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Lily toxicity in cats
Lilies, that is, species of Lilium (Liliaceae) (true lily) and
Hemerocallis (Hemerocallidaceae) (day lily), cause renal
damage in cats. All parts of the plant are toxic and a
small amount of plant material can have serious
consequences if ingested. The mechanism of toxicity
remains unknown. Signs develop rapidly with
gastrointestinal irritation, followed by polyuria,
dehydration and then acute kidney injury. Seizures can
occur in severe cases. Treatment is aimed at reducing
absorption with emesis and/or activated charcoal and
enhancing renal perfusion with intravenous fluid
diuresis for at least 48 h. Once acute kidney injury has
occurred treatment options are limited and referral
should be considered. Prognosis is good in cats where
decontamination is prompt and treatment has been
started before the onset of renal impairment. Cats with
acute kidney injury have a more guarded prognosis.
L
ilies, that is, species of Lilium (true lily) and
Hemerocallis (day lily), cause renal failure
in cats. Cats are the only species known to
develop renal damage from lilies and this was
first reported in 1992.1 Studies and clinical data
have shown that these plants do not cause
renal toxicity in dogs, rats or rabbits.2
It is important to be aware that many plants
have lily in their name, such as lily of the valley
(Convallaria majalis), peace lily (Spathiphyllum
Key point
Most cases of lily exposure occur
in the home, from flowers in
a bouquet or a pot plant
and owners are often
unaware of the danger such
pretty flowers pose to their
cats.
Keeping cats safe
Nicola Bates
BSc (Brunel) BSc (Open) MSc MA
Nicola has worked in human and veterinary
toxicology for 25 years and has been with the
Veterinary Poisons Information Service (VPIS)
since it started. As well as providing
emergency advice via telephone she has
written extensively on veterinary toxicology.
In addition to service provision, she is
involved in training of VPIS staff and
veterinary professionals. She is currently the
congress abstract editor for the European
Association of Poisons Centres and Clinical
Toxicologists (EAPCCT).
species) and calla or arum lily
(Zantedeschia aethiopica). These
have different toxic effects; only
Lilium (Figure 1) and Hemerocallis
species (Figure 2) are discussed
here (Table 1).
Exposure
Most cases of feline lily exposure
occur in the home, usually from
flowers in a bouquet or a pot plant
(although these species are grown
outside as well). Consequently,
house cats are more at risk of
toxicity. In a review of cases of lily
exposure in 57 cats in 48
households, almost half of the lilies
were a gift to the cat’s owner.3
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Keeping cats safe
Table 1: Lilies that are toxic to cats
Scientific name
Common name
Hemerocallis species
Day lily
Lilium x asiatica
Asiatic lily
Lilium x asiatica americana
Figure 1: Lilium species
Lilium candidum
Madonna lily
Lilium hydridum
Japanese showy lily
Lilium lancifolium
(Lilium tigrinum)
Tiger lily
Lilium longiforum
Easter lily
Lilium orientalis
Stargazer lily; oriental
lily
Lilium regale
Royal lily
Lilium speciosum
Lilium rubrum
Rubrum lily
Lilium umbellatum
Western or wood lily
Figure 2: Hemerocallis species
Mechanisms of action
The toxic principle(s) and
mechanism of lily toxicity are
unknown,4 but renal damage is due
to necrosis of renal tubular epithelial
cells. The basement membrane
remains intact,5,6 and prompt,
aggressive treatment can result in
regeneration of tubular epithelial
cells.5 The mechanism of toxicity
involves two processes; initially there
is damage to renal tubular
epithelium resulting in polyuric renal
failure (acute kidney injury) which in
turn results in severe dehydration.7
Whatever the toxic agent, either
something in the plant or a felinespecific metabolite, it appears to be
eliminated within 48 h; this
contention is supported by the
observation that fluid diuresis for 48
h can prevent lethal acute kidney
injury.8
In a small number of cases
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pancreatic degeneration has been
reported and this may be due to a
different mechanism.9
Toxic dose
All parts of the plant, the pollen,
flowers, stem and leaves are toxic.
Ingestion of less than one leaf,5 or
part of a flower,7 could cause severe
poisoning. There are also reports of
cats developing renal failure after
exposure to only pollen (Veterinary
Poisons Information Service data).
In an experimental study in cats the
Key point
Ingestion of less than one
leaf, part of a flower or
just brushing against the
plant resulting in pollen
exposure can be fatal.
