Feline high-rise syndrome: 119 cases
), B. Pirkic
, D. Matic
, B. Radis
, M. Stejskal
, M. Kreszinger
, N. Lemo
Clinic of Surgery, Orthopaedics and Ophthalmology, Veterinary Faculty, University of Zagreb,
Heinzelova 55, 10000 Zagreb, Croatia
Clinic of Internal Medicine, Veterinary Faculty, University of Zagreb, Heinzelova 55,
10000 Zagreb, Croatia
Revised 18 June 2003; accepted 18 July 2003
Summary High-rise syndrome was diagnosed in 119 cats over a 4-year period.
59.6% of cats were younger than one year, and the average height of the fall was four
stories. High-rise syndrome was more frequent during the warmer period of the year.
96.5% of the presented cats, survived after the fall. 46.2% of cats had fractured
limbs; 38.5% of fractures were of the forelimb, 61.5% of the hindlimb. The tibia
was fractured most often (36.4%), followed by the femur (23.6%). 78.6% of femoral
fractures were distal. The mean age of patients with femoral fractures was 9.1
months, and with tibial fractures 29.2 months. Thoracic trauma was diagnosed in
33.6% of cats. Pneumothorax was diagnosed in 20% of cats, and pulmonary contu-
sions in 13.4%. Falls from the seventh or higher stories, are associated with more
severe injuries and with a higher incidence of thoracic trauma.
Ó2003 ESFM and AAFP. Published by Elsevier Ltd. All rights reserved.
High-rise syndrome is the term used in cases of cats
falling from balconies or windows of highrise build-
ings in urban areas, the minimal height of the fall
being the second storey. The cause of the fall in
most cases is related to play when the animal
jumps from the window or over the balcony, when
chasing a bird or insect, or slipping whilst walking
on the edge of the balcony railing or window.
High-rise syndrome has also been described in dogs
(Gordon et al., 1993) and humans, when the terms
‘‘high-ﬂyer syndrome’’ or ‘‘jumpers syndrome’’
are also used (Reynolds et al., 1971;Smith et al.,
Feline high-rise syndrome has been described by
several workers (Barth, 1990,Dupre et al., 1995;
Flagstad et al., 1998;Papazoglou et al., 2001;
Whitney and Mehlhaff, 1987). Some workers have
reported that the relationship between the height
of fall and the severity of the injuries follows a cur-
vilinear pattern (Flagstad et al., 1998;Papazoglou
E-mail address: email@example.com (D. Vnuk).
Journal of Feline Medicine and Surgery (2004) 6, 305e312
1098-612X/$30.00/0 Ó2003 ESFM and AAFP. Published by Elsevier Ltd. All rights reserved.
et al., 2001;Whitney and Mehlhaff, 1987), while
others argue that the severity of injuries increases
linearly with the height of the fall (Dupre et al.,
The object of this study was to statistically eval-
uate 119 cats with this syndrome admitted during
a 4 year period. The cats fell from at least the sec-
ond storey, all in greater Zagreb. The injuries of all
the cats were documented. We wanted to exam-
ine any association between the height of the fall,
severity of injuries, and the type of injury.
Materials and methods
In the period between January 1, 1998 and
December 12, 2001 at the Clinic of Surgery, Ortho-
paedics and Ophthalmology of the Veterinary
Faculty, 119 cats were treated after a fall or jump
from a balcony or window, where the owners saw
the fall, or where there was a reasonable suspicion
that a fall had occurred. Only those cats that fell
from the second or higher stories were included.
The owners brought the cats for treatment within
varying periods of time after the fall (from 30 min
to over a month). Each animal was examined, and
radiographical, haematological and biochemical
examinations were performed depending on the
results of the clinical examination. After the diag-
nosis was made, and in consultation with the
owners, conservative or surgical treatment was
undertaken in most cases. Some owners requested
euthanasia of the animal.
In evaluating the severity of the injuries the fol-
lowing criteria were used:
Contusions, abrasions, wounds, lacerations, pul-
monary contusions, haematuria, epistaxis,
dental fracturesdscore: 1.
Limb fractures, limb luxations, hard palate
fractures, mandibular fractures, pelvic frac-
tures, temporomandibular joint luxations,
haemothorax, pneumothorax, abdominal
wall rupture, diaphragmatic rupture, rupture
of urinary bladder, vertebral fractures/
If an animal had several injuries, the points for
each injury were summed up. For example, if
a cat had a fracture of both radius and ulna, the
score was 4; if there was a fractured radius and
ulna and fractured tibia, the score was 6; if a cat
had a limb fracture with some skin contusions on
the same limb, the score was 2C1Z3.
