Hyperkeratosis in dogs (the build-up of keratin and skin cells) can cause changes to the texture and appearance of the nose and/or foot pads. Sometimes it is just a cosmetic issue, but other times hyperkeratosis becomes painful or points to a bigger problem. Integrative veterinarian Dr. Julie Buzby explains how to recognize the signs of hyperkeratosis and discusses the causes, diagnosis, and treatment.
How often do you look closely at your dog’s feet or nose? While admiring your dog’s toe beans or booping his or her snoot can make you smile, knowing what your dog’s paws and nose normally look like can also help you catch changes like hyperkeratosis before they potentially lead to problems.
What is hyperkeratosis in dogs?
Hyperkeratosis is a condition where keratinocytes (skin cells) accumulate in an area such as the nose or paw pads and lay down an excessive amount of keratin (the protein that makes up skin, hair, and nails).
Normally, keratinocytes migrate to the surface of the nose, paw pads, or other areas of skin, persist for a time, and then are shed into the environment. However, in hyperkeratosis, the keratinocytes multiply more quickly than normal and/or fewer of them are lost.
As inappropriate amounts of keratinocytes and their product, keratin, accumulate at these sites, the outer layers of the skin become dry, thickened, and firm. Over time, the skin can worsen to the point of cracking or fissuring. Some dogs also develop painful erosions or ulcerations.
Where does hyperkeratosis occur?
Hyperkeratosis primarily affects the nose and the paw pads (both the weight-bearing pads on the foot and the accessory pads higher on the legs). But it can also result in callus formation over pressure points. Dog elbow calluses are discussed elsewhere, so the focus here will be on nose and/or paw pad hyperkeratosis.
Some dogs will develop nasodigital hyperkeratosis, in which both the nose and paw pads are affected. Alternatively, the dog may only have paw pad hyperkeratosis (digital hyperkeratosis) or dog nose hyperkeratosis.
What causes hyperkeratosis in dogs?
Dogs may develop nose and/or paw pad hyperkeratosis for a variety of reasons.
Age-related hyperkeratosis
Simply being a senior dog is one of the most common contributors to hyperkeratosis. Older dogs tend to have a harder time shedding skin layers. Plus, they typically move around or explore their environment less than younger dogs. As a result, they may not rub the keratinocytes off their feet or noses as effectively.
Additionally, pain due to osteoarthritis in dogs can cause senior dogs to bear weight unevenly. This can contribute to hyperkeratosis of the lesser-used area(s) of the paw pads.
Breed
Brachycephalic breeds such as the English Bulldog, French Bulldog, Boxer, and Boston Terrier are more likely to develop nasal hyperkeratosis. Their short faces make it harder for normal wear to occur (licking their noses, rubbing their noses on rough surfaces, etc.) that would normally aid in keratinocyte shedding.
Additionally, Irish Terriers, Basset Hounds, Beagles, and American and English Cocker Spaniels all have a higher genetic predisposition to developing hyperkeratosis.
Hereditary conditions
Some dog breeds can develop genetic conditions that lead to hyperkeratosis:
- Nasal parakeratosis, a heritable condition in Labrador Retrievers, causes the nose to become dry, rough, crusty, or cracked.
- Dogues de Bordeaux are prone to familial footpad hyperkeratosis, leading to the splitting and cracking of the paw pads as early as six months of age.
Zinc deficiency
Siberian Huskies and Alaskan Malamutes can develop hyperkeratosis and other skin changes due to zinc deficiency. This condition is called zinc-responsive dermatosis. In these Arctic breeds, the zinc deficiency most likely stems from inherited abnormalities in zinc absorption or metabolism, even when fed a well-balanced diet.
On the other hand, rapidly growing puppies can also develop zinc-responsive dermatosis. But for them, it usually occurs due to a poorly balanced diet.
Infections
Canine distemper virus leads to unchecked keratinocyte production, resulting in paw pad hyperkeratosis. This is how it earned the nickname “hard pad disease.” Leishmaniasis, which is a parasitic infection from a sandfly bite, causes a similar overproduction of keratin. However, both of these conditions also tend to cause systemic symptoms, not just hyperkeratosis.
Autoimmune skin diseases
Autoimmune skin conditions such as discoid lupus erythematosus (DLE) and pemphigus foliaceus (PF) occur when the immune system attacks healthy skin cells. Symptoms can include hyperkeratosis of the nose and/or paws (depending on the disease) as well as other changes to the skin, such as ulceration and redness.
Hepatocutaneous syndrome
Hepatocutaneous syndrome (also known as superficial necrolytic dermatitis) occurs as a result of pancreatic issues or liver disease in dogs and usually carries a poor prognosis. Affected dogs have thick, cracked, ulcerated, and painful paw pads and crusting around the eyes or mouth.
