Field castration is considered to be a routine procedure that is commonly carried out. As any owner who has castrated horses knows, there is also a very high complication rate (18-33%) associated with field castration. Both owners and veterinarians have accepted this as normal. It is not uncommon to revisit a horse a week after castration to re establish drainage and administer antibiotics. Every year we also deal with a handful of chronically infected wounds requiring surgery. The cost of treating complications is often many times the cost of the original castration.
In an attempt to decrease complication rates with field castration we have recently purchased a Henderson Tool and have had great success to date. A closed castration (tunic left over the testicle) incision is used and the testicle and cord exteriorised. The tool is clamped over the cord and the other end of the tool is then placed in the drill bit. Initial turns are made to form a 'knot' in the cord and then the speed is increased and traction is applied. This results in a very tight seal that has very little blood loss. This decreases post castration complications including swelling, haemorrhage, trauma and infection. Due to the tight seal there is less chance for infection to enter into the abdominal cavity. This technique is faster than traditional castration and therefore decreases anaesthetic times and risks as well.
Everybody who works with horses has an opinion about horses' teeth. When should they be done, by whom and how often? Do you take wolf teeth out?And do you need to use sedation? There has recently been debate, at times heated, around the world about who should be doing horses' teeth. Basically someone competent and who has undergone formal training gets our vote. There are not enough vets in the country to properly do all the horses' teeth. Correspondingly some horses will require sedation to be done properly and some will require procedures greater than just routine rasping provided by a lot of equine dental technicians. This is where we can definitely help.
A routine dental examination and rasping is designed to serve four purposes:
to remove sharp enamel points
to improve mastication (chewing), which enhances the
digestion of feedstuffs
to alleviate stress on abnormally worn teeth
to prevent discomfort associated with the bit.
A dental care programme actually starts from when a foal is born, as we inspect them at this time for any birth defects like a parrot mouth (over shot) or sow mouth (under shot), or a cleft palate.
The next examination should coincide with yearling preparation at around nine months of age. This is also the time when all of the deciduous (temporary) teeth have erupted. At this time we should be removing sharp enamel points, any developing hooks, and considering removing any wolf teeth.
The horse, at this time, is also learning to accept a bit. Bits are for communication and it is not necessarily the type of bit used but rather how it is used (or misused) that can cause a problem. Trauma associated with a bit can be due to excessive pressure on the bars or soft tissue injuries to the tongue or cheeks. The cheeks are pulled back onto the edges of the first cheek teeth, especially the lowers, and if these are sharp, severe ulceration and pain will occur.
It is sensible to have a dental examination and rasp before breaking in, to reduce oral trauma and pain during this impressionable first phase of education.
Bit seating is a commonly performed technique but the term is somewhat misleading, as the teeth are not actually shaped to fit the bit. In fact the bit should not be in contact with the teeth at all if it is used correctly. The concept of a bit seat is to remove the sharp prominences on the first cheek teeth that can damage the soft tissues if they are pulled hard against them. This involves essentially rounding them off. Care must be taken not to be too aggressive as it is unnecessary and may risk exposing the pulp cavity and introducing infection, especially when machine tools are used.
It is without doubt that a full mouth speculum (gag) must always be used to allow a detailed and thorough oral examination and proper routine rasping of the dental arcades. To enable this to be done safely for the horse, the handler and the person performing the examination, sedation may often be required. This needs to be assessed on a horse by horse basis. Only veterinarians may use intravenous sedatives legally in New Zealand.
Wolf teeth are small (usually 1 to 2 cm) with variable size roots (0.5 to 3 cm). They erupt at between 6 to 12 months of age and can occur on the lower jaw but are more commonly on the upper jaw just in front of the first cheek tooth. Some are lost when this first temporary cheek tooth is lost at around 30 months of age.
They are blamed for many behavioural problems and for interfering with the bit and are therefore frequently extracted.
One argument is that they never do any good, and may sometimes do harm, so remove them. However it is also generally accepted that enlarged, abnormally placed wolf teeth are more likely to cause a problem so are good candidates for removal. Whereas normal sized and placed wolf teeth, especially in older horses showing no signs of a problem, are probably okay. Removal is not necessarily an innocuous procedure as the roots are sometimes large, deeply embedded, and a major artery runs close by (the palatine artery). Infections and fracturing the tooth off above the gum line when attempting to remove the tooth may result in an ongoing painful local swelling.
In summary, horses up to five years of age should have their teeth checked more often (every 6 to 12 months). This is a time of rapid change in the horse's mouth and they are going to erupt 40 teeth during this time. Serious problems can be managed or prevented with proper early intervention.
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Endoscopic evaluation of a horse's upper airway is most commonly performed at rest. Resting endoscopic examination of the upper airway is an effective diagnostic tool for identifying structural abnormalities of the larynx.
