Keep an eye on those eyes!

As the weather gets nicer and the horses go out, more flies are around and we tend to see more eye problems. Examples are swelling of the eye, tearing at the corner of the eye, squinting of the eye or wounds to eyelids or the eye itself. The problems can be related to infection, injury, the bright sunlight or can even be hereditary (inherited or auto-immune conditions). 

Conjunctivitis

Conjunctivitis is inflammation of the lining of the eyelids (the so called conjunctiva), eyes can be swollen, red and discharge can be seen to emerge from the corner of the eye. Conjunctivitis is more commonly seen when more flies are around as they irritate the conjunctiva and can spread infection. Treatment often consists of antibiotic eye drops to stop the infection. It can be prevented by turning horses out with an eye mask.

Uveitis

Uveitis is inflammation of the iris and related structures and can be very painful. Signs of this disease are squinting of the eye, mild discharge and a very constricted (small) pupil. Treatment is aimed at stopping the inflammation and relaxing the constricted pupil. As this disease is very painful and can cause long-term damage to the eye it is crucial that treatment is started as soon as possible. Uveitis is usually an auto-immune condition or can be caused by a bacteria known as leptospira spp.

Corneal ulcers

A corneal ulcer is a defect of the superficial layer (cornea) of the eye that can be caused by trauma to the eye, such as, rubbing of the eye, sand in the eye, or scratching of the eye by with a foreign object such as a branch of a tree. It is diagnosed by staining of the eye with fluorescein, and the defect will be colored green (as can be seen in the picture). Antibiotic drops and artificial tears are commonly used to treat these ulcers.

Injury of the eye

Injury of the eye can be caused by blunt force (such as a kick) or sometimes by a laceration. Therefore it is important that after an accident to the face the eye is thoroughly checked too. Sometimes the trauma can be obvious, but sometimes the initial injury looks very minor; however their still may be damage to the eye, so it is important to get it checked out.

Figure – This horse has a large ulcer, obtained after he injured his eye on electrical tape. As treatment was started immediately the ulcer resolved within a week.

Besides these common problems other issues can occur to all structures of the eyes. It is good to remember that eye problems can deteriorate rapidly. It is key to call your veterinary surgeon within 24-48 hours after problems arise. Most problems can be treated successfully when treatment is started promptly. So keep an eye on those eyes! 

The equine breeding season is now in full swing which means that our vets have been busy scanning mares as well attending mares and foals for routine post-partum checks as well as unfortunately, in some cases, illness.

Many of you may wonder, if the birthing process proceeds uneventfully, why the need to check mare and foal postpartum. For the remainder of this piece we will explain why this is so important in a little more detail.

Following birth, the one, two, three ‘rule’ is important to remember-

• One: the foal should stand within one hour of birth
• Two: the foal should show ability to nurse within two hours of birth (most mares should have expelled their placenta within this timeframe also)
• Three: the foal should be actively nursing and consuming colostrum within three hours of birth.

If the above three timepoints are not achieved then a veterinary examination is warranted sooner rather than later. Otherwise if mare and foal are doing well, the above timepoints have been met and the mare has passed her placenta then a postpartum check should be performed within the first 24-36 hours following parturition (birthing). It is important to remove the placenta from the mare’s bed as soon as possible following expulsion and retain it for veterinary examination.

At the post-partum check, the attending vet will generally ask questions about the mare’s pregnancy and the birthing process.  A full physical examination is subsequently performed on the foal whereby the attending vet will examine the foal’s heart, chest, joints, umbilicus and check for evidence of hernias. They will also check the foal’s mouth for cleft palate and ascertain it’s jaw alignment- has it an overshot/undershot jaw. Occasionally foals have turned in eyelids which results in their eyelashes rubbing the cornea (entropion) so it is also really important to check there is no evidence of this. We will generally check the foal’s nursing also.                                                                                                        

It is highly recommended that a blood sample is taken to ascertain the foal’s IgG status. But what is this and why is it so important?

Foals are born immuno-naive which means that they are incredibly susceptible to infection should they consume inadequate quantities of colostrum (the mare’s first milk) or the mare’s colostrum is of insufficient quality. This ‘failure’ is known as ‘failure of passive transfer.’ If the mare has run milk for days on the lead up to birth, there is a distinct possibility that she will have lost the protective antibodies that would normally be concentrated in the colostrum. On the other hand, if the mare’s colostrum is of sufficient quality but the foal fails to consume sufficient quantities within the first 12 hours of life or so then the foal will consume and absorb insufficient amounts of antibodies. Both scenarios lead to failure of passive transfer. The foal’s gastrointestinal tract is capable of absorbing these antibodies most effectively during the first 12 hours of life but some absorption continues, albeit at a reduced amount, up until approximately 24 hours of age. The IgG blood test determines the foal’s antibody level. This simple blood test is performed on yard with results within a few hours at the latest. The best-case scenario is that results return indicating successful passive transfer but if test results indicate failure then the time postpartum determines the action required. If heading towards 24hrs plus postpartum, then a plasma transfusion is indicated. Your vet will discuss the most appropriate course of action with you.

