The signs of heatstroke in domestic cats are arguably quite important today with climate change and with some extraordinary temperatures, recently, in the north-west of America and up into British Columbia Canada where there have been temperatures approaching 50°C. They lasted for several days causing shock among the citizens and expert observers. People do not expect the effects of climate change to be so dramatically apparent so quickly. It was caused by a 'heat dome' but the underlying cause is almost certainly global warming, a man-made catastrophe.
Cat panting. Photo taken from video screenshot on YouTube. |
For this reason, although heatstroke in domestic cats is, I am sure rare if not very rare, it is a possibility and it is therefore useful for cat owners to know the signs of heatstroke in domestic cats and what to do about it.
The first point is that it is an emergency requiring immediate recognition and rapid treatment. The main way that cats cool down is by panting in which they exchange warm air for cooler air. It also uses the cooling effect of the latent heat of evaporation. This is an early possible sign.
Signs
Heatstroke begins with noisy, frantic and rapid breathing. The mucous membranes such as the gums and the tongue are bright red. Saliva is thick and tenacious. The cat will often vomit. The temperature as measured with a rectal thermometer (which ideally should be in the first-aid kit) rises sometimes to 41°C or 106°F.
The temperature is taken to confirm what is probably evident by the appearance and behaviour of the cat. Left untreated the cat eventually staggers and becomes unsteady. They have diarrhoea which might be bloody and they become progressively weaker. The lips and mucous membranes become a pale blue or grey.
Eventually the cat collapses and goes into a coma and dies if the heatstroke is left untreated.
Causes
Common causes would be these extraordinary temperatures I've mentioned combined with the cat being perhaps in a place in a home where she is unable to cool down. I'm referring to an increased environmental temperature. Another example would be in a carrier in a car where she might have been inadvertently left for too long. A cat suffering from airway disease which interferes with the removal of heat from her body through rapid breathing may suffer from heatstroke. Along those lines a cat suffering from heart or lung disease which also interferes with efficient breathing may overheat
Finally, a cat that generates their own heat through exercise, seizures or a high fever may go on to have heatstroke.
Treatment
The treatment would be to call a veterinarian for advice and take prompt action. If you have a thermometer check body temperature. But do it carefully for obvious reasons. My reference book suggests the obvious (not a criticism) which is to cool your cat down. You can do this in various ways such as using ice packs applied to the head and groin area, cold towels under the armpits and groin as well as the head, or submerge the cat's body in cool water et cetera. And then you check temperature again.
When the temperature has dropped it is recommended that you see your veterinarian because delayed "secondary problems can include kidney failure, cardiac arrhythmias and seizures". There may be swelling of the throat. This makes the situation worse. A veterinarian may provide a cortisone injection to treat the swollen throat.
Obviously, preventative measures are better than reactive ones and I'm sure that's responsible cat owners do this. But I know there have been many premature human deaths because of the extraordinary high temperatures referred to and therefore it is not beyond the bounds of possibility that some domestic cats have died as well through heatstroke.
Reference: Myself and Cat Owner's Home Veterinary Handbook third edition.