These include:
Laryngeal hemiplegia
Rostral displacement of
The palatopharyngeal arch
Epiglottic entrapment
Lymphoid hyperplasia
Epiglottic hypoplasia
Subepiglottic cysts
Arytenoid chondritis
Persistent dorsal displacement of the soft palate
Abnormalities that decrease the diameter of the airway and increase airway resistance can cause respiratory noises due to air turbulence. This is heard as a roar or a whistle during inspiration at exercise. If the degree of obstruction is severe enough, then exercise intolerance or poor performance may result.
In marginal or subtler cases the evaluation is repeated using video endoscopy, which results in an easier procedure for the examiner. Videotapes of the examination may then be reviewed at a slower rate to accurately assess the type and degree of obstructive abnormality. Ultimately, this can be done while the horse is exercising on a treadmill to show dynamic changes that may not be seen at rest.
Laryngeal Hemiplegia ... in more detail
This is a disorder whereby the symmetry in movement of the rim and vocal cords of the larynx are affected causing a functional obstruction during exercise. This is due to a partial or complete paralysis of the nerve that supplies, usually the left, vocal cord. These abnormalities in resting laryngeal function involve the corniculate process of the arytenoid cartilage (vocal cord) and have been categorised into five grades:
Grade I: all movements are synchronised
Grade II: all major movements are symmetrical and full abduction is achieved, although it may be delayed, especially on the left side
Grade III: full abduction is still achieved although activity on the left side is reduced and it may appear asymmetrical at rest
Grade IV: the left side is not capable of full abduction. Asymmetry is obvious
Grade V: true hemiplegia. Complete paralysis and no movement on the affected (usually left) side
Grades IV and V fail the scoping panel examination and Conditions Of Sale (Section 16) at the Karaka Yearling Sales as it is likely severe enough to limit the horse's performance.
Treatment of horses exhibiting laryngeal hemiplegia involves performing a prosthetic laryngoplasty (tie-back procedure). Prognosis for a successful return to previous level of work after laryngoplasty is reported to be 50% to 70%. Resection of the vocal cords and Hobday operation (ventriculectomy) may also be performed at the same time to help enlarge the opening (rima glotties) during exercise and this will help with eliminating the roaring noise usually heard.
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| Figure 1 - Grade I {Fig.7-1 A, Equine Endoscopy Second Edition. Traub-Dargatz, Brown} |
Figure 2 - Grade III {Fig.7-12, Equine Endoscopy Second Edition. Traub-Dargatz, Brown} |
Figure 3 - Grade V {Fig.7-13, Equine Endoscopy Second Edition. Traub-Dargatz, Brown} |
Foaling your mare
Understanding what is normal during foaling and when to seek assistance during or after foaling are the keys to ensuring that both your mare and foal survive the event safely.
What is normal?
Predicting when your mare will foal can be very difficult. Waxing occurs in about 95% of mares 6 to 48 hours before foaling. However it can also occur several days before foaling or sometimes not at all.
Scientific studies have shown that it is the foal that determines the length of the pregnancy while the mare decides the actual hour.
The actual process of foaling is divided into three stages.
The first stage is characterised by obvious changes in the mare's behaviour. She will become restless and she may show signs of colic (intermittent lying and standing, pawing at the ground, rolling) and may have patchy areas of sweating. Inside the mare during this time, the foal turns from its normal position of lying on its back to one where its backbone is next to the mare's backbone with its head facing towards the mare's tail. The cervix begins to dilate and the uterus begins to contract. First stage labour ends when the membranes rupture (‘waters breaking'). On average, first stage labour lasts about one hour but can range from five minutes to three hours. First stage labour lasting more than three hours can indicate a problem and the mare should be examined by a vet immediately.
The second stage of labour is the period when the foal is actually delivered. It is characterised by strong abdominal contractions and the appearance of the foal's feet at the vulva. Most mares foal lying down and they should not be forced to remain standing during delivery if it is progressing normally. The white membrane (amnion) that surrounds the foal should appear at the vulva within five minutes of the waters breaking. One foot usually appears 5-10cm in front of the other foot and the soles of the feet should be pointing downwards. The foal's head normally rests between the knees. Second stage labour should take less than 20 minutes. Virtually all foals (98.9%) are delivered with the front feet and head first (anterior presentation), 1% of foals are presented in posterior presentation (breech) and 0.1% (1 in 1000) are found in a crossways presentation. Both posterior and crossways presentations are abnormal and veterinary assistance is required immediately.
The third stage of labour involves the expulsion of the membranes which usually takes between ten minutes and three hours. If the membranes are still present six hours after foaling, call your vet.
Remember, 95% of mares will foal with no complications and require no assistance at all. Intervening during a normal foaling can do more harm than good.
