There are certain things held sacred here at Springhill Equine. One of those is the mission to make the world a better place for horses. Sometimes that mission means the kindest option we have is euthanasia. Wow, that got heavy in a hurry. The life of a clinic cat isn’t all foals and fun though. There are tough days, too. This week I want to talk about euthanasia since there is a very important drug shortage affecting how we euthanize horses. Don’t worry, my Docs still have very safe, kind, humane ways to be sure your horse doesn’t suffer. It simply might look a little different than it has in the past. 

Pentobarbital

For reasons which aren’t entirely clear to this cat, pentobarbitol, which is the main ingredient in euthanasia solution, is on backorder. This happens periodically, and as with many of these backorders there isn’t often a clear reason. I’m going to guess they have clinic cats too, and they, as I sometimes do, revel in doing fun things like holding down the escape key with my paw then watching the humans become increasingly frustrated with the weird things the computer is doing. In this case, I imagine it shut down a factory. This is what Teenie and I talk about on weekends. 

Anyway, pentobarbital is an anesthesia drug with the ability to cause the brain and heart to stop when given as an overdose. It has been used for many, many years for this purpose so my Docs have a good feel for how it works, and how horses are going to respond. In general, my Docs give a very large dose, the horse falls asleep, and then passes away over a few minutes. 

The Problems with Pentobarbital

Recently scientists have found a few problems with pentobarbital. The first is groundwater contamination. It’s tough to think about, but when a horse gets buried it slowly decomposes away. Pentobarbital is one of those things that sticks around for a very, very long time, and loves to head for water. This is not something you want happening, especially since many of you humans live on farms with wells. This is one reason several groups who write euthanasia guidelines began discussions on some other options. 

Speaking of pentobarbital sticking around, it also remains very active in the body after death. This becomes an issue if burial or removal of the body is delayed for any reason. Scavengers like vultures, coyotes, and bald eagles, among others (like your dog), are attracted to the body and do what Mother Nature designed them to do. This can be a big problem in areas where the ground freezes in the winter, and burial can’t happen until Spring. I’m going to insert a bit of an aside here that as a sun-loving cat, the thought of ground freezing is awful. Anyway. Scavengers can be affected by pentobarbital and inadvertently killed. 

The Alternatives

There are many alternatives. The goal of all of them is to allow the horse to pass as peacefully as possible. The three most commonly used by my docs may look a little different, but work very similar to pentobarbital. These are an overdose of potassium chloride, an overdose of magnesium, or an injection of lidocaine into the space around the spinal column. 

All three start by placing your horse under general anesthesia, exactly like that used for surgery. Then the medications are administered, and the horse passes away over the next few minutes, much like they do with pentobarbital. These medications are all safe for the environment and scavengers, if there is an unexpected delay in burial or removal. Gunshot, or captive bolt, is a very humane option if you have someone very knowledgeable about the proper location. The key here is that horses don’t have the psychological trauma of a gun pointed at them. My Docs recommend the horse be sedated to minimize the risk of last-second movement.

After reading a not-so-great article recently about the shortage of pentobarbital, I wanted to assure my readers that my Docs have got a plan in place. They always have the safety and comfort of your horse on their minds. 

Until next week,

~Tony

P.S. The humans just recorded a podcast that goes into a lot more areas on the topic of euthenasia. If you haven’t become a listener yet, this is a great time to start! You don’t even have to read it, you just listen while you’re riding, or driving, or whatever it is you humans do. You can check it out over on the Podcast Page.

“No hoof, no horse”. Since you’re a horse person, you’ve probably heard this old saying, and it will always ring true. Let me purr-suade you to learn a little more about a common hoof problem – White Line Disease. You may have even seen it without realizing!

Mild white line at the toe

Also called seedy toe, white line disease can start with just a little separation at the hoof wall. Maybe you’ve gone a little too long between trims and your horse’s hooves have gotten a bit too long. You notice a small gap between the outer hoof wall and the sole, and some dirt is packed in there. That can be how WLD starts, and at this early stage it can be pretty manageable, but it can get out of control before you know it. Let’s go into what white line disease is, what causes it, and what you can do about it.

What is White Line Disease?

