You asked @theequinevet – Which vaccines are right for my horse?

Bionca from Illinois writes –

Dear Dr. Bedford, I have 8 horses and vaccines for all of them is expensive. Are there any vaccines that I can skip or are there certain vaccines that you would recommend?

@theequinevet – Bionca, thanks for your question! This a great question and one that is frequently asked by my clients especially with the current economy, we are all trying to cut a few corners and save some money. Unfortunately, there is not an easy answer to your question. Which vaccines are right for your horse depends on many different factors such as age of the horses, travel, intermingling on the farm, geographic location, reproductive status, ect. The most important factor in determining which vaccines are most appropriate for your horse is risk of exposure to the specific diseases that the vaccines protect against.

In my opinion, Eastern/Western Encephalitis (also known as sleeping sickness) and West Nile virus should be considered core vaccines since these diseases are transmitted by mosquitos and exposure to mosquitos is difficult to control. Also, the mortality rate is fairly high nearly 90% for Eastern Encephalitis. These 3 diseases are neurological diseases and if the horse were to survive, residual deficits are likely.

Tetanus (usually included with Eastern/Western Encephalitis combo vaccines) is also in my opinion a core vaccine since this bacteria is found in the soil and horses are highly susceptible to this bacterial infection. Tetanus is a fatal disease. Remember to booster this vaccine if your horse sustains a laceration, hot nail, or hoof abscess > 6 months since previous tetanus vaccination.

Rabies, in my opinion, should also be considered a core vaccine. I often have owners say that their horses are not at risk because they are kept primarily in the barn and only turned out in small paddocks close to the barn. My response is that this is the cheapest vaccine of all of them and the disease is fatal – to horses and humans! In most states, this vaccine can only be purchased and administered by a licensed veterinarian.

Influenza, Rhinopneumonitis (Herpes Virus 1,4), and Strangles are all respiratory diseases that are transmitted from one infected horse to another. If your horse does not travel to shows, ect and exposure to outside horses is minimal these vaccines may be optional. An exception to this would be boarding facilities where your horse may not travel to shows, but is exposed to other horses in the barn that are traveling to shows. In this case, I usually recommend vaccinating for these diseases. It is important to note that there is no vaccine currently available to protect against the neurological form of Herpes Virus 1. If you have a pregnant mare – vaccination for Herpes Virus 1 (killed vaccine) is recommended at 5,7,9 months of gestation to prevent abortion.

Potomac Horse Fever vaccination is controversial. The vaccine only protects against one strain of the Neorickettsia risticci and there are a total of 26 strains, therefore vaccination may not prevent disease. In my opinion, having practiced in geographical locations where Potomac Horse Fever infection was endemic to the area, I believe that vaccination provides some cross protection resulting in less severe clinical signs if the horse does become infected.

I hope this answered some of your questions Bionca!

If you are unsure which vaccines are right for your horse, please consult with your regular veterinarian.

Remember – An ounce of prevention is worth a pound of cure!

 

 

Read my article published in the Aiken Horse

What Could Your Horse’s Cresty Neck Be Telling You?

Holly Bedford, DVM, MS

 

 

Do you have a horse with a cresty neck? When you stand to the side of your horse do you see uneven fatty deposits along the hindquarters (especially above the tail head), behind the shoulders, or slightly bulging above the eyes? Do you describe your horse an “easy keeper”? Has your horse had repeated episodes of mild laminitis (founder)? If you answered yes to any of these questions your horse could be at risk for Equine Metabolic Syndrome.