There are several guidelines which can help you decide when assistance is required:
Stage one labour longer than three hours
Stage two (straining) longer than 20 minutes
Appearance of the "red bag" at the vulva (this is an emergency because it means that the membranes have not ruptured - the foal could suffocate)
White bag appears (inner membranes) but no body parts
Active straining but no progress
Absence of straining
Appearance of only one hoof at vulva
Hooves upside down
Hooves above nose
Head presented with no hooves or only one hoof
Foal's tail presented
If you encounter any of the above, phone your vet immediately.
While waiting for your vet to arrive there are several things that you should do - wrap the mare's tail, keep the mare walking and don't let her lie down. By keeping her walking she is less likely to strain which will prevent her from doing more damage if she is in difficulty.
What to do after the foal is delivered
After delivering the foal most mares will continue to lie down for 5-10 minutes, exhausted after the effort of abdominal straining.
The foal should be sitting up within two minutes of birth and should stand within an hour. It should be able to suckle the mare unaided within two hours. If the foal does not behave in this way within these time periods, seek veterinary advice.
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A horse health check should include:
Vaccinations
This includes tetanus and strangles in all horses, herpes virus in pregnant mares, (which can cause abortion), and consider rotavirus as well in your mares (causes diarrhoea in foals) plus salmonella in foals or at risk horses.
Worm treatment
Worm resistance has now been reported in horses to ALL families of drenches! Routinely, the strategy on properties has been to rely on frequent dosing with wormers, sometimes as often as every four weeks. This practice actually encourages resistance to develop and will only work while the chemicals are working.
So what can be done to slow the development of resistance?
Interestingly enough, we actually want horses to be exposed to low levels of worms so they develop natural immunity against them (once they are old enough ie. 3 years) and we want to leave in the worms that we can kill, not select the ones we can't. Therefore we should aim to dose horses based on the results of a faecal egg count (FEC) test and not on a predetermined schedule. Talk to one of our vets about arranging FEC tests for your horse, stable or farm.
Dental examination
The practice of rasping your horse's teeth is again being recognised as the important job that it is. You shouldn't underestimate the effect a good mouth has on a horse's overall health, handling and riding. These benefits are then further reflected in their athletic performance and reproductive performance because the horse is properly utilising the nutrients that it is being fed. The vets at MVS know the importance of good dental care for all types of horses, including some individuals special requirements. Two of our equine vets have further knowledge and experience from training in the United Kingdom. To compliment our array of instruments and diagnostic tools we have also now invested in a Foredom Power float especially imported from the USA and available for those cases requiring removal of hooks and more involved dental realignment procedures. Feel free to contact us to make an appointment for a dental examination and rasping.
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IRAP is an exciting new treatment now available at MVS Equine for treatment of lameness in horses.
It utilises the body's healing mechanisms by the vet collecting the horse's own blood into a syringe containing glass beads and incubating this overnight. White blood cells bind to the glass beads and the cells are then stimulated to produce regenerative and anti-inflammatory proteins which are collected and injected back into the horse's affected joints. It is therefore an autologous process and contains no drugs but is used effectively to treat osteo-arthritis, join pain, inflammation and cartilage damage.
There is low risk of side effects but the blood collection and joint injections must be done aseptically with the special IRAP syringes, and case selection is important to enhance the chances for success.
Contact MVS Equine to discuss if this may be appropriate for your horse.
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The following are some of the procedures that may be performed on your mare at the stud farm during the breeding season.
Ultrasound scanners are now used routinely for most breeding examinations and help considerably in accurately visualising the reproductive tract and maximising fertility rates for mares on the stud farm.
Genital examination (GE) - refers to the palpation of all genital organs (ovaries, uterus and cervix) and is most commonly used to predict the best time for mating your mare.
Pregnancy testing - a pregnancy test is essentially the same procedure as a GE, only the detection of a foetal sac is the prime objective. The first pregnancy test is done at 14 to 16 days after service. This timing allows us to identify twins if they are present and to reduce one (‘twin crush') so only one foetus remains. Further pregnancy tests are routinely done at 20, 28 and 42 days. This is because if a pregnancy is lost prior to 42 days, the mare can be re-served.
Caslick - this is a surgical procedure in which portions of the vulval lips are sutured to prevent vaginal wind sucking. This latter condition predisposes to uterine infection, which is a major cause of infertility in mares.
Uterine swab - to detect uterine infection a swab is taken from the uterus and examined in our laboratory for the presence of bacteria and inflammatory cells.
Irrigation - the mare's uterus is irrigated (flushed) with appropriate therapeutic solutions in certain circumstances. For example, where pathogenic bacteria have been cultured, or immediately after breeding, particularly where a mare has poor resistance to the normal contamination of breeding.
Antiseptics, antibiotics, or saline are generally used.