The statistical data processing was performed
using the programme Statistica, ’99 edition,
version 5,5, StatSoft, Inc. The programme was also
used to make charts. The Student’s t-test was used
for the age comparison between cats with frac-
tured tibia and fractured femur.
During the deﬁned period, 1402 cats were admitted
to the clinic, and in 8.5% (119) of them high-rise
syndrome was diagnosed. 96.5% (115/119) cats sur-
vived after the fall. The mean age of the cats was
1.8G2.2 years (MGSD) (range, 2.5 months to 10
years). The age of 5 cats was unknown. 59.6%
(68/114) of cats were under one year (Fig. 1).
53.8% (64/119) were female, 42.0% (50/119) were
male, 3.4% (4/119) were male neutered, and the
sex was undetermined in 1 cat (Fig. 2). The mean
storey from which the cat fell was 4.0G0.2 (range,
2 to 16). The median was the fourth storey (Fig. 3).
65% (77/119) of cases occurred in the period
from April 1 to September 30 (Fig. 4).
Injuries of the cats are listed in Table 1. In 6 cats
euthanasia was carried out; in 2 cases because of
the poor prognosis (vertebral fractures/luxations),
and in 4 cases because of the cost of treatment. Of
the remaining 113 cats, 4 died within the ﬁrst 36 h
following the fall (3.5%). The age range of the cats
that died was between 8 months and 5 years, and
the fall occurred from between the second and
the ninth storey.
46.2% (55/119) of cats had fractures of limbs,
excluding pelvic fractures. The mean age of pa-
tients with fractures was 1.8G2.1 years. Multiple
metacarpal or metatarsal bone fractures of the
same limb were counted as 1 fracture. A single
fracture of the forelimb was found in 18 cats, and
a single fracture of the hindlimb was found in 28
cats. That is, 83.6% (46/55) of the cats had only
one fracture. The other 9 cats had multiple frac-
tures. So, 55 cats had 65 fractures. Of 65 fractures,
38.5% (25/65) were in the forelimb, while 61.5%
(40/65) were in the hindlimb.
The tibia was the most frequently fractured
bone (20 cats), and two cats had fractures of both
tibia. Thus 22 of a total of 65 fractures (33.8%) were
tibial. The femur was the next most frequently
fractured bone, comprising 21.5% (14/65) of all
fractures. 13 cats had femoral fractures as one
had fractures of both femurs. Of the 14 fractures,
78.6% (11/14) were in the distal bone, and of these
82% (9/11) were distal physeal fractures (these
fractures occurred in immature animals). The
mean age of the patients with fractured femur
was 9.1G6.3 months, while the mean age of the
306 D. Vnuk et al.
patients with fractured tibia was 29.2G30.7
In the forelimb, the humerus was fractured in 8
cats and the radius and ulna in 8 cats. Open frac-
tures were recorded in four cats, all of the tibia.
In 30 cats, surgical repair was performed, whilst
in 25 cats fractures were treated conservatively
either because it was the most appropriate, or be-
cause the cost of surgery was prohibitive. In 3 cats
luxation was diagnosed; one case of coxofemoral
and 2 cases of talocrural luxation. The coxofemoral
luxation was treated by closed reduction, and the
talocrural luxations were managed surgically.
9% (11/119) of cats had pelvic fractures, all of
which were treated conservatively. In 3 cats verte-
bral fracture/luxation was presentdin one cat the
thoracic column was injured, in two cats the lum-
bar spine was injured. Of those three cats, one
died, and two were euthanized.
Fractures of the mandible were diagnosed in 4
cats, and all were fractures of the symphisis. These
fractures were stabilized with cerclage wire. Hard
palate fractures were recorded in 6 cats. These
were repaired by suturing the mucous membrane
of the hard palate. In one cat we recorded tempo-
romandibular joint ankylosisdthe owner brought
the animal to the clinic one month after the fall
because the cat could not open its mouth.
In two cats a diaphragmatic rupture was diag-
nosed. In one cat urine was aspirated during
abdominocentesis and during an exploratory lapa-
rotomy rupture of the bladder was conﬁrmed.
Traumatic abdominal rupture was recorded in two
cats. Repair of the rupture was performed between
the 3rd and the 5th day after trauma. In 5% (6/119)
of cats a perineal wound was found.
In cats with abnormal respiration (a rapid respi-
ratory rate) and tachycardia, decreased respira-
tory sounds and possible cyanosis, thoracic
radiography was carried out. Thoracic trauma was
diagnosed in 33.6% (40/119) of cats. Pneumothorax
was present in 60% (24/40) of these cats. Pulmo-
nary contusions were diagnosed in 40% (16/40) of
cats with thoracic trauma, and haemothorax in
Figure 1 Age distribution of cats with high-rise syndrome.
