RECENTLY I received a call-out to a 15-year-old gelding with a swollen sheath.

The owner explained that the swelling had been gradually increasing in size over a three to four day period.

She explained that she had washed the sheath area with warm water and disinfectant and whereas that treatment plan had worked for her in the past, this time her efforts appeared to be in vain.

The gelding was able to urinate but was becoming more painful in the area of the sheath and now resented her efforts to intervene and she was afraid that he might start to kick.

When I arrived in the yard, the owner walked the gelding out of the stable. The sheath was very oedematous and he was very stiff walking. When I tried to palpate the sheath, he was having none of it and started to kick out. The only solution was to administer sedation.

When sedated, the horse relaxed. Using a gloved hand lubricated with KY jelly I was able to clean the sheath area with warm water and a commercial sheath cleaner (Excalibur). After washing, the area was rinsed with warm water. Rinsing the area is important in case any substance used in the cleaning process might cause irritation of the sensitive skin.

The sheath was full of black waxy material called smegma. Sebaceous glands in the lining of the sheath produce a secretion called sebum, this mixes with sloughed skin cells and dirt to form smegma which can be flakey or can build up to form a soft waxy deposit.

As the horse was under sedation and was relaxed, it was possible to catch and draw down the penis and to clean the entire area properly. It is essential to do this in order to properly clean the area.

URINARY DIFFICULTIES

At the tip of the penis, there is a fold of skin called the diverticulum which lies near to the opening of the urethra. In some cases of swollen sheath, a plug of smegma referred to as a bean can get lodged in the diverticulum. This can cause a lot of pain and can, in some cases, lead to difficulty in urination. However, there was no bean present in this horse.

When smegma builds up in the sheath, it can attract bacteria which set up an infection. This can lead to irritation of the tissue in the area causing inflammation. This in turn leads to increased blood supply to the area. Fluid can move out from the blood vessels into the tissue causing the sheath to swell.

Cleaning as described above is essential. In many cases antibiotics will be needed to deal with bacterial infection. Exercise also is important to increase circulation and help to reduce the swelling.

Geldings are more prone to this condition than stallions because they do not extend their penile shaft beyond the confines of the sheath with any frequency. They need regular cleaning of the sheath and penis. This should be done twice a year.

If geldings are washed on a regular basis from a young age then it should be possible to keep problems at bay. Unfortunately sheath cleaning is often not done when it should be because there is either a reluctance to do it as it is an unsavoury job or there is a lack of knowledge about the condition and how to deal with it.

With a young gelding it can be a good idea to get the veterinary surgeon to sedate the animal and demonstrate the cleaning technique the first time after which the owner can begin to do the job themselves as the animal becomes more familiar with the routine.

Safety should come first and if a gelding is becoming difficult then the veterinary surgeon should always be called for assistance.

CAUSES

Apart from infection, there are other causes of sheath swelling. If, after treating a gelding as described above, there is no improvement, you should get your veterinary surgeon to investigate if there could be another cause for the sheath swelling.

These other causes could include:

1. Trauma due to a fall

2. Tumours of the prepuce or penis. These can include sarcomas and carcinomas. They can be serious but, if caught in time, can be successfully treated.

3. Congestive heart failure causing a build-up of fluid in the sheath area.

If the veterinary surgeon suspects that some of the above causes are involved then they may organise tests such as blood tests or ultrasound exam of the tissues involved or tissue biopsies to assist them in coming to a diagnosis.

Sheath swelling is a nasty painful condition that in most cases can be prevented by regular cleaning which, just like vaccinations, should become part of a gelding’s planned treatments.

Denis Doyle MVB MRCVS is a veterinary surgeon in Wicklow town and is a member of the Equine Group of Veterinary Ireland

Email: hq@vetireland.ie

Telephone: 01 - 457797