Dr. John Bradshaw in his book Cat Sense writes that if a mother is highly stressed during her pregnancy her stress hormones may cross the placenta and impair the development of her kittens’ brains and endocrine systems. The endocrine system refers to the kitten’s hormones. I wanted to check this and expand on it. I have found a study which rather ironically is about pregnant rats who were exposed to acute stress by the presence of a cat.
I don’t like this sort of experiment. It’s unkind and I think unnecessary but in any case the researchers exposed pregnant rats to stress during the 10th, 14th or 19th gestational day. They studied their offspring in terms of anxiety, neo-phobic and social behaviours. They found that when a pregnant mother was exposed to stress during the 10th and 19th days of gestation their offspring were more anxious and less aggressive than is normal for rats of that age. Stress exposed to the pregnant mother at day 14 did not have the same result.
They decided that the decrease in sensitivity i.e. hyposensitivity, during day 14 was due to an important plasticity of the developing gross nervous structures. That’s not particularly relevant but what is relevant is that stress during pregnancy can affect the character and therefore the behaviour of offspring.
The question is whether that behaviour is carried forward to adulthood. “Anxious and less aggressive” implies timidity. Is it fair to say that kittens born to be more anxious and less aggressive because their mother suffered stress during pregnancy might grow up to be timid cats when they are adult which in turn makes them less adoptable?
People like confident adult domestic cats because they interact more freely and with more confidence. People want domestic cat to interact because it supports companionship. People adopt cats for companionship, primarily.
Perhaps, therefore, it is fair to say that many unwanted cats at shelters who are ultimately euthanized were exposed to the stress hormones of their mother who was herself stressed. As we are talking about domestic female cats usually living in someone’s home, the stress will have been caused by the human environment in which they were placed. We could therefore trace the fault or the failure back to a stressful human environment created by an individual person.
Is it possible to argue that cat owners who irresponsibly allow their females to become pregnant are also carelessly exposing their pregnant female cats to stresses which has long-term consequences?
The study referred to: Effects of prenatal stress on anxiety and social interactions in adult rats (2005) by V. Patin, B. Lordi, A. Vincent, J. Caston.
SOME MORE ON PREGNANCY: