Feline injection site sarcomas

Feline injection site sarcoma (FISS), formerly known as Vaccine Associated Sarcoma (VAS) is a rare, but life-threatening disease. The incidence estimates have varied from 1 case of FISS per 1,000-10,000 cats vaccinated in North America and between 1 per 5,000-12,500 vaccination visits in United Kingdom. It has been primarily associated with vaccine administration, but several other injectable materials/substances have been implicated as aetiologic agents, namely lufenuron, penicilin, metilprednisolone, meloxicam, non-absorbable suture material and microchip. FISS can have a large latency period (three months-13 years), but eight years old is the average age of onset. They are tumours that arise subcutaneously, reaching a variable number of layers beneath the skin (muscle, bone). They are firm, not painful, solid and variable in size. Clinical assessment and biopsy are the basis for FISS diagnosis. In order to prevent FISS, vaccination should be carefully planned and be provided in easily resectable regions. Hind legs, tail and flanks, are preferable regions for vaccine administration