When cats groom themselves, they drag dead cells and dead hair of their bodies. Usually, cats which ingest this hair expel it through their faeces. However, in some cases of:
1. races with long hair/fur
2. animals with excessive grooming; we could mention over anxious animals which use it as a trait.
3. in periods of moulting (shedding) its fur.
The quantity of hair is more than its intestines are able to handle. This produces gastric problems, even obstruction of its intestines. We will notice the cat seems "down" and it has lost its appetite, with no normal explanation for such problems. If you recall what we mentioned in previous lessons, cats bury their faeces, which makes it complicated for us to know for how long it hasn't been defecating.
When this problem is detected in time, it can be treated. However, when we are dealing with hardened faeces inside its intestines, it can only be solved through surgery.