Groundsel Poisoning in Dogs

The groundsel plant, Senecio vulgaris, is a flowering plant in the Asteraceae family that grows throughout the northern hemisphere. It is also known as old man of the spring, and it has large lobed leaves with disc-shaped yellow flowers. This plant contains an alkaloid, which, when eaten in large quantities or regularly over an extended period of time, can cause damage to the liver itself. Fortunately, it takes a large amount of plant material to become toxic and the plant itself is unpalatable so canine  poisonings from this plant are exceptionally rare.

The groundsel plant (Senecio vulgaris) is a flowering plant that contains low concentrations of hepatotoxins throughout the plant.

In most cases, groundsel poisoning occurs after chronic exposure to the weed, although it has been known to occur when substantial portions are eaten. The toxin attacks the liver, so symptoms are those of liver failure. If your dog does ingest large enough amounts of this plant to be toxic, the following signs will occur. 

• Dull coat
• Excessive thirst
• Excessive urination
• Fluid in the abdomen
• Head pressing
• Jaundice
• Lethargy
• Loss of appetite
• Restlessness
• Staggering
• Abdominal swelling
• Weight loss

Types

It is exceptionally rare for a dog to be poisoned by groundsel as the plant is not palatable and a great deal would need to be eaten before toxicity occurred, often over a long period of time. The symptoms of groundsel poisoning generally take several weeks to occur, but if your pet eats large quantities of vegetation, intestinal blockages are also a concern. The canine digestive system is not designed to process large quantities of plant material. Although most dogs do not tend to do more than sample plants, some dogs may develop pica, an overwhelming craving for non-food items. This can cause the consumption of large amounts of inappropriate materials, such as plants, which can lead to intestinal blockages. Symptoms of intestinal blockages usually start within a few hours of ingestion and can include:

• Abdominal pain
• Distended abdomen
• Fever
• Inability to eliminate
• Loss of appetite
• Shock
• Straining on defecation
• Vomiting

The toxins found in the groundsel plant are pyrrolizidine alkaloids, which act as hepatotoxins when they are introduced into the system in sufficient quantities. The damage that is done to the liver by these alkaloids may be manageable but usually is not reversible. These pyrrolizidine alkaloids are present in all parts of the plant, although the flowers have the highest concentrations. Although most dogs would not eat enough plant material to cause problems, some dogs may develop pica, an overwhelming craving for non-food items. This may cause them to eat large quantities of materials they would ordinarily leave untouched.

Your veterinarian will question you regarding your dog’s health history, as well as a timeline of the onset of symptoms. Special note will be taken regarding any opportunities for inappropriate eating as well any concurrent prescriptions or supplements that your dog is on. Certain drugs, like NSAIDs, can also antagonize the liver and should be ruled out. A complete blood count, biochemistry profile, and urinalysis will need to be done at this time as well. These tests can help determine if the alkaloids are still circulating in the system as well as information regarding the functionality of the kidneys and liver. The pyrrolizidine alkaloids are only detectable in the blood and urine for 24 – 48 hours, so by the time symptoms begin, the alkaloids that caused the damage have already exited the body. Abdominal pain or swelling may prompt your veterinarian to get x-rays to check for swelling of the liver or intestinal obstructions as well.

Treatment for hepatotoxins like groundsel is mostly supportive. If the ingestion of the plant material was recent, within two hours, your veterinarian may instruct you in the proper technique for inducing vomiting in dogs, and may administer activated charcoal to soak up toxins in the stomach so that they don’t reach the bloodstream. In addition, any required supportive treatment will be administered at this time. This can include pain medication, intravenous fluids, and even gastroprotective treatments. 

Prognosis of this condition can be mixed. Any damage that has already occurred to the liver is not reversible, however, careful management can keep further damage from occurring. There are several factors that would have an effect on the outcome, including the dog’s overall size, the amount ingested, and how long it has been since the ingestion occurred. If the consumption of this plant has occurred over several days or weeks toxicity can build up, and damage the liver.

If your pet eats enough of this plant to cause toxicity, a calm and quiet environment is needed to recuperate in when they return home. Patients recovering from anesthesia, as would be needed for a gastric irrigation, may have difficulty with coordination and muscle control when they first return home, and they are often disoriented. Isolation from children and other pets is often wise until the anesthesia has fully cleared the patient’s system. Even minor dehydration can exacerbate the liver issue, so it is also vital that fresh water is available for your dog at all times during convalescence. Any medications that were prescribed by your veterinarian should be given as directed. Dogs that recover from groundsel poisoning will likely need follow-up appointments to check their ongoing liver function.