The most common burn a pet is likely to suffer is a thermal burn from something hot, such as boiling water or from a fire. Other burns a pet may sustain are chemical burns or sunburn.
If your pet suffers a thermal burn, prompt cooling of the burn area with a cool, clean, wet cloth can prevent the burn penetrating into the deeper tissues. But also bring your pet to the vet straightaway.
If your pet suffers a chemical burn, any chemical visible on the skin should be washed off with lukewarm, flowing water. Then bring your pet to the vet immediately.
The best treatment for sunburn is prevention. One of the commonest sites for sunburn is the ears, especially when the ear tips are white, and the face in general. High factor sun creams can be used to prevent sunburn. Animal-specific sun creams are available.