The fastest dog in the world – the Australian Reintel – can reach a speed of 70 kilometers per hour. However, the speed of dogs varies according to their size. If we talk about small dogs, the Jack Russell Terrier is the fastest, with a speed of 40 km/h, ranking 25th in the world’s fastest dogs; if we talk about medium-sized dogs, their fastest speed can reach 64 km/h, created by the so-called “small Reintel”. The fastest speed of 64 kilometers per hour is set by the “miniature linden”, the Whippet, which can reach the maximum distance with the most concise movements. Most of these fast running dogs have excellent physical conditions, such as the Reintel, which has a streamlined structure that minimizes air resistance, plus its powerful limbs that are full of muscle, allowing for an instant burst of speed, and its unusually wide nasal cavity that allows it to inhale more oxygen, and because of the deeper chest cavity, it also allows the heart to get more room to stretch and burst more blood, thus more conducive to improve speed in a short period of time.
