Soggy Britain can cause heat-related illness in domestic cats (June and July)

There is a study on the Internet, published on the Open Veterinary Journal website called: Surveillance of heat-related illness in small animals presenting to veterinary practices in the UK between 2013 and 2018. The scientists concluded that cats with heat-related illness on occasions presented to veterinary clinics in the UK (those who participated in the survey) between May and September, with 75% during June and July.

Cats hunting in hot weather may rarely suffer from heat-related illness. Image: public domain.

In all, the study found that 16 cats with heat-related illness ended up at veterinary clinics. They were suffering from hyperthermia which describes a body temperature elevated above the accepted normal. The study is a warning (primarily with respect to dogs who suffer from hypothermia mainly through over exercise), that, even in soggy Britain, it is possible for domestic cats to suffer from heat-related illness.

A particular vulnerability for domestic cats is that they seek out warmer areas within the home, perhaps in a catio, to sleep and snooze. They might also become trapped in a greenhouse or shed in warm weather. Sometimes, rarely, cats can suffer from heat-related illness (HRI) due to exercise in a hot environment. This would typically occur when hunting on a hot day in a British summer. It seems that cats don't recognise the onset of hyperthermia in the symptoms.

Cats presenting with HRI might suffer from a range of symptoms including: abnormal breathing, lethargy, vomiting, diarrhoea, hyper-salivation, ataxia and haemorrhagic diarrhoea. Of the 14 cats presented to veterinary clinics with HRI, 6 had abnormal breathing, 10 were lethargic and 3 suffered from vomiting. Each of the following symptoms affected one cat: diarrhoea, hyper-salivation, ataxia and haemorrhagic diarrhoea.

Cats over the age of 15 made up 25% of HRI cases. The scientists concluded that older cats are more at risk of suffering from HRI due to age-related changes to thermoregulation combined with an increased prevalence of underlying cardiac, respiratory and renal disorders. These could impair thermoregulation through mechanisms such as respiratory function and increased likelihood of dehydration.

As most of these cats suffered HRI when hunting outdoors, the scientists speculated that some of them may have died outdoors and become lost to their owners. HRI might be so severe as to prevent the cat recovering and making their way home.

The fact that some cats might have died in unknown places, may have affected the statistics collated by the study. In other words, more cats may suffer from HRI than counted.

The study is a warning, perhaps, to cat owners who think that there is little chance that their cat may be affected by heat. Cats go towards heat. They love it because of their wildcat inheritance. Sometimes they get it wrong and become overheated. Cat caregivers should be alert to this potential at least. Although it would have to be pretty rare.