White line disease is basically an infection in your horse’s foot caused by bacteria and fungi getting into a gap in the hoof wall. The infection takes place in the tissue between the outer hoof wall and the sensitive inner tissues of the hoof. It doesn’t take any special evil organisms to cause this problem, it’s just the normal bacteria and fungi in your horse’s environment that are just waiting for the opportunity to find a nice place to set up shop. What they love is a dark, moist place, and a little space inside the hoof wall is their real estate dream. As the bacteria and fungi work their way into the hoof wall, they eat away at the tissue that should be keeping the hoof connected to the deeper structures. It’s a vicious cycle – once they access even further up inside the hoof and have a lovely dark, protected area, it gets much more difficult to clean them out. If you look at a foot with WLD, you’ll see a cavity between the outer hoof wall and the sole. You may be able to stick a hoof pick up in there and pick out some crumbly material that is the degraded hoof plus dirt, bacteria, and fungi.

This foot has several spots where bacteria and fungi have invaded

You can find WLD on just one or two feet, or it can affect all four. In the early stages, your horse may not yet be sore, but as the tissue invasion becomes extensive, it can cause lameness. It can even progress to a very serious stage where the coffin bone loses connection to the hoof wall and begins to rotate (similar to, but different from, laminitis).

Half of this hoof wall is separated

Look how far up inside this horse’s foot the dirt, bacteria, and fungi have travelled. The outer layer of the hoof wall has been cut away to treat the infection.

Severe WLD has caused this coffin bone to rotate

What causes it?

Like I said, bacteria and fungi are involved in WLD, but it’s not so simple as that, because the bacteria and fungi are always there in the environment, and not every hoof gets WLD. So how do they get into a foot?

It comes down to a separation that occurs in the hoof that gives the organisms a chance to invade – the bacteria and fungi are just there to take advantage of it. Why does that separation occur in the first place? Poor trimming or sometimes a conformational issue such as club foot can be the cause. A horse with chronic laminitis can also be at greater risk due to the loss of integrity of the hoof. Most commonly, a long toe or overgrown foot can distort the hoof and cause mechanical stress that leads to the hoof wall separating near the white line. Just another of the 10,000 reasons it’s important to stay on top of your horse’s hoof care and get him a quality trim at a regular interval.

Any age, sex, or breed of horse can be affected.  While it can occur in any climate, it’s more common in humid conditions (ahem, Florida anyone?) since wet footing can soften the hoof and allow the organisms easier entry into the tissues.

How do we treat and prevent White Line Disease?

First, we have to recognize the WLD. You’ll want to pay close attention to your horse’s feet when you’re picking them out. If you think there are any areas of separation, pockets of dirt, and crumbly hoof near the white line, talk to my doc and your farrier. If your horse wears shoes, it’s a little trickier to observe this area, so your farrier should take a good look when she removes the shoe to trim the foot. One of the best things you can do to prevent WLD is just to have your horse trimmed frequently (about every 5 weeks, depending on the horse) and to make sure the toes don’t become too long. A well-trimmed foot is much less likely to develop this problem. On top of that, pick your horse’s feet regularly and give them a chance to dry out. Admittedly, the drying part can be tricky during some times of the year.

A hoof wall resection. You can see the new healthy hoof growing down from the coronary band.

If your horse does develop white line disease, my doc and your farrier should work together to develop a treatment plan. Unfortunately, just picking the cavity out and applying medications is unlikely to stop the progression. A very minor WLD may be able to be trimmed out by your farrier during a routine visit. Larger areas of separation will require additional treatment. My doc may need to take a radiograph to see how extensive the damage is within the foot. She’ll need to correct any abnormal forces on the foot (such as an overgrown toe) that are causing the separation. All the other treatment will not really be effective if the primary cause isn’t fixed.

Next, my doc has to stop that bacteria and fungus in their tracks. The most important part is to remember what those organisms love – a nice dark, moist space that can’t easily be cleaned out. So my doc takes the roof from over their head by performing a hoof wall resection! Those critters don’t stand a chance once their hiding place is exposed to light and air. My doc uses a hoof nipper or Dremel to remove the outer layer of hoof wall from over the cavity. The organisms are prevented from hiding up there, and the infected area is exposed for medications to be applied. Medical treatment is almost never useful unless the hoof wall over the infection is removed, so don’t waste your money on the various lotions and potions that make lofty claims.