Vaginal speculum examination - the cervix and vagina is examined visually using a long tube (speculum) passed into the vagina. This enables diagnosis of damage to the cervix or the presence of pus (infection) in the vagina.
Before sending your mare to the Stud Farm it is worthwhile considering:
Vaccinations - your mare should be vaccinated one month prior to foaling with Tetanus and Strangles vaccine and Salmonella to boost their own immunity and to ensure that adequate protection is passed on to the foal in the mare's colostrum milk. You may have already vaccinated your mare for Herpes Virus (causes abortion) and Rotavirus (causes diarrhea in foals) during her pregnancy.
Foot care - ‘no foot - no horse' is still a very important phrase and the importance of good foot care cannot be overemphasised. Sore feet and in severe cases, laminitis are still a significant problem in broodmares and we tend to forget how it will effect their overall health and well-being, influencing their milk production, ability to raise a healthy foal, and subsequent fertility.
Teeth care - feed utilisation directly influences milk production and has a proven relationship to fertility rates. Horses are prey animals, and so are very good at disguising illness and pain, for instinctive fear of being pushed down their herd's pecking order, or being singled out by predators. Only through educated owner observation or a thorough dental examination, will dental pain and disease be detected.
De-worming - you want your valuable investment, the foal, to be protected and the stud farm needs to protect their stock and other people's horses from the dangers of introducing high worm burdens. De-worm your mare before taking her to the stud farm.
Communication - communicating with the farm any ongoing issues with respect to lameness, injuries, previous illnesses or behaviour will make sure your mare receives the right care and attention while at the stud farm.
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Optimal feeding of horses combines both art and science. The science provides the information about the digestive and metabolic processes, the nutrient requirements and the principals behind feeding practices. The art is the ability to then convert this theory into practice for the individual horse and its needs.
Maintenance feed requirements are defined as the daily intake that maintains a constant bodyweight and body composition as well as the health of the horse. Additional amounts are then required for the increased demands of growth, reproduction and exercise.
Roughage is the foundation of any horse's diet, even those hard in work. In New Zealand our pastoral based farming systems mean we (generally) have good access to plenty of good quality roughage in the form of pasture, hay, haylage or chaff. Many pastures and forages will not provide all of the necessary energy or essential nutrients that a horse needs for maximum health or performance. In these circumstances nonforage based feedstuffs and supplements are added.
So what does a horse need? A horse, like any other animal, needs the basic nutrients of energy, protein, minerals, vitamins and water. These nutrients need to be supplied in the proper proportions, levels and form to provide adequate nourishment and will vary with the size, age and use of the particular horse. The National Research Council (NRC, 1989) provides reference guidelines for these requirements. It is important to note though, that these figures give minimal rather than optimal requirements.
A good ration must also be palatable. Unless the horse consumes the ration readily, it is not successful regardless of how well balanced it may be.
In future articles specific requirements for these nutrients will be discussed but for now we will limit ourselves to reviewing some points for consideration at strategic times of year.
Pregnant mare: the in foal mare in late pregnancy requires greater energy levels for the needs of the foetus. It is recommended that thoroughbred mares during the 9, 10 and 11 months of pregnancy receive 1.11, 1.13 and 1.2 times the maintenance requirements respectively. In lactation they need maintenance plus an allowance for milk. Milk production will vary from around 2-4% bodyweight daily and peaks at about 2 ½-3 months after foaling.
Barren mares: these can be kept in good condition on pasture/forage. In the early spring (July) they should be started on a small quantity of concentrate to coincide with artificial lighting to stimulate their oestrus cycles. Individuals that get too fat may be difficult to get in foal.
Weanlings: the period between weaning and two years of age is critical in terms of nutrition. It is essential that energy and nutrients are provided in adequate quantities and kept in balance to ensure proper growth and development. The young horse should be fed to grow at a moderate rate, not a maximal rate. Rapid weight gain increases the incidence of skeletal,bone and joint disorders (Developmental Orthopaedic Disease including Osteochondrosis OCD). Recommended average daily gain values range from 0.28-0.39% of the horse's body weight for weanlings.
Nutrient quality
While it is possible to determine the energy and nutrient quantity of hay or other forage by laboratory analysis, it is more difficult to get a handle on the quantity of nutrients that pasture contributes to the nutrition of a horse. This is because the conditions of pasture vary over time due to temperature, rainfall, pasture management practices etc. Consequently, pasture alone should not be considered adequate to meet a horse's entire nutrient requirements at all times. For maximum health, reproduction or sports performance the addition of a supplement to the diet is necessary. Consider Platinum Performance Equine as a complete feed supplement that doesn't add substantially to the energy content of the diet coupled with other added
benefits (see Supplement - Platinum Perfornance).
It must be emphasised that in addition to a well-balanced diet, regular parasite prevention and control, proper dental care, exercise and conditioning and preventative medicine (vaccinations etc) are also essential for the wellbeing of the horse.
