String of dolphins is toxic to cats. This popular trailing succulent, a hybrid of string of pearls and candle plant, belongs to the Senecio/Curio family of plants, which contain pyrrolizidine alkaloids. These compounds cause liver damage and can affect other organs when ingested by cats.
Why String of Dolphins Is Dangerous
String of dolphins (formally known as Curio × peregrinus or Senecio peregrinus) contains pyrrolizidine alkaloids throughout the plant, including the leaves, stems, and sap. More than 350 toxic alkaloids with a pyrrolizidine base have been identified across plants in this family, and a single plant can contain several of them.
The alkaloids themselves aren’t the direct threat. Once your cat swallows part of the plant, its liver processes the alkaloids into highly reactive compounds called pyrroles. These pyrroles are the real problem: they damage the nuclei of liver cells, essentially crosslinking strands of DNA and disrupting the cells’ ability to divide and function normally. The liver is the primary target, but the kidneys and lungs can also sustain damage because the toxic byproducts circulate through the bloodstream and attack epithelial and vascular tissue in those organs.
Symptoms Don’t Always Appear Right Away
One reason pyrrolizidine alkaloid poisoning is so concerning is that it can be cumulative. A cat that nibbles small amounts over days or weeks may not show symptoms immediately, but the liver damage builds with each exposure. By the time signs become visible, significant harm may already be done.
Common signs of poisoning in cats include:
- Loss of appetite and lethargy
- Vomiting or diarrhea
- Jaundice (yellowing of the gums, ears, or whites of the eyes)
- Drooling or excessive salivation
- Abdominal swelling from fluid buildup, a sign of liver failure
In severe cases, chronic exposure has been linked to the development of liver tumors. Even without tumor formation, the characteristic damage to liver cells, where they swell abnormally and lose the ability to replicate, can lead to progressive liver failure that is difficult to reverse.
What to Do If Your Cat Eats the Plant
If you catch your cat chewing on string of dolphins or suspect it has eaten any part of the plant, contact your veterinarian or an emergency animal clinic right away. Do not try to make your cat vomit at home. Inducing vomiting without veterinary supervision can cause additional harm, and your vet has safer methods to manage the situation in a clinical setting.
Bring a sample or photo of the plant with you if possible. This helps the veterinary team identify the specific toxin involved and choose the right course of treatment. Your vet may induce vomiting under controlled conditions, administer activated charcoal to limit further absorption, or run blood work to assess liver function. In cases where a larger amount was consumed or symptoms are already present, imaging and more intensive supportive care may be needed.
Keeping Cats Safe Around Succulents
Cats are drawn to trailing plants. The dangling vines of string of dolphins look a lot like toys, which makes this plant particularly risky in a home with cats. Hanging the plant high isn’t always enough, since cats are skilled climbers and fallen leaves on the floor can be just as dangerous.
The safest approach is to keep string of dolphins in a room your cat cannot access, or to choose a non-toxic alternative. Several trailing succulents and houseplants pose no risk to cats, including string of hearts (Ceropegia woodii), spider plants, and Boston ferns. If you’re unsure about a specific plant, the ASPCA maintains a searchable database of plants rated for pet toxicity.
Other plants in the same Senecio/Curio family carry the same risk. String of pearls, string of bananas, and blue chalksticks all contain pyrrolizidine alkaloids and should be treated with the same caution around cats.