Kitten to Cat 67
were far quicker to approach, investigate and interact with novel objects and
unfamiliar people than those fathered by less confident males. Turner et al. (1986)
found a similar effect when laboratory cats were tested regarding their friendliness
towards familiar people. In both studies, as is usual for cats, the father had no contact
at all with the kittens so this influence can only be genetic.
Prenatal stress
Described briefly, stress is an emotional and physiological reaction to a physiolog-
ical, psychological or emotional challenge. The stress response is an important and
necessary function because it increases the ability to escape from or defend against
danger. But the chemical changes within the body that stress causes, particularly
the production of ‘stress hormones’, can have detrimental effects on both health
and welfare if produced excessively or long-term (see Chapter 6).
Prenatal stress is stress experienced by the mother during pregnancy, which has
been shown to have physiological and behavioural effects on the developing foetus
(Weinstock, 2008).
epigenetics. Literally meaning ‘above genetics’, epigenetics relates to how the
expression of DNA, but not the DNA sequence, can be altered by external influ-
ences (Jensen, 2013). Stress hormones produced by the mother during pregnancy
can cross the placenta and cause epigenetic changes to her developing offspring,
altering how they deal with stress in later life. This can be advantageous for the kit-
tens if the level of stress they encounter throughout life matches that experienced
by their mother during pregnancy but, if not, then their stress response will be
excessive and maladaptive to their environment. This can result in individuals that
show signs of increased emotionality, including anxiety, fear and reactivity, which
in turn can be linked to increased aggression and antisocial behaviour (Simonson,
1979, cited in Bateson, 2000).
the nutritional status of the mother. Undernourishment of the mother is one cause
of prenatal stress but it can also have other critical influences. Smith and Jansen
(1977) (cited in Bateson, 2000) found severely undernourished mothers gave birth
to kittens with growth defects in the brain, resulting in abnormalities in both motor
and behavioural development. Further studies have also found that kittens born
to mothers subjected to insufficient nutrition during pregnancy show increased
emotionality, reduced learning ability, poor motor skills and are more likely to be
aggressive towards other cats (Simonson, 1979, cited in Bateson, 2000; Gallo et al.,
1980).
Postnatal physical development
The motor skills and senses are far from fully developed at birth (Fig. 5.3) but a kit-
ten’s tactile, thermal and olfactory senses are sufficiently well developed for these to