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Keeping cats safe
Laboratory findings
Acute kidney injury
Acute renal failure should now be termed
‘acute kidney injury (AKI)’ to bring
veterinary medicine in line with human
medicine, and to reflect more accurately
the spectrum of pathology occurring in the
kidneys, with only a subset of patients with
severe disease suffering renal failure. The
International Renal Interest Society has
useful information on AKI and chronic
kidney disease (CKD), the term now used
in place of chronic renal failure. See
http://www.iris-kidney.com/ for more
information.
A mild elevation in liver enzymes
may be noted but may be due to
severe anorexia and hepatic stress.7
Pancreatitis has been reported in a
few cases.9,12
toxic component was found to be
water-soluble, and the aqueous
flower extract was more toxic than
the aqueous leaf extract. A cat given
a dose of 3.84 g of extract
(equivalent to eight flowers) died
within 4 h.9
Prognosis
Prognosis is good in cats where
decontamination is prompt and
treatment has been started before
the onset of renal impairment. It is
generally stated that treatment
started more than 18 h after
ingestion is associated with a poor
outcome,5 however, a recent analysis
of 25 cases found that outcome was
good in cats treated with
gastrointestinal decontamination,
intravenous fluid diuresis or both
within 48 h of ingestion. It is worth
noting however, that in this study
most cats (68%) presented within
6 h and only eight (32%) presented
after more than 6 h. Of these, five
Clinical signs
Initial signs after ingestion of lilies
are due to gastrointestinal irritation
and usually start within 1–6 h,
whereas the later effects are due to
uraemia.
Clinical signs first observed may
include hypersalivation, vomiting,
anorexia, weakness, lethargy and
depression. The vomiting usually
resolves within 12 h, but recurs again
at 36–48 h due to uraemia.2
There is polyuria from around 12–30
h, followed by dehydration at 18–30
h. As acute kidney injury develops
owners may note depression,
weakness, anorexia and vomiting.10
Physical examination will show signs
typical of acute kidney injury such as
dehydration, oral ulceration, uraemic
breath, enlarged, painful kidneys and
reduced urine production (anuria).10
Seizures can occur in cats with
severe acute kidney injury.9
The main finding in cats with lily
exposure is severe azotaemia.
Biochemical changes with rising
urea, creatinine, potassium and
phosphorus concentrations
generally occur from 18–24 h.8 The
creatinine may be disproportionably
elevated compared to the urea.10,11
There is tubular necrosis with
haematuria, proteinuria, glycosuria,
isosthenuria, squamous and
epithelial cells in the urine and
numerous urine casts.
Tip
Prompt treatment with gastric
decontamination and fluid
diuresis is associated with a
good outcome so any cat
with suspected or confirmed
exposure should be seen and
treated immediately. Cats treated later and
cats with acute kidney injury have a guarded
prognosis.
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Keeping cats safe
had vomited at home and in two
cases it was likely to have occurred
within 6 h of ingestion.4
In a review of 55 cases of feline lily
exposure with known outcome, 48
cats (87%) had either brief clinical
signs or remained asymptomatic.
Three cats (5.5%) had continuing
abnormalities in renal parameters, one
(1.8%) had aspiration pneumonia and
three cats (5.5%) were euthanased
with renal failure. In this group of 55
cats, six (11%) developed renal signs.3
Cats with acute kidney injury have a
guarded prognosis and those with
anuria have a grave prognosis.10 In
cats given no treatment death can
occur 3–7 days after ingestion of
lilies.2,8 In cats that survive chronic
kidney disease may occur as a
long-term consequence of lily
nephrotoxicity.10
Monitoring
Monitoring of renal function is
essential. The hydration status
should also be monitored by
calculating fluid in and fluid out,
which allows appropriate
adjustment of the fluid rate as
required. Placement of a urinary
catheter is important to allow
accurate monitoring of urine
output. Urine analysis will show
evidence of renal tubular injury (eg,
renal casts, isothenuria, glucosuria)
before the onset of azotaemia,11 and
these changes can be observed as
early as 12 h after ingestion.7,8
Treatment
The aim of treatment is to reduce
absorption and support renal
function. If exposure to lilies is
suspected advice should be sought
from the VPIS and a veterinary
specialist, with prompt referral to a
specialist centre considered.
Decontamination
An emetic and/or activated charcoal
can be given if ingestion was recent.
If vomiting has already occurred an
antiemetic and activated charcoal
should be given. It is important to
wash the cat thoroughly to remove
any residual pollen on the coat, face
or feet.
Tip
Wash exposed cats
thoroughly to remove any
residual pollen on the coat or
feet but monitor temperature
to avoid hypothermia.
