Category: EQUINE

Pinworm (Oxyuris equi) infection is manifest by affected horses itching their peri-anal and tailhead regions. Adult worms reside in the large intestine with the female worm travelling down the small colon to lay eggs on the skin surrounding the anus (often indicated by a yellow discharge as seen in photo one below). This usually causes intense irritation manifest by rubbing. Occasionally, mature worms are visible protruding from the anal sphincter which we can also see in this photo. 

Diagnosis is confirmed through microscopic examination of a sellotape impression taken from the peri-anal skin or yellow discharge (if present) which will reveal the pinworm eggs (seen in photo two below). 

Most commonly used wormers are effective for pinworm (ivermectin, avermectin or pyrantel based wormers) and should be administered to clinical cases. The peri-anal region and underside of the dock should also be washed using dilute hibiscrub to remove the eggs. We generally recommend cleaning for three to five consecutive days. The stable should also be thoroughly cleaned and disinfected to endeavour to remove environmental eggs.

Pinworm infection should always be considered in cases of tailhead itching but it is also important to consider other potential causes including sweet itch, other allergies, mites and lice. It is also important to remember that pinworm infection is generally not indicated on faecal worm egg counts as the eggs are deposited on the skin surrounding the anus. Therefore, horses with negative faecal worm egg counts may still succumb to pinworm infection.

As always, should you have any questions, please do not hesitate to contact the equine team. 

Colic is the term used to describe abdominal pain. This is usually from the gastrointestinal tract but can be from any abdominal organ (e.g. the ovaries). Colic signs include curling of the top lip, pawing the ground, flank watching, rolling, increased recumbency (lying down) and change in the amount and/or consistency of droppings. Most cases require a veterinary examination to determine the cause and instigate treatment, from pain relief through to life-saving surgery. 

Initially the vet will observe the horse to see how severe the signs are. The cardiovascular system is then assessed. The mucous membranes (gums or inner eyelids) are examined to establish how well the blood is circulating round the body. The membranes should be salmon pink, and when blanched this colour should return within two seconds (the capillary refill time or CRT). Any discoloration of these membranes, with or without increased CRT, are a sign of poor circulation. Dry mucous membranes are a sign of dehydration. 

A heart rate will then be taken. Slight increases in heart rate can often be attributed to increased stress levels in the horse, but a very high rate is generally an indication of dehydration and disrupted circulation. The digital pulses (at the level of the fetlock) may also be felt – a lack of indicating poor circulation, and an increase potentially indicating toxic laminitis (caused by gut toxin leakage into the circulation). 

Poor circulation results from the leakage of toxins from damaged gut into the circulation. The gut becomes damaged when it gets twisted or stuck, cutting off the blood supply that keeps it alive and functional. Mild dehydration can arise from reduced water intake or sweating. Severe dehydration normally occurs when the damaged gut is no longer capable of absorbing fluid into the body. 

Following cardiovascular assessment, a respiratory rate is obtained. An increased rate can be due to the horse being in pain and using more energy whilst colicking. It can also be due to chemical changes in the blood caused by toxin release. Rarely, an increased respiratory rate can be caused by something in the abdomen pressing on the lungs e.g. a stomach impaction (where food fails to leave the stomach causing expansion and discomfort). 

Next the vet will listen with a stethoscope at four points on the abdomen. A moderate amount of noise should be heard, as gas and food move through the guts (borborygmi). Increased noise is generally an indication of spasmodic movement of the guts. Decrease in, or absence of noise usually indicates that gut movement has stopped or that the portion of gut that is normally positioned in this area has been displaced, which can indicate a more serious problem. 

The horse’s temperature is then taken. A low temperature can indicate poor circulation, and a high temperature generally indicates infection. 

If the vet is now satisfied that the horse merely has some spasmodic gut pain, the colic examination is complete and appropriate medication can be administered. However, if a more serious cause of colic is suspected, a rectal examination will occur. A lubricated, gloved arm is inserted into the horse’s rectum so the vet can feel deeper into the abdomen. The size, position and content of different portions of the gut (and other structures e.g ovaries, tumours) can be assessed allowing an accurate diagnosis of which part of the gut (or otherwise) is affected. Rectal examination has huge benefits but also carries a small risk of tearing the lining, hence it will not be carried out if deemed unnecessary. 

