Experienced and professional animal trainer provide their insights in answering this question :
A. You should see a vet as soon as possible to check what is going on and start proper treatment. It can be caused by allergic reaction, hot spot, behavioural problem, artritis… It is impossible to say without clinical exam

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

As with other dog behaviors, there can be several reasons that lead dogs to lick or chew their paws. These include injuries; skin problems; environmental, parasite, or food allergies; and boredom or anxiety.
The most common reason dogs lick their legs is because of some kind of allergy. Allergies can be seasonal or environmental. Seasonal allergies are typically caused by tree and plant pollen. Spring tends to have the most pollen in the air, but dogs can experience seasonal allergies any time of year.
“The most common cause of paw licking is generally environmental allergies, also called atopic dermatitis,” Dr. Flynn says. “Other causes of licking paws can include ectopic parasites such as fleas or mites, referred pain from arthritis — licking the feet or limbs since they can`t reach the painful joint.”
Frequent licking builds up moisture in a dog`s paws that can lead to a bacterial or yeast infection, according to the American Kennel Club. These issues only aggravate paw licking and may cause swelling or redness. Work with your veterinarian to diagnose and treat bacterial yeast infections.
Dog Paw Allergies

Allergies are common and can be caused by the environment, food, or an irritant that comes into contact with your dog`s skin. Redness, dark pigmentation, or brown staining on the paws from constant licking may be signs of allergies.

Stress and Anxiety

If your dog is starting to chew on his fur and no underlying medical condition is apparent, he may be lonely or bored. Other destructive behaviors may accompany separation anxiety or stress, such as incessant barking, destroying furniture, or scratching at doors and walls.

The excessive licking behavior in dogs has been, for many years, attributed to anxiety and stress release. While this may be the case for some canines, recent research has suggested that gastrointestinal issues may actually be a major factor in the development of the behavior for many canines.
If you find that your pup`s paws are dry or cracked, you can use coconut oil to help soothe and heal them. Make sure to rub the coconut oil thoroughly into your dog`s paws, or your dog will mistake this treatment for a snack and lick off all of the oil!
Once a week, spray your dog`s fur with the mixture. Although not scientifically proven to get rid of flea, the acidic taste of the vinegar may repel fleas and other parasites. If your dog dislikes being sprayed, dip a washcloth into the mixture and rub your dog`s coat. There is no need to rinse your dog afterward.
This is called a lick granuloma — or acral lick dermatitis — and the exact cause is debated. Some believe it is a self-soothing behavior in response to anxiety or boredom. Other causes can be an injury or sore, or arthritis or joint pain, that then becomes somewhat of a chronic obsession.
Coconut oil is another excellent natural remedy for your dog`s red paws. It is known for its antibacterial and antifungal properties. Gently massage a small amount of coconut oil between your dog`s toes. It helps to soothe irritation, moisturize the skin, and even ward off parasites.
It feels good – Licking can also be a self-soothing mechanism when a dog feels nervous, lonely, or bored. When dogs groom themselves or lick another dog or human, endorphins are released, creating a sense of safety and calm. It`s tasty – Dogs simply like to taste (and eat) everything.
Dogs choose their favorite people based on positive interactions and socialization they have shared in the past. Like humans, dogs are especially impressionable as their brains develop, so puppies up to 6 months old are in their key socialization period.
As stated, dogs will lick their paws and other body parts at night to groom themselves before bed. The action of licking releases the same hormones that made them feel safe and loved as puppies when their mother licked them. It is also a standard part of doggy self-care to clean and soothe themselves by licking.
Why Is My Dog Constantly Licking Their Lips? Dogs will lick their lips non-stop as an appeasement gesture when feeling threatened, anxious, or nervous or when they experience a health-related problem such as nausea, oral discomfort, allergies, or internal pain.
Weather extremes (too hot or too cold) can hurt tender feet – whether human or canine. Apply warm olive oil and massage onto the footpads to soften, soothe and heal your pet`s paws. Treat dry skin and maintain a shiny coat. Treat your pet`s dry, itchy flaky skin from the inside out with olive oil.
Coconut Oil for Itchy Dogs

The best oils for dogs are those that offer the kind of viscous protection needed to create a natural barrier between angry skin and the environment. For this reason, coconut oil is among the best oils for canine skin, which is why so many products for pups use it as a key ingredient.

