Most cats, even healthy ones, vomit from time to time. Although it can be very distressing if your cat keeps throwing up, this is perfectly natural and does not necessarily mean that there is anything seriously wrong with your cat. There are several non serious factors which may cause your cat to throw up.
You may notice your cat bringing back a meal shortly after eating it; in fact it will often appear to be completely undigested. Cats will often bolt their food, or eat more than their stomach can handle at a time, so the stomach will reject it. This may be more common in multi-cat households, where cats sense competition for their food. Cats' digestive systems are very sensitive, and a sudden change in your cat's food can also induce feline vomiting.
Hairballs are one of the most common causes of feline vomiting. They are caused when your cat ingests fur whilst grooming itself. Long haired cats are more likely to suffer from hairballs, although all cats can suffer from time to time. You should be able to spot clumps of hair in the vomit. Hairballs can be reduced by regular grooming or adding essential Omega-3 Fatty Acids or fish oils to your cat's food to allow cat hair to pass through the cat's digestive tract.
Sometimes your cat may throw up if it has eaten something inappropriate, such as garbage or a poisonous plant. If you suspect that it has eaten something which may be poisonous, such as slug pellets, cleaning fluids, plants etc take it to the vet immediately. Feline vomiting may also indicate that your cat has swallowed something which may cause an obstruction, such as a bone or piece of string. In this case the vomiting may be accompanied by foam or froth around the mouth. Again, take it to the vet if you suspect this.
Cats will often eat grass and other plants; it is thought that this provides them with roughage in their diets. However, it can also cause them to vomit. In this case the vomit will be frothy in appearance, with the plant matter clearly present.
Other non serious causes of feline vomiting are stress and nervousness. Elderly cats can throw up more frequently as their bodies start to wear down and their immune system lowers.
Feline vomiting can also indicate a more serious problem. It can indicate parasites such as worms; you may be able to see these, resembling grains of rice or thread, in the vomit or feces. If you think that your cat has parasites, consult the vet. Regular deworming can help to prevent this.
It can also indicate an infection, such as salmonella, feline leukemia, or a bacterial or viral infection. In this case, the vomiting may also be accompanied by diarrhea. Your vet should be able to give advice on treatment.
Certain diseases can also cause feline vomiting, such as liver disease, kidney disease, Feline Panleukopenia, diabetes and bowel disorders.
If you notice symptoms such as blood in your cat's vomit or other symptoms such as diarrhea, weakness, obvious pain or breathing difficulties, or your cat keeps throwing up for longer than a couple of days, contact your vet as soon as possible.