‘High index of suspicion’ needed in extreme temperatures, vets warned

Clinicians have been advised to maintain a “high index of suspicion” for heat-related illness as heatwaves continue to blaze across the United States.

July was the hottest month ever recorded in the country, with an average temperature of 76.9°F (25°C) – 3.3°F (1.8°C) higher than the 20th century average for the contiguous United States – and peaks of 115°F (46°C).

Kate Cappe, medical director at VEG ER for Pets in Mount Pleasant, South Carolina, and lead staff veterinarian at virtual care platform Vetster, advised colleagues to remain vigilant for the rest of the summer.

Sustained periods

She said: “The biggest piece of advice I would give all veterinary professionals is to maintain a high index of suspicion for heat-related illness, particularly during periods of sustained high temperatures and humidity.

“Heatstroke is not always as obvious as an animal arriving collapsed with a markedly elevated body temperature.

“Early signs can include excessive panting, hypersalivation, weakness, restlessness, vomiting, diarrhoea, altered mentation and ataxia.”

Initial heat exposure

Dr Cappe noted body temperature at presentation may not reflect how severe the initial heat exposure was.

She advised veterinary professionals to be alert for complications including hypotension, hypoglycaemia, electrolyte abnormalities, acute kidney injury, gastrointestinal injury, coagulopathies/DIC, neurologic dysfunction and multi-organ failure in more severely affected patients, adding such patients can deteriorate even after their temperature is normalised.

Combination

She added: “I also encourage owners and veterinary professionals to pay attention to humidity and heat index rather than relying solely on the outside temperatures. The combination of temperature and humidity is often more clinically meaningful than temperature alone.

“High humidity significantly reduces the effectiveness of evaporative cooling, making conditions that might otherwise be tolerable much more dangerous to both humans and animals.”

She highlighted dogs as being especially vulnerable due to their reliance on panting for heat dissipation, particularly brachycephalic breeds for which that process is “significantly less efficient”.

Pre-existing conditions

Dr Cappe also warned of the impact extreme temperatures can have in exacerbating pre-existing conditions.

She said: “Cardiac and respiratory disease are major concerns because the body’s efforts to dissipate heat place additional demands on both the cardiovascular and respiratory systems.

“Animals with chronic kidney disease may also have less ability to compensate for dehydration.

“Endocrine and metabolic conditions, obesity, and neurologic or mobility disorders can similarly interfere with an animal’s ability to respond appropriately to heat or independently seek out water, shade, or a cooler environment.”

The vet also highlighted individualised advice as being “incredibly important”.

She concluded: “A healthy young dog and an elderly brachycephalic dog with cardiac disease have very different levels of risk. Helping owners understand their individual pet’s vulnerabilities allows them to make better decisions.”