Flat Chest Kitten
number of chest wall deformities have been described in cats and dogs in the
veterinary literature. In cats, the two most common are pectus excavatum
("funnel chest") and flat chest (FCK). There are over a dozen
reports about pectus excavatum in the literature, including papers
describing surgical correction, but very little about FCK. It is important
to understand the difference between the two conditions so they can be
sectional diagram of a normal chest:
chest cavity is oval in shape, with the spinal column at the top and the
sternum at the bottom. The black squares represent the costochondral
junctions, the point where the cartilage portion of the rib attached to the
sternum joins the boney portion of the rib attached to the spine.
sectional diagram of a pectus excavatum chest:
pectus excavatum, the chest cavity is narrower top to bottom as the sterum
is displaced upward. In severe cases, the lack of space compresses the heart
and lungs. Common signs in moderate to severely affected cats include
exercise intolerance, trouble breathing, cough, weight loss or failure to
sectional diagram of FCK:
the ribcage is angled sharply at the costochondral junction, causing the
ventral part of the chest to be flattened. FCK varies from very mild to very
severe and life-threatening. The condition is not apparent at birth, but
becomes obvious within the first few weeks of life. Mildly affected kittens
may appear perfectly normal as adults. Moderate to severely affected kittens
will have difficulty breathing and poor weight gain. The worst affected
kittens will die.
has been reported in many breeds of cats. Some FCK kittens also have a
spinal curvature or may have pectus excavatum. A 1997 study in the U.K.
reported that 3 to 4% of all Burmese born there are affected with FCK. The
same study tried to evaluate potential causes and concluded that the defect
is inherited, but must also be influenced by some other factors, possibly
environmental or nutritional. For example, Burmese kittens in the study had
much higher blood and skeletal muscle taurine levels than normally expected
for cats. It is unknown what association these high taurine levels may have
with FCK. No association between FCK and any particular diet or any
particular dietary supplements has been found.
North America, FCK has been seen in many breeds, but the overall incidence
in any breed is not known. Until more information is known about this
defect, breeders should not use any FCK-affected cat in a breeding program,
even if it appears normal as an adult. It would also be wise to avoid
breeding a queen that has produced FCK kittens with a sire that has also
produced FCK kittens.
R et al. Pectus excavatum in dogs and cats. Comp Contin Edu Pract Vet 12(3):
TW et al. Pectus excavatum in eight dogs and six cats. J Am Anim Hosp Assoc
JF, Harvey CE. Repair of pectus excavatum by percutaneous suturing and
temporary external coaptation in a kitten. J Am Vet Med Assoc 194(8):
C. Flat chested kittens - does taurine have a role to play? Burmese Cat Club
News (U.K.), vol 12, no 8, 1995
CP, Waters L, Gruffydd-Jones TJ et al. Investigation of the association
between whole blood and tissue taurine levels and the development of
thoracic deformities in neonatal Burmese kittens. Vet Rec 141:566-570, 1997
kitten (on the bottom) with flat chest kitten defect. FCK has been reported
in many pedigreed cat breeds, and in random bred cats too.
of a kitten with pectus excavatum. Note the pronounced upward deviation of
the sternum indicated by the 2 black arrows.
Dr Susan Little's