Figure 2 Sex distribution of cats with high-rise
Feline high-rise syndrome 307
10% (4/40) of cats. Haemothorax was diagnosed by
thoracentesis, after the thoracic radiographs had
shown the presence of ﬂuid. Thoracentesis was
carried out in 8 cats. Epistaxis was found in 8.4%
(10/119) of cats.
Shock was diagnosed in 10.9% (13/119) of cats.
The shock state was recognized by clinical evalua-
tion. The clinical signs of the shock syndrome were:
increased heart rate, weak pulse quality, pale
mucous membrane, prolonged capillary reﬁll time,
increased respiratory rate and decreased core
and peripheral temperature. Shock was treated
with intravenous ﬂuids and corticosteroids.
The cats that fell from the second storey
had an average injury score 1.98G0.92, those
which fell from the third storey 2.71G1.23,
from the fourth 2.70G1.31, from the ﬁfth
2.52G1.28, from the sixth 2.62G1.06, and from
the seventh and higher stories 3.50G2.27
Figure 3 Monthly incidence of high-rise syndrome.
Figure 4 Histogram showing number of cats falling from different heights.
308 D. Vnuk et al.
High-rise syndrome occurs in urban areas with
tall buildings (Barth, 1990;Dupre et al., 1995;
Flagstad et al., 1998;Papazoglou et al., 2001;
Whitney and Mehlhaff, 1987). High-rise syndrome
is seen mostly in younger cats, mainly the result
of behavioral differences between younger and
older animals. Younger cats fall from balconies
and windows whilst playing (chasing a bird, a but-
terﬂy, or playing with other kittens), or they slip
and fall whilst walking on the window or balcony
rim. The mean age of the cats in our study
was 1.8 years. 59.6% of cats were under one year.
Whitney and Mehlhaff (1987) reported that 65% of
cats were under 3 years. The mean age of the cats
in our study is lower than that reported by Dupre
et al. (1995)d2.5 years, Flagstad et al. (1998)d
2.3 years, and Whitney and Mehlhaff (1987)d2.7,
but higher compared to the work of Papazoglou
et al. (2001), where it was 1.2 years. The mean
age of dogs is higher, reported as 3.2 years by
Gordon et al. (1993), and in man most falls
involve children (Reynolds et al., 1971).
Papazoglou et al. (2001) reported 51% males,
46% females, 1% castrated males, 1% spayed males
and 1% unrecorded gender status. Whitney and
Mehlhaff (1987)reported 48% males, 48% females
and 4% unrecorded gender status. In their studies
23% of the males were castrated and 27% of the fe-
males were spayed. In the USA where neutering and
spaying are routine, the ratio of castrated and
spayed cats with high-rise syndrome is higher. The
routine castration and spaying of cats in Croatia is
not common. Therefore, some of injuries may be
The mean fall in our study was four stories. Most
cats fell from between the second and the sixth
storey (92%). Most buildings in Zagreb are not high-
er than six stories. Papazoglou et al. (2001) re-
ported mean fall of 3.7 stories, Whitney and
Mehlhaff (1987) reported 5.5 stories, and Flagstad
et al. (1998) 3.1 stories. In the latter work the
average is lower because cats which fell from
the ﬁrst storey were also included. For the dogs,
the mean fall is reported as 2.8 stories (Gordon
et al., 1993). High-rise syndrome describes trau-
matic injuries in cats resulting after falls of two
or more stories. Only Flagstad et al. (1998) includ-
ed cats after falls of the ﬁrst or higher stories. In
our study, we have not recorded cats with any se-
rious clinical signs after falls from ﬁrst storey. Most
falls occurr during the warmer months; 65% of cats
fell in the period between April 1 and September
30. Papazoglou et al. (2001) reports that 84% of
cats fell between March and November. Flagstad
et al. (1998) found a correlation between average
daily temperature and the number of falls. Cats
fall mostly from balconies and open windows and
since owners keep windows open during warmer
weather, the correlation between increased
temperature and increased number of falls is not
Table 1 Results of clinical assesment in 119 cats
with high-rise syndrome
Injury Number of
Limb fractures 65
Radius, ulna 8
Phalangeal fracture 1
Hind limb 40
Closed fractures 36
Open fractures 4
Open fracture 4
Limb luxations 3
Hip joint 1
Talocrural joint 2
(not associated with fractures)
Facial (including epistaxis) 12
Abrasions, wounds, lacerations
(not associated with fractures)
Hard palate fractures 6
Dental fractures 1
Mandibular fractures 4
Pelvic fractures 11
Vertebral fractures/luxations 3
Intervertebral disc protrusion 1
Temporomandibular joint ankylosis 1
Sacroiliac luxations/fractures 3
Rupture of urinary bladder 1
Traumatic abdominal rupture 2
Diaphragmatic rupture 2
Pulmonary contusion 16
Feline high-rise syndrome 309
Robinson (1976) characterized high-rise syn-
drome by the following triad of injuries:
2. hard palate fracture
This triad of injuries was found in only 33% of
cats in our study. Since, in our study the incidence
of limb fractures in the high-rise syndrome cats
was signiﬁcantly higher than the incidence of
Robinson’s triad, we suggest the inclusion of limb
fractures in the injuries which characterize the
high-rise syndrome, turning the triad into the
In our study, epistaxis was found in 8.4% of cats.
