Sarcoids the most common equine tumours found in analysis of lab results

Sarcoids were identified as the most commonly diagnosed equine tumours in an analysis of 29 years of records kept by a diagnostic pathology laboratory in Britain.

In all, 964 cases were included in the survey, the findings of which have been published online ahead of print in the Equine Veterinary Journal.

Sarcoids accounted for 24 percent of cases, followed by squamous cell carcinomas, at 19 percent, lymphomas at 14 percent, melanomas at 6 percent, gonadal stromal tumours at 6 percent, and mast cell tumours at 4 percent.

The researchers investigated the diagnoses at the pathology lab at the University of Bristol for samples from January 1982 to December 2010

They looked, in particular, for any changes in the types of tumours diagnosed and any relationships between tumour type and the age, sex and breed of the animals.

The researchers found increasing age to be a risk factor for tumour development. Mares, they found, were at reduced risk of squamous cell carcinomas when compared to the thoroughbred/thoroughbred cross and gelding as a reference.

Arabian and Arabian-cross horses had a higher risk of mast cell tumours.

Cobs and cob crosses had an increased risk of squamous cell carcinomas and mast cell tumours, while ponies had an increased risk of melanomas.

The research team found that the mean age of submissions increased in each successive decade and the breed composition became broader.

Sarcoids and lymphoma formed a smaller proportion of diagnoses in later decades.

They said the types of tumours submitted to the laboratory had changed over the last 30 years, suggesting further studies were warranted to follow trends.

E.J. Knowles, W.H. Tremaine, G.R. Pearson and T.S. Mair.
A database survey of equine tumours in the United Kingdom.
doi: 10.1111/evj.12421

The abstract can be read here.