Ragwort contains pyrrolizidine alkaloids which are highly toxic to most mammals. These alkaloids cause damage to the liver by inhibiting cell division in the organ. It is the process of digestion within the liver that causes these toxins to become harmful. If ingested over time, the liver will begin to shrink and be permanently damaged. Acute reactions are also possible, leading to liver enlargement and, in severe cases, sudden death. This is often caused by liver cell death preceded by hemorrhage. Neurological issues may also develop secondary to liver failure, leading to a syndrome often called “walking disease” or “sleepy staggers”. Cases of ragwort poisoning in cats are rare but do occur.

The ragwort plant is a perennial herb that grows wild in fields all over the United States. Its scientific name is Senecio jacobaea of the Asteraceae family of plants. Ragwort is also known by the names “golden ragwort”, “tansy” and “stinking willie”. It grows tall with clusters of yellow flowers at the tops of wooded stems. The flowers have both yellow centers and petals. The leaves of the ragwort are green and have ragged edges. This plant can survive harsh winters and returns in the spring. Dried ragwort is difficult to differentiate from other field plants. 

Acute or chronic liver damage may develop. The syndrome can take as long as a week to fully manifest. All signs to watch for are listed as follows:

As ragwort often grows in fields or meadows, cats in rural areas or on farms may be more likely to come into contact with the plant. Cats allowed in barns may be inadvertently exposed to ragwort as it can be harvested with straw or hay. It is just as toxic in its dried form as when live. The plant is not pleasant to eat, which deters most cats from ingesting very much of it. Consuming small amounts of ragwort may still lead to liver failure.

If serious symptoms begin to develop, rush your cat into a nearby veterinary clinic or animal hospital. You may be asked to provide your cat's full medical history to help pinpoint potential causes of liver failure. At this point you also may be asked if you live in a rural area or if your cat has access to farmlands or barns. It can be difficult to identify ragwort poisoning, as symptoms develop in such a delayed manner. 

The veterinarian will perform a complete physical examination of the cat. A neurological examination will also likely be done, assessing any abnormalities in the animal. Blood will be taken from the cat for chemical analysis. This may help identify toxic metabolites. A biochemical profile will likely be completed, showing slightly increased levels of bilirubin, glutamates and fibrinogen. The level of ammonia in the blood is likely to be very high. A biopsy of the liver may be needed to fully determine the cause of liver damage. This damage will have to be differentiated from many other liver diseases. In some instances, a full diagnosis may not be completed until the time of autopsy. 

There is no way to reverse the syndrome that follows ragwort poisoning. The main goal during this time will be to keep the cat comfortable and stabilize its body functions if possible.

Removing any leftover plant matter in the body may prevent the cat from having a worse reaction. Washing out the oral cavity can remove bits of plant that have remained in the mouth. Inducing vomiting or performing a gastric lavage (stomach pumping) may also remove materials before they have been digested. These methods are only effective in cases which the cat has very recently eaten ragwort.

To keep the cat in a calm and comfortable state, certain things may be done to stabilize the body. This may include ad intravenous fluid administration to prevent the cat from becoming dehydrated. If severe skin reactions have developed from heightened sensitivity, treatment to soothe the skin may be needed.

The prognosis for cats who have developed liver failure from ragwort consumption is not good. Euthanasia if often required to end the cat's suffering. If only a small amount has been consumed, survival may be possible but lasting effects may exist, requiring further treatments. 

Removing this highly toxic plant from your property may be a good idea if you have cats or other animals. It is easiest to remove ragwort when it is flowering, as it is then simple to differentiate it from other plants. Using gloves and removing the plants by hand is preferable. Burning the plant material is an effective way to destroy it one it has been dug out. Keeping your cat inside may prevent it from coming into contact with ragwort or other toxic plants.