Bay laurel is a common garden plant that is widely grown across the United States and Europe. Although commonly used in cooking, the raw flowers and leaves can be very poisonous to cats if ingested. In small amounts, the toxins contained within the plant can cause serious problems in the digestive tract and in larger doses (or with prolonged exposure) can result in death. 

A cat that has ingested bay laurel leaves will display several very noticeable symptoms. Unfortunately, they are not unique to bay laurel poisoning, so a vet will usually be required in order to make a complete diagnosis.

About thirty minutes after eating the bay laurel, the cat will usually begin to vomit. Although not different in color or consistency from regular feline vomit, continued retching and vomiting are indicators of a more serious problem than normal indigestion. The animal may also throw up fragments of (or even complete) bay leaves, helping owners diagnose the problem. Sustained vomiting can be dangerous to the cat's health however, as it can cause rapid dehydration.

As the body attempts to void the ingested toxins from its digestive tract, the cat may also begin to experience diarrhea. Owners should be aware that this can cause even worse dehydration than vomiting.

Bay leaves are very tough and even once cooked the human digestive system can have a hard time breaking them down. Smaller animals such as cats are, for this reason, very susceptible to the bay leaf causing a blockage of their digestive tract. Such a blockage can be very uncomfortable, resulting in behavioral changes such as visible discomfort and increased aversion to being touched. 

Raw bay leaves also have remarkably sharp edges and taper to a noticeable point. As it moves through the body, the leaf can scratch, gouge and even lacerate the lining of the esophagus and gut. The most visible indication of this is blood appearing in the cat's stool or vomit. Untreated, this can result in a reluctance to eat (causing weight loss) and even bacterial infection.

The main factor in bay laurel poisoning is the presence of eugenol and other essential oils within the plant. When ingested, the eugenol is filtered through the liver, where it causes damage to the surrounding tissues, causing oxidizing agents to be released. For many of the cells in the liver, this can be extremely dangerous and can cause them to not only malfunction, but also die off. This liver toxicity will cause toxins to be released into the bloodstream and can potentially have extremely serious side effects. In an effort to cleanse the body of the material causing the poisoning (in this case, the bay laurel leaves), the digestive system will purge its contents via the mechanisms of vomiting and diarrhea.

When an owner presents their cat to the vet, the vet will most likely perform a physical examination of the cat to try and rule out the more common causes of digestive discomfort. The next step they will take is to draw blood for testing and perform an imaging scan via ultrasound or endoscopy (this is especially useful in the case of an obstruction). The vet will most likely have a number of questions for the owner about the cat's habits and living environment (i.e. what plants and substances is it coming into contact with on a daily basis), so attending the clinic with some answers prepared will be helpful for diagnosis.

The bulk of cats suffering from bay laurel poisoning will typically only require the intravenous administration of additional fluids. By introducing more liquid into the body, the vet can 'purge' the toxins from the liver and allow them to be excreted via urine. Afterwards, the cat will slowly be able to resume eating food again. For more gravely affected animals, however, more drastic measures may be needed. Cats suffering from serious liver damage will in all likelihood wish to avoid eating food altogether. However, energy is needed in order to allow the liver to properly regenerate and resume normal functionality, so the vet may opt to insert a feeding tube down the esophagus or directly into the stomach. This will allow the owner to feed the cat small amounts of liquid food and prevent the onset of serious illness. In total, even the most serious cases of poisoning will usually be resolved in under a month, provided that there are no secondary complications.

In cases of both mild and serious levels of bay laurel poisoning, it will be necessary for the owner to restrict the activity of the cat, in order to ensure that they are well-rested and the liver recovers properly. They will also only be capable of eating a small amount of food at a time and will require plenty of fluids. Depending on the seriousness of the case, the vet may wish to book a follow-up appointment within a week of the original diagnosis, in order to ensure the cat is healing properly.