Never give undiluted apple cider vinegar directly to your dog. For skin and ear issues, topical use is ideal. Use a diluted 50/50 water and apple cider vinegar mixture in a spray bottle or on a cotton ball to clean out the ears.
According to Courtney Jackson, DVM, a veterinarian and owner of the Pets Digest blog, apple cider vinegar is safe for dogs to use on their skin and take internally if given in moderation and at recommended doses.
Mild licking is considered as self grooming but if the licking and chewing lasts more than an hour, three to four times daily, then it is excessive. The saliva tends to accumulate and soak through the fur. This will result in bad odour which will attract bacterial and fungal growth.
Excessive paw-licking should always prompt a call to your veterinarian to determine the cause of your dog`s paw-licking. These are some of the most common causes of paw-licking behavior: Allergy or irritation: Like humans, dogs can have allergic reactions to substances like pollen, spores, and mites.
A lick granuloma, also known as acral lick dermatitis, occurs when a dog obsessively licks at an area, often on a lower limb, most commonly the wrist or carpal joint of the front limb. These dogs find a spot to lick and start a cycle of self-trauma, inflammation, and infection.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. My dog licks his feet and legs and they are turning brown. He is a white dog. Can you help?
ANSWER : A. Licking the feet and legs can be caused by a number of things in dogs including allergies, illness or even stress behaviors. Allergies are the most common in dogs, with yeast infections coming in second. Allergies can cause the area to become red and itching, making your dog want to lick and chew on them. Over time, the area may become stained from saliva, especially in lighter or white-coated dogs. Yeast infections are also common between the toes, and may cause a smelly “corn chip” smell to appear near your dog’s feet. Again, dogs will attempt to lick and chew to relieve the itch. Keeping the feet clean and dry can help relieve both allergies and infections and pet wipes or a baby wipe of all paws when your dog comes in from outdoors may also help. Keeping your dog from licking the space with either dog booties or an Elizabethan collar is also good as it will prevent secondary infection and staining of the paws and legs. If your dog is determined to keep licking and keeping the feet clean and dry do not help, then your vet can help by providing a medication to treat any infection or provide relief of allergies.

Q. Whenever I take my dog on walks he always barks at people and others dogs in my neighborhood. What should I do to resolve the problem
ANSWER : A. The very first thing to do is to make sure your dog is getting sufficient physical and mental exercise every day. A tired dog is a good, happy dog and one who is less likely to bark from boredom or frustration. Depending on his breed, age, and health, your dog may require several long walks as well as a good game of chasing the ball and playing with some interactive toys.

Figure out what he gets out of barking and remove it. Don’t give your dog the opportunity to continue the barking behavior.

Ignore your dog’s barking for as long as it takes him to stop. That means don’t give him attention at all while he’s barking. Your attention only rewards him for being noisy. Don’t talk to, don’t touch, or even look at him. When he finally quiets, even to take a breath, reward him with a treat. To be successful with this method, you must wait as long as it takes for him to stop barking. Yelling at him is the equivalent of barking with him.

Get your dog accustomed to whatever causes him to bark. Start with whatever makes him bark at a distance. It must be far enough away that he doesn’t bark when he sees it. Feed him lots of good treats. Move the stimulus a little closer (perhaps as little as a few inches or a few feet to start) and feed treats. If the stimulus moves out of sight, stop giving your dog treats. You want your dog to learn that the appearance of the stimulus leads to good things.

Teach your dog the ‘quiet’ command. Oddly, the first step is to teach your dog to bark on command. Give your dog the command to “speak,” wait for him to bark two or three times, and then stick a tasty treat in front of his nose. When he stops barking to sniff the treat, praise him and give him the treat. Repeat until he starts barking as soon as you say “speak.” Once your dog can reliably bark on command, teach him the “quiet” command. In a calm environment with no distractions, tell him to “speak.” When he starts barking, say “quiet” and stick a treat in front of his nose. Praise him for being quiet and give him the treat.

As in all training, always end training on a good note, even if it is just for obeying something very simple, like the ‘sit’ command. If you dog regresses in training, go back to the last thing he did successfully and reinforce that before moving on again. Keep sessions short, 15-20 minutes max, and do this several times a day.

Q. Why does a dogs pads on his paws turn such a pink color?
ANSWER : A. I’m confused here. Are your dogs paw pads typically black, but they turn a reddish pink? You may want to see your veterinarian about this to make sure there isn’t anything wrong with his paw pads. I’ve met dogs who have extremely fragile paw pads due to some bad genetics.. they end up getting injured on their paws very easily. I’ve met dogs who are unable to even walk on cement without wearing little doggy booties. It could be that your dog is dealing with some serious discomfort, and you want to get that checked out immediately.

If your dogs paw pads just seem a little bit irritated, you may want to try something like “Musher’s Secret” on them. This is an ointment that you rub on your dogs paw pads to keep them healthy, and smooth. I use this in the winter when there is rock salt all over the ground.. it keeps her paw pads from getting irritated and tearing open. It’s like lotioning your skin to keep it from getting dry and cracked. If you think your dog is dealing with something that is a little more extreme than just some dry irritated paw pads, then see your vet immediately instead of purchasing the Musher’s Secret.

