Spider Lily Poisoning in Dogs

The name spider lily is applied to several plants within the Amaryllidaceae family. These plants are classified in the either the crinum, hymenocallis, or lycoris genus. Although each variety is toxic, the alkaloids causing the toxicity can vary between groups. They should not be confused with the spider plant Chlorophytum comosum. Despite their similar names, the plants are not closely related and the spider plant, unlike the spider lily, is non-toxic. If your pet consumes any portion of a spider lily plant, you should contact your veterinarian right away for further instructions. Symptoms like muscle spasms and diarrhea can occur; a visit to the clinic is imperative with ingestion of the spider lily.

Spider lily refers to several plants in the Amaryllidaceae family with large dramatic flowers. Each of these plants contains a combination of natural alkaloids which can be toxic.

The symptoms of poisoning by the bulbs from any of the spider lilies are due primarily to the alkaloids that they produce. Different types of spider lily may have differing types and concentrations of these compounds. Symptoms that could arise include:

• Abdominal pain
• Collapse
• Diarrhea
• Drop in blood pressure
• Electrolyte imbalance
• Excessive drooling
• Increase in urination
• Lack of coordination
• Muscle spasms
• Paralysis
• Seizures
• Slowed heart rate
• Vomiting

Types

There are three different groups in the Amaryllidaceae family of plants that are commonly referred to as the spider lily. All three have strap-shaped leaves with showy flowers that sit on top of a tall stalk. 

Crinum genus

• This plant category includes approximately 180 species of plant worldwide, many of which are types of spider lilies or swamp lilies
• Most Crinum plants contain toxic concentrations of the alkaloid galanthamine

Hymenocallis genus

• The Hymenocallis genus is comprised of approximately 60 species of perennials found naturally in Central America, the Caribbean, Mexico, and the southeastern portion of the United States
• The clusters of grand looking white, green, or yellow flowers are quite fragrant, but they contain crystalline alkaloids lycorine and tazettine

Lycoris genus

• The smallest family that includes spider lily plants is the Lycoris genus, with only about 20 species, and are also known as hurricane lilies due to their tendency to bloom after big storms
• The bulbs from the Lycoris genus contain both galanthamine and lycorine

The causes of toxicity in these plants are all naturally occurring alkaloids that react poorly with the body. The three primary toxic alkaloids are: 

Galanthamine

• This alkaloid has been studied for many decades as a treatment for mild Alzheimer’s and other memory impairments due to its acetylcholinesterase inhibiting properties
• In high enough doses this alkaloid becomes toxic by interfering with the parasympathetic nervous system

Lycorine

• Lycorine is toxic due to its ability to inhibit protein synthesis within the body

Tazettine

• This alkaloid is known to be hypotensive, and can reduce the blood pressure to a dangerously low level

If you see your pet consuming the bulbs or any other part of a spider lily plant contact your veterinary clinic to alert them of your arrival. If your canine ate a flower bulb and you are uncertain of the type, bring a sample of any remaining plant material into the veterinarian to ensure a speedier identification for treatment. Although the toxin found in the spider lily usually results in a mild to moderate response, the bulbs of other flowers, such as tulips, are more likely to cause lethal reactions. 

The veterinarian will discuss with you the event of the spider lily ingestion, and will ask if you have knowledge of the time delay between your pet eating the plant and your arrival at the clinic. The veterinarian will give your dog a thorough physical examination including heart rate, pulse, and breathing sounds. If your dog is on medication or you have given him supplements of any kind, let the veterinarian know so she can look for possible contraindications. A biochemistry profile is likely to be completed at this time, along with a urinalysis, and a complete blood count. Particular attention will be paid to results regarding liver and kidney functionality. If any plant material is found in the vomit or stools, this will assist in confirming the diagnosis.

Initial treatment will depend on how long it has been since the bulb was ingested and which symptoms the patient is exhibiting. In many cases, ingestion of the plant material other than the bulb only causes mild symptoms, and may be treated at home. Consumption of large quantities of plant material or the ingestion of the bulbs themselves can intensify the reaction, however, and a visit to the veterinary clinic will become necessary. 

If the spider lily was consumed recently and vomiting has not begun naturally, it may be induced to prevent the absorption of the noxious alkaloids into the bloodstream. Activated charcoal will probably be administered as well, in an attempt to soak up as many of the toxic compounds as possible. If it has been a longer period of time and the intake was excessive, the veterinarian may choose to perform a gastric lavage under general anesthetic to remove as much toxin from the patient’s stomach as possible. There is no antidote to the alkaloids, so treatment beyond decontamination is supportive in nature. This treatment is likely to include intravenous fluids with combinations of electrolytes and sugars to prevent imbalances and to combat dehydration, and monitoring of the respiratory and circulatory systems.

Clinical effects should wear off after just a few hours, although with more severe reactions your pet may require a stay at the clinic for supportive therapy and monitoring. A quiet and calm environment to return home to will help your pet fully recuperate. Plenty of fresh water should be made available, and extra bathroom breaks should be expected as the toxins and medications make their way through the digestive system. Patients that are recovering from anesthesia for gastric lavage may have coordination difficulties when they first get home, and they are often confused and disoriented. Isolation from other pets and from children may be wise until the medication has been fully expelled from your companion’s system.