Category: EQUINE

CASE STUDY: MR T’S MELANOMA

Meet Mr T, who earlier this year developed a slight swelling on the left hand side of his back, under the saddle region. He didn’t seem overly bothered about this swelling, but his owner asked Sarah to check it out as they were concerned that it was steadily growing bigger.

Sarah was a bit perplexed – the swelling felt to be a solid lump under the skin attached to one of Mr T’s ribs. The lump was therefore ultrasound scanned, which showed it was a soft tissue mass and was spreading between the ribs and expanding down towards his chest cavity. Given its location and the fact that it was growing bigger and likely to be causing Mr T some discomfort, it was decided that it was best off being removed. A biopsy was taken to determine what the mass was and the degree of malignancy as this would determine the ‘margin’ required at surgery.

MELANOMAS

Melanomas are typically found in the perianal region, under the tail, inside the sheath, around the vagina or inside the mouth, although some horses will develop them under the skin elsewhere or internally.

Melanomas themselves are not generally too much of an issue if located externally, unless they become very large and ulcerated and therefore sore, but removal is most straightforward whilst they are small. Also, there is some evidence that the fewer melanomas a horse has present, the less they will go on to develop, so early removal is now generally recommended.

SYCAMORE POISONING: THE FACTS

Many of you may have noticed the characteristic helicopter seeds present in sycamore trees as of late, so we thought it would be a good time to remind you about sycamore poisoning, also known as atypical myopathy.

WHAT IS IT? A highly fatal muscle disorder that occurs following the ingestion of sycamore seeds or leaves in autumn, or seedlings in spring, that contain the hypoglycin A toxin.

SEVERITY: There is sadly a 75% fatality rate with most non-survivors succumbing within 72 hours of the development of clinical signs.

PREVELANCE: The toxin is not present in all sycamores and toxin levels may differ at different times of year and under different climatic conditions. Cases often follow an adverse change in weather conditions such as frost or rain.

CLINICAL SIGNS: Weakness, stiffness, muscle tremors, a fast (sometimes irregular) heartbeat, difficulties in breathing and dark red/brown coloured urine. Other clinical signs include depression and signs of colic. Severely affected horses become recumbent and others may be found already deceased.

TREATMENT

Time is of the essence and rapid initiation of treatment is essential to improve prognosis. Suspected cases are generally hospitalised to facilitate intensive medical management.

Treatment is predominantly based on supportive care including administration of large volumes of intravenous fluid therapy. The provision of adequate pain relief is vitally important and the administration of vitamins can be advantageous.

CANKER

Max presented after his owner noticed the frogs of his feet had become soft and irregular. Upon examination it was clear that he was suffering from Canker in three out of four feet.

GUTTURAL POUCH MYCOSIS

Ralph recently presented due to the development of mild head shaking behaviour and an abnormal respiratory noise when ridden. He subsequently developed an orange coloured nasal discharge but was otherwise well.

Fortunately, guttural pouch mycosis is rare. Sadly, the disease can prove fatal in up to 50% of cases. The poor survival rate is due to fungal plaques breaking down the lining of the pouch, resulting in fatal bleeding or damage to nerves affecting the ability to swallow and breathe. It is not fully understood why or how this infection occurs and it can affect any horse of any age. Often the first presenting sign is a small nosebleed, which is why it’s important that we investigate nosebleeds in equine patients.

DOUBLE TROUBLE

A couple of months ago Sarah attended the lovely Sally who had a surprise in store for all of us!

Sally was at stud to foal down and was noted to be going into the early stages of labour by stud owner Liz. However, it was soon apparent that she wasn’t progressing as expected – two legs had appeared but she was struggling and seemed exceptionally painful. Liz was quickly on the phone to vet Sarah who whizzed down to the stud as fast as Ribble Valley’s police find acceptable!

AN UNEXPECTED DISCOVERY

Upon feeling inside Sally, Sarah was able to identify one foal which was presented with their head and neck twisted over. However, it seemed very much stuck, despite being not overly large. A little more feeling further back revealed something no one was expecting – an extra pair of legs also within Sally’s pelvis – narrowing the gap and wedging the foal in place. At first Sarah wasn’t sure if these were the back legs of one very badly presented single foal, but after further palpation discovered that they were actually another set of front legs. It was at this point that the cavalry (Sarah’s second on call vet Julia) was called in to lend extra assistance if required.

