The domestic cat is a small, typically furry, carnivorous mammal. They are often called house cats when kept as indoor pets or simply cats when there is no need to distinguish them from other felids and felines. They are often valued by humans for companionship and for their ability to hunt vermin.
I am sorry to hear about your loss.
It is narrated that the Prophet (S) said: “Keep many domestic animals (al-dawajin) in your houses so that the shayatin (demons) are occupied with them instead of with your children.” (See Tibb al-A'immah)
I think there is some truth to this.
Of course, maybe your cat just died and there was no other reason for it. The lifespan of animals is also in the hands of Allah, and this life is transitory for all of us.
At least you got to enjoy some time together, and one thing I have always admired about animals is that they handle death with grace and acceptance.
With salaams and du'as
The number is not mentioned, but in fact, if it's like a bunch of hair then prayer in these clothes should be avoided.
Question: Does cat hair affect ones prayers?
Answer: If there is a few cat hairs (one to three) on a person's body or cloth, his prayer is in order but if there are more than that, his prayer becomes void, as an obligatory precaution.
Yes we are allowed to keep them as pets, there is no evidence in the Shari'ah which prohibits having cats as pets. But we have to be carefull that we do not pray with the cat hairs on our body or cloths of prayer.
With regards to the cat's hair, see the mas'ala on "dress for prayer" in the risalahs of the maraji`. Ayatullah Khu`i, for example, says: The dress for prayer should "not be from the parts of the animal whose meat is not halal...this would also apply to the hair found on the cloths, etc." (Minhaju 's-Salihiyn, vol. 1, p. 138) Cat is surely an animal whose meat is not halal, and, therefore, its hair should not be on the dress of one who wants to do salat.