Mud fever management

The weather is changing from hard ground to soft and with it comes the endless mud and the topic of mud fever returns to our chats around the yard. What works best? Is this mud fever or feather mite infestation? Should I apply barrier cream/pig oils or not? Its one of the simplest conditions to diagnose, but actually one of the most difficult to manage so what can be done?

What is mud fever?

Mud Fever (or pastern dermatitis) is a skin infection, caused by a variety of different bacteria and fungi. Typical signs include scabbing, pain, swellings, discharge and ulcerated areas in the skin. More severe cases can progress to lameness and lower limb swellings, or even a generalised whole body infection if not spotted early enough.

mud fever

What causes it?

Essentially, damage to the surface of the skin predisposes a horse to mud fever – most commonly wet conditions that harbour bacteria/fungi (eg. mud). This softens the skin and allows breaks in the defences to occur, creating an ideal environment for bacteria/fungi to set up an infection. This is exacerbated in heavily feathered breeds where moisture gets under the hairs, softening the skin further and making it more susceptible to infection. In this way, using oils/grease etc once infections start tend to make things worse – so check the pasterns thoroughly for scab/swellings before applying these.

How is it diagnosed?

Clinical signs are often classic, but swabs to check for bacteria/fungi and hair plucks/skin scrapings to rule out mites are sometimes performed. Mite infestations often cause a more generalised, lower leg itchiness (that classic Cob scratching its legs on the fence post) and smaller scabs, though sometimes they can predispose to mud fever by causing breaks in the skin. In an ideal world, swabs should be taken to check for the predominant cause (e.g. fungi or bacteria) and therefore target treatment appropriately, resulting in a faster resolution of signs. Whilst this costs a little extra money, we see cases where a response to treatment has been less than ideal, and swabs have indicated a multi-resistant bacteria. This has resulted in another course of treatment and further expense – something to bear in mind when discussing treatment options with your vet.

How is it treated?

The most important part of treatment is to keep the leg dry – remove the mud and wet conditions and the skin hardens. Initially, clip the leg and remove any scabs that you can feel – which can be done using dilute hibiscrub (chlorhexidine) and some gauze swabs (can get from the pharmacy/supermarket). These can be very stubborn in certain cases, and creams such as dermisol may need to be applied under a bandage/cling film for 12-24hours to make them easier to remove. Some horses are exceptionally painful, and will only allow removal under sedation (either Sedalin/Domosedan or by the intravenous route).

Once this is done, dry the leg completely (e.g. paper towel/hair dryer if your horse will tolerate it! – towels often don’t dry the skin enough). It goes without saying that you need to remove from all wet conditions until the infection is under control otherwise response to treatment may be delayed or even fail. After this, you can start to think about treating the condition. Depending on their severity, different treatments may be recommended to hopefully get on top of the mud fever e.g.

  1. Mild/Exudative; Topical application of an anti-fungal/anti-bacterial cream – e.g. Flamazine or a cream your vet may make up (we make creams that contain both an anti fungal and antibacterial component) +/- dressing changes.
  2. Mild/Scabby; Appropriate anti-bacterial/anti-fungal dressings – these can be left on for 24-72hrs and may need repeated dressing changes to work.
  3. Severe/Systemic; Course of systemic antibiotics/anti-inflammatories prescribed by your vet – often a last resort.

If in doubt – feel free to contact your vet or even send them a photo for a chat about what treatment your horse may need. Horses may need a prolonged course of treatment depending on severity, and in between treatments the same protocol should be adhered to ie. Keep away from mud, clip, remove scabs, wash/dry the leg and then treat appropriately.

How can mud fever be prevented?

Simple – Avoid mud! Or if this is unavoidable, ensure for a period of the day your horse stands somewhere where it can dry off (e.g. stable, hardstanding). When the mud is dry, brush off or wash off with WARM water if they are stubborn – but ensure the leg is dry afterwards. Unfortunately, in some cases removing those prized feathers is the only way of preventing the condition – gutting but often the show season is finishing and so there is plenty of time for regrowth.

Barrier creams/oils are useful, however, the horse’s legs must be exceptionally dry and clean before each application, or they may compound the problem. The same goes for turnout boots, which should be removed and the leg dried daily. The three top tips in preventing it would probably be:

  1. Check your horse’s legs daily to ensure the condition is caught early.
  2. Keep your bedding clean and DRY
  3. Always allow time each day to make sure the legs are dry and any mud is removed.

Written by Chris Neal BSc (Hons) BVSc MRCVS, November 2016

Scott Dunn’s Equine Clinic is part of CVS (UK) Limited, a company which owns over 300 veterinary practices in the UK. Company Registration Number 03777473. Registered Office CVS House, Owen Road, Diss, Norfolk, IP22 4ER