Horses are unable to vomit, so if your vet is suspicious that the passage of food and liquid through the stomach is obstructed, they will pass a tube via the nostril to aspirate excessive fluid build-up. Without the ability to vomit or the act of stomach tubing, a horse’s stomach can eventually rupture. Once your vet is confident that no excess ingesta is present in the stomach, they may use it as a route of treatment for dehydration, administering fluid and electrolytes. 

This is routinely the end of an ‘on-yard’ colic examination. If your horse needs to be admitted to a clinic, further examinations may take place. These include abdominal ultrasound, blood sampling and peritoneal fluid (the fluid lubricating the abdominal organs) sampling. These samples can be looked at with the naked eye or machine analysed to provide information about how the rest of the body is coping with the problem causing the colic signs. 

Ultimately, the vet will be able to make an accurate diagnosis and appreciate how sick the horse is. Appropriate treatment can be advised with the vet able to predict the horse is well enough to recover after treatment, or if (on some sad occasions) euthanasia needs to be considered. 

Approximately 90% of colic are diagnosed as medical. Of these, only a very small proportion will require more than one treatment. The sooner the horse arrives at a surgical facility, the better the prognosis. In all cases, this detailed examination will limit any period of discomfort and distress for both you and your horse. 

There are many different causes of skin disease in horses and ponies, with the most common being associated with parasites and insects. However, occasionally immune mediated skin conditions can occur spontaneously or as a reaction to a drug or stressful situation. Below is a picture of a horse presented to us for excess scabs which had originally started on the lower leg but had progressed rapidly and was now affecting the belly and flanks (see picture on the left).

Skin biopsies are required to diagnose immune mediated conditions and the process is well tolerated by horses. Local anaesthetic and a punch biopsy tool (like a small apple core) are used in several areas to obtain samples which are then sent to the lab. The lab can then determine based on the cells present which condition is causing the skins appearance. 

In this case pemphigus foliaceous was diagnosed. In this disease the body directs antibodies against the cells on the skin surface and in doing so causes blister and excessive crust formation. The mainstay of treatment for autoimmune conditions is immunosuppression using corticosteroids. Autoimmune conditions carry a good to guarded prognosis depending upon how well the immunosuppressive therapy works. However, we are pleased to report that in this case the corticosteroids have worked wonders. The pony is back in full work and as you can see the skin appears completely normal (like in the picture at the top). The pony will be closely monitored to detect any future recurrence. If you have any queries about your horse/ ponies’ skin then please call us to speak to one of our vets on 01772 861 300.

Summer time is hopefully a period that we are blessed with good weather and sunshine and while this is inevitably good for the soul, the sunshine and resulting UV, sadly can have negative implications for our equine patients namely in the form of sunburn and photosensitization. 

The first, simple sunburn, occurs when light- coloured skin, including flesh marks, becomes red and scaly following excessive exposure to UV light. Similar to humans, the severity of the damage depends on the strength of the radiation and the individual’s skin sensitivity. Light-coloured skin is predisposed due to a lack of melanin pigment which absorbs UV light and scatters the radiation. Hairless skin is also more severely affected. The most common affected area is arguably the muzzle.

Mild cases generally self-resolve provided further exposure to UV light is prevented and the skin is given a chance to heal. More severely affected patients require veterinary attention and topical medications are frequently indicated (usually steroid-based creams).

Prevention is based on avoiding exposure to intense sunlight by stabling at periods of intensity, use of water-repellent sunblock and if the muzzle is an ‘at risk’ area, use of a face shade mask (which includes a shade to cover the muzzle area).

Ragwort 

· Whilst intact, ragwort is generally quite unpalatable and horses don’t tend to eat it unless no alternate forage is available. Ragwort becomes much more palatable for horses when it is treated using a herbicide but hasn’t yet fully decomposed or when it is cut down and subsequently dries out. Therefore, one of the main sources of exposure to our horses is when it is inadvertently incorporated into hay or haylage. 

· The toxin in ragwort, pyrrolizidine alkaloid, is generally a cumulative toxin. While a toxic dose may be consumed on one occasion, it is much more common for a patient to consume the toxic dose over a longer period of time i.e. years. 

· The toxin causes irreparable damage to the patient’s liver which can lead to liver failure which is fatal. Clinical signs of liver failure are often only apparent when greater than 75% of a patient’s liver is affected. Clinical signs include depression/abnormal demeanor, reduced appetite, weight loss, jaundice, diarrhoea and photosensitisation to name but a few. 

