If you cat has regular episodes of cystitis with no obvious cause they may be suffering with ‘feline idiopathic cystitis (FIC)’.
Pets can get sunburnt just like people, especially if they are light coloured or have a thin/patchy coat. Sunburn is painful, causes skin damage, and can lead to certain types of skin cancer.
Very minor wounds (cuts, grazes, burns, bites and bruises) often heal themselves. More serious wounds should always been seen by a vet.