Utility of preputial cytology to diagnose hyperoestrogenism in a dog with an intra-abdominal Sertoli cell tumour with concurrent thrombocytopaenia and intracranial haemorrhage

A 6-year-old unilateral cryptorchid dog presented with episcleral haemorrhage and ecchymosis. The complete blood count was consistent with pancytopaenia. Abdominal imaging confirmed the presence of a caudal abdominal mass suspected to be a Sertoli cell tumour (SCT) with associated myelotoxicity. The presence of myelotoxicity induced thrombocytopaenia and the delay in obtaining serum oestradiol results could make it challenging to confirm hyperoestrogenism in suspected SCTs without overt feminisation. Preputial cytology was used as a rapid and simple way to diagnose hyperoestrogenism in a dog without overt signs of feminisation and where the risk of significant haemorrhage precluded abdominal mass sampling. This technique could potentially detect hyperoestrogenism before clinical signs of feminisation and can readily be carried out in first opinion practice. A postmortem examination following sudden deterioration confirmed the presence of an SCT in the retained testicle and intracranial haemorrhage secondary to thrombocytopaenia.