Feral cat numbers in the UK are thought to number around one million and the Dogs Trust estimates it dealt with just over 110 000 stray and abandoned dogs in 2013. This scenario is common across the world and in the developing world in particular the control of feral populations is an ongoing challenge as well as a huge welfare issue. The only options currently available are expensive surgical neutering, or euthanasia of otherwise healthy animals. There is an urgent need to develop new approaches to deal with this growing issue. To address this issue and reduce these numbers we are developing a single-dose, non-surgical sterilant for cats and dogs as an alternative to surgical neutering and euthanasia.
To achieve this goal we have designed a targeting strategy based upon the inclusion of bespoke peptide sequences into the measles virus hemagglutinin envelope protein, permitting specific targeting of testicular Sertoli cells (essential for sperm development). Combining this cell-specific targeting approach with delivery of miRNAs against key genes, we demonstrate that a single injection leads to persistent knock-down of gene expression required for sperm production, resulting in infertility which is maintained for many months. This proof of concept study highlights the potential of this novel approach, which is now being taken forward for preclinical trials.