Overview

• Plants in the Lilium and Hemerocallis genera-widely used ornamental plants; very toxic to cats; Lilium-Easter lilies, tiger lilies, Japanese show lilies, rubrum lilies, numerous Lilium hybrids; Hemerocallis-daylilies.
• Ingestion of leaves or flowers-results in a severe nephrotoxic syndrome; as little as 2–3 leaves reported to be lethal.
• Toxic principle(s) not elucidated, but found to be in the water-soluble plant fraction.

Signalment

• Cats-systemic poisoning.
• Dogs-only mild gastrointestinal upset, even after ingestion of large quantities of plant material.
• No age or breed predilections noted.

Signs

• Sudden onset of vomiting-gradually subsides within 2–4 hours.
• Depression and anorexia-onset about the same time as vomiting; both persist throughout the syndrome.
• Polyuria and dehydration-by 12–24 hours; leads to anuric renal failure.
• Vomiting-recurs by 36 hours; accompanied by progressive weakness.
• Recumbency-by 2–4 days.
• Death-by 4–7 days post-ingestion.

Causes & Risk Factors

• Plants-Easter lilies; tiger lilies; Asiatic hybrid lilies; Japanese show lilies; Lilium hybrids; daylily; primarily when used in cut-flower arrangement or as household potted plants.
• All ingestions by cats of plant material from the Lilium and Hemerocallis genera should be considered potentially lethal.
• Exclusively indoor cats-predisposed to ingestion of newly introduced plants.

Differential Diagnosis

CBC/Biochemistry/Urinalysis

• Stress leukogram.
• Moderate to severely high BUN, phosphate, and potassium.
• Creatinine-severe increase common; usually 15–29 mg/dL; may be into the 40s.
• Increased AST, ALT, and ALP late in disease.
• Severe proteinuria, glucosuria, and low specific gravity; numerous tubular epithelial casts. Early in the syndrome, tubular cell detail can be seen in the casts.
• Crystalluria-not caused by ingestion of these plants.
• Increased amylase and lipase may occur with very large ingestions.

Other Laboratory Tests

N/A

Diagnostic Procedures

• If possible, examine plant to verify that it has been chewed.
• Have plant positively identified by a professional horticulturist or other expert if necessary.

Pathologic Findings

• Gross-swollen kidneys; empty gastrointestinal tract; moderate to severe perirenal edema.
• Histologic-severe acute renal tubular necrosis with intact basement membranes; mild to severe interstitial edema; severe cast formation in the collecting ducts; later in the syndrome may note evidence of mitotic figures in the remaining tubular epithelium.

Drug(s)

• Decontamination-activated charcoal (2 g/kg PO).
• Cathartic-sorbitol (2.1 g/kg PO) or magnesium sulfate (0.5 g/kg PO).

Contraindications/Possible Interactions

• Avoid fluids containing potassium.
• Avoid drugs eliminated by renal clearance.
• Diuretics (mannitol, hypertonic fluids, furosemide, thiazides) are not effective at initiating urine production once anuric renal failure has occurred.

Patient Monitoring

Periodically follow serum chemistries to ensure normal renal function; especially important after dialysis.

Expected Course and Prognosis

• Dehydration from polyuric renal failure; required for the disease to progress to anuria.
• Prevention of dehydration (early fluids) prevents the progression of the syndrome to anuria. Prevention of anuria generally allows a gradual return to normal over 24–48 hours.

See Also

• Poisoning (Intoxication) Therapy
• Renal Failure, Acute

Abbreviations

• ALP = alkaline phosphatase
• ALT = alanine aminotransferase
• AST = aspartate aminotransferase
• NSAID = nonsteroidal anti-inflammatory drug