Papazoglou et al. (2001) reported epistaxis in 2% of
cats, Flagstad et al. (1998) in 13.5%, and Barth
(1990) in 64.4% of cats.
Hard palate fractures were found in 5% of cats in
our study. Papazoglou et al. (2001) reported hard
palate fracures in 3% of cats, Flagstad et al.
(1998) and Dupre et al. (1995) in 11% and Whitney
and Mehlhaff (1987) in 17% of cats.
Thoracic trauma was present in 33.6% of cats.
Pneumothorax was diagnosed in 20% of cats, pul-
monary contusions in 13.4%, and haemothorax in
3.4%. Barth (1990) found pneumothorax in 62%,
and pulmonary contusions in 58% of cats. Whitney
and Mehlhaff (1987) diagnosed thoracic trauma in
90% of cats, pulmonary contusions in 68%, and pneu-
mothorax in 63% of cats. Papazoglou et al. (2001)
reported thoracic trauma in only 13% of cats, pneu-
mothorax in 4%, and pulmonary contusions in 6.8%.
Flagstad et al. (1998) diagnosed pneumothorax in
only 7.1% of cats. Whitney and Mehlhaff (1987)
recommended thoracic radiography in all cats and
thoracic radiography was performed on 69% of the
cats. Papazoglou et al. (2001) reported that tho-
racic radiography was carried out in all cats. The
differences between the studies might be ex-
plained by different protocols in assessing thoracic
trauma. Also, such differences could be explained
by the length of time between the fall and the ad-
mission to a clinic. Dyspnea and tachypnea may be
due to pneumothorax or be the result of shock and
acute pain. The breathing pattern may improve
with time as acute pain and shock diminish. In this
case thoracic trauma may not be suspected and ra-
diography will not be performed. Because in our
study, thoracic radiography was only carried out
on those cats showing the abnormal respiration,
and that may explain why the incidence of thoracic
trauma was perhaps signiﬁcantly lower. Some ani-
mals with thoracic trauma may have minimal clini-
cal signs, or even none (Aron and Roberts, 1993). In
these animals, possible thoracic trauma was not
In addition to the triad of injuries reported by
Robinson (1976), limb fractures are also very com-
mon. In our study, 46% of patients had limb frac-
tures. Papazoglou et al. (2001) found fractures in
50% of patients, Whitney and Mehlhaff (1987) in
39%, and Flagstad et al. (1998) in 50% of patients,
but they also included pelvic fractures. The lower
percentage of limb fractures reported by Whitney
and Mehlhaff (1987) may be due to a greater fall
height, where the animals are not falling with their
extremities extended. In our study, the ratio
Figure 5 Graph showing the relationship between injury score and height of fall.
310 D. Vnuk et al.
between forelimb and hindlimb fractures is 1:1.6.
In the study by Papazoglou et al. (2001) this ratio
is 1:2, while Whitney and Mehlhaff (1987) and
Flagstad et al. (1998) state equal numbers of fore-
limb and hindlimb fracture. Gordon et al. (1993)
reported that forelimb fractures are more common
in dogs since dogs initially land on the forelimbs.
Femoral fractures in our study were found in 24%
of cats with fractures. Papazoglou et al. (2001)
diagnosed femoral fractures in 40% of cats with frac-
tures, Whitney and Mehlhaff (1987) in 46%, and
Flagstad et al. (1998) in 18%. Whitney and Mehlhaff
(1987) found that 93% of patients with femoral frac-
ture were under one year. In our study the tibia was
fractured in 36% of cats. All of the four open frac-
tures were at the tibia. In 79% of cats the femur
was fractured in its distal part. The mean age of pa-
tients with a fractured femur was 9 months, but 29
months in the case of the fractured tibia. This can
be explained by the fact that femoral fractures
were mainly in distal part, near the growth zone.