The term Equine Metabolic Syndrome (EMS) was first coined in 2002 to recognize a clinical syndrome in horses that exhibited obesity, tissue insulin resistance, and repeated episodes of mild laminitis. The typical clinical picture in horses with EMS are obesity which may be generalized or regional, appearing as fat pads along the tail head, behind the shoulder, or above the eye sockets. The mammary gland in mares or prepuce (sheath) in geldings are also common sites of abnormal fat deposition. The hallmark sign and the anatomic region where the most clinically significant and metabolically active fat deposition occurs is along the nuchal ligament (neck) giving the classic cresty neck. While obesity is common in horses with EMS, not all overweight horses or horses with cresty necks have EMS and some horses with EMS may appear normal or lean with noticeable fatty deposits in the previously described areas. In addition to obesity, horses with EMS historically have had repeated episodes of mild laminitis that may have been previously attributed to other causes of lameness such as arthritis, sole bruising, or recent foot trimming. Obese horses with a history of repeated episodes of mild laminitis, especially if associated with feeding changes or pasture access that cannot be attributed to any other causes should be evaluated for EMS.

Historically, horses with EMS have been described by their owners as “easy keepers” and it is because of this that for years past horses with EMS were suspected of and treated for hypothyroid (low thyroid hormone). Why horses with EMS have a greater tendency towards obesity remains undetermined. Some researchers suspect that obesity may be related to genetics with EMS horses being more metabolically efficient than non-EMS horses, although level of activity, feeding, and management practices also likely play a role in the development of obesity.

The clinical significance of obesity lays in fat tissue’s function as an endocrine organ. Previously, adipose tissue (fat) was looked upon as an inert storage depot for excess energy. Today, we now know that fat behaves more like an endocrine organ versus simply a storage depot and is responsible for secreting many hormones including adipokines and adipocytokines. These hormones play an integral role in initiating the inflammatory cascade suggesting that obese horses may be in a chronic state of low-grade systemic inflammation.

As mentioned previously, tissue insulin resistance is a key feature in horses with EMS and demonstration of hyperinsulinemia (elevated insulin levels in the blood) supports the diagnosis. The presence of reduced tissue sensitivity to circulating insulin and subsequent high blood glucose liken this condition to type II diabetes in humans. Under normal conditions, insulin is secreted by the pancreas in response to elevated glucose levels in the blood that occurs following ingestion of a meal. Insulin then binds to insulin-specific receptors in body tissues which then facilitates uptake of glucose from the blood into the tissues for energy production. In obese horses, body tissues are not as sensitive to insulin, meaning that they do not respond to insulin’s binding to the receptor, resulting in less uptake of glucose from the blood and subsequently elevated blood glucose levels in blood samples. It has been proposed that the adipokines and adipocytokines secreted by adipose tissue and the state of chronic inflammation may be contributing factors to the reduced tissue sensitivity to insulin in obese horses. Alteration to the normal composition of the insulin tissue receptor negatively affecting insulin’s binding capability may also play a role in decreased tissue insulin sensitivity. The body’s response to combat reduced tissue sensitivity to insulin and high blood glucose levels is to secrete more insulin from the pancreas which produces the hyperinsulinemia (elevated insulin levels in the blood) observed in some horses with EMS.

The link between the presence of excess adipose tissue (fat) and laminitis is not completely understood and continues to be the center of ongoing research on EMS. A key piece to the puzzle may be hyperinsulinemia. Experimentally, laminitis has been induced by intravenous administration of supraphysiological amounts of insulin over 2-3 days in ponies. It has been recognized that insulin has vaso-regulatory effects on blood vessels meaning that the presence of insulin can cause constriction or dilation of blood vessels, including the blood vessels in the horse’s foot which may be the connection between laminitis and insulin resistance in horses with EMS. Activation of the insulin receptor in tissues that occurs following binding of insulin to the receptor leads to activation of two possible pathways resulting in either dilation or constriction of blood vessels. In humans with insulin resistance, studies have shown that the pathway leading to constriction of blood vessels is stimulated, resulting in enhanced blood vessel constriction. The significance of blood vessel constriction in the horse’s foot is an overall reduced blood supply which may deprive laminar tissue in the foot of glucose needed for normal metabolism and cause increased production of free radicals causing oxidant damage and inflammation in the foot leading to laminitis.

