Just did some more googling.
what affect does summer heat have on greyhounds, and what can we do to help them best cope?
Keeping Cool
Probably the biggest difference between us and greyhounds is the different ways in which our bodies work to maintain a stable operating temperature. For humans, body sweat is used to cool our skin, but greyhounds can’t sweat all over like we do, instead only sweating through glands on the pads of their feet and nose. Greyhounds instead rely on evaporative cooling from their respiratory system – panting to move air across wet membranes.
This system of cooling has limitations and has important consequences for the greyhound. Firstly, the evaporation can only occur if the humidity in the air allows it – the higher the humidity the less this system works. So when in a confined space such as a car, trailer or kennel, humidity can increase quickly as evaporated water from the greyhound stays in the air.
The second problem with this sort of cooling is that it can lead to huge losses of body fluids and can alter the acid-base balance in the dog’s blood from the increased amount of oxygen-carbon dioxide exchange in the lungs. These changes are hard to measure because you may not be able to actually see them.
What will you see?
Heat Stress – panting, salivating, increased heart rate, listlessness, vocalisation/whining
Heat Stroke – excessive or loud panting, thick saliva, vomiting, diarrhoea, wobbliness, strange behaviour, seizures, collapse, and death