Professor Tim Gruffydd-Jones, University of Bristol, presented
at the FAB conference, October 2002
TERM 'FADING KITTEN' IS OFTEN interpreted as linked to a specific
form of death in young kittens. However it is purely a descriptive
term giving no indication of the underlying cause and can
be very misleading. A much more appropriate term is neonatal
mortality. This covers death around the time of birth (peri-natal
mortality) and death during the first few weeks of life when
the kittens are still highly dependent on their mother.
mortality rates can be quite high – up to 10 per cent or more,
and constitute the bulk of cases of deaths prior to weaning.
are relatively tolerant of hypoxia (low oxygen) In addition
their haemoglobin type maximises the efficiency of oxygen
transfer. It is therefore worthwhile persisting for some time
in efforts to revive any kittens which appear reluctant to
have little thermoregulatory control over the first few weeks
of life and depend on the warmth provided by their mother's
body and a dry, warm nesting environment. Chilling will
soon lead to depression of the suckling reflex with consequent
hypoglycaemia (low blood glucose) and death. Most queens have
very strong maternal instincts and make good, attentive mothers.
If a cosy nest box is provided the queen's body heat will
ensure that the immediate nesting environment temperature
is adequate. Again, it is important that the queen is settled
in the nest box. If not she may constantly be moving the kittens,
lead to chilling. Nest boxes should be made of material that
can be suitably disinfected or discarded after use.
suckling, particularly immediately after parturition, is vital.
Neonates are vulnerable to hypoglycaemia and regular feeding
is necessary to ensure this does not occur. Hypoglycaemia
leads to suppression of the suckling reflex which accentuates
the hypoglycaemia and will rapidly end in death.
in the first few days of life is also important to ensure
that good levels of maternally derived immunity (MDI) are
achieved. Negligible levels of antibodies are usually obtained
by placental transfer prior to parturition and kittens depend
on colostrum for MDI although colostral transfer may continue
for up to 72 hours, most occurs within the first 24 hours
and it is therefore vital that the kittens suckle well during
this period. Regular use of vaccine boosters for the queen,
preferably just prior to mating, will also assist in ensuring
levels of MIDI are achieved.
kittens spend around 90 per cent of their time sleeping for
the first few weeks of life. they are born blind and their
eyes begin to open seven to 10 days after birth. From around
three weeks of age they become more adventurous, emerge from
the nest box and begin to feed themselves, often sharing some
of the queen's solid food before they learn to lap fluids.
problems in young kittens
critical nature of the neonatal period has been emphasised
above and certain losses are inevitable over this period,
even with optimum neonatal management It is important, therefore,
in investigating kitten mortality in a cattery to establish
the extent and pattern of losses and to assess whether these
losses are acceptable. Extensive databases on kitten mortality
exist for cat colonies, but much less information is available
for breeding catteries. An acceptable maximum figure for mortality
rates up to weaning is probably around 10 per cent, half of
this representing stillbirths. Average birthweights of mixed
breed, colony-maintained cats are around 100g. However, much
lower normal birthweights should be expected in some pedigree
kittens, particularly of the lighter framed Oriental breeds,
to have much larger litters.
weighing of the kittens can provide a useful assessment of
performance and had the added advantage of accustoming the
kittens to handling from a young age. Colonymaintained cross-bred
kittens will gain up to 30g daily, but weight gains may be
much more modest for pedigree kittens, particularly for kittens
from large litters.
are limited ways in which young kittens demonstrate distress,
irrespective of the underlying cause. They may be much more
restless than normal, fail to sleep contentedly for prolonged
periods as should normally occur and may cry excessively.
They tend to wander aimlessly predisposing themselves to chilling.
The queen may appear to neglect sick kittens and they maybe
found away from the next box. They cease feeding and the suckling
reflex becomes depressed. In view of the limited range of
clinical signs sick kittens display, clinical examination
is generally unrewarding. In many cases a diagnosis can be
made only at post-mortem examination and this will often reveal
infections and congenital abnormalities which would otherwise
pass unnoticed. This may ennoble preventative action to protect
the remainder of the litter or may provide useful information
on which to base future breeding plans.
major causes of death in young kittens are environmental and
managemental factors, maternal factors, infections and congenital
and management factors
mortem examination fails to reveal a clear cause of death
in a large proportion of kittens which die within the first
few days of life. Undoubtedly environmental and management
factors, particularly chilling and failure to suckle, considered
above, are responsible for many of these. The loss of occasional
kittens may simply reflect inattentive queens, but major losses
in the first few days of life suggest some basic mismanagement
problem. This can be investigated satisfactorily only by visiting
the cattery, by detailed study of the normal husbandry measures
and by assessment of breeding records.
of the queen is crucial in the general management over the
neonatal period. Maternal factors may also play an important
role in infectious problems either through contributing
to protection or predisposing to infection.
queen is the major source of early protection against infectious
agents in the form of MDI derived from colostrum. However,
the queen may also predispose to infectious disease by acting
as a source of infection as a consequence of her carrier status
or development of mastitis. She may also play a role in umbilical
important route of infection in new-born kittens is the umbilicus.
The kitten may be infected by vaginal organisms during birth
or by opportunist organisms in the environment after
birth. Infection may track up the umbilical vessels to cause
a liver abscess or it may lead to peritonitis. Several kittens
in the litter, or frequently the complete litter, may be affected.
Close examination of the umbilicus will sometimes reveal slight
discoloration or swelling. Antibiotics are indicated for treatment,
but the response in established cases is poor.
quite common source of infection in pre-weaning kittens is
infected milk from mastitis in the queen. In acute mastitis
the queen will show clinical signs, but in chronic mastitis
the queen may seem well and her mammary glands may appear
normal. Mastitis leads to gastroenteritis in the kittens with
diarrhoea and occasionally vomiting. The kittens must
be separated from their mother and hand-reared.
and chlamydial infections
can be a major cause of disease in young kittens in breeding
catteries but not usually until a little later. Kittens are
most vulnerable between four to six weeks of age when maternally
derived immunity is waning. The respiratory viruses and chlamydia
are generally the most important infections in kittens.
kittens are very vulnerable to trauma and this is an important
cause of death. External injuries may not be obvious, but
recent trauma may become evident on post-mortem examination.
condition involves an incompatibility in the blood group of
the kittens and their mother It can occur if a group B queen
has group A kittens. Some such queens have potent antibodies
against group A blood. These antibodies are present in the
colostrum and will be absorbed for up to the first 24 hours
after birth. They destroy the red blood cells leading to anaemia. Affected
kittens may die in the first two to three days. This problem
is more frequent in certain breeds which have a high prevalence
of group B individuals – such as British Shorthairs, Birmans
and Devon Rex.
are many congenital abnormalities of cats which may become
apparent during the first few months of life and some of these
may cause death of young kittens. Some will be discovered
on casual examination of the kittens, but in other cases a
post mortem examination will be required to reveal their presence.
Many inborn errors of metabolism are recognised in man and
other species and these can only be diagnosed in life, often
requiring sophisticated laboratory investigation. A few such
congenital defects of metabolism have been recognised in cats,
but they have received little consideration in this species
and it is likely that they may account for some of the occasional
losses encountered in young kittens.