Malassezia spp are normal commensal yeast of skin and mucosa in cats^[1].

Malasezzia spp yeast can result in feline paronychia, seborrhoeic dermatitis in the Sphinx, generalized dermatitis and paronychia in the Devon rex and otitis externa in most breeds of cats^[2]. It is also seen associated with idiopathic facial dermatitis in Persianand Himalayan breeds^[3].

Species of Malassezia which affect cats are M. pachydermatis (most common), M. obtusa, M. globosa, M. slooffiae, M. sympodialis, M. furfur and M. restricta. Interestingly, M. nana appears to be more frequently isolated from the ear canal, whereas M. slooffiae more often isolated from the claw of cats^[4].

In most cases Malassezia spp infection is a secondary problem. It can occur in conjunction with allergies, immune mediated disease, chronic bacterial infections, long-term antibiotic use and seborrhea. It may also occur as a primary infection such as the sphinx. It also has been reported in cats treated for Pseudomonas spp infection (a bacteria), probably because treatment for that condition requires long term antibiotic use with broad spectrum antibiotics^[5].

 

Clinical signs

95% of cats with otitis externa have Malassezia infection, either as a primary etiological agent, or secondary to other causes^[6][7].

Malassezia species are frequently isolated from younger cats (1 to 4 years of age), suggesting that feline otitis externa may be associated with lipid-dependent Malassezia species in addition to the non lipid-dependent species M. pachydermatis (Khosravi et al, 2009).

Sphinx often have a greasy exudate, which to a varying degree accumulates on the surface as a thin sticky, dark brown or reddish brown layer. Accumulation of greasy material may be particularly noticeable around the claws and in the palmar and/or plantar interdigital web. Within the breed there are many individuals with a varying degree of dark brown, greasy exudate around their claws, and at other sites, including axillae, groin and sometimes ears^[8][9].

Sphinx cats carry significantly higher numbers of Malassezia spp yeast than other breeds of cats, excepting the Devon rex. No correlation between Malassezia spp infection and diet, housing conditions and genetics of individual Sphinx lines has as yet been reported. Many Sphinx owners bathe their cats regularly, often every 7-14 days, to remove the excessive greasiness from the body, claws and ears. For many Sphinx cats, greasiness becomes increasingly obvious the longer it has been since their bath.

 

Diagnosis

It can take extensive diagnostic work to correctly identify the underlying cause of yeast infections when they are recurrent. Tests for immune system disorders like feline leukemia (FeLV) or feline immunodeficiency virus (FIV), hormonal disease, allergies, bacterial infections, parasites (ear mites, Demodectic mange, etc.) and careful review of medication histories may be necessary to establish the diagnosis of the primary problem, as retroviral infections do make cats more prone to Malasezzia infection^[10].

In Persian cats, this needs to be distinguished from hereditary greasy seborrhoea.

 

Treatment

Itraconazole appears to be the drug of choice in treating these cases that do not respond to products such as Malaseb and other anti-fungal shampoos.

 

References

1. ↑ Cafarchia C& Otranto D (2008) The pathogenesis of Malassezia yeasts. Parassitologia 50(1-2):65-67
2. ↑ Bond R (2010) Superficial veterinary mycoses. Clin Dermatol 28(2):226-236
3. ↑ Chung TH et al (2009) Topical tacrolimus (FK506) for the treatment of feline idiopathic facial dermatitis. Aust Vet J 87(10):417-420
4. ↑ Bond R et al (2008) Carriage of Malassezia spp. yeasts in Cornish Rex, Devon Rex and Domestic short-haired cats: a cross-sectional survey. Vet Dermatol 19(5):299-304
5. ↑ Khosravi AR, Shokri H, Rad MA, Jamshidi S. (2009) Occurrence of Malassezia Species in Persian and Domestic Short Hair Cats with and without Otitis Externa. J Vet Med Sci Dec 1
6. ↑ Shokri H et al (2010) Occurrence of Malassezia species in Persian and domestic short hair cats with and without otitis externa. J Vet Med Sci 72(3):293-296
7. ↑ Ahman, SE & Bergstrom, KE (2009) Cutaneous carriage of Malassezia species in healthy and seborrhoeic Sphynx cats and a comparison to carriage in Devon Rex cats. JFMS 11:970-976
8. ↑ Ahman, S et al (2007) Carriage of Malassezia species yeast in healthy and seborrhoeic Devon Rex cats. Med Mycol 45:449-455
9. ↑ Ahman, S et al (2007) Treatment of Malassezia pachydermatitis-associated seborrhoeic dermatitis in Devon Rex cats with Itraconazole – a pilot study. Vet Dermatol 18:171-174
10. ↑ Reche A et al (2010) Cutaneous mycoflora and CD4:CD8 ratio of cats infected with feline immunodeficiency virus. J Feline Med Surg 12(4):355-358