· Diagnosis is based on the presence of compatible clinical signs, with/without a history of grazing ragwort-infested pasture, blood work and ideally, a liver biopsy. 

· Treatment is generally of a palliative nature.

Did you know taking a blood sample from your horse can not only aid in the diagnosis of disease but can be performed for many other reasons? Once collected, samples are analysed either in our clinic or sent to a veterinary laboratory externally. Some tests are quick to run, while others can take several days or longer to complete before the results are available. 

Apart from helping the vet diagnose a disease, blood sampling can also be used to: 

1. Monitor the response to treatment after diagnosing an illness – this may be to ensure tissues are healing, an infection is resolving or assessing response to treatment. For example checking the dosage of ‘Prascend’ is suitable in Cushing’s disease cases. 

2. Screen normal animals – Although animals may not show any signs of being unwell, there may be early indicators of disease that can be blood on routine haematology and biochemistry blood analysis. This is particularly relevant with older animals or those recently exposed to a contagious disease. 

3. Pre-purchase examinations – blood is routinely collected prior to purchase by the attending vet to allow for future testing of medicines that may mask signs of illness or injury. These are collected and stored frozen for six months. For example, if a lameness issue arises shortly after purchase then the sample can be tested for anti-inflammatory and pain relief medicines. 

4. Confirm exposure to infectious diseases – during an outbreak exposure to diseases such as equine influenza and strangles can be confirmed or ruled out. In some cases a second sample may need to be taken two weeks later if results are considered borderline or inconclusive. 

5. Confirm the health status of an animal before export/import – horses may need to be free from certain disease before entry into another country. Blood tests are used to rule out several serious diseases and maintain the disease-free status of a country. Diseases may include equine infectious anaemia, equine viral arteritis, African horse sickness or equine influenza etc but each country has its own specification for which tests must be taken. 

6. Confirm the health status of a mare or stallion prior to breeding – some diseases can be spread during the breeding process, affecting both mare and stallion with fertility or illness. These include equine infectious anaemia, equine viral arteritis and strangles in some cases. 

7. Monitor a patient prior to and during a general anaesthetic (GA) – Bloods are often checked before surgery to identify any additional risks of performing a GA. These can be repeated during surgery to allow the anaesthetist to respond to any deterioration during the procedure. 

8. Identify banned substances during competition – Professional equestrian competitions (e.g. BHA, FEI etc) monitor for the presence of prohibited performance enhancing drugs. The blood (and urine) of competitors may be tested to prevent any unfair advantage. For example, administration of anti-inflammatory and pain relief medication such as phenylbutazone (bute).

Itching or ‘pruritus,’ as it is known in veterinary terms, is an unpleasant sensation that triggers a desire to scratch. Horses are often seen to bite, rub or chew their skin which can be very distressing for horses and owners alike. Not only can horses inflict a significant amount of self-trauma but fencing, field shelters and stabling will often get harmed in the process too! Horses may rub themselves to the point of removing their fur/hair and damaging the underlying skin resulting in raw sores that may become infected. Hives (urticaria) may accompany the itching depending on the cause.

Working with your vet is really important to try establish the cause of the ‘pruritus’. This will in turn enable treatment and preventative strategies to be put in place. There are many tests which can be performed including analysing hair or skin samples down the microscope, taking skin biopsies or performing intradermal allergy testing in our clinic. 

Causes of pruritus include but are not limited to the following: 

Ectoparasites or infectious agents including: 

· Lice 

· Mites 

· Biting flies and insects 

· Pinworm 

· Fungi 

· Bacteria 

Immunological causes including: 

· Atopic dermatitis (allergic reaction to an environmental allergen) 

· Culicoides hypersensitivity (sweet itch) 

· Contact hypersensitivity 

· Food allergies 

Other miscellaneous causes including: 

· Drug reactions 

· Liver (hepatic) dysfunction 

· Pruritus secondary to internal cancerous lesions 

Treatment 

Many different treatments are available depending on the cause. These may include shampoos, sprays, topical creams, worming, antibiotics, anti-inflammatories, anti-histamines, avoidance strategies or allergen specific immunotherapy. 

If you have any concerns regarding your horse’s skin whether there are lumps, bumps or ‘pruritic’ areas, please have a chat with our equine team. We can help advise you on the best course of action and get to the bottom of why your horse may be pruritic.

