The Horrible Dog Hot Spot: 5 Causes and Treatment Tips


It’s a warm summer day.


When taking your pooch out for a walk yesterday, you noticed your beloved pup scratching at something on his neck, but you didn’t really see much there.


But you get home today and grab the leash to take him out. When he comes up to you, he’s now digging at a spot on his neck. And what yesterday looked pretty unremarkable now looks more alarming.


There’s a shiny, and wet looking area of matted fur on his neck. And underneath the skin looks brick red, irritated, and really uncomfortable.


It’s the dreaded “hot spot”. It seemed to come out of nowhere. But what are hot spots and how do they happen? Even more importantly, what do you do?


In this article, we’re going to discuss what hot spots really are, some underlying causes that contribute to their formation, and most importantly, what you can do about them.

What Are Hot Spots?


The technical term for a hot spot is acute moist dermatitis. Some doctors will also refer to it as pyotraumatic dermatitis.


At the point they occur, hot spots are areas of skin that are extremely red and inflamed, with a significant component of moisture. The moisture may be secondary to licking that your pup is doing because of how irritating these are. The moisture may also be secondary to oozing that occurs from the broken, damaged skin, as well as discharge from microbial infection from bacteria or fungal yeast.


Hot spots most often occur in areas where there is fur or hair, which is often matted with discharge from the irritated and infected site. What you have is a matted, sticky, painful spot that couldn’t feel worse for your poor pup.


How Do Hot Spots Happen?


Although they often develop over a short period of time, sometimes less than 24 hours, hot spots don’t just “happen”. They always have some kind of initiating cause.


Whatever the cause is, there is some kind of focal site of itching or irritation for a dog, which leads to licking and chewing of the site. These areas then get so inflamed that the protective skin barrier that keeps things out gets compromised, allowing bacteria and sometimes yeast to grow very happily.


Because these organisms already exist on the skin naturally in certain numbers, the simple inflammation and defect in the skin’s natural barrier may simply lead to overgrowth. But when your pup licks and chews at these sites, she introduces a whole host of mouth bacteria that are all too happy to join the party.


So it is important to understand that while hot spots are pretty much always infected as a rule, these infections are a secondary effect, and not the primary problem.


So what is?


We have to get back to the initial source of irritation that sets off this cascade of redness, irritation, and vicious cycle of further self-trauma on the part of your pooch.


There are several underlying causes of hot spots but they can for the most part be divided into 5 categories, which we’ll discuss next.


5 Causes of Hot Spots


Skin Allergies

Skin allergies, which in and of themselves comprise different underlying causes, are one of the biggest contributing categories that cause hot spots. This is especially true if your dog has recurrent ones.


Skin allergies in dogs are very complex, since a dog’s skin is actually a very complex organ with complex immune function. A dog’s skin is constantly peppered with allergens from the surrounding environment, and immune components in the skin layers react to these allergens in different ways.


Some dogs’ immune systems will react quite severely to certain allergens, like pollens or molds, leading to a cascade of inflammation in the skin that will lead to itchy, irritated skin, and sometimes your hot spots as a result.


A dog may only have allergies to a small number of allergens, and sometimes only during certain times of the year, like the summer. Or, some dogs unfortunately will have severe allergic responses to countless allergens, contributing to a condition called atopic dermatitis, or “atopy” for short.


But environmental allergens aren’t the only type of allergens that cause these skin changes. Food proteins like chicken protein, beef protein, or less commonly even wheat gluten, can also contribute to allergic response that manifests with problems of the skin, ears, and even the anal glands.


Skin allergies are the most common cause of recurrent ear infections, skin infections, and anal gland problems. And because these conditions are itchy, red, and irritating, they also commonly lead to hot spots in the same regions of the body they affect.


Wet, Moist Fur

As we’ve mentioned, moisture plays a big part in the development and severity of hot spots, and contributes a lot to infectious organisms really overgrowing and making things worse.


For dogs with thicker, heavier hair coats that love to go swimming or get bathed regularly, we can see an increased occurrence of hot spots. This is most likely due to moisture getting trapped underneath the thick hair.


