DESEXING is the most commonly performed surgery in daily small animal practice and is well known to be the most efficient technique for reproduction control (Howe 2006). However, there is an increasing demand for non-surgical alternatives in pet species (Goericke-Pesch 2010, 2013, Goericke-Pesch and others 2014). There are several reasons for this: surgical desexing is known to induce not only desirable but also unwanted side effects (for example, urinary incontinence in bitches [Reichler 2009, 2010a, b]); it is irreversible and therefore not suitable for animals intended to be bred from later (Goericke-Pesch 2010, 2013, Goericke-Pesch and others 2014); and, depending on the country and culture, ethical frameworks (for example, castration of males being considered unethical) or legal restrictions (for example, animal protection laws that prohibit the removal of organs without medical