Tips for feeding
Feed little and often
Feed by weight, not volume
Make any changes in feed gradually. This allows the hindgut microbes time to adapt. Rapid changes can result in digestive disturbances/colic.
Keep to a routine with regular feed times
Store all feeds appropriately to avoid spoiling or contamination.
Provide a constant supply of fresh, clean water. Clean containers regularly.
Do not give large amounts of water immediately after hard exercise. Give repeated small amounts (5-6) swallows.
After particularly tough, dry summers, one of the biggest issues facing many farms becomes addressing pasture survival.
Some pastures will recover but many won't recover adequately to be productive moving forward. In general terms, paddocks that have been repeatedly undersown with Italian ryegrass will struggle to survive especially dry conditions. Many perennial ryegrass pastures New Zealand wide, will likewise suffer "severe thinning". There is no right or wrong way to address these problems, so consulting your pasture management consultant is probably necessary. An underperforming pasture will result in reduced livestock performance.
Worthy of note: in autumns following very dry summers there is a high likelihood of significant broadleaf weed pressure. Being the "opportunists" they are, there is plenty of room for them to grow and compete with desirable forages following markedly dry weather. These weeds should be monitored carefully and treated accordingly to maximise the potential for the new or existing pasture that will be recovering after the dry.
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OCD is a developmental condition affecting the cartilage and underlying bone of joint surfaces.
Lesions vary from a lucency or deficit seen on x-ray (radiographs) in the early stages or cartilage involvement, to more advanced lesions which may include discrete fragments. These fragments can then become mobile with-in the joint.
Just as lesion types vary, so too does their significance in terms of their effect on the soundness of any particular horse.
As research into the racing performances of horses with and without OCD continues it is apparent that many horses with unquestionable OCD findings as yearlings are just as unquestionably sound later on as racehorses. In other instances an OCD lesion can become significant, causing lameness and limiting performance.
In cases where lesions become problematic, management by way of surgery and or medication is indicated. Arthroscopy (joint surgery) can be curative where lesions are diagnosed early and minimal degenerative joint disease (arthritis) has occurred. In addition to this, some lesions found in very young horses may spontaneously resolve as the animal matures.
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| Figure 1 Distal intermediate ridge OCD Talus (Hock) |
Figure 2 Medial femero-condylar OCD (Precystic lesion) (Stifle) |
Figure 3 Dorsal sagital ridge OCD (Type I) (Fetlock) |
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| Figure 4 Lateral trochlear ridge OCD Talus (Hock) |
Figure 5 Lateral trochlear ridge OCD (Stifle) |
Figure 6 Plantar Fragment OCD (Type I) (Fetlock) |
One of the most frequently asked questions from our Equine clients is what supplement they should use and for what ever reason? Confusion over supplements and their place in the diet are common. Therefore, at MVS Equine we actively researched and evaluated a range of products and finally discovered a complete equine supplement that has all of the credentials that we as a vet clinic required. We can confidently recommend Platinum Performance Equine.
Platinum Performance (Registered pursuant to the ACVM Act 1997 No. 9995) is the complete supplement indicated in a multitude of scenarios for effective basic preventative, therapeutic, or sports nutrition of any horse. We are already receiving positive feedback from clients who are using Platinum Performance in only the short time we have been promoting it. Available now at MVS. Please feel free to contact the clinic to discuss.
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An eight month-old thoroughbred filly (Star) underwent surgery for colic. The affected small intestine had telescoped inside the caecum causing an obstruction to the flow of food (an intussusception). The small intestine was resected and transposed onto some new adjacent caecum, thus creating a new opening.
Star made an uncomplicated recovery from the surgery and was discharged from the hospital five days later. All was going well until the abdominal staples were removed at day 14 and a purulent (puss) discharge was noticed.
The wound was cleaned daily but the swelling increased, so a sample was collected for culture at the laboratory.
Results from the culture grew a organism that was only partially sensitive to two of the antibiotics most commonly used in horses. The antibiotics were changed to one of these and the discharging wound sinuses flushed daily with some dilute iodine.
Another five days on and Star had shown little improvement and a second culture now grew a multiresistant organism that was only fully sensitive to an antibiotic called amoxicillin clavulanate. But the use of this antibiotic in horses has been associated with fatal colitis (diarrhea) because it upsets the hindgut flora. It was decided to administer it topically with a cattle preparation normally used for treating mastitis (Clavulox LC). Tubes were squeezed into the discharging sinuses wounds twice daily. After four days the discharge was reduced and by day seven there was no more discharge and the antibiotics were stopped.
Star has gone on to make a complete recovery and is about to go off to the breaker's yard!