The lack of air exposure and the warm, moist environment makes a prime breeding ground for bacteria and yeast. As the areas develop, your pup finds them irritating, leading to licking and chewing, and further trauma and irritation to the sites.


That’s why it’s always important to make sure your pup always gets thoroughly dried after baths and swims. This is also true for the ears. After any water activities, I always recommend using an ear cleaner that contains a drying agent that will help to evaporate any water that’s sitting down in the ear canal, as this may help prevent an ear infection from developing.


Matted Fur and Poor Grooming

Unless you have a breed, like a Poodle, that doesn’t shed, you’ve probably got a regular problem of pulling dog hair off your clothes and vacuuming it off the carpet and couch.


While how to stop a dog from shedding won’t be a topic we cover here, dogs with heavy coats that shed a lot may be at a higher risk for hot spot development.


Dogs with thick coats, especially Nordic breeds like Huskies that have a thick winter undercoat, often need extra help to pull that thick fur out when it starts to die and come out naturally.


Because the undercoat can sometimes be very long, it gets tangled with the newer, outer coat, leading to mats of fur that are difficult and frustrating to remove by simple brushing alone.


Fur mats aren’t healthy for the underlying skin either, because the skin can’t breathe well and turn over skin cells naturally when clogged by mounds of hair. Matted fur also traps moisture and debris and the combination of all of this leads to the perfect conditions for hot spots to develop.


This is why it’s really important to brush your dog regularly if she has a really thick coat. Using a product like the Furminator, or even a simple slicker brush, can help to pull out the dead undercoat hair better than a simple brush or comb will.


Bites and Wounds

Anytime your pooch gets even a small wound, it can be pretty irritating to him. This can include not just cuts and scrapes but also insect bites and stings.


With these types of injuries, the wound itself is usually small, but develops into a hot spot due to self trauma of excessive licking and chewing of the site. I have a patient who once got a small nick on his skin from clippers when he went to the groomer. He excessively licked the area and in just a day or two had a really red sore a good 1-2 inches across.


Insect bites and stings can vary in severity depending on your dog’s sensitivity. Dogs can actually be allergic to the saliva of fleas and ticks, leading to an irritating reaction to an otherwise tiny bite site.


Stings almost always cause some kind of local swelling and irritation thanks to a load of histamine and other inflammatory components that flock to the site.


These causes of hot spots simply raise the importance of being vigilant so you can catch any types of small lesions like these early on and keep your pup from irritating them further. It also highlights the importance of flea and tick preventative use.


If your pup has sensitivity to bites, there are some veterinary-approved products that have repellency action and also keep away other biting insects like mosquitoes and biting flies. Make sure to discuss preventative options with your vet.


Orthopedic Irritations

This last category usually only occurs with our older pups that start developing issues with their bones and joints.


Arthritis can be painful and irritating, and a dog’s common response to most things that are painful or irritating is to lick at them.


Thus, we sometimes find that a dog who chronically licks at a painful joint will develop a moist area of skin irritation there, developing into a hot spot.


Older pets may also lose muscle mass and fat over time, leading to more prominent bony areas. They also tend to slow down with age, leading to more sitting, laying down, and resting.


As more pressure is placed on more prominent bony areas like the elbows, knees, and hips, you might start to see what’s kind of like chafing occurring from the constant rubbing on hard surfaces.


As these chafed areas get more sore, pups might lick at them more, leading to hot spots developing over time.


If you have an older pup with some joint issues, who’s a little thinner than he used to be, it’s important to provide more cushioned areas where he can rest. If you have hardwood floors, consider providing areas of carpeting both to provide cushion as well as traction for feet that are less steady than they used to be. Also provide some nice cushy dog beds where he can sleep without putting pressure on those sore areas.



Healing the Horrible: Treatment for Hot Spots

So now that we’ve discussed why and how hot spots happen, let’s chat about what to do if you encounter one or more on your pup.


Initial Treatment at Home

Most hot spots will require an exam and treatment by your veterinarian to be cleared up successfully. But as often happens, you might notice one develop at the most inopportune time when you can’t get your pup in right away. So here’s some guidelines to help you so that the hot spot doesn’t get worse in the meantime.


