Malassezia Dermatitis

Malassezia pachydermatis is a yeast that is commonly found on certain areas of the skin of healthy dogs. In dogs that suffer from other skin conditions, for example flea allergy dermatitis, food allergies, atopy (allergy to air born antigens) or hormonal upsets, malasezzia organisms can overgrow and cause inflamed oily scaly itchy skin and ears often with a characteristic pungent odour.  We call malasezzia an opportunistic infection because it doesn’t cause a problem unless there is an opportunity provided by a primary skin issue. Some dog breeds, such as basset hounds, cocker spaniels and pugs, are more susceptible to malasezzia infections than others.

The characteristic feature of malassezia skin infections is the pungent odour accompanied by oily/scaley skin.  We can readily demonstrate the budding yeasts under the microscope.

Most dogs with malassezia have a problem localized to their ears, or to their ears and feet, and may lick or shake their heads constantly. When infections are really chronic the skin loses all its hair and becomes thick and black (we call this hyperpigmented and hyperkeratinised skin and the oily flakiness is called greasy seborrhoea).

Treatment for malassezia infections is always in two phases:

  • treatment of the yeast infection itself
  • treatment of the underlying condition that has predisposed to malasezzia infection. This is often ongoing or “maintenance” therapy, as once a dog has had a malassezia infection he/she is likely to get it again if there is no preventative care, due to his/her underlying medical condition

 Phase One treatment

Many vets have different preferences, but once we have made a positive microscopic diagnosis we like to use the following regime:virus

  • if your dog’s ears are very waxy and black, first clean all the wax and discharge out with an ear cleaner eg oticlens – in some cases it is necessary to do this under sedation. Keep oticlens handy as it (and similar products) are the best ear cleaning products available and should be used weekly as required and definitely instead of methylated spirits, olive oil or other products.
  • otomax ear drops morning and night for affected ears
  • malaseb shampoo – 10 minute soaks twice a week – NB it is important to know that malaseb is keratolytic – that is, it helps remove the top layer of dead skin cells where the malasezzia organisms are residing – for this reason, if your dog has a severe infection, the first one or two baths he/she has in malaseb may appear to make the condition worse – but rest assured this is quite normal and indicates that you are on the road to successful treatment
  • If your dog has a lot of scaly skin, at the end of the ten minute malaseb soak, use a face washer to gently rub all the scale away and expose smooth skin underneath this can take two or three shampoos if things are really bad! If you are having trouble, ask us to do the first bath or two for you.
  • After the first week of treatment, if your dog’s ear infection is severe, we may recommend that you rinse your dog’s ears daily in a 1/30 dilution of malaseb for two weeks. If wax builds up again be sure to clean it out with oticlens (the oily ear cleaner). Keep up the malaseb soaks twice a week during this time.
  • some dogs are so badly affected that they need a course of oral antifungal tablets – we will prescribe these if necessary. These courses typically last for three weeks or longer
  • Ensure adequate flea control with one of the newer flea products, and also ensure that your dog does not eat “histamine releasing foods” such as chocolate strawberries tomatoes and “no name” dog food.

Phase Two treatment

This is where we get to treat the primary problem that your dog has – if necessary. If your dog has an ongoing itch after malassezia treatment, and you have him/her on good flea control, we can then work out what the allergy problem is – see associated notes on atopy/food allergies.

For general natural anti-inflammatory care use aloveen shampoo, soaking 10 minutes all over once to twice per week. DO NOT use malaseb in this phase of treatment as it can be irritant to the skin. Topical cortisone products such as cortavance or neocort can be useful.   Antihistamine tablets, cyclosporine and sometimes prednisolone can also be useful at this stage.  NB Prednisolone should NEVER be used while there is an active malasezzia infection

The important thing to realise is that once your pet has been diagnosed with malasezzia he/she is likely to need life long preventative treatment of his underlying allergies – just as if he were an asthmatic child.  Early recognition of return of malasezzia is important.  If you suspect a repeat infection (by odour or appearance of skin) give him/her a good soak in malaseb shampoo,  and, if ears are involved, rinse them daily for a week or so with diluted malaseb shampoo.

If you are unsudogre of how to medicate your dog with his ear drops (as the ear canal is long and not straight and it is important to get medication right to the ear drum without damaging it) please ask us to show you how.

 

 

 

, , , , , ,