Most dog owners know the summer rules by now: avoid hot pavement, bring water, find shade and watch for signs of heatstroke. But veterinarians in Arizona are drawing attention to a much less familiar heat injury, one that can affect a dog even without burned paws or an obvious emergency at the time.
It is called dorsal thermal necrosis, or DTN, a rare condition linked to prolonged exposure to direct sun and high environmental temperatures.
Arizona Humane Society recently treated a dog named Claire for it. She recovered fully and has since been adopted, but her case highlights why the condition can be easy to overlook.
The injury can be easy to mistake for something else
DTN affects the skin along a dog’s back, where the body receives some of the most direct sun exposure. Unlike paw-pad burns, it does not require contact with a scorching surface.
Veterinary reports describe redness, hair loss, soreness, crusting and, in more serious cases, deeper burns that require treatment. The complication is that these changes may not become obvious immediately.
Dr. Raegan Wells, an emergency and critical care veterinarian interviewed by Arizona Family, said signs can take about a week to develop. By the time the skin changes appear, the earlier heat exposure may be easy to forget. The redness or scabbing can then look more like an allergy or another common skin problem.
DTN appears to be rare
The reassuring part is that dorsal thermal necrosis does not appear to be common. Wells told Arizona Family that she has seen roughly one case a year over nearly two decades of practice, and published research on the condition remains limited.
One retrospective veterinary study examined 16 dogs diagnosed with DTN in the southwestern United States between 2009 and 2016. Fifteen of the cases occurred between May and September, and many of the affected dogs had short, dark coats, suggesting that this coat type may be associated with greater risk.
The sample was small, though, and DTN was not limited to those dogs. Some affected dogs had lighter coats, while others had longer hair. The study points to a possible pattern, not a simple rule about which dogs are most vulnerable.
Researchers also found that only a minority of the dogs had shown earlier signs of heat exhaustion or heatstroke. That matters because DTN does not necessarily follow an obvious heat emergency.
What dog owners should watch for
Because DTN is rare, most dog owners will probably never encounter it. Still, it adds another reason to limit prolonged exposure to direct sun during periods of extreme heat.
If redness, hair loss, tenderness, crusting or another unusual skin change appears along a dog’s back after significant heat exposure, that recent history is worth mentioning to a veterinarian. Even when the skin problem seems unrelated at first, knowing that the dog spent an extended period in intense sun can help provide useful context.
Prevention is straightforward: avoid long stretches outdoors during the hottest part of the day, provide reliable shade and water, and bring dogs inside before they spend prolonged periods in extreme heat.
Claire’s case had a good ending. She recovered from the injury and has since found a home.
Her story is a reminder that extreme heat can affect dogs in ways that are less obvious than heatstroke or burned paw pads, and some of those injuries may not show up right away.
Sources: Arizona Family and Veterinary Dermatology / PubMed.
