Only one sport in Olympics has involvement of Animals in it. That event is called Equestrian which comprises of 3 categories.
Equestrianism made its Summer Olympics debut at the 1900 Summer Olympics in Paris, France. It disappeared until 1912, but has appeared at every Summer Olympic Games since. The current Olympic equestrian disciplines are Dressage, Eventing and Jumping. In each discipline, both individual and team medals are awarded. Women and men compete together on equal terms.
Equestrian disciplines and the equestrian component of Modern Pentathlon are also the only Olympic events that involve animals. The horse is considered as much an athlete as the rider.
Is it relevant in Olympics where most of the events involve only the human effort and the human will to surpass the limits?
USA and Germany might disagree as they have the biggest haul of medals in the event.
On a survey taken by FiveThirtyEight a leading sports analytics website, Equestrian was voted as the least interesting sports present in the Olympics.