Greyhound machine for medals

Why does the greyhound appear in the pedigrees of European sled dogs and other similar sled-sport hybrids? It's definitely because the greyhound is a real dog athlete! In the following lines, I decided to list interesting facts about greyhounds that distinguish them from other breeds.

Where there is money, there is research

Over the past 20 years, Dr. Ross Staaden in Perth drove greyhounds on a high-speed treadmill to measure energy and oxygen consumption, heart rate and other physiological parameters. Another "gray" researcher is Dr. Robert Gillette of the University of Alabama in the USA, who measured step by step the movement patterns and distribution of forces in running. Thanks to these gentlemen, we have gained a good overview that greyhounds function as a very finely and precisely tuned racing machine.

Due to the huge popularity of greyhound racing, we have a lot of data and information today. The pursuit of top performance has thus given the green light to many studies.

Šlupka, Foto Kateřina Vojáčková, "Black line" from breeder Jiří Suchý (CZE)

Energy use

I wrote about this topic in the article The energy of a dog athlete. Muscle glycogen stores and the ability to use carbohydrates as a primary energy source have been shown to be ineffective in dogs. For greyhounds, the latest studies from 2018 show that it is as follows: In the first 7.5 seconds, ie only in the phase of initial acceleration, the greyhound metabolizes large energy creatines and glycogen stores in the muscles without the need for oxygen. Subsequently, it will switch to the use of fat reserves. The study does not take into account the body's energy supply for more than 1 minute, so it may not be completely relevant for mushring needs. It can be assumed that in the case of repeated starts and pulling up a steep hill, the dog reaches for carbohydrates to a limited extent.

Acceleration and speed

The Greyhound reaches a speed of up to 70 km / h within 30 meters after the first rebound. Another animal on the planet that can accelerate faster over the same distances is just a cheetah. It reaches a speed of 109 km / h within 3-4 steps from the start. Greyhound muscles generate 75-80% of their strength from anaerobic metabolic pathways during the first 30 seconds of exercise. When running for more than 30 seconds, the energy supply is taken over by fat metabolism, which ultimately accounts for up to 90% of the total resource.

Heart

RTG Greyhound heart

Cardiac output (blood discharge) increases from approximately 200 ml per kg body weight per minute at rest to more than 1000 ml per kg at full gallop. The greyhound's heart pumps up up to 15 liters of blood in 30 seconds of exercise.

The heart weight of a greyhound ranges from 1.18 to 1.73% of its body weight or from 390 to 519 grams for a 30 kg greyhound, which is more than the elite racehorse, which is 1.0 to 1.3% body weight. Other breeds of dogs have a heart weight of 0.77% of their body weight. To imagine the human heart makes up 0.5% of its total weight.

The average human athlete weighing 70 kg has a heart as big as a 30 kg greyhound. In addition, however, the heart supplies blood almost twice as fast. When galloping, it beats at a frequency of 310-340 beats / minute, compared to humans 170-210 beats / minute. The greyhound is many times more effective in its ability to oxygenate the body and the muscles that work. This is one of the reasons why the greyhound manages to oxygenate muscles even when lactate accumulates above 8 mmol / l, which is about twice the human anaerobic threshold.

Blood and red blood cells

Fany&Olly Foto: Šimon Cipro ( breeder Jiří Suchý CZE)

The Greyhound has the highest blood volume of any known animal athlete. Blood makes up 11.4% of its total cash flow, compared to 10.5% for racehorses and 9.5% for human sprinters and 7.2% for other pet dogs. Greyhound in the bone marrow and spleen produces about 5 million red blood cells per second. Greyhound has about 3 liters of blood consisting of about 2 liters of red blood cells. Lots of red blood cells = lots of oxygen for working muscles. Such an enormous amount of red blood cells with a unique ability to oxygenate the body literally makes it a race machine!

In conclusion

If we think about the fairness of the races and the comparison of individual dogs in mushing with each other, we must clearly conclude that the 30-kgs hybrid ESP, greyster and other greyhounds must naturally dominate other breeds over 25 kg. Therefore, dividing categories by weight will never lead to "fair play".

Links to used resources:

Physiological parameter values in greyhounds before and after high-intensity exercise https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5918126/

Greyhound Athelete Facts

http://www.easypetmd.com/doginfo/greyhound-athelete-facts

Grayhound Medical Idiosyncrasies

https://www.greyhoundfriends.com/wp-content/uploads/2016/03/Greyhound-Health-Packet-2016.pdf