It is equally as important to check the mare and her placenta as well as the foal. A full physical examination should be performed and the placenta checked. The mare’s perineal area should also be examined for birthing trauma. Finally, the mare’s bag (udder) should be checked and should be soft and well nursed. A hard, engorged bag is not normal and is often the first tell-tale sign that a foal is poorly and nursing insufficiently.

A nerve block is the deposition of local anaesthetic into the area immediately surrounding a nerve body or ending. This stops the nerve from transmitting signals relating to pain back to the brain, hence pain is prevented or “blocked”. Practically, the term nerve blocking is often used to describe the placement of nerve blocks in the truest sense, and also the deposition of local anaesthetic into joints and into the tissue surrounding the spinal cord (an epidural), rather than around nerves. 

Placing needles into highly sensitive and sometimes painful areas of a horse is obviously potentially risky to the personnel involved. However experienced, calm, sympathetic handling & restraint (often coupled with some form of oral enticement!) is often sufficient to allow the placement of a block. Where this is not possible, the administration of mild sedation prior to the procedure, often allows for it to be performed safely in the vast majority of horses. 

By preventing sensation of pain, nerve blocks can be used to allow the performance of certain surgical procedures under standing sedation rather than under general anaesthetic which can decrease the risk of a procedure to the horse, and the cost to the owner. Examples of this include cheek tooth removal, sinus surgery, surgical correction of “kissing spines” (dorsal wedge ostectomy) and wound reconstruction. 

Another use is localisation of pain, most commonly orthopaedic pain or lameness – know as diagnostic analgesia. Whilst observing a lameness informs us that a horse has pain in a certain limb, it does not tell us where in the limb the problem originates. Sometimes this is obvious i.e the presence of heat, swelling and/or pain on manipulation of a certain part of the limb, but in many cases there is no visual or palpable sign of pain. It is such cases where nerve (or joint) blocking can prove invaluable. 

The procedure involves observing the horse moving in a straight line, on circles on both reins and on firm and soft surfaces. This allows grading and characterisation of the lameness. A nerve block is then placed, stopping the sensation of pain in a specific area. Once this has had chance to take effect, the horse is once again observed moving as previously. Any substantial reduction of lameness can therefore be attributed to pain coming from within the area that has been desensitised by the nerve block. If the lameness is unchanged, it can be deduced that the source of pain is not within the blocked area of the limb, and further nerve blocks can be performed to desensitise other area of the limb until the source of lameness is known. 

Once the area responsible for the lameness is known, diagnostic imaging (e.g. radiography, ultrasonography, MRI) can be performed allowing the identification of abnormalities. It is important to mention at this point, that untargeted imaging of the whole limb often results in the identification of abnormalities or variations from normal. Without having confirmed that the area being imaged is definitely the cause of lameness, it can be difficult to decide whether these abnormalities are significant 

to the lameness or just incidental findings (i.e. slight abnormalities which are present but not causing any problem). 

In conclusion, the use of nerve blocking allows identification of the region of the limb causing the lameness. This in turn allows focused imaging which results in the identification of significant abnormalities only, and a precise diagnosis. This means that the best treatment plan can be selected. It also allows an accurate and realistic prognosis to be given, i.e. how likely a full recovery is, how long it will take, and what the horse will be capable of in the future. 

The aim remaining at all times, to make your horse pain free and able to provide enjoyment to you as their dedicated owners.

During these unprecedented times, we are closely following the guidance issued by our governing body, the Royal College of Veterinary Surgeons (RCVS). We are entirely committed to protecting the health of the public, our clients and our staff, whilst maintaining the highest possible standard of care for your horses. As of Tuesday, April 14^th the RCVS have relaxed the restrictions placed on the veterinary industry. We have considered this information very carefully and whilst we will continue to provide advice on a case-by-case basis, we feel that the following guidelines contain essential information on our practice policies from April 14^th:

• We will be returning to performing annual vaccinations to horses that are due (please delay making an appointment if your annual vaccination is not due within the next 3 weeks). We will not be performing 6 monthly booster vaccinations (other than 3^rd vaccines of the original course). 

• We will continue to see any horse in an emergency situation and any horse who’s welfare is compromised. 
• We will also be able to perform other essential veterinary work that cannot be delayed for a further 3 weeks, please ring to discuss any concerns you have with one of our vets in the first instance.
• We will not be performing routine dentistry or other routine procedures which are non-essential.

Upon our vet’s arrival at your yard. For our mutual protection we would appreciate that the following social distancing/hygiene measures are taken:

• We will meet one allocated person at the yard only (client), who is not self-isolating, high risk or displaying any COVID-19 symptoms. 
• Both the vet and client will sanitise their hands and wear gloves.
• The client will hold horses for us whilst maintaining social distancing measures, and avoiding face-to-face contact if at a distance of less than 2m (for instance as the horse is being injected).

These measures are extremely important, as the safety of our clients and our staff remain the top priority during this time. 

We are also expecting the phone lines to be busy on Tuesday morning, so please try to delay your query/appointment booking unless it is urgent.

THANK YOU ALL for being so patient and understanding during these difficult times, we are all in this together!