Climate change has led to an increase in global temperatures, and increased heat-related illness (HRI) in companion animals - especially dogs.
A study of dogs with HRI in the UK found that flatter-faced breeds, such bulldogs and French bulldogs, and larger dogs were at increased risk.
Older animals, and those with pre-existing heart or airway disease, are also at increased risk of severe HRI.
There are two main causes of HRI in animals: high environmental temperatures or over-exertion. The latter is more common in dogs, but is exacerbated by high temperatures.
HRI is worsened by confinement (because confined animals are less able to control their temperature by moving out of the heat), humidity and water deprivation.
Thus animals kept in cages or hutches, such as guinea pigs, rabbits and birds, are prone to HRI.
Worse still, their enclosures often incorporate metal, which heats up when exposed to high temperatures. Unfortunately, many of these smaller pets succumb to HRI.
For example, guinea pigs may die when the ambient temperature is just 28 degrees Celsius. Many don't make it to the vet in time.
HRI needs to be treated early. Signs of HRI in dogs include panting and increased breathing effort, going off food, vomiting, diarrhoea, haemorrhages on the mucus membranes, loss of coordination and collapse.
Affected animals need immediate veterinary care. Cooling them down isn't enough. The mortality rate for severely affected dogs is up to 60 per cent.
Despite warnings, every year dogs die in hot cars. Experiments have shown that winding down the window an inch or two has minimal impact on the temperature inside a hot car.
A few years ago, one of my clients ducked into the clinic to pick up some medication, leaving her dog and the keys in the car.
The dog got excited and bumped the central locking mechanism, locking himself in the vehicle. By the time the NRMA arrived and freed the dog, he was already showing early signs of HRI. Animals should never be left unattended in a motor vehicle.
As with so many illnesses, when it comes to HRI, prevention really is better than cure.
Since the 1960s, the number of record hot days in Australia has doubled. These are events we should expect and plan for.
So how can companion animal owners plan for hot weather?
- CHECK the forecast. The Bureau of Meteorology website is updated regularly and provides extreme weather warnings: http://www.bom.gov.au/
- ACCESS: Ensure access to pet doors is not impeded.
- WATER: Ensure all animals have access to fresh, clean, cool water from multiple sources in case one tips over or runs out. Remember water heats up in the sun.
- SHADE: Ensure all animals have access to, and shade all day. Be prepared to bring animals inside on hot days. Be aware that hutches and cages are often made of metal components which can become dangerously hot in the sun.
- TEMPERATURE: Move animals into a cooler or air-conditioned environment if possible.
- VENTILATION: Confined animals should be kept in a well-ventilated area. Be aware ceiling fans can injure free-flying birds.
- EXERTION: Avoid exercising pets in the hottest parts of the day, and restrict exercise to slow, gentle activity. Dogs that exert themselves due to noise phobias or separation anxiety may require medication.
- SUPERVISION: If you are at work, consider having a friend or neighbour check on pets during the day.
The best way to protect animals (and ourselves) from intensifying heatwaves is to rapidly reduce greenhouse gas emissions, driven by the ongoing use of fossil fuels including coal and gas.
Dr Quain BVSc (Hons), MANZCVS (Animal Welfare), Dip ECAWBM (AWSEL) is a lecturer at the Sydney School of Veterinary Science and a practising veterinarian.