We have some Good Dental News for you all!! But first we would like to take this opportunity to say a massive thank-you for your patience and co-operation during this time where our services have been limited due to Coronavirus restrictions. 

We are now, under our governing body guidelines, able to perform routine dentistry providing social distancing guidelines are adhered to. The specific requirements for social distancing is assessed on an individual basis. However this is likely to involve two of our staff members attending appointments for multiple horses to have routine dentistry performed. This will enable us to maintain social distancing for the time required to perform the procedures to a high standard. 

As you will appreciate this will require some prior planning! We kindly ask that if any of you would like a routine dental to be performed on your horse, that you book onto a yard visit well in advance to facilitate these new guidelines. In addition, we will ideally be performing multiple ‘routine dentals’ at once in order to maximise the efficiency of the procedure. For this reason it would be especially helpful if yards could co-ordinate prior to booking individual appointments.  

We will inevitably have some catching up to do, and therefore appreciate your patience at this time. If your horse has a more urgent requirement for dental care, please do not hesitate to contact us for an immediate appointment as it is important these horses are seen quickly.

We look forward to getting back on the horse, or in its mouth, as it were!

Thanks for your ongoing support.
The Oakhill Equine Team.

Equine asthma (formerly known as COPD/RAO) occurs when inhaled allergens initiate a cycle of bronchospasm (airway constriction) and airway inflammation (increased inflammatory cells and mucous). Two forms commonly occur- summer asthma secondary to pollen and the more ‘renowned’ form triggered by dust which can occur throughout the year.

Horses typically present with an increased breathing rate and effort as well as a cough. Clinical signs vary in severity from those patients that present with a history of poor performance or a mildly increased respiratory rate to those severely affected presenting in respiratory distress. Diagnosis is often based on the presence of compatible clinical signs but is confirmed following respiratory tract endoscopy and submission of bronchoalveolar lavage and tracheal wash samples to the lab for cytological evaluation. These samples are also submitted for culture to rule in/out bacterial involvement (and in turn the need for concurrent antibiotic treatment).

Ascertaining the actual trigger for an asthma episode can be challenging. Dust can play a significant role so minimising dust in the patient’s environment is of paramount importance. Utilisation of ‘dust free’ bedding (paper/cardboard) should be considered and cobwebs should be hoovered from stables quarterly. Grooming should take place outside to minimise stable dust. Investment in a hay steamer should be considered.

Managing Summer asthma relies heavily on drug therapy. Allergy testing is possible in horses (intradermal skin testing or allergy bloods) but results are often unrewarding.

Drug therapy is based on relieving bronchospasm/airway constriction through the use of bronchodilators and on relieving airway inflammation through the use of steroidal anti-inflammatory drugs. Drugs may also be administered to break up mucous (mucolytics). Airway inflammation is slow to resolve and treatment may be required for a period of months. In some cases, if ongoing allergen exposure is present, treatment may be required on an ongoing basis or repeatedly when flare-ups occur.

Oral therapy is still considered ‘gold’ standard drug therapy. This is facilitated through use of clenbuterol which opens up the airway and relieves airway spasm & steroidal anti-inflammatories to reduce airway inflammation. Mucolytics, which break up airway mucous, may also be added to food. Some authors advocate eucalyptus as a mucolytic.

In some patients, oral therapy is not effective, which means we need to explore other ‘drug delivery methods’ such as nebulisation or inhalation.

Both bronchodilator and steroid drugs may be delivered through a nebuliser. The initial investment is high but long term, the drugs will work out less expensive than oral therapy.

Alternatively, human asthma inhalers may be used through a paediatric face mask. This is relatively cost effective but inhalers require very frequent administration and drug delivery may be prohibited by airway mucous.

Seeking out the best horse insurance for you and your horse can be an overwhelming task! Insurance is a vital part of responsible horse ownership and not only can it provide cover for vet’s fees in case your horse becomes ill or injured but there are many other things it can cover too. Some lesser known options include human dental cover, hire of a replacement horse due to theft or straying and holiday cancellation fees if your horse needs life-saving surgery.

There are many polices out there which may be suitable for your needs including foal, leisure use, small ponies, veteran, catastrophe cover, competition or sports horse policies.

So what can be covered on Insurance?