The predisposition for laminitis in horses with EMS and the tendency for laminitis to reoccur is why early clinical recognition, accurate diagnosis, and proper dietary management are imperative to preserving long term soundness. Diagnosis is based on abnormal fat deposition present on physical exam, evidence of laminitis on radiographs of the feet, and results of laboratory screening tests. At present, the recommended laboratory screening tests consists of measurement of fasting insulin and glucose which can be obtained from a simple blood draw. Horses with EMS typically have elevated insulin levels; however, normal insulin concentrations have been observed and do not necessarily rule out EMS. Glucose levels are rarely above the normal reference range due to compensatory responses to hyper secretion of insulin, but are typically in the higher end of the normal reference range. In cases where screening tests are inconclusive, dynamic testing is recommended to properly assess tissue insulin sensitivity. Dynamic testing is accomplished by performing a combined glucose insulin tolerance test where a dextrose (sugar) solution and insulin are administered simultaneously and the body’s response is observed over time by serial blood glucose measurements. This is a relatively simple test and following intravenous catheter placement can be completed in an hour at the farm.

Following diagnosis, dietary management and weight loss play an important role in treatment of horses with EMS. Goals of dietary management are to facilitate weight loss in obese horses by reducing the amount of energy provided in the diet and lowering the carbohydrate content of the diet to reduce glycemic and insulinemic responses to meals. Current recommendations are to feed obese horses 1.5% of their “ideal” body weight in hay per day (1.5 lb hay per 100 lb body weight) to facilitate weight loss. If weight loss does not occur within a 30 day feeding period hay amounts can be reduced to 1% of body weight. Ideally, hay with a lower structural carbohydrate level should be selected; however, carbohydrate concentrations in hay can be reduced by soaking hay in water for minimum of 30 minutes prior to feeding. In obese horses concentrates should be replaced with a low-calorie commercial protein-vitamin-mineral supplement (ration balancer) fed in small amounts (0.5–1.0 kg total per day) to balance the low vitamin E, vitamin A, copper, zinc, selenium, and other minerals typically found in mature grass hays . In non-obese horses or horses that cannot be managed on forage alone, feeding low-carbohydrate feeds supplemented with fat such as vegetable or corn oil may be an acceptable alternative to higher carbohydrate feeds.

            Since many horses with EMS have seasonal episodes of laminitis associated with the non-structural carbohydrate content (fructans and starches) of grass, the question of whether it is safe to turn out a horse with a history of laminitis and EMS on grass pastures is a gray area. Initially, restricting pasture access may be necessary to control caloric intake or in cases with active laminitis that require stall rest. A conservative approach to pasture management is to avoid grass pasture until insulin sensitivity has improved (weight loss) because carbohydrates consumed on pasture can trigger gastrointestinal events that lead to laminitis in susceptible horses. Once weight loss has occurred and insulin sensitivity and clinical signs of laminitis have improved turn out on grass pasture may be possible in some horses with EMS, but care must be taken to restrict pasture access when the grass is going through dynamic phases, such as rapid growth in the spring or preparation for cold weather in the fall. The use of grazing muzzles or restricting pasture size or limiting turnout time may be reasonable options. The safest grazing time, in regards to carbohydrate content of grass, is early morning except after a hard frost. Conditions that increase carbohydrate (fructan) content in grass include regular cutting, cool, and bright conditions and predominance of certain grass species such as ryegrass. Unfortunately, despite the best of efforts, some horses with EMS suffer repeated episodes of laminitis when returned to grass pasture and must be confined to dirt paddocks indefinitely.

In addition to dietary control, regular physical exercise is also key to facilitating weight loss, maintaining a healthy weight, and improving insulin sensitivity. Exercise should be included as part of the immediate treatment plan provided that the horse does not have active laminitis. Initially, 2–3 exercise sessions per week (riding and/or lunging) for 20–30 minutes per session is recommended. Over time, the frequency, duration, and intensity of exercise can be increased with the end target of 5 sessions per week.