What are the symptoms of hyperkeratosis in dogs?
With canine hyperkeratosis, you may not see many changes in the nose or paws at first. However, as the condition progresses, the excessive keratin deposition will cause the paw pads and nose to begin to look and feel abnormal.
Mild hyperkeratosis signs
When hyperkeratosis is mild, you may notice:
- Slight firmness to the top of the nose or the foot pads
- Foot pads that look and feel smoother due to loss of texture
- A decrease in the cobblestone pattern on the nose
- Dry skin appearance to surface of the nose or paw pads
- Abnormal tissue projections (keratin fronds or feathers) on the edges of paw pads or the top of the nose that may look like a shag carpet
Typically, mild hyperkeratosis is not painful or problematic for most dogs. Taking steps to manage the abnormal keratinization at this point is ideal, as it can potentially decrease the chances of the hyperkeratosis continuing to worsen.
Symptoms of severe hyperkeratosis
In some situations, keratinocytes and keratin continue to accumulate. This can lead to more significant symptoms of hyperkeratosis in dogs, such as:
- Severe thickening of the skin on the surface of the nose or paw pads
- Cracked paw pads in dogs or fissures in the nose, which may bleed
- Crusting of the nose or foot pads
- Limping or impaired mobility due to the abnormal and painful foot pads
- Excessive licking of the feet
- Discharge, crusts, and inflammation of the nose or paw pads due to secondary yeast or bacterial infections
- Enlarging areas of frond-like tissue that may eventually cover most of the paw pad
Other abnormal structures made of keratin: corns and cutaneous horns
It is also worth noting that independent of paw or nose hyperkeratosis, dogs can develop other abnormal structures made of keratin, such as corns or cutaneous horns.
Corns are distinct, firm, round, painful areas of hyperkeratosis on the footpads of the digits. While they can occur in any dog, they are most common in sighthounds, such as Greyhounds.
Cutaneous horns, as the name would imply, are focal, conical structures made from keratin that may protrude from the foot pads, nose, or haired skin. There are a variety of causes of cutaneous horns, ranging from papilloma virus to benign or cancerous masses.
Should I take my dog to the vet for hyperkeratosis?
If you suspect your dog might have hyperkeratosis, pause and evaluate the severity of his or her symptoms.
The presence of cracks, crusting, bleeding, discharge, pain, and discomfort all indicate that the hyperkeratosis is severe. These dogs need to see a vet to rule out more serious problems, like autoimmune skin diseases, and to give them some relief. Additionally, dogs who are showing symptoms that extend beyond the feet or nose (lethargy, skin problems in other locations, poor appetite, etc.) should also go to the vet promptly.
On the other hand, if you have only noticed a very mild firmness or slight change in texture to the nose or paw pads, you may be safe to keep an eye on it and mention it to your vet at the next regular appointment. That being said, if you are concerned or notice the symptoms progressing, reach out to your vet sooner rather than later.
How will the vet diagnose a dog with hyperkeratosis?
During the appointment, the vet will start with gathering a history and performing a physical examination. For mild cases, your vet might be able to tentatively diagnose hyperkeratosis in dogs based on the appearance of the nose and/or paw pads.
However, sometimes the vet may recommend a biopsy. This involves collecting a small piece of nose tissue or paw pad tissue and sending it to the lab. There, a veterinary pathologist will use special stains to visualize and analyze the tissue. Your veterinarian may recommend a biopsy if any of the following apply:
- Your dog is a certain breed known for inheriting hyperkeratosis
- There are more clinical signs present than just hyperkeratosis of the nose and paw pads
- The hyperkeratosis or other symptoms are so severe that the vet suspects an autoimmune disease
Additionally, if the vet is concerned that there might be a secondary bacterial or fungal infection, he or she may perform a skin cytology and/or culture and sensitivity. These tests allow the vet to detect infectious agents and develop a treatment plan.
Does hyperkeratosis need treatment?
After evaluating your dog, your vet will discuss the next steps. Sometimes the hyperkeratosis is mild and does not bother the dog, so no further action is needed. (In other words, you may want to try some of the home remedies we will discuss, but it isn’t critical to do so.)
Other times, there is an underlying condition that the vet will want to treat, or the hyperkeratosis is severe enough that it needs to be addressed for your dog’s comfort and health.
What is the treatment for hyperkeratosis in dogs?
Treatment for nasal and paw pad hyperkeratosis will depend on the underlying cause and severity. Generally, though, it focuses on addressing the cause of the hyperkeratosis (if there is one) and managing the hyperkeratosis and associated problems.
Addressing the underlying cause
Autoimmune disorders generally require immunosuppressive medication, and dogs with zinc deficiency benefit from zinc supplementation. Managing those issues should help the hyperkeratosis resolve.
