremely sensitive, and even slight discomfort can make them disagreeable.
There are other more significant signs that your horse may have a dental problem, such as facial swelling and nasal discharge. If you horse has an infected tooth or sinus, the nasal discharge is typically only from one side of the nose. You will notice a very bad smell, in addition to the yellow/green discharge. While this doesn’t technically qualify as an emergency, be sure to have a veterinarian come check the horse as soon as possible. Leaving a rotten tooth can cause infection to weaken the surrounding teeth and jaw bone, causing more complications when the tooth is removed. In rare cases, the jaw bone can weaken enough to fracture.
If you’ve noticed a change in your horse or are just concerned that they may be in need of a dental exam, please give us a call!
We are often asked by clients if their horse is too fat or too skinny. As we don’t currently have a scale in the trailer, our next best tools are body condition scoring (BCS) and weight tapes. BCS is based on the Henneke (“Hi-nec-kee”) horse body condition scoring system first developed in the 1980’s. The scale ranges from 1, being poor, to 9, being extremely fat/obese. Most healthy horses range between 4-6, depending on their use.1 I personally use half points, if needed on certain horses, to give a more precise number. There are 6 main points on the horse’s body that store fat and are used to assess BCS. These include the neck, withers, back, shoulders, ribs, and tailhead (see picture below). By using a combination of palpation (touch) and visual observation, we can arrive at a score.
Many different conditions can have an effect on BCS. If a horse has a low BCS, it could be because of inadequate feed intake/poor quality feed, poor dentition, excessive exercise, harsh weather conditions, illness or disease, parasites, ect. If a horse has a BSC that is too high, it could be caused by too much feed/lush pasture, Equine Metabolic Syndrome, lack of exercise, ect. I’ve attached a BCS chart at the end of this article so you have an idea of what each score looks like. If your horse isn’t in the ideal range, feel free to ask us what you can do to help improve your horse’s condition during our next visit!