Hot, humid weather is upon us in most parts of the country, and while it often means outdoor summer fun and vacations, it can wreak havoc on your animals’ skin. Two common side-effects of muggy weather are “rain rot” (aka dermatophilosis) in horses and “hot spots” (aka acute moist dermatitis) in dogs. Both conditions are common and treatable but can cause frustration in animals and owners alike until they’re cleared up.
Rain Rot
Let’s start with the less sinister of the two. Rain rot, also called rain scald, is a persistent and irritating issue for horse owners in more humid climates. It’s actually a bacterial infection (caused by Dermatophilus congolensis) – and, as it were, many horses carry the bacteria, but don’t necessarily show symptoms of rain rot. When the skin is compromised in some way (usually by biting insects), the bacteria causes an infection that causes raised mats of hair. Underneath that hair there are scabs, and when those scabs are removed, there is either a small oozing wound or bare, gray skin.
Depending on the location of the infection, your horse may not be bothered by rain rot at all. If it’s on the horse’s back or withers – aka, underneath where a saddle would go – it could itch and hurt when the horse is being ridden, but other than that, the animal may not even know anything is awry. In many cases, the most irritating part of rain rot is curing it! The cure requires removal of the scabs, which can tickle or sting.
Most cases of rain rot can be cured just by removing the scabs and opening up the affected skin to the fresh air. Bathing the horse and softening up the skin and scabs is generally the best way to go, and softly curry-comb the area and watch the paintbrush-like tufts fall off. Allow the horse to dry completely and brush again. Mild shampoo works, but an anti-microbial shampoo is best; according to Merck, the best weapon against the bacteria is Chlorhexidine. (Fun fact: antimicrobials are the active ingredient in many human mouthwash products. For more mild cases, there are reports that a spray bottle with 1 part Listerine and 1 part water can help clear up rain rot!)
It may take a few weeks for rain rot to clear up, especially if your horse doesn’t like the feeling of you working with the scabs. Keep repeating the bathing-and-brushing routine until the horse’s coat is back to looking the way it should be.
Rain rot is one of those rare conditions that can spread from species to species, so be sure to wear gloves and wash your hands thoroughly after dealing directly with the affected area on your horse.
It is often said that rain rot will clear up on its own, but since it has the potential to cover large parts of the body and could spread from horse to horse, it’s always best to clear it up as soon as possible. For more severe cases of rain rot, in which multiple layers of the skin have been compromised, a vet’s attention may be required for antibiotic injections.
Rain rot, since it is a bacterial infection, is spreadable from horse to horse (either by direct contact or via biting insects), so be sure to use different tack and grooming tools as you work with other horses. Also bear in mind that things like fenceposts, which horses may use to scratch, can become infected with bacteria as well and may transmit rain rot to another horse.
Hot Spots
A dog that is perfectly fine one day suddenly develops a massive, raw, red, bleeding, oozing sore on its side, or behind its ear, or by its tail! What in the world happened? Chances are it’s a hot spot, and yes, we won’t mince words – it’s awful. But thankfully they are easily treated and can be prevented.
Even the tiniest bit of moisture on a dog’s skin can create the perfect environment for a hot spot to form. The skin doesn’t always need to be scratched or broken for bacteria to take hold. A small red spot can turn into a palm-sized sore literally overnight. Long-haired dogs are particularly susceptible to hot spots because their hair can trap moisture more easily, so vigilant grooming is an absolute must.
The most important thing to do for a hot spot is to get it to dry out. This can require clipping or shaving the affected area, and if the spot is sore enough, your dog could put up a serious fight if you try to do this yourself. If you have never dealt with a hot spot before, it’s generally a good idea to call your vet anyway to make sure it’s not a more serious problem – but if your dog is acting difficult when you try to touch or examine the sore, you will definitely need a veterinarian’s help in treating it.
At least once a day – and maybe three or four times a day in the beginning – clean the hot spot with antibacterial soap, perhaps something prescribed by a vet, and dry it extremely well. If it has started to scab over, once you have moistened it with soap and water, rub it gently with a washcloth to remove the scabs to allow fresh, dry air to get to the area.
Unless otherwise advised by a veterinarian, don’t dress it or bandage it up! It’s important that fresh air flows to the area and that moisture doesn’t get trapped by the skin; this could cause the hot spot to grow even larger, or for new ones to form.
If it is an area that your dog could reach to lick, it’s best to employ some Bitter Apple spray to make the area taste terrible so your dog won’t bother it again. Bitter sprays are made precisely for reasons like this, and won’t irritate the sore area, and are a great tool to get your dog to leave its wound alone.
If the hot spot has penetrated multiple layers of the skin – or even if it hasn’t, and is just seriously infected – your vet may prescribe oral antibiotics to speed up the healing. It’s always a good idea to talk to your vet if you have any questions about whether your dog’s hot spot is healing properly.
Even the most well-taken-care-of dog can develop hot spots, so, while neglect can lead to sores, a hot spot doesn’t necessarily mean the dog has a bad owner. As far as prevention of hot spots goes, especially with dogs with longer hair, it is very important that you examine your dog daily (especially in humid summer months) to see if there is any spot that seems red or sore. Pay special attention behind the ears, because this is a prime spot for warmth and moisture. Always dry your dog well after baths and swims, and keep an eye on its skin for a few days after each water-related activity.
Brush your dog often, and, in longer-haired dogs, avoid mats – mats are a perfect vehicle for holding moisture near the skin. Besides, mats can irritate the skin even without added water. One very important time to keep an eye on your dog is if they are wearing an e-collar (aka the Cone of Shame). A cone, while a vital medical tool, can trap moisture around the neck and ears, causing a prime hot spot-forming environment.
Sometimes, hot spots can be indicators of another problem. A dog may have been scratching at its ear because of an infection, and that self-trauma may cause a hot spot. A dog licking at the base of its tail may be trying to reach an irritated anal gland but causes a hot spot instead. A dog trying to lick to relieve arthritic pain in its paw may cause a hot spot there instead. If you have any indication that your dog may have some issue other than just the hot spot, certainly talk to your vet.
All in all, summertime is a wonderful time of the year for fun with your animal, but remember that each season comes with its own health challenges! Just know your animal and pay close attention to your pets’ health and everyone should enjoy this fantastic season together.