What causes paw chewing in dogs? Is your dog obsessively licking or chewing its paws? Is your dog’s area between the paws red, swollen and inflamed? Excessive licking and chewing in dogs are almost always due to an underlying medical condition. Sometimes the underlying medical condition is urgent and sometimes it is not. Regardless, it always requires veterinary attention. In a nutshell, if your answer to the above stated questions is "yes" it is advisable to read this article and then have your dog checked by a veterinarian.
Paw Chewing in Dogs due to Allergies
An allergy is an abnormal reaction of the immune system to a foreign substance. In most individuals, the substance produces no symptoms, but in a susceptible individual, it triggers an allergic reaction.
When dogs have allergic reactions, they develop itchy skin. The skin may become so itchy that dogs damage themselves by increased scratching, licking and chewing. There are several types of allergies in dogs but the most common include:
1) Atopic Dermatitis
When allergens such as dust mite droppings, human dander or seasonal pollen are inhaled or settle on the skin, they provoke an excessive antibody immune response thus triggering inflammation and itchiness. Atopic dermatitis takes time to develop and usually starts in dogs from six months to three years old. Affected dogs obsessively lick their paws, groin or armpits. Bacterial and yeast complications are quite common.
What's the diagnosis and treatment for atopic dermatitis in dogs? A thorough medical history and clinical evidence from a full year of changing seasons offer the best information for accurate diagnosis. Intradermal skin testing and ELISA are both useful for finding the specific cause. Antihistamine drugs, corticosteroids and desensitizing vaccines are all possible treatment options.
2) Food Allergy Dermatitis
After a dog has ingested a trigger food, irritating chemicals are released. The resulting rash very often involves the ears, paws and groin.
What's the diagnosis and treatment for food allergies in dogs? A presumptive diagnosis is made when a new or hypoallergenic diet is fed and the condition clears up. A hypoallergenic elimination diet is one consisting of foods that he dog has never eaten before. This diet must be fed for at least six weeks to enable a confirmed diagnosis of food allergy dermatitis.
3) Flea Allergy Dermatitis
Flea saliva is injected into the dog’s skin as the flea feeds. The saliva contains inflammatory histamine-like chemicals. In hypersensitive dogs, a single flea bite is enough to trigger a dramatically itchy response.
What's the diagnosis and treatment for flea allergy dermatitis in dogs? If the dog scratches and licks but has no signs of skin damage and fleas are present, it is safe to assume that the diagnosis is flea allergy dermatitis. ELISA and intradermal skin test can be used to confirm the diagnosis. Treatment involves eliminating the fleas and preventing their return.
4) Lick Dermatitis
This common condition is also known as lick granuloma or acral dermatitis – the variety of names is a clue to its complexity. The essential sign is licking, usually on the forelegs, leading to localized thickening of the skin and associated hair loss. The skin becomes pinkish-red, shiny and sore and the surrounding hair is stained a mahogany color from saliva. Continued licking may lead to ulceration of the skin. Lick dermatitis is most common among mature male dogs.
What's the diagnosis and treatment of lick dermatitis in dogs? Diagnosis is based upon the dog’s medical history and elimination of other possible causes of hair loss. Treatment involves prevention of further licking and secondary bacterial infections. An Elizabethan collar prevents licking while healing of the skin occurs. In some instances, damage is so severe that surgery, cryosurgery (freezing) or local steroid injection is necessary.
There has been some reported success using anti-anxiety drugs such as amitriptyline (used off-label) and clomipramine to reduce licking behavior, although it is not known whether these drugs reduce anxiety or simply lessen the tingling pain sensation. Boredom is thought to play an important role in this condition, so any treatment involves a reevaluation of the dog’s lifestyle.
"Constant licking prevents the area from healing, and it may become erythematous, raised, and ulcerated. It is likely that the licking and the inflammation also cause the area to become pruritic, which leads to more frequent licking and perpetuates an itch-lick cycle."~Dr. Ian B. Spiegel veterinary dermatologist.
Foreign Body Reaction
Any object that can penetrate the skin (grass seeds, shards of glass, fiberglass fibers, rose thorns, cactus spines or even a dog’s own short coarse hair) can cause an inflammatory reaction when it breaks through the skin surface. Inflammation and swelling then cause the hair over the region to fall out.
The most common cause of a foreign body reaction is the foxtail grass seed or awn. The seed’s shape enables it to penetrate the skin and once it has done so, it can only move forward, into the skin and not backward.
Although foxtails can penetrate any part of the skin, hair between the toes easily captures them. As a result, the seeds penetrate the skin between the toes and cause the development of an interdigital cyst. The body responds by forming a granuloma or an abscess, either of which can cause pain. Dogs lick regions of the body, such as the skin between the toes, where foreign objects have penetrated. Ultimately the combination of licking and tissue reaction cause swelling and hair loss at the site of the foreign body.
Under local, or more commonly, general anesthesia, the swelling is lanced and the subcutaneous tissue searched with alligator forceps for the foreign body. This can be a needle-in-a-haystack search. Antibiotics are also given when there is a secondary bacterial infection.
Canine pad corns can be defined as circular and focal areas of hyperkeratinization located on the digital paw pads. Pad corns in retired sighthound breeds (Greyhound, Whippet, Lurcher) are particularly common.
It is believed that pad corns develop as a consequence of repeated mechanical trauma. However, foreign body penetration and viral infections can also lead to development of pad corns.
The corn’s unique appearance is enough to set the diagnosis. The treatment includes surgical removal followed by applying pressure relief bandage on the foot. Sadly, corns tend to reappear within six months of removal. Another alternative is to inject fat or silicone into the footpad to provide additional cushioning and prevent recurrence.
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia. She currently practices as a veterinarian in Bitola and is completing her postgraduate studies in the Pathology of Domestic Carnivores at the Faculty of Veterinary Medicine in Zagreb, Croatia.