Inducing Vomiting in Cats

The induction of vomiting (also known as emesis) is the administration of a substance with the intention of making the cat sick. This is most commonly done when a cat has eaten something that is injurious to their health. Thus voiding the ingesta from the stomach reduces the likelihood of it being absorbed from the stomach into the bloodstream. 

Inducing vomiting is only beneficial when performed promptly after the cat has eaten the offending item. The time frame is relatively tight, with there being little point in attempting to induce vomiting once two hours have passed. 

When an owner observes or suspects their cat has eaten a harmful substance, speed is of the essence. In the first instance they should record what was eaten and how much. Then they should phone their veterinarian for advice. 

Based on the information about what, when, and how much was eaten the vet may suggest different courses of action. For example: 

• There is no need to induce vomiting if a less than a toxic amount was eaten
• Induce emesis at home which can save precious time if the owner lives some distance from the facility. This usually involves slowly syringing a weak, 3% solution of hydrogen peroxide into the cat's mouth. This is often the most successful way of inducing emesis.
• Transport the cat to the vet clinic for induction of emesis. The vet has a number of drugs at their disposal, such a xylazine, medetomidine, and apomorphine which are given by injection (or drops into the eye in the case of apomorphine) to induce sickness. Different drugs have different pros and cons, and the clinician will decide on which is most appropriate on an case by case basis. 

Unfortunately, it is notoriously difficult to induce vomiting in the cat. This is because the physiological mechanism that generates feelings of nausea and eventual vomiting in the cat are different to the dog. Drugs such as apomorphine which are the main emetic used in dogs, have a disappointing action in cats because their chemoreceptor trigger zone in the brain is relatively insensitive to its action. 

It is also unfortunate that many of the drugs used to induce vomiting in the cats are actually sedatives (and the emetic action is a side effect.) Thus, it's possible or even likely that the cat may be given an emetic and not be sick, but become sedated. Fortunately, some of the drug options have reversing agents so the sedation does not have to be prolonged. 

Where effective, most of the options induce vomiting with 5 - 10 minutes. Since it is their mode of action that is deficient, it is generally not beneficial to repeat the dose or give at a higher initial dose. 

Giving dilute hydrogen peroxide by mouth does have potential complications. If it is syringed into the mouth too quickly and the cat inhales some of the liquid, it can cause a serious aspiration pneumonia. Also, some cats are prone to inflammation of the stomach lining (or gastritis) and hydrogen peroxide is an irritant known to trigger gastritis. 

When the vet administers an emetic, they monitor the cat for vomiting. Once vomiting has occurred, if the cat has become sedated a reversing agent may be given. If no sickness has happened after 30 minutes it is unlikely to take place and reversal given. 

In those cases which the cat did not vomit, they may be placed on supportive therapy. This includes intravenous fluids to protect organ function and activated charcoal to decrease absorption of drugs from the gut. 

Dilute hydrogen peroxide is cheap and readily available, and represents an inexpensive option for treatment. However, it is often the nature of situations requiring the induction of vomiting often happen when the shops are closed or after hours. Thus the owner may be faced with an emergency surcharge to have their pet seen. 

A first opinion veterinary clinic will charge anywhere upwards of $150, in addition to the fee for a regular consultation of around $40 - $60. The choice of drug made by the clinician could also impact the cost, with apomorphine being a more expensive option. Even though the dose of apomorphine used is small, the vet may have to breech a vial or bottle of drug which doesn't keep once opened. Thus, the cat owner may be charged for the whole bottle, rather than partial use, which could be $80 or so. 

On the whole, the need to induce vomiting in the cat is a mercifully rare occurrence. This is fortunate since there is no guarantee that drugs will be effective at voiding unwanted substances from the cat's stomach. However, this does not mean that it's wrong to try, because a cat's metabolism makes them vulnerable to organ damage when even low doses of certain medications are ingested. 

In addition, should the attempt at inducing vomiting be unsuccessful, the clinician is placed to monitor for complications from the ingested substance and to give supportive care as necessary, which helps to protect the organs from damage.

The cat's natural discretion when it comes to eating things they don't recognize is ultimately their best defense. Because of the unpredictable effect of emetics on the cat, prevention is far preferable. Even though cats are notoriously fussy eaters, the odd accident does happen when a pill is dropped on the floor and the cat mistakes it for a treat.

Therefore, all medications (both human and animal) should be stored safely in a cabinet out of the cat's way. Medications should be kept in childsafe containers, which carry the full details of the drug name and strength. This allows the clinician to make potentially life-saving judgement calls about the most appropriate course of action, should the need arise.