Most horses and ponies with EMS can be effectively managed by controlling diet, providing regular exercise, and limiting access to grass pasture. In cases where dietary management alone is not enough or exercise is contraindicated weight loss and insulin sensitivity may be improved by use of certain medications, such as metformin and levothyroxine sodium (Thyro-L). Chromium, magnesium, cinnamon, and chasteberry (Vitex agnus-castus) are common ingredients found in over the counter supplements recommended for the management of EMS; however, at this time there is insufficient scientific evidence to support their efficacy in the treatment of EMS.

If you are concerned that your horse may be at risk for EMS, please consult your regular veterinarian for further evaluation, diagnostic testing, and treatment recommendations as the treatment options mentioned here may not be suitable for all horses with EMS.

 

Clostridial myositis…Could your horse be at risk for this potentially deadly disease?

 I have advised clients on countless occasions against administering flunixin meglumine (commonly known as Banamine, Flunixamine, Flumeglumine, Flunixiject and Prevail) in the muscle to horses. While many take my advice, I always run across a few clients that are more resistant, explaining they have given this medication in the muscle for 20 years and never had a problem…. My response – it only takes one disaster and you’ll never give it in the muscle again.

During my career I have seen multiple horses die or euthanized due to complications from a serious secondary bacterial infection (Clostridial sp.) stemming from single or multiple intramuscular injections of flunixin meglumine. Interestingly, it is important to note that flunixin meglumine is labeled and FDA approved for intramuscular use in horses and certainly not every horse that recieves an injection in the muscle will develop an infection, but there is undoubtedly an inherent risk. Other medications have also been implicated in causing this serious infection when injected into the muscle including antihistamines, phenylbutazone, and anthelmintics (dewormers). These medications are irritating to muscle tissue when injected which may lead to focal tissue necrosis at the injection site. This is problematic because blood flow and oxygen (carried by red blood cells) is reduced in areas of devitalized tissue. Clostridial sp. require an absence of oxygen to thrive.

Clostridial spores are ubiquitous in the environment and are present on skin and hair even when it appears clean. When the needle is pushed through the skin into the underlying muscle tissue during an injection, Clostridial spores may be inadvertantly innoculated into the tissue. Spores can also be introduced through penetrating (puncture) wounds. Oftentimes this does not create a problem unless the conditions of devitalized tissue and low oxygen are present to support germination of the spores causing rapid widespread tissue necrosis and systemic toxemia. There are multiple Clostridium species present in the environment and any one of them can cause an infection. However, the severity of the infection is dependent on the species with C. sordelli the most deadly.

Clostridium bacteria causes local necrosis of muscle tissue and systemic toxemia through production of a multitude of toxins. Clinical signs develop rapidly (12-24 hrs) and include heat, pain, and palpable gas pockets (crepitous) under the skin at the site of injection. Typically, the horse has a fever and is depressed and inappetant. If the injection was given in the neck or hind leg, oftentimes the horse is reluctant to lift or turn its neck and may be lame.

Since this infection can be fatal, treatment should be instituted immediately and involves surgically opening up all pockets of fluid (abscesses) to expose the bacteria to air (oxygen) and debriding (removing) dead tissue. Aggressive antibiotic therapy is also instituted along with required supportive care. Prognosis for these cases depends on the Clostridial sp.(s) involved and the severity at the time treatment is initiated.

Prevention of this disease is far easier than treatment and many of the forementioned drugs have oral preparations available that are safe and effective.  The injectable liquid form of flunixin meglumine can also be safely and effectively administered orally. For my clients, I recommend administering flunixin meglumine orally if they are not confident in venipuncture.

As always, please consult with your veterinarian before administering any medications to your horse.

What is the BEST treatment for proud flesh?

Proud Flesh right hock

What is the best treatment for proud flesh?

PREVENTION. That’s right. PREVENTION by proper wound management from day 1 or as close to day 1 as possible.