Read Full Q/A … : Discolored Pads in Dogs

Q. What can I do to stop my dog from barking at people and front doors?
ANSWER : A. Ignore your dog’s barking for as long as it takes him to stop. This means don’t give him any attention at all while he’s barking. Your attention only rewards him for being noisy. Don’t talk to him, don’t touch him, and don’t even look at him. When he finally quiets down, even to take a breath, reward him with a treat. To be successful with this method, you must wait as long as it takes for him to stop barking. If he barks for an hour and you finally get so frustrated that you yell at him to be quiet, the next time he’ll probably bark for an hour and a half. Dogs learns that if they bark long enough you’ll give them attention.

Teach your dog the ‘quiet’ command. It may sound nonsensical, but the first step is to teach your dog to bark on command. Give your dog the command to “speak,” wait for him to bark two or three times, and then stick a tasty treat in front of his nose. When he stops barking to sniff the treat, praise him and give him the treat. Repeat until he starts barking as soon as you say “speak.” Once your dog can reliably bark on command, teach him the “quiet” command. In a calm environment with no distractions, tell him to “speak.” When he starts barking, say “quiet” and stick a treat in front of his nose. Praise him for being quiet and give him the treat.

When your dog starts barking, ask him to do something that’s incompatible with barking. Teach your dog to react to barking stimuli with something that inhibits him from barking, such as lying down in his bed.

Make sure your dog is getting sufficient physical and mental exercise every day. A tired dog is a good dog and one who is less likely to bark from boredom or frustration. Depending on his breed, age, and health, your dog may require several long walks as well as a good game of fetch and playing with interactive toys.

Q. How do I determine how much my overweight pet should weigh?
ANSWER : A. There are many tools to determine overweight and obesity levels in pets. A new tool, morphometric measurements and body fat index, are available to accurately determine a pet’s ideal weight; this will allow an accurate determination of the amount of food a pet should receive to achieve weight loss. Feeding the correct amount will lead to greater weight loss success.

There are many weight loss food options to help pets reach their ideal weight. Your veterinarian can help make a ideal weight recommendation. Here are some tips to help your dog lose weight in a healthy and safe way:

1. Diet: Providing a healthy and well balanced diet is essential to your pet’s overall health. Finding the right food for your dog can be a challenging process. For those overweight animals many commercial dog companies offer weight loss diets, but it is important to evaluate food labels for adequate nutritional content.

You want to ensure you are not missing other essential vitamin or mineral content. Volume of food is also important and the amount of food that works for one breed of dog may not be the same for another breed of dog. Portion control as opposed to free-choice feeding can help your dog to drop a few unnecessary pounds.

There are also prescription weight loss foods designed by veterinary nutritionists, such as Hill’s r/d (http://bit.ly/1AoENSd). Some pet owners find that home cooking is the best option for helping to provide a well-balanced and realistic diet plan. There are websites such as balanceit.com that offers recipes to fit your dog’s specific needs. Consulting with your veterinarian or a veterinary nutritionist to find the appropriate diet is a great way to help your dog be as healthy as possible.

2. Exercise: Another great tactic for weight loss for your dog is exercise. Whether this is through running, walking or playing with a favorite toy all of these are wonderful types of exercise to help keep your dog at a lean and healthy weight.

For those pet owners with busy schedules utilizing professional dog walking services or playtime through dog daycare services is another option. It has been shown that those pet owners that exercise regularly with their pets generally live a healthier lifestyle.

3. Physical therapy: As animals age pet owners offer encounter their favorite canine having more difficulty walking and have a dwindling desire to play with toys. Physical therapy, specifically hydrotherapy is a wonderful way to help older and arthritic animals gain more mobility and lose weight. Hydrotherapy has been proven to have several therapeutic effects on the body including, muscle strengthening, relief of swelling, decreased joint pain, less stiffness in limbs, improved circulation, weight loss, and increased tissue healing to name a few. For more information on the benefits of hydrotherapy:
http://bit.ly/1w1qqoy

4. Veterinary visit and blood work: Weight gain can also be related to underlying health concerns such as hypothyroidism or other endocrine disorders. Scheduling a veterinary evaluation and routine blood work can be another important component in increasing the longevity of your dog’s life. Conditions such as hypothyroidism that predispose dogs to gain weight can be treated with a daily medication to improve hormonal balance. If feel that your dog is unnecessarily overweight there can be an underlying health condition that needs to be addressed.