This hoof required an extensive resection to remove the diseased tissue. Normal hoof will grow downwards from the coronary band over the next few months. This horse was walking sound right after the resection.

I’ve been watching my docs do a bunch of hoof wall resections lately from my spot in the middle of the barn aisle. It can look a bit dramatic to see a bunch of hoof wall removed, but don’t worry, it’s actually only the outer part of the hoof that is already disconnected. So there’s no bleeding, and it’s not painful to the horse. It’s much better than leaving the bacteria and fungus to eat away at the hoof. If a lot of hoof wall must be removed, a shoe can be helpful to stabilize the foot until new hoof grows down.

A rocker shoe is being used in this case to support the hoof and to improve the horse’s breakover. This is the same horse as in the x-ray above.

Once the outer hoof wall is removed, you’ll need to keep the hoof clean. My doc likes to soak the hoof in CleanTrax once a week to disinfect the hoof. The new, healthy hoof wall will grow downwards from the coronary band and as long as you have corrected the primary problems, your horse should grow in a normal hoof!

Until next week,

Tony

P.S. If this wasn’t enough info to make you purr, you should check out the podcast my humans recently did on White Line Disease. It’s loaded with interesting discussion, and you can listen free right from your phone or computer. Check it out over on the Podcast Page of my website.

I am always up for a full day of laying around in the sun. I hear some people even worship the sun.  Horses also seem to enjoy a good nap laying out in the middle of the field. Half the time I think they enjoy scaring you into thinking they’re dead, but in reality, they are just enjoying basking in the warm sun. Unfortunately, the sun is not always so nice to your body, and just like it can be harmful to you and your skin, it can also cause irreparable damage to your horse. 

 With the summer months ahead of us there are many problems that can pop up and plague your horse, like anhidrosis (when they stop sweating), bugs, allergies, and overall heat intolerance.  Rarely do we think about how the sun and UV light can affect our horses. Many of us live in Florida for the beautiful spring and summer days when the sun is shining, and the air is crisp. However, with every sun-filled day comes inherent risk to your horse.  Risk of sunburn, risk for cancer, risk of losing your horse.

 Sunburn

Some horses develop what is called photosensitization, which is a sensitivity to sun exposure and different from sunburn. Photosensitization results from ingestion of certain forages including clover and alfalfa, as well as administration of sulfa medications and secondarily from liver damage.  Photosensitization can occur in similar locations as sunburn and therefore can sometimes be mistaken for sunburn.  Sunburn is diagnosed by ruling out potential causes of photosensitization. 

 The skin is the largest organ of the body. It is also one of the most vulnerable organs of the body, as it is exposed to the elements, bugs, and every part of the outside world. Just as with people, horses are at risk for developing sunburn with too much sun exposure.  Horses with pale or non-pigmented skin are more susceptible to developing sunburn, and breeds like paint and pinto horses, appaloosas, and cremellos are most susceptible.

 Sunburn can affect every part of your horse’s body but is most commonly seen around their eyes and muzzle. Horses with pale skin over their necks and backs can also develop sunburn in those areas which can lead to behavior changes. That does not mean that if you have a horse with dark skin and dark coat that they are completely risk free, but their risk is lower. My docs tell me that sunburn can sometimes go unnoticed until it has progressed and is painful. They often get reports of horses who have suddenly become head shy and may even develop head shaking. Saddling and riding can also present an issue for horses who have developed sun burn over their backs. I don’t know if cats are at risk for getting sun burnt but I am certainly willing to risk it for my daily sun naps.  Plus, I have my minions to cater to my every need should I need treated for sun burn. 

 Cancer

In addition to discomfort and behavior changes, sunburn poses other risks. In people, sunburn can lead to skin cancer. With every insult to the skin that results in sunburn, your horse’s risk for developing cancer increases as well. Horses with non-pigmented or pale skin are at an even higher risk for developing squamous cell carcinoma. They don’t even have to have developed sun burn! Exposure to UV rays alone increases the risk for development of squamous cell carcinoma. SCC develops around the eyes, particularly on the third eyelid, around the nose and muzzle and around the anus.  All of these areas are more commonly surrounded by lighter skin, have significantly less hair present and are easily exposed to sun and UV rays.  Squamous cell carcinoma does not just occur in areas where sun exposure occurs, it can expose in and around the sheath and vulva, in the stomach, and other mucosal tissues such as the surface of the mouth and nasal passages.  However, sunburn markedly increases the risk of developing cancer.