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Figure 3: Prompt fluid therapy is the mainstay of
management of lily toxicity but consult with a
specialist for advice
Prevention of renal injury
Treatment in cats with lily exposure
is aimed at preventing anuria and
enhancing renal perfusion. Fluid
rates (Figure 3) should be based on
percentage dehydration at
presentation, ongoing losses (via
polyuria and vomiting for example)
and adequate to enhance renal
perfusion without volume overload.
Monitoring blood pressure,
bodyweight and urine output is
recommended, with measurement
of central venous pressure ideal but
often unavailable. The fluid should
be either isotonic saline or a
polyionic solution such as
Hartmann’s solution.10 In all cats,
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Keeping cats safe
of chronic kidney disease. Raising
awareness and prevention are
therefore key to reducing cases of
lily-induced renal failure in cats.
References
1
Figure 4: Lilies may look attractive, and
feature in many a bouquet, but ingestion can
be fatal
particularly those with reduced urine
production or cardiomyopathy,
volume overload should be avoided
with close monitoring (see Fluid
therapy in cats 1 and 2 Feline Focus
2015; 1(1): 7–12 and 2015; 1(2): 41–47).
Rehydration and restoration of renal
perfusion and urine output usually
corrects metabolic abnormalities,
but severe hyperkalaemia should be
treated appropriately (dextrose,
insulin).10
Management of acute kidney injury
Once renal damage has occurred
treatment options are limited.
Although haemodialysis and
peritoneal dialysis have been
successful in some cases,6,7,13
availability may be limited. Other
drugs commonly used in the
management of acute kidney injury,
such as furosemide or mannitol, are
not very effective in cats with lilyinduced renal toxicity.7,10 As
mentioned previously, consulting a
veterinary specialist for advice on
treatment, or referral is strongly
recommended.
Conclusions
Cats appear to be uniquely sensitive
to lilies (Figure 4) and develop acute
renal injury following exposure.
Successful treatment relies on
prompt decontamination and fluid
diuresis to maintain renal function.
Once renal failure occurs treatment
options are limited and there is a risk
Hall JO. Nephrotoxicity of Easter lily (Lilium
longiflorum) when ingested by the cat
[abstract]. J Vet Intern Med 1992; 6: 121.
2 Hall JO. Nephrotoxicity of Easter lily (Lilium
longiflorum). In: Panter KE, Wierenga TL and
Pfister JA (eds). Poisonous plants: global
research and solutions. Wallingford: CABI
Publishing, 2007 pp 271–278.
3 Slater MR and Gwaltney-Brant S. Exposure
circumstances and outcomes of 48
households with 57 cats exposed to toxic lily
species. J Am Anim Hosp Assoc 2011; 47:
386–390.
4 Bennett AJ and Reineke EL. Outcome
following gastrointestinal tract
decontamination and intravenous fluid
diuresis in cats with known lily ingestion: 25
cases (2001–2010). J Am Vet Med Assoc 2013;
242: 1110–1116.
5 Volmer PA. Easter lily toxicosis in cats. Vet
Med 1999; 94: 331.
6 Volmer PA. How dangerous are winter and
spring holiday plants to pets? Vet Med 2002;
97: 879–884.
7 Hall JO. Lilies. In: Peterson ME and Talcott PA
(eds). Small animal toxicology, 3rd ed. St Louis,
Missouri: Elsevier, 2013, pp 617–620.
8 Fitzgerald KT. Lily toxicity in the cat. Topics
Compan Anim Med 2010; 25: 214–217.
9 Rumbeiha WK, Francis JA, Fitzgerald SD, et al.
A comprehensive study of Easter lily
poisoning in cats. J Vet Diag Invest 2004; 16:
527–541.
10 Tefft KM. Lily nephrotoxicity in cats. Comp
Contin Educ Pract Vet 2004; 26: 149–157.
11 Malik R. Lily intoxication. Control and Therapy
Series 2011; 263: 26–27.
12 Langston CE. Acute renal failure caused by lily
ingestion in six cats. J Am Vet Med Assoc
2002; 220: 49–52.
13 Berg RIM, Francey T and Segev G. Resolution
of acute kidney injury in a cat after lily (Lilium
lancifolium) intoxication. J Vet Intern Med
2007; 21: 857–859.
Do your clients know the dangers of lilies?
Educate your clients about the risks of
lily toxicity in cats. Are they aware of
the potential for fatal injury following
contact with lilies? Create a client
education handout and download a
poster to display in your practice from:
http://icatcare.org/cat-campaigns/lilytoxicity
1(9) feline focus 337