Fungi in cats. Combining cryosurgery and itraconazole to combat sporotrichosis
Sporotrichosis is a subcutaneous mycosis, of variable evolution, caused by a saprophytic fungus. All forms of sporotrichosis are caused by the fungus Sporothrix schenckii, which is considered a dimorphic fungus, that is, it develops in mycelial form in the environment or in vitro at temperatures of 25–28 °C, and as a yeast in vitro or in vivo at 37 °C.
Fungi in cats. What is feline sporotrichosis?
Sporotrichosis is a subcutaneous mycosis, of variable evolution, caused by a saprophytic fungus. All forms of sporotrichosis are caused by the fungus Sporothrix schenckii, which is considered a dimorphic fungus, that is, it develops in mycelial form in the environment or in vitro at temperatures of 25–28 °C, and as a yeast in vitro or in vivo at 37 °C.
This microorganism is found throughout the natural environment, mainly in senescent plants or soils rich in organic matter.
Clinical signs
Sporotrichosis is much more common in cats than dogs. Affected cats tend to be outdoor cats, male mixed breeds and between 2 and 3 years old. The main route of infection is during fights, followed by contact with diseased cats and iatrogenic infection.
Tegumentary lesions are ulcerated or scabby, usually located on nodules, where they fistulise and drain. They are mostly found on the head, in places such as the nasal planum and ears. They may also be located on the fore- and hindlimbs, as occurs in dogs.
Some cases course with nasal, oral or genital mucous membrane involvement and general signs, such as fever, decline and anorexia.
- Canine sporotrichosis: this type of fungus in dogs usually develops in a localised cutaneous or cutaneous lymphatic form, with multiple, firm nodules that may become necrotic in the centre; often associated with verrucous, fistulated and exudative areas. Normally there is no pruritus or pain.
Feline sporotrichosis: diagnosis
The diagnosis should focus on identifying the agent, mainly by mycological culture.
Feline sporotrichosis: treatment
A recent study assessed the efficacy of cryosurgery combined with itraconazole for the treatment of feline sporotrichosis in cats naturally infected with fungi from the Sporothrix schenckii complex.1 The diagnosis was confirmed by cytology and fungal culture and each subject received oral itraconazole 10 mg/kg/day for different durations prior to cryosurgery and the same protocol was maintained for 4 weeks after the lesions had healed completely.
The study concluded that the combination of cryosurgery and itraconazole was effective in the treatment of feline sporotrichosis and reduced treatment duration compared to protocols using medication alone.
If you would like more information about dermatology, specifically about atopic dermatitis, please download this clinical report by clicking here.
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de Souza CP, Lucas R, Ramadinha RH, Pires TB. Cryosurgery in association with itraconazole for the treatment of feline sporotrichosis. J Feline Med Surg. 2016 Feb;18(2):137-43.