SPRINGING INTO ACTION

Sally was quickly sedated, given pain relief, and an epidural placed in her spine to stop uterine contractions. Once contractions had stopped and she was more comfortable, Sarah was able to push the second foal further back beyond the pelvis, leaving room for the first foal to be repositioned and delivered. This was no mean feat and required both Liz and Sarah to pull on one leg each, as well as a lot of lubricant! Despite giving everyone a scare when she went limp half way through, Babette was soon wriggling round on the floor.

Julia arrived and was quite confused as to why Sarah was still two arms deep in Sally’s uterus, despite there being a foal on the floor, when Bettina (with her exit route now completely clear) made a swift entrance into the world. Due to being quite squashed up in the womb with her big sister, Bettina’s limbs were initially much weaker than hoped, and so Julia stomach tubed her with some colostrum in case she struggled to stand.

Babette and Bettina are now two months old and are both doing really well, full of character and sass. Sally has been a fantastic mother and is doing her best to look after both foals, ably assisted by stud owners Ian and Liz, who have worked tirelessly to supplement and support these twins.

A CALCINOSIS CIRCUMSCRIPTA CONUNDRUM

Occasionally as a vet, there are cases that exercise our brains VERY hard! This was certainly the case with Zeus, a two year old gelding.

Zeus was found severely lame on his left hind limb whilst out grazing. On initial clinical examination, no localising signs could be found to explain the lameness. Intravenous pain relief was administered to facilitate returning Zeus to his stable. After 48 hours, his owners noted that some swelling had started to develop in the region of the stifle. Zeus was examined on yard to establish his fitness to travel, before coming into clinic for further investigations.

The question was, were the two findings (the muscle mass and the stifle joint inflammation) related? What was certain was that the extremely painful, inflamed joint required arthroscopic (keyhole) flushing under general anaesthetic to give Zeus a reasonable chance of recovery. Whilst the exact nature of the mass remained uncertain, it was decided that removal was the best plan of action.

Calcinosis circumscripta usually remains as a single defined mass. However, in Zeus’s case material from the mass appeared to have tracked up the tendon and penetrated the joint before causing extreme aggravation of the joint surface resulting in a severe inflammatory response.

Whilst Zeus remains a phenomenon of veterinary medicine, his recovery to date is extremely promising. He is now back enjoying being a youngster in the field with his friends prior to a check-up and medication of the joint at ten weeks post surgery!

Iris cysts are a common finding in the equine eye. More often than not, they do not cause any issues and are an incidental finding. Some; however, can grow to a size where they begin to affect a horse’s vision. Such horses generally present to us due to spooky behaviour. This is most apparent in sunny conditions, when the horse’s pupil is small and the cyst blocks light rays from reaching the back of the eye.

Treatment options

We will recommend treating iris cysts if we feel they are clinically significant – the horse in question is showing visual deficits or has started to spook.

Traditionally the treatment for iris cysts was laser ablation. We recently undertook a new technique to drain an iris cyst called ‘standing trans-corneal aspiration.’ This technique, which can be performed in suitable candidates, is performed under standing sedation, and local anaesthesia of the eye. A very thin needle is inserted into the eye, and the fluid from inside the cyst drained. The patient requires minimal medication following the procedure and most tolerate it really well.

If you would like to know more about iris cysts, please get in touch to discuss it with one of our equine vets.

Breeding season is in full swing and the team have been busy seeing lots of beautiful mares and foals.

When it comes to the actual birth, the biggest difference between horses and other species, such as cattle, is the speed of foaling. Once stage 2 (active labour) has commenced, the foal should be born within 15-45 minutes. Foals ‘dive’ out of the mare with two front feet followed by the muzzle. You should call your vet within 10 minutes of active contractions beginning if the foaling isn’t progressing, or any issues are noted. There are a variety of options available to deliver the foal, from manually repositioning to a surgical caesarean section (which fortunately is incredibly uncommon).

Staging of foaling

Stage 1 – 1-4hrs – The mare is preparing for foaling, and starts to become restless, pawing, pacing and getting up and down. She may sweat up and frequently urinate and defecate.
Stage 2 – 15-45 minutes – This is active labour, when the mare’s waters break, contractions begin and the foal is delivered.
Stage 3 – 2-4 hrs following birth – Passing of the placenta

Two complications we see during foalings are red bag deliveries and retained foetal membranes (retained placenta). These are two conditions at the opposite ends of the spectrum involving the release of the placenta.