 Treatment

Once sunburn has developed there is little to do for treatment besides supportive care.  I have trained my minions well in pampering me, so I am certain if you ask them what you need to do to pamper your horse if he is sun burnt, they would be happy to teach you their ways.  The most important thing to remember about a horse who has developed sun burn, is that sun burn can take months to heal. During the healing process it is important to protect the new skin. Keeping areas that are sun burnt clean, dry and moisturized is important in aiding in healing and prevent cracking.

 Squamous cell carcinoma should be treated quickly and aggressively. You all know your horses better than anyone else and should you notice any areas on your horse that look abnormal, I highly recommend getting my docs out to take a peek.  The sooner you do this the better.  Treating SCC early is essential to its possible cure. Treatment may include surgical removal of the affected area, intralesional chemotherapy and/or topical chemotherapy. Oftentimes, treatment is multimodal, meaning it involves surgical removal with chemotherapy.  Unfortunately, if left untreated for too long, squamous cell carcinoma that involves the eye can lead to your horse losing his eye or even worse, losing his life. 

 Prevention

Prevention is key when it comes to sunburn.  Sunscreen is useful, however, as with people, it is necessary to reapply frequently. Everyone here raves about Kinetic Vet SB (SB stands for Sun Block). This time of year, the docs and techs all come back after a long day of work with white streaks on their face. Come to find out, they have used the SB on themselves. The great thing about SB is that it stays on for days at a time, which means it does not require application every day even if your horse is playing in the water troughs. 

 Another way to prevent sun burn is to avoid the sun completely.  I can’t imagine not basking in the sun for hours, but if you want to help prevent your horse from getting sun burned it’s recommended that you keep your horse in a stall during the day and turn him out at night. If your horse lives out 24/7 or nighttime turnout is not an option for whatever reason, please, invest in a good, sturdy fly mask.  Most fly masks will provide some protection again UV rays, and you can get fly masks that have ear covers as well as long nose covers to protect your horse from the sun.  If your horse has areas on his neck or back that get sun burnt as well, you may also want to invest in a full body fly sheet.

 As always, my docs are here if you have questions. And watch out for me when you come to the clinic, as I’ll likely be sleeping in the sun out front.

Until next week,

~Tony

P.S. Wondering about other summer troubles? Rain rot? Insect bite hypersensitivity? We have a couple of great videos on our YouTube page from previous seminars. Titles to look for are Summertime Blues or Skin Funk. They are packed with useful information; including one of our favorite pharmaceutical lines, Kinetic Vet. They make our favorites, SB, CK & IBH to name a few.

Connoisseurs of the crooked foal, let’s get into part 2 of our series – flexural limb deformities! Last time in part 1, we talked about angular limb deformities, which are inward or outward deviations of the leg from midline, when viewed from the front of the foal. A flexural limb deformity, on the other hand, means that the limb is abnormally flexed or extended when viewed from the side of the horse. You’ve probably already heard of one kind of flexural limb deformity – a club foot. We’ll get more into club foot and some other kinds of FLDs shorty.

First, there are 2 types of flexural limb deformities – hyperextension and hyperflexion. Let’s deal with hyperextension to start with, because it’s easy and I’m a lazy cat.

                                           Hyperflexion caused by tendon laxity

                                               Hyperflexion of the carpus (knees)

Hyperextension

This is common in newborn foals, especially when they’re premature. The flexor tendons that run along the back of the legs are weak and allow the leg to stretch too far. Both front or hind limbs can be affected. The great thing about hyperextension is that it usually fixes itself in a few days or weeks. But it’s important to have my doc out to make sure the bones in the legs are fully formed and there isn’t incomplete ossification to complicate the tendon laxity (see part 1 of crooked foals). As long as my doc says the bones are fine, the foal will need some controlled exercise to help strengthen the tendons. We don’t want to lock these guys up in a stall full time, but we also don’t want them overdoing it and galloping around in a pasture with mom. A small paddock is usually good to allow limited exercise. Resist the urge to put a splint or heavy bandage on the legs! That will make the tendons even looser and worsen the condition. If the baby’s heel bulbs are hitting the ground, a very light wrap around the pastern can protect the skin, or my doc can put a glue-on extension on the foot to help the foal stand. No heavy bandage, got it? Generally, hyperextension is pretty easy to deal with, so I don’t lose too much cat nap time over it.

