90 Chapter 6As with FOPS the exact cause of hyperaesthesia is unknown. It is likely that it is not
a separate disease but a collection of symptoms related to a wide range of undiag-
nosed, skin, musculoskeletal or nervous system conditions. Exposure to long-term
stressors appears to be a predisposing factor, and acute stressors may act as a trigger
factor (Bowen and Heath, 2005; Heath and Rusbridge, 2007).
The cardiovascular system
Because of their direct influence on the heart and blood pressure, prolonged or
frequent release of catecholamines can have potentially damaging effects on the car-
diovascular system (Cohen et al., 2007).
Lifespan
Human and canine studies have shown that chronic stress can shorten lifespan and
accelerate ageing by causing changes to DNA (Dreschel, 2010; Ahola et al., 2012).
Although there are no specific studies on this in cats, it is possible that they may suffer
the same effect.
The Impact of Stress on Mental and Emotional Health
Emotions such as fear, anxiety and frustration are all a part of stress, which can be
detrimental to mental health and welfare.
Chronic anxiety can increase the risk of mental health issues in humans and it
is possible that there is a similar effect in animals. For example, there is a recognized
link between anxiety and compulsive disorders in animals (Overall, 1998).
Stereotypic behaviours in animals can also arise from long-term anxiety, conflict or
frustration (Mason, 1991). A further effect of stress is an increase in the rate of
cognitive decline in animals already suffering from cognitive dysfunction syndrome
(Mills et al., 2014).
Stress and common feline behaviour problems
Aggression
Sympathetic activation produces the ‘flight or fight’ response and increased startle
and defensive reactions. If a cat is restrained, otherwise unable to escape or too close
to a perceived threat that an attempt to escape could place the cat at increased risk,
then aggression can be the only remaining means of defence.
Persistent ‘background’ stress can also raise long-term arousal sufficiently to
produce exaggerated responses, e.g. startle or aggression in reaction to minor or
moderate threats or stressors that might otherwise produce very little or no
reaction.