Wound infections are a common complication following abdominal surgery. Most resolve with simple daily cleaning while gravity does the rest. The emergence of 'superbugs' (usually multiresistant staphylococcal organisms like or MRSA) in horses presents major problems and treatment options are often limited. Adopting alternate delivery systems with antibiotics such as regional or topical usage however, increases the available armoury for combating these infections while not compromising the patient. It improves the chances of success, as in this case, and reduces the risk of further resistance development because high concentrations of antibiotic are delivered to the affected areas compared with systemic use.
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Rye grass staggers is a neurological disease which affects horses, sheep, cattle, deer and alpacas.
This disease is caused by the ingestion of a toxin produced by a fungus (or endophyte) in perennial ryegrass. The highest concentrations of endophyte is in the leaf sheath and seed head. Endophytes are found in their greatest concentrations during summer and autumn in the oldest leaves (those closest to the ground). Consequently, at during late summer and autumn when horses have to graze close to the ground they tend to pick up more of the causative organism. High concentrations of the endophyte may also occur in perennial ryegrass hay.
The endophyte toxin has a specific damaging effect on the cells in the brain that coordinate movement. As the name suggests, affected horses lose their ability to walk properly and stagger. They can become difficult to handle and dangerous to ride. Signs of staggers worsen if the horse is stressed. The disease itself is not fatal, but there is a real risk of injury or death as a result of accidents. Symptoms appear 7-14 days after access to toxic pasture.
What can be done to prevent ryegrass staggers in horses?
Restrict grazing on perennial ryegrass pasture in the summer and autumn, remove horses from such pastures or try to graze these pastures lightly.
Sow some low endophyte ryegrass or other species of grass for feeding at that time of year (novel endophyte).
Endophyte infection diminishes in stored ryegrass seed, which if stored at room temperature, will eventually lose viable endophyte. So, before planting ryegrass you should ask what its endophyte level is and store it accordingly.
If safe pasture is unavailable, yard horses and feed hay.
Commercial feed additives are available which bind fungal toxin in the horse's digestive system. See your vet to discuss which product would be most suitable for your specific situation.
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Read any textbook or magazine article about lameness in horses these days and it will mention Nuclear Scintigraphy (bone scan). Nuclear Scintigraphy is a relatively recent advance in diagnostic imaging pioneered in Europe in the late 1970's. It provides us with information regarding normal bone physiology (health) and early pathology (disease), long before bony changes become apparent on x-rays. There are currently 3 Nuclear Scintigraphy machines for horses available in New Zealand - one at Matamata Veterinary Services in the Waikato, one at Massey University in Palmerston North and one at Canterbury Equine Clinic in Christchurch.
As an imaging tool. Nuclear Scintigraphy works alongside the more familiar mainstream diagnostic methods such as regional nerve blocks, x-rays and ultrasound. However, becase Nuclear Scintigraphy is much mroe sensitive than radiography in picking up early changes in bone structure it can be used to help prevent the development of more serious or even catastrophic injuries.
How does it work?
Nuclear Scintigrpahy involves the intravenous injection of a radio-active diphosphonate salt (labelled with Technetium 99m) that is selectively taken up by bone. Normal bone is made up of calcium phosphonate which is continuously being resorbed and replaced at a very slow rate. When bone is injured this process speeds up considerably as damaged bone is resorbed and replaced with new bone. Therefore, when a horse is injected with the radio-acive diphosphonate salt this is incorporated in proportionally higher amounts in areas of damaged or activated bone, forming 'hot spots' of radioactivity. The horse is then scanned with a camera that documents the levels of radioactivity in different bones, showing us where the 'hot spots' are.
Indications for Nuclear Scintigraphy
Because Nuclear Scintigraphy allows us to image multiple limbs simultaneously, as well as sites that are otherwise difficult to image like the back, pelvis, shoulders and neck, it has become a valuable diagnostic tool for lamenesses that are difficult to localise using standard diagnostic methods such as nerve blocks and radiography. It is especially useful for lameness cases that have no abnormal radiographic findings, suspected upper hind limb or pelvic lamenesses, horses with sore backs, horses with multiple lesions or multi-factorial lamenesses and fractious horses unsuitable for nerve block examination.
Because of its sensitivity for early bone injury it can also be used to evaluate the extent of the injury and monitor the healing process over time.
Summary
As a profession it must be our goal to research, devise and advise regarding factors that may be employed to reduce the incidence and severity of injury and poor performance in horses. Scintigraphy makes it possible to make an accurate diagnosis and give effective treatment.
There is need for greater undertsnaing and awareness of the problems faced by our equine athletes so that there is a willingness to diagnose and properly treat injuries by employing good science.
To discuss any cases prior to referral please do not hesitate to contact one of our senior clinicians.
Wounds involving the lower limb are commonly associated with the development of excessive granulation tissue, otherwise known as ‘proud flesh'. The various lotions and potions used over the decades to try and treat proud flesh are as numerous as the cases themselves, and yet it remains a commonly seen problem.