                                                         A heel extention shoe

Hyperflexion

The hyperflexion kind of FLD is commonly called “contracted tendons”. This name really bristles my fur because it’s usually incorrect. The tendons are not usually “contracted” at all, just functionally too short compared to the bony column.  If a tendon is actually contracted, that means there is a defect in the tendon, and that can happen in adult horses after an injury but it’s usually not the problem in foals. Nevertheless, you will hear the term “contracted tendons” term used. But now you can feel superior and correct your friends if you hear it.

Hyperflexion can be present when the foal is born, or it can develop later. If it’s there at birth, the cause might be a toxin or disease the mare had during pregnancy, or it could have been caused by the position of the foal in the uterus. If it develops later, it may be caused by incorrect nutrition or excessive energy intake in the first weeks and months of life, causing rapid growth of the bones. If the bones grow longer quickly, the tendons can’t keep up and a flexural deformity results.

This is most often a problem of the front limbs, though rarely the hocks can be affected. It usually occurs at the level of the foot, the fetlock, or the knees. My doc will need to examine the foal and feel the tendons to determine which ones are affected and she’ll probably need to take X-rays of the legs. The structures involved determine which kind of deformity is present. Then the treatment plan will depend on the deformity. Let’s talk about the different kinds of deformities.

Club foot

Club foot is a flexural deformity at the level of the coffin joint in the foot. It’s caused by a deep digital flexor tendon that is relatively too short compared to the bones of the leg. Since the DDFT attaches to the back of the coffin bone (down in the foot), if the tendon is too short it pulls the coffin bone and the hoof wall backwards, creating an abnormal steep angle to the hoof. In a normal horse, the front of the hoof and the pastern should be at the same angle, but a club foot will have a hoof that is more upright than normal with a short toe and high heel.

Flexural deformity at the fetlock

If the superficial digital flexor tendon is relatively too short, it causes the fetlocks to be too straight or even knuckle over. The SDFT attaches to the bones of the pastern instead of the coffin bone, so that’s why you’ll see the fetlock knuckled over even though the hoof might be normal.

Flexural deformity at the carpus (knee)

This deformity is usually present at birth and can be a cause of dystocia (difficult birth). The tendons and ligaments around the back of the knee prevent it from extending.  A mildly affected foal should be treatable but unfortunately, if the condition is severe, the foal may be unable to stand and correction may not be possible.

So what can we do to fix hyperflexion?

What exactly my doc will do to straighten your foal’s legs will depend on its age and how severe the deformity is. Once of the most important things my doc will do is balance your foal’s nutrition and perhaps reduce his energy intake, because rapid growth can be one of the main causes of this problem. Exercise should be limited, and pain medications may be recommended. With very young foals, my doc may be able to give a dose of a medication called oxytetracycline that allows the tendons to stretch. Corrective trimming and toe extension shoes might be used. Remember how I told you never to use a heavy bandage or splint for hyperextension because it can make them even looser? Bandages and splints can actually be really useful in hyperflexion because loosening is what we want in this case.

For foals that are either more severely affected or unresponsive to conservative treatment, surgery might be needed. The procedure my doc will choose depends on the type of deformity and how severe it is. For example, a young horse with a milder club foot may respond very well to cutting the accessory ligament of the deep digital flexor tendon and still have a good prognosis for an athletic career. A severe club foot may require cutting the deep digital flexor tendon itself, and would be unlikely to be an athlete. Horses less than a year old respond best to surgery.

If the horse is younger, there are generally more options for treatment, and more likelihood of success, so don’t wait long before giving my doc a call. Are you surprised that advice applies to pretty much any problem your horse could have? If you’ve been reading my blog like you should, you won’t be!

Until next week,

Tony

P.S. – If this is the  first time you have come across my blogs; or you read them on facebook, be sure to sign up below to get them emailed to you a day before everyone else gets to read them! Also, make sure you are listening to my docs podcast. It is filled with an incredible amount of useful knowledge. You can find it right here.