Staggerbush Poisoning in Cats

Staggerbush (commonly referred to as 'lyonia') is the name of a family of trees and shrubs that is native to North America and temperate regions of Asia. The staggerbush has not enjoyed much in the way of ornamental cultivation by gardeners due to its relatively lackluster flowers, meaning that the species has by and large remained confined to its areas of origin. Perhaps another reason for the staggerbush's lack of popularity is its surprisingly high level of toxicity, which can provoke a range of unpleasant symptoms in a variety of animals, including cats.

Though the symptoms of staggerbush poisoning are deeply unpleasant for the affected animal, they do provide the owner(s) with ample time to act. It is imperative to seek professional veterinary assistance if the animal in question is indeed displaying multiple symptoms of any form of serious plant poisoning.

• Vomiting
• Diarrhea
• Loss of Coordination
• Depression 
• Excessive salivation
• Weakness in limbs
• Slowed heartbeat 
• Low blood pressure. 
• Difficulty breathing 
• Congestive heart failure

If large amounts of staggerbush are eaten, the cat can experience:

• Cardiac arrest
• Unconsciousness
• Coma 
• Death

The staggerbush plant contains large amounts of a substance known as 'grayanotoxin'. This chemical's purpose is to prevent the plant from being eaten by grazing animals by causing very uncomfortable and potentially lethal side effects. The mechanism via which the grayanotoxin causes damage to the target organism is by passing through the cell membranes in the affected organism and 'depolarizing' the cell, meaning that it can no longer transmit the electrical impulses that carry information around the nervous system. This effectively means that the brain can no longer regulate the processes occurring in organs poisoned by the grayanotoxin. This results in diarrhea, vomiting, loss of motor control and organ failure. 

When the cat arrives at the clinic, the vet may choose to take a blood sample for analysis in a lab. This will help identify the chemical cause of the symptoms and will help rule out the presence of other substances. Next, the vet will perform a physical examination of the cat in order to check their vital signs and assess the symptoms for themselves. An ultrasound scan may be required in order to verify the proper function of the heart. They will also have questions for the owner both regarding the poisoning and the events leading up to it, but also about the cat's medical history and its living environment. Owners should try to be thorough, as this information can be of great help to a vet.

The first thing that the vet can be expected to do is to start the cat on fluid therapy, which will directly introduce more fluids into the animal's body. This will both help stimulate the production of urine (thereby removing the grayanotoxin from the cat's system) and will help counteract the effects of dehydration brought on by vomiting and diarrhea. The vet may also feel it necessary to give the cat a dosage of activated charcoal in order to absorb any grayanotoxin that may have been left behind in the digestive system, thereby preventing the symptoms from flaring up again. If the heart rate has slowed to dangerous levels, it is sometimes required to use a stimulant such as atropine or epinephrine to maintain a healthy rhythm, though such a procedure is usually reserved for emergency use only.

Grayanotoxin poisonings generally require some time to recover from, with most cats taking a few weeks to fully regain their strength. It is important for owners to keep the cat confined to the house in order to conserve its energy and give it plenty of opportunity for rest. Furthermore, to give the digestive system ample time to recover, the vet may prescribe as bland a diet as possible for the first few weeks. Most animals will not need a follow-up visit, though those that have suffered from additional heart or dehydration-related complications will obviously need more stringent aftercare.