The eyes may be the windows to the soul, but a dog’s feet are often the windows to her health. Liver disease, allergies, and certain autoimmune conditions are just a few of the illnesses that play out on the feet of our canine pets. Here’s a quick guide to some of the most common diseases to strike dogs on their feet, how to recognize them, and how to treat them.
Allergies: Although allergies can manifest themselves on various areas of a dog’s body, they often show up on the feet.
Signs. Your dog might keep licking or biting at one or more feet. You might also see swelling, redness, or discharge. A rusty color between the toes represents salivary staining (not blood, as many people think).
Treatment. If the doctor diagnoses allergies to things in the environment, she will prescribe any one of a number of drugs to quell symptoms, such as Cytopoint, Apoquel, or cyclospor-ine. In some cases, immunotherapy is recommended.
Interdigital follicular cysts: Such cysts are associated with uneven weight bearing of the feet caused by factors such as obesity, joint disorders, allergies, or anatomical abnormalities.
Signs. Inflamed soft bumps between toes that result from the constant increased pressure on the skin there. The bumps can become infected over time.
Treatment. Correcting the predisposing condition, if possible, along with anti-inflammatory treatment.
Symmetric Lupoid Onychodystrophy: This immune-mediated disease is restricted to a dog’s nails.
Signs. The nails can slough or grow abnormally, becoming very brittle or stump-like with possible defects such as grooves and pits. In some cases, this disease can prove very painful; nails might bleed.
Treatment. Mainstay treatment involves long-term or lifelong immunosuppressive treatments. If the nails are sloughing off and are very painful, some dermatologists recommend initiating treatment by pulling them off under heavy sedation along with pain management.
Footpad diseases
Some conditions break out on a dog’s footpads—those black shock absorbers on the underside of their toes and on their “palms.” The pads may thicken or erode, making walking painful. Worse still, affected footpads are often the signs of very serious internal diseases. Three of the most concerning:
Pemphigus Foliaceus: One of the most common autoimmune diseases in dogs, it’s a condition in which the immune system attacks the proteins that hold together the skin cells. The result: the skin cells flow apart, and little pustules form on the surface of the foot pads.
Signs. Crusting on the dog’s footpads. You’ll never see the pustules themselves because a dog keeps breaking them open as she walks.
Treatment. Once the disease is diagnosed (via biopsy), the dog is treated with immune-suppressing drugs— for life.
Hepatocutaneous Syndrome: If a dog has this disease, it generally means the liver is not allowing amino acids—the building blocks of protein—to form new proteins that help build skin.
Signs. Lesions on the footpads (breaks in the skin there); a limp because the condition is often painful.
Treatment. After diagnosis by checking liver enzyme levels and perhaps conducting an ultrasound of the liver (which has a very specific appearance with this disease), a dog is given amino acids intravenously and perhaps protein powders. But prognosis is very poor, with many dogs not lasting more than six months after diagnosis.
Note: Sometimes the disease is about a problem in the pancreas rather than the liver, but the prognosis remains equally grim.
Ischemic Dermatopathy: With this condition, blood flow to the skin is compromised.
Signs. It looks like somebody took a hole punch to the foot pads—either the central pad or any of the ones on the toes. These are little round erosions or ulcers.
Treatment. Treatment often starts out with steroids to help reduce pain and inflammation but continues longterm with a drug called pentoxifylline. That makes the dog’s red blood cells very flexible, which in turn allows them to change their shape and make their way into blood vessels that may have been damaged. It helps fill in the circular erosions.
Tumors: “It’s pretty common to see dogs with tumors on their feet,” says John Berg, DVM, a soft tissue surgeon and editor-in-chief of Your Dog. Sometimes the tumor is cancerous, often squamous cell carcinoma. Mast cell tumors, skin lymphoma, and osteosarcoma (bone cancer) also arise in canine feet.
Signs. You may see an outgrowth, but you may also see a nail fall out without any trauma to the foot because squamous cell cancer can strike the nail bed.
Treatment. Because there’s not much room on the foot, it’s hard to do a wide-enough incision to cut away the tumor and close up the skin. Veterinarians often end up amputating a toe (or toes) where tumors occur. It sounds drastic, but a dog can get around quite well without a toe or two.