In horses, the distal limbs (from the knee down for front limbs and hocks down for hind limbs) are the most problematic area anatomically for developing proud flesh (exhuberant granulation tissue) in horses. While quickly developing granulation tissue allows for rapid healing of wounds, when left unchecked, this healing process oftentimes goes a wry! Leaving a lumpy, bumpy, non-healing, bleeding wound that depending on the location and size of the excess tissue (I have seen softball to basketball sized!) can impede mechanical function of the leg. 

A key fact is that skin cannot grow over a mountain or a valley. Skin needs a FLAT structure to grow across until the torn edges meet in the middle of the wound and it is healed.

This is the reason why if at all possible I will try to suture lacerations (to bring the skin edges together) so I can avoid this whole scenario. In my experience I generally only suture minimally contaminated, non-infected wounds which means you need to act quickly after the initial incident, which is where the whole small window of time for suturing myth developed.  You can and I have sutured a wound several days after the fact in cases where I have cleaned and examined the wound and the horse is on proper anti-inflammatory and anti-microbial therapy along with proper wound care and bandaging in the interim. This is usually my approach in wounds that are relatively fresh but heavily contaminated. I do not nor do I recommend suturing a wound that is infected.

Sometimes suturing is not possible and you are left with an open wound.

There are many reports out that compare different wound dressings (technology in this is pretty amazing) and many vets have their own favorites. There is also some debate over whether oxygen exposure to wounds or lack there of increase the risk of developing exhuberant granulation tissue.

What I recommend to my clients and has worked for my patients –

1. Stall rest: Many cringe at this, but stall rest is imperative to healing distal limb wounds in horses (even if they are sutured!) because limiting movement reduces wound tension. Everytime the horse moves it moves the skin across the leg and the weakest area will be the area of the wound. So as the skin moves it disrupts healing by increasing surface tension across the wound. This is especially true for wounds across joints. Remember, the goal here is prevention, which will pay off in the long run, even if it is less than ideal in the short run.

2. Bandaging: I recommend keeping a well padded standing wrap on at all times. I will also put a non-stick absorbable pad over the top of the wound secured by conform wrap (white, stretchy mesh gauze bandage). I recommend changing the bandage as necessary depending on the amount of wound drainage, usually every 24 hrs initially and then every 2 days depending on how the wound is healing. Bandaging not only keeps the wound clean, but applies light pressure to the wound to help keep it flat.

3. Cleaning: Remember any type of irritation to the wound will stimulate production of granulation tissue (this includes insects!). So be judicious here (follow instructions by your veterinarian).

4. Wound Ointments: Production of granulation tissue can be inhibited by the use of salves that contain a steroid. I like Animax, Panalog, Quadritop (these are all the same, different names) because it is a steroid, antibacterial, and antifungal. You can also try Preparation H in a pinch, but I have not had as favorable results with this. Apply the ointment after cleaning the wound and then bandage.

Balancing production and inhibition of granulation tissue can be tricky. You want the wound to heal (fill in with granulation tissue – remember skin cannot grow over a valley), but you don’t want too much granulation tissue (proud flesh – remember skin cannot grow over a hill either). So I usually allow the wound to fill in until it becomes flush with the level of the surrounding skin margins, then if there are ANY signs that the area is becoming raised (higher than the level of the skin margins) I will start applying the steroid ointment. I usually apply daily initially, then decrease the frequency to every 2 days if the wound seems like the healing process has slowed.

Following these guidelines has worked for me in my practice, but may not be appropriate in all cases. If you horse sustains any type of wound, call your veterinarian immediately for evaluation and a possible tetanus booster (booster if > 6 months since last tetanus vaccine). Your veterinarian can then recommend the best treatment for your horse.

An ounce of prevention is worth a pound of cure!

