Vomiting is triggered when the vomiting center, located in the medulla of the brain is stimulated by input from various receptors around the body. These receptors can be found in the gastrointestinal tract and organs such as the liver, pancreas, bladder, and pharynx. Cranial nerve VIII will stimulate the vomiting center if the animal has vestibular disease or motion sickness. The vomiting center can also be affected if the cat has a disease of the central nervous system. Once stimulated the vomiting center will then cause vomiting by triggering the stomach and diaphragm muscles to contract thereby forcing stomach and upper digestive tract contents up the oesophagus and out of the mouth.
Vomiting is often seen in cats but it is usually only an occasional occurrence. If you notice your pet vomit only once then there is unlikely to be a problem. However, if vomiting is frequent or occurs over a period of more than a couple of days there may be an underlying problem which is causing it. The seriousness of vomiting depends upon any underlying cause and the severity and duration of the vomiting itself. If the vomiting is only occasional and does not go on for a very long time then there is probably little to worry about, especially if your pet is bright, alert and active. If your pet is dull, lethargic, inappetant or collapsed obviously there is a need to seek urgent veterinary attention. Also if your pet continues to vomit for longer than a day or two, or the vomiting is associated with other problems such as diarrhoea it would be wise to see your vet. If vomiting is prolonged or severe and goes untreated then it may lead to complications such as dehydration and malnutrition as well as chemical imbalances caused by the constant loss of fluids and nutrients.
There are a vast number of conditions which may cause vomiting in cats but please remember when reading the rest of this article that the vast majority of of vomiting pets do not have a serious underlying disease! I have tried to order the following discussion about the causes of vomiting so that the most common problems are discussed first. As you will see these are the least serious problems and also the most easily treated ones.
In cats vomiting is often caused by fur balls. If this is the case you will often notice wet, matted "slugs" of hair being vomited up. This common condition is easily treated with a laxative preparation to aid the passage of hair through the gut. See Furballs.
Worms are another factor commonly causing cats to vomit. Kittens tend to be affected most by roundworms which may cause a partial intestinal blockage that leads to vomiting; adult cats may also vomit if they have worms and sometimes these worms will be present in the vomit and seen by the owner. Worming your cat every three months is a good idea if such problems are to be prevented. See Worming.
Vomiting can be caused by dietary factors, especially if your cat has a sensitive stomach. Your cat may be overeating or eating too quickly, although this is less common in cats than in dogs. Sometimes cats may not tolerate rich or fatty foods. It may be a good idea to use one of the Hills diets such as i/d or d/d if this is the situation with your pet. Alternatively a home prepared bland diet may be used such as cooked chicken or white fish, although if these are used long term it may be necessary to give vitamin and mineral supplementation. Any changes to the diet should take place gradually over a period of about 10 days.
Colitis may cause vomiting, but will mainly cause diarrhoea which may appear to have mucus or blood in it. This condition will often resolve if a bland diet is given following 24 hours without food to rest the gut.
If your pet has an infection of the stomach (gastritis) this will obviously cause vomiting. The upper intestine may also be affected so that the cat has diarrhoea as well. In this situation it is wise to starve the animal for 24 hours and introduce a bland diet with plenty of access to water throughout. Most such diseases are self limiting and will resolve in a few days. Remember that there are a few serious diseases which cause vomiting and diarrhoea which are zoonotic (humans can catch them) these include Salmonella, E. coli and Campylobacter so always wash your hands after handling your pet or their excrement or vomit. If cleaning up after a pet with gastrointestinal problems it would be wise to use gloves.
If vomiting is occurring frequently but there are no faeces being passed then you should visit your vet immediately because there may be a foreign body causing a blockage in the intestinal tract. Surgery is often required to remove such foreign bodies but occasionally they may pass on their own. However you should never delay in seeking advice from your vet because foreign body obstruction is a very serious problem which can even result in the death of affected animals if left untreated. Common foreign bodies found in cat's intestines include needles, wool and toys.
Liver, kidney and pancreatic diseases can all cause vomiting as can sepsis and metabolic imbalances. Disease of the central nervous system, congestive heart failure and cancer may also cause vomiting. All of these conditions are serious and will require veterinary treatment.
Gastric ulcers and tumours do not often occur in cats but if your cat is vomiting blood or has black tar like faeces these conditions should be considered as a possible cause and urgent attention sought.
Many people come in to the veterinary surgery with a vomiting cat and are very concerned that their pet has been poisoned. This does occur but is very rare in cats because they are such fastidious eaters. It is difficult to treat poisoning if the vet cannot identify the actual poison used so if you have the packet of the substance you believe your pet has consumed take it along with you when you go to the vet.
The way in which vomiting is treated will obviously depend upon the cause and the severity of the symptoms. In the vast majority of cases the problem will not be serious and can be easily treated; however if your cat has a more serious underlying condition the outcome will of course depend upon the disease being diagnosed treated.
In uncomplicated cases of vomiting where the pet is bright , active, alert, passing faeces and not vomiting too frequently the cat is usually treated as an outpatient. Initially the animal is starved for 24 hours but offered plain water or Lectade to prevent dehydration. Over the next few days the cat may be given a bland diet such as chicken or fish, or if preferred a special diet such as one of the Hills range may be given. Food should be given little and often in about 4-5 feeds per day over the next 3-4 days until the vomiting has resolved. Once the cat is better the normal diet should be gradually re-introduced over the next week or so. During this time it may be a good idea to keep your cat inside with a litter tray so that he cannot obtain food elsewhere and you can also observe the faeces and watch out for diarrhoea. If vomiting does not resolve during the first few days go to see your vet who may need to carry out some diagnostic tests. Remember to treat your cat for worms regularly and treat hairballs as necessary.
If vomiting is severe enough to cause dehydration then your cat may need to be admitted to the veterinary hospital for fluids and other treatment to be given. In this situation every effort will be made to determine the underlying disease. Tests which may be carried out include blood sampling, x-rays, ultrasonography, endoscopy and faecal sampling.