The single biggest thing you can initially do if you see a hot spot on your pooch is to keep her from licking or chewing at it. As we’ve talked about, licking and chewing may not always be part of the cause of a hot spot, but it always makes one worse.


The simplest and best way to keep your pup away from a hot spot is with an Elizabethan collar, or what’s more often known as the “cone of shame”. These devices are unattractive and most dogs don’t like them, it’s true.


But the trade-off is that you’re preventing an already irritating lesion on your pup’s skin from getting more irritating and painful. And if you can prevent the stress and expense of a vet office visit by getting a small lesion to resolve by itself, most pup parents would agree the “cone of shame” is worth it.


E-collars can be obtained from your vet office as well as local pet stores. If your vet provided you with one after a procedure or a previous skin problem, make sure to hold onto it because you never know when it might come in handy.


There are a few particulars to E-collars that are important to know. For one to be effective, it has to reach past your dog’s nose. Dogs are truly masters of contorting their bodies to reach hard-to-get areas. If the cone is not past his nose, it’s more likely he’ll still be able to reach the affected area.


Also, don’t be fooled by the “donut” E-collars. Are they less scary-looking? Sure. Will your dog look less depressed wearing it? Absolutely. But do they actually work? Rarely.


Donut collars can only restrict neck movement a small amount, so unless you have a hotspot that is on the neck or shoulder, they simply don’t provide protection. This is especially true if the hot spot is anywhere past the front legs.


Some folks, in an attempt to avoid use of any type of collar, will try to cover or wrap the hot spot with something, like a bandage or a sock. This doesn’t work very well however. The whole problem with hot spots is that they’re moist and irritated and often don’t have good air exposure because of matted hair.


Covering them only further traps moisture and debris. It’s also pretty common for dogs to still get to the wrap or bandage material and chew at them, sometimes ingesting the materials. Hot spots are far better addressed by exposing them to open air as much as possible.


The next best thing you can do is apply some kind of topical product to the lesion, like Aller 911 Hot Spot Spray. These have limited ability to kill any bacterial or yeast growth, but they often have ingredients like aloe vera and witch hazel that can help to calm these lesions enough to further keep your pup away from them.


But it is really important with any topical product to make sure your dog can’t lick them off, especially with aloe vera, which can cause digestive upset if ingested in larger amounts. This is why an E-collar is still important to have.


What about using hydrogen peroxide, rubbing alcohol, or iodine solution? Hydrogen peroxide bubbles up amazingly and looks fantastic, but actually has very little antiseptic qualities compared to other things we use in medicine. Veterinary staff rarely if ever use hydrogen peroxide to clean wounds or hot spots.You also have to be extremely careful using it around the ears and eyes.


As for alcohol? Never use it on a hot spot. Have you ever gotten rubbing alcohol in a small cut? Remember how much it stung? Now imagine doing that on a much larger, painful area of skin. While alcohol does kill bacterial growth, it’s simply too painful to apply to bare, irritated skin.


Iodine solution has to be heavily diluted with water to keep it from being irritating to the skin. It also stains just about everything. So while it’s true that it’s a good antiseptic, it has to be used properly, and for that reason I don’t advise liberal use of it at home. You’re very much more likely to be annoyed by how much of a mess it makes.


What about using a triple antibiotic cream like Neosporin? While applying Neosporin would be harmless, it’s important to remember that it’s intended for use on human skin, not dog skin. It can help with small cuts scrapes to be sure, but it simply will be insufficient to address a hot spot.


If there’s thick, matted hair, should you try to cut or clip the hair away? It kind of depends. You should be exceedingly careful about using clippers if you don’t have much experience grooming your dog, and you should never use scissors.


The skin of dogs is much more elastic and flexible than people think. When the fur is heavily matted, it becomes very difficult to know where the skin stops and hair begins. I have thus had to treat many patients for cuts and razor burn caused by well-meaning pet parents trying to remove hair mats.


Sometimes though, the hair matting isn’t super thick and you can see the red, irritated skin beneath. In these cases, taking a pair of clippers with a safety guard on them could be really helpful to expose that irritated skin.