Understanding the factors that contribute to the development of proud flesh is the key to a successful outcome. First, we need to understand normal wound healing which can be separated into different phases. In real time each phase overlaps with the next.
The inflammatory phase is characterised by heat, pain and swelling and occurs within the first few hours.
The debridement phase involves invasion of the wound by white cells to combat wound contamination and infection and is often associated with pus formation.
The granulation phase marks the beginning of wound healing with the invasion of fibrous tissue and new blood vessels to provide a scaffold for new skin migration at the wound edges (epithelialisation).
The remodeling or healing phase is associated with scar remodeling and wound contraction (the wound gets smaller).
The lower limb is unique as far as wound healing is concerned. Wounds near joints and tendons are often associated with a lot of movement that constantly disrupts the granulation phase and leads to more and more tissue being laid down in an effort to stabilise wound margins. Movement is probably the biggest contributor to proud flesh formation.In addition, lower limb wounds are often heavily contaminated and infection is common. This perpetuates the inflammatory and debridement phases, which inhibits wound healing. The skin of the lower limb also has some special features that don't help. Wounds could be described as being under tension. There is no free skin available to assist wound contraction and epithelial (skin) cells differ from their counterparts elsewhere on the body. To demonstrate this, skin grafts taken from the belly or neck, transplanted into healthy granulation tissue in the lower limb visibly inhibit proud flesh formation around their margins and assist wound healing. In contrast, when the grafts are harvested from anywhere on the lower limb, proud flesh continues to develop.
So, faced with a fresh wound at the start, prevention is better than cure. If wounds can be manually debrided to reduce contamination, closed primarily before swelling gets in the way and stabilised under a support bandage, they should be, to optimise wound healing.
The presence of proud flesh in older wounds presents an immediate physical barrier to wound healing. New skin cannot migrate over a lumpy mountain; it needs a smooth carpet of healthy, flat granulation tissue at skin level first. The easiest way to deal with this is to cut it back with a sharp scalpel. Fortunately, granulation tissue lacks innervation so cutting it back is usually straightforward under moderate sedation. Thereafter, preventing its recurrence hinges on the principles of wound management mentioned earlier. Bandaging wounds also helps prevent proud flesh formation by applying pressure to the wound. Steroid based creams under a bandage are useful to prevent recurrence. They slow the granulation process, minimising excessive tissue production but still allow wound healing. Large wounds may need cutting back several times before the wound edges have contracted sufficiently for wound closure.
The dorsal aspect (front) of the hock is a common place for large wounds to occur that then become associated with proud flesh production. Although most eventually heal, they often do so with thick ugly scars that can inhibit the normal range of movement.
The use of skin grafts in large wounds and cases of wounds to the lower leg speeds wound healing while inhibiting proud flesh. Though there is a significant cost involved with any grafting procedure, this is offset by the time saved and reduced bandaging expenses as well as producing a more cosmetic and functional result.
back
Why vaccinate?
Vaccines are among our most potent weapons against disease. Over the past 100 years they have saved many thousands of horses' lives and helped render many terrible equine diseases exceedingly rare.
Routine vaccination should be part of any comprehensive health maintenance program for ALL horses.
The objectives of vaccination fall into three categories;
To prevent disease
To reduce the severity of disease
To minimise the extent to which horses spread disease
If you have only one horse, then the important aspect is disease prevention; but if you own a big farm, you will want to reduce the impact of an outbreak.
How vaccines work
Vaccinations work by introducing weakened or killed microorganisms into the body to 'train' the immune system to recognise and destroy specific disease-causing viruses or bacteria (pathogens). On subsequent exposure to a specific pathogen, the horse is then able to mount a much more rapid and effective response to prevent or minimise the clinical symptoms.
A horse's vaccination regimen should be based on its age, occupation, and social arrangements, as well as the prevalence of particular diseases in the local area. Therefore an old companion in the back paddock will have different requirements to an elite athlete that travels the world.
Vaccines are currently available against the following diseases:
Tetanus (Toxoid) - provides immunity against a rigid paralytic disease caused by the toxin of Clostridium tetani, an anaerobic bacteria that lives in soil and faeces but can infect wounds.
PLEASE NOTE that Tetanus Anti-Toxin (TAT) is just that, it is an anti-toxin that is only useful as a preventative cover when we don't know the full vaccination history or status of an animal. It is NOT a vaccine and only protects the horse for up to six weeks. That is, for the period of the wound that you may be treating it for.
Strangles - highly contagious infection of the lymph nodes, usually of the head, caused by bacteria. The abscesses may become so large they restrict the airway (hence the term ‘strangles') and may break internally, draining thick yellow pus through the nose, or externally through a spontaneous or surgical opening in the skin.
