86 Chapter 6had the disease, or they may become latent carriers of the infection, becoming a risk
to other cats during or following a period of stress (Gaskell et al., 2007).
Upper respiratory tract infection
As well as feline herpesvirus, other diseases including feline calicivirus (FCV), chla-
mydia, bordetella and mycoplasma have been identified as causes of upper respira-
tory tract infections in cats (Bannasch and Foley, 2005). Tanaka et al. (2012) found
that cats admitted to a rescue shelter were more likely to exhibit high levels of stress
and were five times more likely to develop an upper respiratory tract infection than
those exposed to less stressful situations.
Dermatological conditions
Psychogenic alopecia (stress-related over-grooming)
Short episodes of self-grooming are a normal feline displacement activity and response
to acute, mild to moderate stressors (van den Bos, 1998). But excessive grooming
resulting in hair thinning or bald patches can occur as a behavioural response to severe
chronic stressors. This is often referred to as ‘psychogenic alopecia’ but it cannot cor-
rectly be considered as a ‘true alopecia’ (hair loss) because, rather than the hair falling
out, it is physically pulled out by the cat or bitten off near the root.
Cats can sometimes be quite clandestine when over-grooming so the behaviour might
not be obvious to the casual observer. One way to tell if hair thinning or bald patches are
due to over-grooming or hair loss is by the feel of the skin in the affected area. If the hair
has fallen out the skin will be fairly smooth to the touch. Whereas in cases of
over-grooming, the area is more likely to feel rough and ‘stubbly’ from where the hair
has been bitten off close to the root and from hair regrowth (Bowen and Heath, 2005).
Over-grooming can occur anywhere on the body that the cat can reach with its
tongue, but it is more common in areas that are easy for the cat to reach, such as on
the flanks or abdomen. The cat may also obsessively bite and pull at the feet and
claws. Another symptom of over-grooming can be regular regurgitation of hairballs
and in some cases this may be the only apparent symptom as the loss of hair might
not be sufficient to be visually evident without close examination.
However, stress is far from the only reason for over-grooming and in the majority
of cases the primary cause is medical, rather than, or as well as, behavioural (Waisglass
et al., 2006). Stress may exacerbate a behaviour initially triggered by a physical cause
but over-grooming that is purely behavioural is rare (Hobi et al., 2011). Veterinary
investigation, possibly involving a veterinary dermatologist, should therefore always
be carried out before assuming the problem to be purely stress related.
Medical differentials for over-grooming include:
● Pathological skin conditions (infectious, allergic and/or parasitic dermatitis) that
cause itching or discomfort.
● Internal pain or discomfort, such as that caused by feline lower urinary tract dis-
ease (Fig. 6.2) (Bowen and Heath, 2005; Griffiths, 2016).
● Neurological conditions.