Managing the hyperkeratosis
For age or breed-related hyperkeratosis, there isn’t really an underlying problem you can fix. Thus, lifelong management is key.
Moisturizers
For mild cases, daily use of moisturizers that are specifically designed for dog paws and noses may be helpful. Your vet likely has a product he or she recommends for managing hyperkeratosis that fits your dog’s specific situation.
Keratolytic products
Additionally, the vet may recommend a keratolytic. These products contain ingredients such as salicylic acid, lactic acid, sulfur, and tretinoin, which function to help break down the excess keratin.
Manually removing excess keratin
In more severe cases of hyperkeratosis, the veterinarian may attempt to soften the hardened skin and then remove some of the excess keratin using a file or Dremel. This can be uncomfortable for your dog, so it often requires sedation. Plus, it is important not to remove too much tissue.
Thus, this is best left to your veterinarian. Do not attempt to remove excess tissue at home unless specifically instructed to do so by your vet.
Addressing secondary infection
If the dog has severe hyperkeratosis and a secondary infection, the vet may prescribe oral antibiotics or antifungals. Or there are some topical antibiotic, anti-fungal, and steroid combinations that can be helpful for healing severely damaged paw pads.
Decreasing pain
If the dog’s paw pads are painful, or if orthopedic pain might be contributing to the dog not moving around as much and wearing the keratin off the pads, the vet may recommend pain medications. This could be a non-steroidal anti-inflammatory (NSAID) like carprofen for dogs. Or the vet might suggest gabapentin for dogs, tramadol for dogs, or other pain relief medications.
Are there home remedies for hyperkeratosis in dogs?
In addition to some of the veterinary remedies discussed above, there are home remedies for dogs with mild cases of hyperkeratosis that you could consider with your vet’s approval.
Soaking the paws in an Epsom salt solution
If your four-legged friend doesn’t mind the bathtub, Epsom salt foot soaks can soften the skin by reducing inflammation and increasing the exfoliation of dead skin cells. However, ensuring your dog doesn’t drink the Epsom salt soak water is important.
When soaking the feet, avoid using harsh soaps because these can further dry out the paw pads, causing more discomfort.
Applying a warm washcloth to the nose
For nasal hyperkeratosis, you could consider carefully holding a warm, wet washcloth on the nose to soften and rehydrate the tissue. Then follow up by applying a moisturizer.
Using a moisturizing product
You can purchase a variety of paw and nose moisturizers as discussed previously. Or, while they may not be as effective as the specially formulated products, Vaseline®, Aquaphor® for dogs, or coconut oil can also be applied to the affected areas.
Some of these moisturizers can cause GI upset if ingested in larger quantities. Thus, it is important to minimize the amount your dog licks. Distracting your dog with a toy, food, or a walk can sometimes keep him or her from licking the area.
If you are using moisturizers on the nose, ensure you don’t block off the nostrils.
Also, you may want to bandage the feet for an hour or so after applying these products so they can soak in and don’t get tracked all over the house. If you choose to bandage your dog’s paws, ensure the bandages aren’t too tight and remove them promptly.
Other moisturizing balms like zinc oxide may be safe in small quantities, but these can be toxic at high doses. Thus, you should not use them without consulting your vet.
Supporting the skin with omega-3s and vitamin E
Diets and supplements that are high in omega-3s and vitamin E can help improve skin health. Omega-3 fatty acids for dogs are known for reducing inflammation. And vitamin E protects against free radicals and supports skin cell regeneration. Since there are a variety of supplements on the market, it is best to work with your vet to find one that is safe, effective, and right for your dog.
What is the prognosis for dogs with hyperkeratosis?
Thankfully, mild hyperkeratosis is unlikely to limit your dog’s mobility or cause him or her pain. And even dogs with more severe cases of hyperkeratosis can still potentially have a good prognosis with consistent topical and/or systemic therapy.
With significant hyperkeratosis or dogs with an underlying disease, the vet will likely want to recheck the feet and nose every few weeks. This allows him or her to adjust the treatment plan accordingly. If your dog has an autoimmune skin disease, he or she may require long-term immunosuppressive medications to keep the condition under control.
Treat your dog to a “spaw day” (or maybe a trip to the vet)
If your senior dog’s snout or paws are looking a bit thick and dry due to mild hyperkeratosis, it may be worth treating him or her to regular “spaw days,” complete with a paw and nose moisturizer. This can be just the ticket for senior dog hyperkeratosis and may prevent it from worsening.
However, keep in mind that sometimes an underlying condition is responsible for the hyperkeratosis. If your dog’s feet or nose are cracked, bleeding, or he or she is showing other symptoms, reach out to your vet. He or she can help sort out what is going on so your dog can continue to put his or her best paw (or nose) forward.
Does your dog have nose or paw pad hyperkeratosis?
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