Red bag delivery

In a red bag delivery mares will deliver the foal within the placenta, rather than it bursting to release the foal. A red velvety bag is seen first, before the foal or any fluids. THIS IS AN EMERGENCY SITUATION as once the placenta has separated from the mare, the foal will not be receiving any oxygen. The foal requires immediate delivery. The ‘red’ bag needs to be broken open using your fingers or scissors. If both the foal’s feet and nostrils are present we recommend pulling to help the foal out quickly to give it the best chance of survival.

Retained placenta

A placenta is classed as ‘retained’ when it is still attached to the uterus (womb) 3–4 hours post-partum. At this point, veterinary advice should be sought as horses are very sensitive to toxins released from bacteria on a retained placenta. These toxins can then cause endotoxemia, colic and laminitis. As vets we usually give these mares a combination of antibiotics and anti-inflammatories, to reduce the risk of endotoxemia. We also administer drugs to stimulate the uterus to contract, flush the uterus, and finally apply gentle traction on the placenta. In some circumstances it can take several visits, and over 24 hours before the placenta has loosened sufficiently to be removed. The mare may require antibiotics and uterine flushing for several days thereafter.

Foal targets

• 1 hour – Standing
• 2 hours – Nursing
• 3 hours – Passed meconium (first droppings)
• 24 hours – Antibody (IgG) blood sample

Once the foal has been born, we expect them to stand and nurse within a couple of hours. This is particularly important as foals are born without antibodies which protect them from diseases in the environment. The mare’s colostrum contains antibodies, but the foal quickly loses the ability to absorb them. Maximum absorption occurs during the first 12 hours of life, with the foal’s gastrointestinal tract gradually losing the ability to absorb antibodies such that by 24 hours absorption has ceased.

We can check the foal has received sufficient antibodies with a blood test taken at the mare and foal’s 24-hour post-partum check. If the antibody levels are insufficient, we can administer hyperimmune plasma to boost the antibody levels to a protective level. This will protect the foal from life threatening conditions such as sepsis.

Planning on breeding your mare this year? Call us on 01772 861300 to request a FREE copy of our Mare & Foal Guide or to discuss the options available with one of our experienced vets.

As the weather improves and pollen levels, as well as insect numbers increase, allergic skin disease is seen more frequently. Horses with allergic skin disease can present with itchiness or hives or both itchiness and hives together.

Sometimes it is easy to identify the trigger but more often than not, the cause is not easy to identify, and management of these horses can be incredibly frustrating with flare-ups common.

Management amendments can be made and the response to these changes monitored but in recurrent cases that we are struggling to control, skin tests (IDAT- intra-dermal allergen testing) can be performed to identify allergens which may be contributing to allergic skin disease. Skin testing remains the ‘gold standard’ diagnostic test for horses with allergic skin disease at this time.

Intra-dermal allergen testing

We are fortunate to be able to offer this service to our patients at Oakhill. Small blebs of common allergens are injected intra-dermally and the response to the allergens is checked 30 minutes, 4 hours and 24 hours following injection.

We subsequently provide our clients with a full written report detailing changes in management which may assist in managing these patients based on the results of the individual patient’s skin tests. De-sensitising vaccinations can also be formulated based on results of the skin tests to further assist in the management of these cases.

If you have any questions regarding allergic skin disease or the diagnosis and management of, please do not hesitate to contact the team.

Isabel presented to Stuart after her owners noticed that she had separated from her field mates. Once brought into the stable she was quidding and unable to eat haylage.

On examination, a significant swelling of Isabel’s right lower jaw was noted. As we were suspicious of a dental issue, after antibiotics and anti-inflammatories were administered to control her temperature and provide some comfort, radiographs (X-rays) were taken. This revealed a tooth root infection of the 3rd cheek tooth on her right lower jaw. The infection had caused lots of bony reaction with thinning and loss of parts of the jaw – the red arrow on the radiograph points towards this.

Once Isabel was stabilised and at the clinic, we proceeded with extracting the infected tooth under standing sedation and local anaesthesia (a nerve block). The tooth came out in one piece and as you can see, it was a whopper!!

Tooth root infections commonly occur in youngsters just several months after tooth eruption. Although Isabel now has one less tooth in her mouth, she is pain free and was very quickly back to eating happily as you can see.