5. Healthy treats: Pet owners love the chance to reward their favorite canine companion with treats and most dogs jump at the chance to consume these delicious products. The problem is many treats, which can include commercial dog treats or table scrapes can add many unnecessary calories to your dog’s daily intake. Reading labels and making note of the calories in these treats is an important component of understanding your dog’s overall health. Treats should not exceed more than 10 percent of your pet’s daily calories. There are healthier treats that can be offered to your pet to keep calories lower yet provide a fuller sensation. A pet owner can add steamed or pureed vegetables, such as carrots, green beans or sweet potato to add more fiber and thus a fuller feeling for your dog.

Q. My dog has a hard time walking on his front legs. I was told he has nerve damage and he was walking on three legs now it seems to be both front legs
ANSWER : A. Problems with walking in the front legs can be caused by a large number of things. Arthritis in older dogs can cause joint pain and stiffness which may make walking hard. Nerve or muscular damage may also cause problems.

With nerve or muscle damage there is often a loss of muscle tone in the affected limbs. Limbs may look skinnier than unaffected ones, and may lose overall muscle mass. In some cases, treatment for pain or soreness may help improve symptoms some. Depending on the severity of the damage, some dogs may recover while others have permanent damage.

It may also be that if your dog was putting all his weight on one front leg to help the other, that the good front leg is now stiff and sore. Restricting exercise, giving a supplement to help joints and bones and following your veterinarian’s recommendations for care can all help your dog to feel a little better.

Q. Rescued a dog almost two weeks ago, and now that her kennel cough is gone her personality shines!! No previous training, how should I start?
ANSWER : A. POST FOUR:

After your dog is familiar with the behavior you lured from scratch, and taught to your dog, you can start to use the “no-reward marker” I talked about. What you do is ask the dog to perform the behavior, and if the dog does not perform the behavior, you simply say your no-reward marker (choose one: eh-eh, hey, uh-oh, oops) show them the treat, put it behind your back, and BRIEFLY ignore your dog. Just turn your back for a second or two, before turning back to your dog and saying, “let’s try that again.” When you’re ready to start over with your dog, make sure you move around. If you are repeating the same cue while in the same position, while your dog is in the same position, you are likely to receive the same results. The more you move around, and start fresh, the better your chances are of having your dog listen to your cue the second time around. BIG rewards when they dog it successfully! Lots of praise and treats.

My no-reward marker is “hey.” When my dog does something wrong I say, “hey” and she immediately understands that she needs to offer a different behavior. This is clear to her. I don’t have to say it in a mean way, I simply say, “hey” in a normal tone of voice and she understands what the word means.

Once you’ve built up that connection and communication with your new dog, you can work on all kinds of fun behaviors! I personally enjoy the more zen-like behaviors: https://www.youtube.com/watch?v=ruy9UMcuGh8

I like to teach my dog fun tricks that offer her a “job” to do of sorts like object retrieval: https://www.youtube.com/watch?v=I4iertZSva8

(object retrieval training completed; what it looks like: https://www.youtube.com/watch?v=jx0Dml28FGY)

Scent-games are fun too! Very confidence building. Hide a REALLY smelly treat in a box, and place that box in a line of boxes. Let your dog go in the room while saying something like “search!” or “find it!” and watch them hunt for that smelly treat! Lots of rewards when they find it!

Q. My dog has no fleas, but is scratching and licking continually. He has been through a round of prednisone and it hasn’t helped. What can I do?
ANSWER : A. Itching can be caused by more than just external parasites, and if your dog is already on a flea medication, then it is possibly not the case. Itching can indicate anything from allergies to even minor skin infections causing problems. If your dog has been treated with prednisone (a steroid that inhibits the immune system) and it did not help, then looking at other options may help.

Food allergies are very common in dogs and can present with itching and licking all over the body rather than on just one spot. Common food allergens include ingredients such as wheat, corn and soy products, however dogs can be allergic to almost anything! Starting a food trial of an allergen-friendly diet from your vet or pet store that avoids these common ingredients may help. The food should be switched over a period of 7-9 days and then given about a month to decide if it is helping.

Small skin infections or yeast in the skin can also cause itching, however this itching is often more specific to a certain area of the body (such as the toes, or base of the tail). Your vet can perform a skin scraping of the area to be cultured at a lab to look for any yeast or bacteria. If they are present, a medication given either orally or placed on the affected area can clear up the infection.

In some cases, licking and chewing can actually be due to a boredom or anxiety behavior. Dogs may lick one spot obsessively to the point of creating sores or wounds in the area. Stopping your dog from licking and chewing either through the use of dog booties, no lick strips, T-shirts or even Elizabethan collars can break the habit and give the area time to heal. Licking and chewing can also cause the spread of bacterial infections so should be deterred even if not behaviorally caused.