SUMMARY A survey of granulomatous and neoplastic diseases of the skin of horses of tropical north Queensland was carried out during the period 1970–1980. Of 338 horses affected, 46.4% suffered from equine fibrosarcoma (sarcoid), 30.2% from phycomycosis, 7.4% from squamous cell carcinoma, 6.8% from other tumours, 4.7% from cutaneous habronemiasis and 4.4% from exuberant granulation tissue.

Most specimens were submitted during the first half of the year after the wet monsoonal season and significantly more diseases originated during the first quarter. There were minor variations with breed, age and sex susceptibility between each disease group. Most lesions were found on the legs and head although other parts of the body were also affected. The size and anatomical distribution of lesions varied with each disease.

When the results of this survey were compared with reports from southern Queensland as well as from Florida and the United Kingdom, major differences between localities were observed. Some reasons for these differences are discussed.