Treatment at the Vet Clinic

So let’s say you’ve put on the E-collar and you’re trying a topical product intended for hot spots, but the area isn’t really getting any better by the next day. Or perhaps the area was too large to begin with.


Most hot spots need to be treated at a veterinary clinic. They’re painful irritating skin infections that can continue to worsen quickly without proper care.


Veterinary staff are the most skilled at trimming the matted hair over them, cleaning them properly, and prescribing more effective topical and oral medications to get them to clear up more quickly and bring relief to your pup.


The first thing we do to address hot spots is to clip any matted or diseased hair from the site. As mentioned this can take very careful and expert work in cases where the fur is very firmly adhered to the skin.


Once any matted hair is removed, we next use an antiseptic solution, usually diluted chlorhexidine, to clean the site, removing debris build-up and decreasing the load of bacterial growth that’s present. Then, we make sure the site is nice and dry.


Clinics may vary in what they use to topically apply to a hot spot after clipping and cleaning it. There are lotions, sprays, and powders that are all commonly used, and oftentimes, one of these is also sent home with you to continue to use on the area.


All of these products, regardless of their form, have a combination of a steroid to help with the inflammation, as well as an antimicrobial. These types of combination products are usually only used in pets, and so can only be found at veterinary clinics.


Last, it is common to treat the larger hot spots with oral medication. Often, this is with a combination of a short course of a steroid coupled with an antibiotic. Sometimes, your vet may wish to get samples of an infected area on the skin to see if other organisms may be involved, like fungal yeast or even mites, which require different medical therapy.


And if you don’t have an Elizabethan collar yet, your pup’s doc is likely to recommend you take one home.


How do most hot spots turn out? With proper care, they usually clear up in just a couple days. I usually recommend medical therapy for my patients for 10-14 days and rarely is there a persistent issue as long as all instructions and recommendations have been followed.


Hot Spot Prevention

But while treatment is somewhat straightforward and the outcome is most often very good, you might ask: “but is it going to happen again?”


The answer is that in most cases, yes a hot spot will occur again. Dogs that get hot spots tend to get them recurrently. Sometimes we notice this is just at certain times of the year, or just under certain conditions. The likelihood of recurrence all depends on what the underlying cause of the hot spot was.


If it occurred secondary to an insect bite or a wound, this may be a one-time incident. But for all the other underlying causes, especially skin allergies, recurrence is likely without proper prevention.


For dogs that appear to have a recurring allergy history, your veterinarian may recommend allergy testing, diet trials, or a trial of an allergy medication or injection. All of these can be beneficial both for determining what the allergy is due to and to reduce the occurrence of flare-ups like hot spots.


For dogs that have more of an issue after swimming or bathing, the best prevention may be using a blow dryer (adjusted to a cool setting to avoid burn risk) to ensure that the deeper layers of moisture are gone. And with ears, remember to use a cleaner with a drying agent after water activities.


If you have a pup with a thick, heavy coat, you should just expect that regular grooming is going to be a big part of your relationship together. Invest in a good undercoat brush or tool, like a slicker brush or the Furminator, and go to town on that coat at least a couple times a week if not everyday. Regular grooming will also increase the likelihood you’ll catch a hot spot early.


We already talked a little about prevention for our older pups with achy joints and knobbly knees and elbows. Make sure to provide plenty of padded surfaces for your senior pooch to lay on and to consider adding carpet or runners to your home if you have wood, tile, linoleum, or other harder, slippery surfaces.


Harrowing but Healable

So that’s it! Hot spots can be really uncomfortable and frustrating but they usually turn out well with the proper therapy, especially if they’re caught early.


Preventing them depends on what the cause is, so keep an eye out for patterns for when they occur and under what conditions they’re being seen.


And lastly, always assume your vet will need to take a look at one of these for the best possible outcome. While some small hot spots may clear up with basic home care, most may only worsen, causing more pain and irritation for your pup.


Posted in

Dr. Chris Vanderhoof, DVM, MPH

Chris is a seasoned veterinarian with over 15 years of animal health experience in small animal, large/farm animal, equine, and public health fields.

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