Papazoglou et al. (2001) and Whitney and
Mehlhaff (1987) excluded pelvic fractures from
hindlimb fractures. If 11 pelvic fractures are added
to the limb fractures, 33% (25/76) fractures are in
the forelimb, and 67% (51/76) are in the hindlimb.
With this correction, however, the ratio of
hindlimbs fracture was not signiﬁcantly changed.
The relatively low incidence of abdominal inju-
ries in our study can be explained by the fact that
forelimbs absorb most of the impact force at
Papazoglou et al. (2001) suggests the large num-
ber of vertebral injuries in their study is due to the
fact that most cats fell from below the ﬁfth storey
and did not have time to achieve a feet-ﬁrst land-
ing. Another reason why cats may not land on their
feet maybe the various barriers, which they might
encounter during the fall (e.g. metal structures
for hanging laundry, potted plants on balcony rail-
Kapatkin and Matthiesen (1991) suggest that the
type of injury depends upon the height of the fall
and the landing surface. The severity of injuries
rises linearly up to the seventh storey. After that
height, the severity of injuries does not rise and
and the incidence of fractures decreases. Of 22 cats
that fell more than seven stories only one died, and
among 13 cats that fell more than nine stories only
one fracture was diagnosed. One cat that fell 32 sto-
ries suffered only mild pneumothorax and a chipped
tooth (Whitney and Mehlhaff, 1987). Robinson
(1976) stated that the maximum recorded heights
for survival were 18 stories on to a hard surface,
20 stories on to shrubbery, and 28 stories on to
awning. Gordon et al. (1993) states that dogs
cannot survive falls from distances higher than
six stories. During free fall, cats have a unique
ability to quickly change the position of their body
and maintain a feet-ﬁrst landing position. Cats
behave like parachutists, achieving a maximum
velocity during free fall. An average-sized cat
(4 kg), in a horizontal position, maximizes drag
and achieves a maximum velocity of approximately
100 km/h after falling ﬁve stories. At the beginning
of the fall the cat instinctively extends its limbs
and if the impact occurs at that moment the
most common injuries are limb fractures. After
the maximum velocity has been achieved, the
vestibular system is no longer stimulated and the
cat orients its limbs horizontally. This horizontal
position could explain the decreased number of
limb fractures, but since the impact is more evenly
distributed throughout the body, the incidence of
thoracic injuries increases.
Papazoglou et al. (2001) determined the total
number of injuries and only orthopaedic injuries.
Whitney and Mehlhaff (1987) determined the total
number of injuries, the number of thoracic inju-
ries, the number of fractures and the number of
split palates. In our study, the injury score is a
sum of injuries. We formed two groups considering
the severity of injury.
In our study, the injury score increased with falls
from between the second and the third storey, it
was variable in falls from the third and the sixth
storey, and increased sharply from the seventh sto-
rey upwards (Fig. 5). Our ﬁndings differ from those
of the study by Dupre et al. (1995) where the injury
score increased linearly with the height of fall.
Flagstad et al. (1998),Whitney and Mehlhaff
(1987) and Papazoglou et al. (2001) state that the
curve has a curvilinear pattern. Our curve does
not reveal any deﬁnite pattern. When falling from
distances up to the sixth storey, where maximum
velocity is not reached, the animal falls with ex-
tended limbs, so that the severity of injury does
not only depend upon the height, but also on the
surface, dexterity of the animal, etc. When falling
from the seventh and higher stories, the animal ori-
ents its limbs horizontally after achieving maximum
velocity so that the impact is more evenly distribut-
ed throughout its body. The body hits the surface
ﬁrst, followed by the head. Fig. 6 shows the per-
centage of cats falling from speciﬁc stories in which
fractures, thoracic trauma and hard palate frac-
tures were diagnosed. The incidence of fractures
decreases with falls from heights above the third
storey, while the occurence of thoracic trauma in-
creases sharply with falls of more than six stories.
80% of cats falling from the third storey had frac-
tures of limbs or pelvis, while 80% of cats falling
Feline high-rise syndrome 311
from the seventh or higher stories suffered thoracic
trauma. This substantiates the theory that cats
falling at least seven stories ﬂex their limbs so that
truncal injuries are more common, while cats fall-
ing from distances lower than seven stories extend
their limbs, the consequence being a greater inci-
dence of limb fractures.
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Figure 6 Graph showing the percentage of cats with particular injuries when falling from different heights.
312 D. Vnuk et al.