Veterinary scientists from the University of Chile’s Veterinary and Livestock faculty may have found a way to control the world’s stray dog population. They’ve been testing a contraceptive vaccine that will sterilise dogs with one quick injection. Their vaccine was developed from an existing vaccine used on pigs.
“It began in Australia more or less in 1989, [and] what we did was to take the concept of immuno-castration, which already existed, and we developed and improved for use in domestic animals, mainly in dogs and to create an alternative for pigs, better than what exists already.” explains Dr Leonardo Saenz from the University of Chile. “The previous one was a vaccine by a pharmaceutical laboratory which needs two doses to take effect. In our case only one dose is needed for the vaccine to take effect.”
The effects of the vaccine should be the same as surgical castration and lack the side effects of existing vaccines, whilst working on both male and female dogs. “There is no progesterone or estrogen in the females and no testosterone in the males, which blocks reproductive activity and is a form of immunological castration,” says Saenz.
Use of the vaccine will not require the same costs, labour and care as surgery, reducing the difficulties associated with neutering stray dogs. “Since it is a vaccine which blocks the production of hormones it does not function as a contraceptive but rather as a immune-castrator,” explains Saens. “The difference is that contraceptives prevent animals from going on heat, it will still engage in reproductive activities but it will not be able to fertilise. In this case there are no hormones so there is no activity. There are no gametes so the animal is sterilised as a result of suppressed hormones.”
Patents have been purchased in Europe, Chile and the United States where scientists hope to reduce the population of un-neutered strays by three times the number that are currently treated through surgical methods. The vaccine is still undergoing further testing.