Possible cat contraceptive injection for the not-too-distant future

Today, The New York Times reports on cat contraception. This, as I see it, is the Holy Grail for many people concerned about the procreation of stray and feral cats. TNR programs are effective in a limited way because they are conducted in a limited way. The task is too big to control the procreation of all feral and stray cats, say in America, via TNR programs unless massive resources are delivered. The world needs something more universally effective. The experts have been researching feline contraceptives for quite a long time.

A study published in the online journal Nature Communications reports on a possible feline contraceptive method. It is not a pill but an injection which delivers a gene that enters the muscle cells of the female cat. This enables the muscle cells to pump out a substance called anti-Müllerian hormone, or AMH. This substance interferes with the development of egg follicles in the ovaries.

As I understand it, this in turn, prevents ‘breeding-induced ovulation’ which in turn, therefore, prevents procreation.

You may remember that the unsterilized female domestic cat (‘queen’) does not have periods like humans. They create eggs (ovulate) when they are mated by a male cat (tomcat). This is breeding-induced ovulation.

If that physiological process is prevented then there will be no kittens. The research is at a preliminary stage and more work is required. The study was small involving six adult female cats over a period of two years.

They analysed over 15,000 fees-dried faeces samples for oestrogen and progesterone levels and examined 1,200 hours of video recording mating behaviour.

AMH does not “impair sex steroids nor oestrous cycling”. This means that the female cats still going to heat in the usual way on my interpretation of that phrase but they don’t produce eggs which can be conceived.

GPT artificial intelligence interpretation of the study abstract is as follows:

That’s an interesting report you mentioned! It appears to describe a study on the use of an adeno-associated viral vector delivering an anti-Müllerian hormone transgene as a potential method for long-term contraception in female domestic cats. The study followed treated female cats for over two years and monitored various factors such as transgene expression, anti-transgene antibodies, reproductive hormones, mating behavior, and reproductive success.

According to the findings you mentioned, the ectopic expression of anti-Müllerian hormone did not affect sex steroids or estrous cycling in the treated cats. However, it did prevent breeding-induced ovulation, leading to safe and long-lasting contraception in female domestic cats. This research could potentially provide an alternative to surgical sterilization for controlling pet population and addressing the welfare concerns and ecological impact associated with free-roaming cats.

It’s important to note that while this study demonstrates promising results, further research and evaluation are typically required before such methods can be implemented on a larger scale. The findings suggest a potential solution for addressing the challenges associated with cat overpopulation and the ethical considerations surrounding euthanasia of healthy animals in overcrowded shelters.

Personal note:

This is very important for cat welfare. If feral cat populations can be controlled, reduced and ultimately eliminated humanely it will reduce the huge amount of distress caused by injury and illness suffered by these animals. It will also stop shooters taking pot shots at feral and stray cats as some like to do such as Woodsman001 in the United States.

Study citation:

Vansandt, L.M., Meinsohn, MC., Godin, P. et al. Durable contraception in the female domestic cat using viral-vectored delivery of a feline anti-Müllerian hormone transgene. Nat Commun 14, 3140 (2023). https://doi.org/10.1038/s41467-023-38721-0