here - Australian College of Veterinary Scientists

Diagnosis
History of access of horses to water-logged pasture or lagoon creeks, or inescapable
rain flooded paddocks.
Clinical signs of pruritus with serosanguineous stringy discharge is almost
pathognomonic.
Biopsy early lesions; send fresh sample for culture and culture immediately on
selective media such as Campy blood agar or on Sabouraud's dextrose agar (if being
transported for over 1 to 3 days, samples are better transported on ice packs and
cultured on non-selective blood agar) (Grooters et al 2002).
Histopathology
Cytological examination of aspirates and direct smears shows granulomatous and
pyogranulomatous inflammation with possible eosinophils. Fungal elements are
often found in foci of necrotic material (kunkers) , Such findings are not definitive
due to the similarity to the hyphae of Basidiobolus haptosporus and Conidiobolus coronatus
Management
There are no reported cases of spontaneous remission with pythiosis.
Surgical excision of the tumour is the most common and successful method,
particularly in the more chronic cases. As the surgery can be both extensive and time
consuming, general anaesthesia is usually preferred (Bridges & Emmons 1961,
Bridges 1972, Restrepo et al 1980).
Surgery on leg lesions is considerably aided if tourniquets are used above the surgical
area. Careful dissection over tendon and joint locations is important and in some
cases, close application of tumour to joint capsule and tendon sheath makes the
surgical approach extremely difficult. Due to the extensive nature of the draining
holes and sinus, the skin edges often cannot be closed.
Strong iodine is packed into the surgical area and pressure bandages are applied to
the lesion. These are left in situ for 2-3 days, and once granulation has commenced,
the wound can be left unbandaged. Local application of strong iodine (10%) may
have some beneficial effect. Repeat surgery is more usual than not when the lesions
occur around tendons and joints.
Intravenous medication with sodium iodide, 1g/15kg b.w. twice at weekly intervals
(Pascoe 1973) is a useful adjunct to surgery, and also aids in the reduction of some
abdominal growths of excessive size. Amphotericin B was used both systemically
and topically (McMullan et al 1977). Intravenous treatment was well tolerated at an
average daily dose starting at 0.38 mg/kg and increasing to as high as 1.47 mg/kg.
ACVSC Proceedings Dermatology Chapter Science Week 2005 101