There are various causes of vomiting in your cat. One of them is the very natural seasonal change of coat.

Cats, being the fastidiously clean animals they are, groom themselves more when the coat changes. This means they ingest a lot of fur, even when they are not long fur breeds.

Since fur has no nutritional value, the cat's body has little reason to pass it through the digestive track, although some do. Most cats, however, will vomit up the fur, sometimes in the form of fur balls (a mass of tightly packed fur), sometimes just loose fur with saliva.

All cats are different and so have different ways of dealing with issues.

One thing that is certain, is the vomiting fur is entirely natural and beneficial.

Most of us care about those we are responsible for. When you don't know about the normal and healthy ways of your charge, you can get into a panic easily.

Cats do have very easy, natural and beneficial ways of helping themselves stay healthy. One of these is their inclination to vomit what their body deems unsuitable.

When the offending substance is vomited out, it doesn't pass through the digestive track where it can be absorbed and so do greater harm and damage.

This wonderful way their body works is in their favour. However, people base things on their experiences.

When we vomit, it can indicate a serious, albeit short, bout of un-wellness, so we incorrectly assume it is the same with cats.

However, when you watch a cat vomit up fur balls, you realise that it doesn't have the same effect. Instead, they seem to be back to normal almost instantly.

The job was efficiently accomplished.

It's important to appreciate that veterinarians do have to deal with both the feline patient and the worrying human. And that can encourage them to over prescribe or to suggest treatments that may help allay your fears, but can cause harm to your cat.

Here are some other causes of vomiting in your cat that are normal and don't need you to worry about.

When cats have a digestive upset, whether acute and minor or chronic and serious, they frequently choose to graze on grass. Cats are carnivores (meat eaters) exclusively and only eat plants for medicinal reasons. 

This means that grass should always be available for them. When they don't have access to grass, they will try anything green, including plants that are poisonous to them.

Mild, acute tummy upsets usually leads to a few chomps on grass, followed by bringing it back up accompanied with saliva. And they feel fine almost immediately.

Some cats will pass the grass through the digestive system to come out the other end.

The more serious or the more chronic the situation, the more grass they will chomp on and the more often, such as daily.

Obviously the once in a while need for grass is not something to worry about, whereas the regular need can be. Even so, the grass does help, so it isn't normally an emergency situation.

Cats on a healthy raw meat and bones diet, will occasionally vomit up little pieces of bone. This is not unusual and does not signify a health issue.

Food poisoning in cats can take on various forms, depending on how healthy they are. The less healthy they are, the more likely they will be sensitive to even small dietary indiscretions.

Cats are fussy eaters for a reason - they prefer to kill what they eat. Which translates as needing very fresh food. Obviously, commercial cat food is a looooong way from being fresh. In addition, plant based foods are added (for carnivores?) plus chemical additives. Cats are extremely sensitive to synthetic chemicals.

Minor food poisoning can last 12-24 hours, with vomiting and diarrhoea. After which the cat may need to fast and sleep to recover. This may not be a cause for concern.

Continuous vomiting can indicate ingestion of a hazardous chemical such as rat or slug bait and this needs quick professional support. 

I strongly recommend that you don't have any chemicals either in the house or outside if you have cats or any other animals. It just isn't worth the risk. Some rat bait is so hazardous, there is no veterinary anti-dote. Even the homeopathic treatment may not be in time, when there is a delay in getting help.

Assess the situation before deciding what to do. What have they eaten? Inspect the vomit. Vomiting in your cat is a natural and normal way to eliminate undesirable substances. So don’t panic immediately. Assess the situation first. Time may be all that is needed.

Here you can find more information on natural cat care.