Horses can get a number of issues with their skin, we are going to do a run of posts on a few common skin issues over the next week:

Sarcoids.

Sarcoids are cancerous growths on the skin.

They can appear anywhere on the horse and range from small skin tag size lesions to large diffuse areas. Malignancy varies depending on the type of sarcoid.

  • Nodular sarcoids: these look like “firm lumps” on or under the skin,
  • Occult sarcoids: these look like flat plaques
  • Mixed sarcoids: normally appear as a large occult with small nodular regions and are more malignant than the two other types individually. However, a mixed sarcoid can be a mix of any two or more sarcoid types.
  • Verrucous sarcoids: these are “warty” in appearance and often present like cracked skin areas grey in appearance.
  • Malevolent sarcoids: The most aggressive type. Often extensive in appearance and grow quickly. These are, thankfully, rare.
  • Fibroblastic: Fleshy masses that grow quickly bleed easily and appear ulcerated.

Treatment options:

There are many different treatment options for sarcoids,

  • AW5 cream is used which is a chemotherapy cream with a protocol designed specifically for your individual horse.
    • This must be applied by a veterinary surgeon.
  • Laser surgery/surgical resection
  • Radiotherapy
  • Injection of specific chemotherapy drugs can be used but these are only considered in abnormal cases.

Treatment of sarcoids can be very time consuming and expensive, however must be done appropriately as otherwise the tumours can become more malignant.

We do not advise banding or surgical removal unless this is advised by Professor Knottenbelt.

Melanoma

Melanomas are most commonly found in grey horses. They are more prevalent in older horses but can occur at any age.  They are normally slow growing and benign; occasionally can be aggressive and metastasise around the body. 

The most prevalent sites for melanomas:

  • Back of the jaw/mandibular area
  • Around the salivary glands,
  • In the base of the ears
  • Inner lips, on the dock
  • Around the anus and sheath of geldings internally and externally.

However, they can occur anywhere on the body, not just these areas.

Melanomas are normally slow growing and benign, but occasionally can be aggressive and metastasise around the body. 

What Causes them:

Melanomas develop when cells that contain the dark pigment melanin (melanocytes) proliferate and multiply. The majority of equine melanomas grow in the skin and are readily visible. They are most often found as clusters of firm, dark nodules or as solitary black bumps.  

Treatment:

Normally we advise monitoring the melanomas for any changes or developments.

Treatment options are fairly limited:

  • Surgical debridement or cryotherapy is most commonly done if required.
  • Chemotherapy is an option but has varying results when done on its own but is useful in conjunction with surgical debridement.
  • Therapeutic vaccines are available but are not licenced for use in horses and case selection is critical.

Sweet Itch:

Sweet itch is a clinical sign of a systemic allergic reaction to midge saliva.

Clinical signs:

  • Severe pruritic (itching response)
  • Mane, tail and head areas
  • Traumatic skin wounds

Treatment and management:

  • Sweet itch vaccine – this is two vaccinations 2 weeks apart. It is to be done before the season starts (Dec – end of Feb)
  • Topical steroid treatment
  • Sweet itch rugs and powerful fly spray
  • Fans in stables to provide a cross wind
  • Stable during the day and out at night avoiding sunrise and dusk

Trying to establish a balance can be very challenging so please feel free to have a chat with us about ways to help this work for you and your horse if needed.

Ringworm:

Ringworm is a zoonotic disease. This means that it affects ALL animals including humans and is very easily caught in all species.

Clinical signs:

  • Circular hairless lesions with a crust/scurfy appearance to the skin.
  • Can be one or two lesions through to the horse being covered in them.
  • Highly contagious and will pass from horse to horse through contact with each other but also humans, equipment, tack, headcollars, saddle pads.

Treatment:

  • When treating not only the horse but all contact areas must be treated too.
  • Remove bedding from stable when disease has settled
  • Treat stable with Virkon.
  • Topical treatments are normally sufficient, Imaverol shampoo is commonly used but other anti-fungal washes are available but only through a veterinary practice.
  • Off the shelf topical anti fungals from saddleries etc are insufficient. 

When treating a horse with ringworm you should always wear gloves, and ideally change your clothing before interacting with other horses. If you have a yard cat, talk to your vet about topical treatments for them too as otherwise they will potentially carry the fungus to others.

Mud fever

Mud fever is a lay term for bacterial pastern dermatitis.

Commonly found on the white socks of horses, however it can affect any part of the body and any colour.

When the issue occurs on the body not the limbs it is normally referred to as rain scald.

There are many opinions as to how to treat this but the basics to remember are:

Treatment:

  • Scab removal: Bacteria lives under the scabs therefore use baby oil or Emollient to soften scabs alongside clingfilm to sweat them off.
  • It is bacterial so antibiotic treatment is required. Once the scabs have been removed, topical is sufficient.
  • Ensuring the legs stay clean and dry as much as possible is vital.
  • Wet skin chaps and any crack or damage to the skin is a viable entrance point for the bacteria and so the infection will continue to spread. 
  • This infection can be very painful and so pain relief may be required from the vet. 

Do NOT put barrier oils on the affected area, especially whilst the infection is active. As mentioned above, the bacteria survives under the scabs, so if barrier oils are applied then this is another barrier for the bacteria and will slow down healing time.

Once the infection is cleared and the skin is normal and healed then barrier cream or oil can be useful. Boots are of minimal use as mud/moisture can get underneath, or the boots may make the limbs sweat and thereby open pores which are again an access point for bacteria. 

If normal treatment and management doesn’t settle what appears to be mud fever, then a blood sample may need to be taken as organ damage/disease such as the liver, can cause a similar looking problem due to photosensitivity. 

If you have any concerns please do not hesitate to contact us.