Herpes virus - a contagious disease caused by herpes viruses (EHV1, EHV4) and characterised by fever, respiratory infection, and in mares' abortion. This can also be one of ‘the viruses' to affect racing yards. There is also a paralytic form of the disease that caused serious losses in the United Kingdom just three years ago.
Rotavirus A - a type of virus that causes profuse diarrhoea in foals younger than three months old. In addition to diarrhoea, infection includes depression, failure to nurse, and recumbency. With this disease you need to vaccinate broodmares at 8, 9 and 10 months of pregnancy.
Salmonella - a highly contagious bacterial disease that causes diarrhoea and colitis in horses of all ages, usually brought about in stressful conditions.
When to vaccinate
The passive absorption of maternal antibodies (colostrum) means that the foals' own immune system won't respond properly to vaccination until around 4 to 6 months of age.
This is the best time to start a programme.
Record keeping
Keeping accurate records is important to the success of any vaccination programme, therefore we have vaccination cards available to help you in your record keeping.
Skin conditions in horses are common and often cause concern to the owner because they affect the appearance or comfort of the horse. Treatment of some of these conditions can also be a headache due to the size of the animal making it expensive and labor intensive. Even a diagnosis can be difficult sometimes, especially as most horse owners have already tried a variety of “home remedies” that in some circumstances may alter the appearance of the lesions.
Insect allergies are the most common causes of ‘itchy’ skin diseases in horses. They are a hypersensitivity reaction mainly to the saliva of biting insects including flies, stable flies and mosquitoes. Raised lumps, scurfiness, crusts, and hairloss as well as itchiness and self-trauma can all be apparent, mainly over the back or stomach.
Topically applied insecticides containing pyrethrins, pymethrins, or organophosphates can be used to repel the insects (see in-store for product details: including Frontline the long acting spray for dogs), and management changes such as covers, and stabling the horse when insect activity is high, like at dusk and dawn.
For skin areas requiring cover protection: Coat with a film of Filta-Bac Cream. Re-apply three to four times weekly. Do not allow Filta-Bac to build up. Remove by washing with warm water and a mild soap.
An ‘atopy’ is similar in appearance but is an inherited allergic skin disease to allergens such as grass pollens, tree pollens, dusts and moulds, etc. These are often diagnosed by excluding insect allergies as a cause and are much more difficult to treat. Oral anti-histamines or cortisone often being the most effective types of therapy.
Sunburn is a consideration at this time of year as well caused by UV A and UV B rays. Areas most likely to be affected are the nose: face: ears: dock: fetlock area.
Most of these vulnerable areas are un-pigmented and hairless skin areas.
While there is a visible white film of Filta-Bac Cream a degree of sun protection will be afforded. If there is an acute problem (normally the nose) then Filta-Bac will need to be applied up to every four hours, as the protective film will be rubbed off while grazing. Normally a white covering applied in the morning will still have some white filming present in the evening and this is still giving a degree of protection.
Do not allow Filta-Bac Cream to build up on areas being protected especially if these areas are weeping. In the case of serum weeping from previously sunburnt and damaged skin do the following.
a: Coat the area with Filta-Bac Cream in the morning. Re-apply if it is substantially removed by grazing etc.
b. If a considerable amount of serum combines with the Filta-Bac Cream bath the area daily with warm water and a mild soap to clean and remove build up. Allow to dry (pat dry) and re-apply a covering protective coat of Filta-Bac.
This application will allow the area to heal, new tissue to form, bacterial contamination will be eliminated and new hair growth will appear.
Melanomas are skin tumours of most commonly gray horses. The tumours appear black and often nodular or ulcerated and sites include the tail base, around the genitalia, ear, neck and eyelid. The high occurrence in grays is likely associated with the pigment changes that they undergo with aging. They lose the melanin pigment in the skin cells which probably results in stimulating the cells to become malignant (or tumorous). The majority of melanomas grow slowly over many years without causing problems although some may become malignant and spread into other organs or interfere with normal function in certain areas, at which time surgical excision, which remains the best form of treatment, may be warranted.
Lacerations A covering coat of Filta-Bac Cream will protect the wound from bacterial invasion, dirt, foreign matter and external chemicals, while allowing the damaged tissue to transpire normally, fostering rapid healing and new tissue formation.
Keeping damaged skin areas covered with Filta-Bac Cream until the vet arrives can therefore be quite useful in some circumstances. Tissue covered by Filta-Bac Cream will breathe normally. Filta-Bac Cream is an oil in water emulsion -not an occlusive ointment.
Galls Girth Galls, Saddle Galls, Harness Galls. Apply Filta-Bac Cream to cover the superficial layer that is usually raw and red. Maintain a cover coating. Avoid all pressure that originally caused the gall. When appropriate stimulate circulation in the immediate area and reapply Filta-Bac to the damaged skin.