Where might you find marbles in a veterinary hospital? The exciting thing at Orange Veterinary Hospital is that you never know what is going to present next. Vet Andrew shares an interesting recent equine case he diagnosed.  

"Sterilised glass marbles have been used for many years to suppress oestrous activity in mares. A small sterilised marble is inserted into the uterus via the relaxed cervix when the mare is close to or just after ovulation. This must be done in an aseptic (near-sterile)  manner to avoid creating a uterine infection. The implant will suppress cyclical activity in about 70% of mares for around 90 days by utilising the mares own progesterone production. The marble can then be manually removed when the mare starts cycling again. If the procedure is done correctly in the right hands it does not impact on future fertility.

I was presented with a mare this season with a history of unusual oestrous behaviour and persistent vulval discharge. The owners had purchased the mare 4 years ago and had competed successfully on her but now want to put her in foal. The reproductive scan showed a pyometron (large pus filled uterus) and no ovarian activity. The mare’s cervix was closed so we set about bringing her into season and flushing her uterus. After several uterine lavages through a still closed cervix I was able to visualise not one but 3 large marbles (3.5cm) sitting at the bottom of the uterus. After several more days of oestrous induction and uterine lavages we were able to manually dilate the cervix enough to remove the marbles. Hopefully the mare will now return to a normal oestrous cycle and with some assistance go in foal. This case points out a few critical issues.

1. If one is good three is not always better!

2. Whilst many veterinary procedures may look simple to owners and onlookers, there is often more to the procedure than meets the eye.

3. If you are purchasing a mare with breeding in mind a breeding evaluation at pre-purchase examination can save a lot of grief and expense down the track."

Vet Andrew Litchfield discusses the risk of your mare having twins and how important it is to manage this in partnership with your vet.

"Whilst some breeds of horses commonly have two ovulations (thoroughbred and warmblood mares) the chances of a mare carrying twins to term and having live viable foals is very low. Normally we see twin pregnancies at early preg test 13-15 days in about 15% of thoroughbred mares. This season we have seen twins at a similar frequency in many other breeds that are normally not associated with twinning. In most situations we are aware that a double ovulation has occurred and one of the twins can be ablated successfully at 13-15 days with 95% survival of the other pregnancy. Resolution of twin pregnancies after implantation (day 16-17) is more complex and treatment is determined by the age of the pregnancies and whether they have implanted in the same or opposite uterine horns.

The diagnosis and treatment of twins can also be more difficult if the mare has not been scanned for service and an ovulation time is unknown. Twin ovulations are often asynchronous (up to 4 days apart) and because good quality semen can remain viable in the oviduct for 5 days even a single cover can result in a 14 day and 10 day pregnancy (difficult to detect)  if tested 14 days post service. Conversely if the mare is covered multiple times and it is possible to have and 18 day and 14 day pregnancy if scanned 14 days after the last cover.  For economic or practical reasons it is not possible to scan all mares to ovulation so timing of pregnancy testing is important. I would encourage mare owners to be guided to the following

1. Known single ovulation - preg test 14- 18 days after ovulation.

2. Known double/triple ovulation - preg test 14 days after first ovulation. If only one pregnancy is found the mare may need a repeat scan 2-3 days later.

3. Unknown ovulation times- preg test 14 days after last cover. Again if there are two ovulations detected on the ovaries then the mare may need a repeat scan if only one pregnancy can be detected.

4. Keep good records of your cover dates and if unsure of the best time to scan then please call to discuss.

Calf scours are nearly all caused by a handful of infectious agents, namely:

1. Rotavirus
2. Coronavirus
3. E. coli
4. Salmonella
5. Cryptosporidium 

In years gone by, it has been difficult to prevent these diseases. However, with progress in vaccinations, we are now able to help prevent the first four very effectively!

Calves are born with no immunity. All immunity they have in the first six weeks of life comes from their colostrum intake after birth. These ‘colostrum vaccines’ supercharge the dam's colostrum with specific antibodies against the bugs mentioned.

Vaccines around calving need careful consideration, we don't want to give too many vaccines at this time, and the timing of vaccination relative to calving is important. We are happy to help design a vaccination program for you.

Obviously as a Veterinary Clinic we need to be sure that these diseases are causing scours in your herd to offer the correct vaccination as a management tool.....which means investigating the cause of calf scours properly (including sending blood and feacal samples to the lab) is required.

Over the summer months we need to be aware of the risk of heat stress in horses and ponies.

During hot and humid weather heat stress may occur:

•  after intense exercise such as endurance or cross-country riding
•  during transport especially in poorly ventilated floats
•  in some horses that lack a normal ability to sweat, which increases their risk of heat stress 

Severe heat stress can progress to systemic inflammatory response, intravascular coagulation, kidney failure, neurological disease and, in extreme cases, death.

Signs of heat stress include hot and dry skin, persistent high heart and respiratory rates, mental dullness, dark gums and poor refill time, weakness and most obviously, an elevated rectal temperature (41 to 43 degrees celsius or above).

It is crucial to seek veterinary attention as soon as possible. The aim of treatment is to lower the horses body temperature quickly. Move your horse to a well ventilated shaded area, apply cool running water and fans to the entire body to allow evaporative cooling to occur. Use these methods as a preventative during high risk weather and exercise.

If required the attending veterinarian will administer intravenous fluids, anti-inflammatory and anti-endotoxic medications.

Please be on the look out for heat stress in your horses and ponies this summer.

Known as gelding, this simple operation is the most common elective surgery performed on horses. Gelding a colt involves surgically removing their testicles. Geldings are therefore unable to reproduce, and lack high levels of testosterone.

The benefits of gelding your horse include:

•  Geldings can be easier to handle, train and ride
•  Reduced aggressive behaviour towards humans, and other horses
•  Reduced injury risk to the horse
•  General ease of management

This operation is usually performed between six months and three years of age. Geldings are often carried out under a short general anaesthetic in the field. The procedure is quick and pain relief is provided. Tetanus protection and antibiotics are given as required. The skin is not usually sutured closed, but left open to drain as the horse moves about. 

Your veterinary surgeon will provide after-care recommendations specific to your horse at the time of operation. Normal management or work can be resumed within a few weeks.

Call us to discuss having one of our skilled vets geld your colt or stallion.