The basic level of insurance for your horse or pony often includes:

• Death or slaughter – if the horse dies due to an accident, illness or disease.
• Theft or Straying – if the horse is not found within 28 days

Optional extras may then include the following, to build up the level of cover according to your requirements:

• Vet’s Fees– often a maximum amount can be claimed per incident (< £3000-£5000), some companies may increase this for specific procedures such as colic surgery (<£7500). Some policies may also cover a certain amount towards complementary treatment such as hydrotherapy, physiotherapy, remedial shoeing etc.
• Public liability – legal liability to a third party for the damages and costs arising from your use of the insured horse
• Permanent loss of use– if the horse has an accident, illness or disease that permanently prevents it from carrying out the functions it is kept an insured for (e.g. an eventer that sustains an injury that means it can no longer event but is suitable for hacking). These horses are often freeze branded with an ‘L’ to denote loss of use. The amount you are entitled to may change with some policies as the horse gets older.
• Personal accident – death, total and permanent loss of sight or hearing, limb loss or disablement.
• Dental cover – emergency dental treatment. This may be reduced if riders are under 16 years of age
• Stable cover – if the stable owned by you is destroyed or damaged beyond use by fire
• Saddlery and tack – Fire, accidental damage or theft following forcible or violent entry to a locked private building
• Hire of replacement horse – this covers a certain amount towards hire of a replacement horse between the date of theft or straying until a claim is made or the horse recovered.
• Livery fees- a contribution if you have to go to hospital
• Holiday cancellation fees – often up to a certain amount if your horse needs life-saving surgery
• Legal costs and advice – providing you with advice and help with the cost of legal representation

So what should you do to ensure your horse remains covered by your chosen policy? Here are a few common insurance mishaps and how to avoid them.

1. Non-disclosure and remember to update – It is essential to declare any illnesses or injuries to your insurance company on renewal, otherwise this may prevent your claims from being paid in the future. If the use of your horse has changed and therefore its value, then perhaps switching to a different kind of policy with your insurer may be more suitable.

• Make sure you do your research – always read the small print, this will help you get the most suitable insurance cover for you and your horse. Things to look for include the excess cost, standard of service you can expect to receive, whether staff are knowledgeable with horses and how long the company has been established.

• Buying first, insuring later – it is always recommended to check that the horse is insurable before committing to a vetting or purchasing the horse. Ask your intended insurer what documentation is required for the intended policy (i.e a vetting certificate or radiographs). These may then be sent to the insurance company for them to validate in some circumstances.

If the purchase goes ahead it is important to insure the horse at purchase, otherwise the vetting certificate may be out of date if this is done weeks or months later.

If you are not vetting your horse, it is still worth purchasing cover as soon as money changes hands. There is often a limitation period of 14 days until your horse is fully covered.

• Policy conditions – make sure you are aware of any conditions the insurance company expects you to abide by with your policy. This may include following a worming programme, arranging an annual dental examination, or keeping up to date with routine vaccinations. Keeping a worming record, always recording your horse’s vaccines in their passport and keeping receipts can make this process much easier should you need to make a claim.

•  Insurance is great, but don’t double up – Insuring yourself twice for the same activity can cause almost as many problems as not insuring at all and be costly in the long run.  This may be the case with public liability and tack insurance. For example, if you are already a member of an organisation such as British Dressage then you will be covered for public liability. Similarly, if you keep your tack at home then this is likely covered by your home insurance. Being insured twice may delay a claim being paid if two difference insurance companies need to agree on who is paying.

• Not insuring for the right activity – It is vital that you let your insurers know if you start a new discipline with your horse or start to compete at a higher level than initially stated. This may increase your risk of an injury and could be an issue if your policy does not reflect this.

• Overvaluing your horse: Most horse insurers offer market value policies. This means that in the event of loss of use or death, regardless of how much your insured for, you would receive the market price for your horse. It is important to be realistic and keep the policy updated with the horses current worth otherwise you could end up paying a higher premium for a horse that’s value may have decreased.

Despite these common pitfalls, quality insurance is so important to have in place should the worst happen and your horse requires unexpected veterinary treatment. Without it you may not be able to provide the level of care needed to treat your horse and look after him during recovery.

In Summary, a few things to remember….

• The cheapest monthly premium is not necessarily the most suitable or cost-effective policy
• Ensure vet’s fees cover is for an adequate level for your horse and the activities you do with them
• Ensure you have third party and public liability cover for both yourself and your horse
• Consider including personal accident cover and cover for when you are riding other horses

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!