 

A cresty neck is no laughing matter! What could your horse’s cresty neck being telling you… Read more…

If I had a dime, or a nickel for that matter, for every horse owner that ignores my warnings about their horse’s cresty neck, I could practice veterinary medicine for free! This used to drive me nuts, until one day I found myself saying the same thing about my own horse – she’s always had that, she’s a draft, drafts have a thicker neck than other light breed horses. Like most, we have had our horses for a long time and see them everyday, which allows sometimes important medical changes to sneak up on us.

So what is the significance of a cresty neck? Fat. We used to think of fat or adipose tissue as an inert storage depot for excess energy, but since then it has been discovered that fat is actually very active, metabolically and endocrinologically. In humans and horses, obesity can lead to insulin resistence. Insulin is important to many tissues as an aid in tissue uptake of glucose (sugar) from the blood following a meal. If tissue is resistant to the effects of insulin, then less glucose gets into these vital tissues resulting in high amounts of glucose remaining circulating in the blood.

Researchers have shown that high levels of insulin and glucose in the bloodstream can lead to LAMINITIS. Researchers have also shown that fat (adipose tissue) releases certain chemical substances related to the inflammatory cycle – making horses at higher risk of laminitis.

Interestingly, in humans the most significant (or detrimental in terms of health) region of body fat in terms of anatomical location is abdominal fat. In horses, researchers have recently shown that nuchal crest fat (that pesky cresty neck!) is the most significant fat!

*most reactive fat depot (with respect to inflammatory signaling)

*accumulation of nuchal crest adipose tissue is a risk factor for laminitis associated with equine obesity

*obese horses with insulin resistance had greater mean neck circumferencescores than non-obese mares

*Accumulation of nuchal ligament adipose tissue has predictive value in assessing risk of pasture-associated laminitis….ponies that have larger neck crests being at greater risk for developing the condition.

That said – not every obese horse or horse with a cresty neck has insulin resistence or Equine Metabolic Syndrome. Further evaluation would be required to determine this in individual horses. If your concerned that your horse may be at risk, call your veterinarian for an evaluation.

My goal is to educate horse owners so we can identify horses at risk and address it through change in diet and management, BEFORE I get a call because the horse now has laminitis.

Source: J Vet Intern Med 2010;24:932–939 Proinflammatory Cytokine and Chemokine Gene Expression Profiles in Subcutaneous and Visceral Adipose Tissue Depots of Insulin-Resistant and Insulin-Sensitive Light Breed Horses. L.A. Burns, R.J. Geor, M.C. Mudge, L.J. McCutcheon, K.W. Hinchcliff, and J.K. Belknap

Love the ease of bute paste, but not the price?

Love the ease of bute paste, but not the price?

Its true, you can purchase 100 tablets of 1 gram phenylbutazone (100 grams) for nearly the price of a 12 gram prepared syringe.

Easy way to make your own paste – Use a syringe case and the syringe case cap as a disposable mortar and pestle – Place phenylbutazone tablet in the syringe case cap and use the end of the syringe case to gently grind the tablet, then you can squeeze the sides of the cap together to form a funnel to pour your powder into the syringe (plunger removed). Replace plunger and draw up water, shake and give. The less water you add, the more paste-like consistency you’ll have. You can also draw up a small amount of karo syrup or molasses for flavoring if you like (caution with carbohydrate challenged horses!). Any syringe size will work (don’t recommend 3 cc size), I have used even a 12 cc syringe (see picture reference on twitter@theequinevet).

How to make your own mortar and pestle… See how..

Have you ever seen a mortar and pestle where the bottom of both are encrusted by a hard layer of pulvermized medication? It becomes the medicinal melting pot. Putting horses at risk of getting medication they don’t need or shouldn’t have.

One solution – Use a large coffee filter to line the bowl! I also will wrap another one around the pestle. You can grind away and you won’t tear through them! Then you can easily fold the filter edges together to make a funnel so that you can easily pour your powder into your dosing syringe or top dress grain. Then throw them away. Its so easy and inexpensive! I have used this trick at my veterinary practice for years, which is especially important since we are grinding lots of different medications for multiple patients per day.