Experienced and professional animal trainer provide their insights in answering this question :
A. It may be local skin infection or even a skin mass that has ulcerated. You should take your dog to your vets to make diagnosis and to get treatment.

How to Identify Common Pet Problems ?

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

A sialocele is a condition of the salivary glands or ducts. The condition appears as swollen structures in the neck near the jaw, under the tongue, or by the eye. It is a buildup of saliva that can often resemble a cyst and it is usually treated by surgery in dogs.
Pyoderma literally means “pus in the skin.” It can be caused by infection, inflammation, or cancer and is common in dogs. Most cases of pyoderma are caused by bacterial infections. Most of these are superficial and secondary to a variety of other conditions, such as allergies or parasites.
Watch for these signs: Firm, raised wart-like blemishes (squamous cell carcinomas) Rubber-like, inflamed sores (mast cell tumors) Strange-colored lumps or bumps on the lips, mouth, pads of feet, toenail beds (melanomas)
Deep bacterial pyoderma is a bacterial infection involving the deep layers of the skin; the dermis and sometimes the subcutaneous tissue. It usually starts as a superficial infection of the hair follicle (folliculitis) that breaks through the follicular wall into the dermis.
A seroma can be evident as a soft, sometimes squishy lump beneath a surgical incision or wound. Serous fluid is typically clear to yellow-tinged and is sticky when touched. A seroma in dogs is not painful and they can vary greatly in size.
Sometimes, dogs may develop what`s called a seroma – an accumulation of plasma that looks like a pocket of fluid at the incision site. These non-painful growths can occur when a dog has licked or chewed the incision site, or has been too active during the recovery process.
Cuterebra is a type of botfly in dogs that lays eggs on the skin and fur of dogs. The eggs hatch and larvae burrow into the skin, feeding off tissue fluids before rupturing from the host animal. Initially, you will notice an inflamed lump underneath your dog`s skin.
Abscesses. Abscesses are swollen lumps that contain an accumulation of pus under the skin caused by an infectious agent. They will generally need to be drained under sedation and copiously flushed with a clean antibacterial solution. In some cases, your vet will prescribe antibiotics if they deem it necessary.
Cancerous or malignant tumors can be hard or soft. The feel of a mass and whether it bothers your dog has little to do with whether it is cancerous or not.
One of the best ways to identify a potentially cancerous lump is to evaluate how that tumor feels when touched. Compared to the soft, fatty characteristics of a lipoma, a cancerous lump will be harder and firm to the touch, appearing as a hard immovable lump on your dog.
Ecthyma is a skin infection. It is similar to impetigo, but occurs deep inside the skin. For this reason, ecthyma is often called deep impetigo.
Seborrhea in dogs appears as a dull, dry coat of fur with dandruff and greasy and oily skin. Your dog`s skin may also have an odor, plaque-like, crusty feel, or skin lesions.
Seromas form lumps under the skin. These are filled with a yellowish to white fluid called serous fluid. This is the same fluid commonly seen in blisters and fresh cuts.
A seroma is a build-up of straw-coloured bodily fluids in an area where tissue has been removed at surgery. The fluid can make the area feel hard and this can become uncomfortable.
A hygroma is a false bursa that develops over bony prominences and pressure points, especially in large breeds of dogs. In young dogs the pathogenesis is believed to be due to trauma. In older dogs, hygromas tend to be result of impaired ambulation and excessive time spent in recumbency on hard surfaces.
The difference between a seroma and an abscess is that an abscess involves the presence of white blood cells, bacteria, and the breakdown products of both. In other words, an abscess is defined as an infection. A seroma, on the other hand, is just fluid, serum that has accumulated in a dead space in the tissue.
Canine Hematoma/Seroma

A hematoma is defined as a localized collection of blood outside the blood vessels. A seroma is similar except that the fluid accumulation contains only serum without red blood cells being present. Hematomas and seromas can occur anywhere in the body.

Dog Cyst vs Tumor: How Do I Tell The Difference? Cysts are fluid-filled sacs under the skin that are usually easy to move around, while tumors are typically more solid. A cyst also may drain a white, yellow, or green discharge.
Mast cell tumors vary in appearance. Some may look like raised bumps within, or just below the surface of, the skin. Others appear as red, ulcerated, bleeding, bruised, and/or swollen growths. Some tumors appear and remain the same size for months or years, while others show a rapid growth pattern over days or weeks.
Cuterebra lesions typically appear as a swollen area under the skin with a small hole in the center. Lesions are often seen near the head or neck but they can be found anywhere on the cat`s body. They are generally non-painful unless they invade sensitive tissues.
On close inspection the bump, which is usually about ½ to 1 inch in diameter, it looks like a volcano with a perfectly round hole at the top and a little discharge coming out of the mouth. On still closer inspection the rear end of the larva can be seen moving up and down inside the hole.
Histiocytoma tumors are often referred to as button tumors because they are usually less than an inch in size, red, raised, and hairless. Often seen in English Bulldogs, Scottish Terriers, Greyhounds, Boxers, Boston Terriers, and Chinese Shar-Peis these tumors typically regress on their own within two to three months.
Should You Pop Your Dog`s Cyst? No, please do not pop it. Squeezing the cyst can force its contents into the surrounding tissue, where it sets up a foreign body reaction, resulting in swelling and inflammation.
Fibrosarcomas are common, fast-growing malignant tumors in dogs. Most are on the trunk and legs and vary in appearance and size. Those under the skin`s surface appear lumpy, while those deep under the skin may be firm and fleshy. They can invade underlying muscles, but most do not spread to other areas of the body.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

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 Bulldog puppy growls, barks and even tries to bite me when I say “no” to him. What can I do?
ANSWER : A. First, avoid scolding him and acting aggressively towards him if you don’t want him to be acting aggressively towards you. There are other methods you can use to communicate to your dog that you don’t want him to continue doing what he is doing. I recommend you stop telling him “no”, scolding him, or raising your voice at him. Everything coming from you should be 100% positive and 100% calm.

Try to figure out ways to clearly communicate what you want to your dog. If you want your dog to leave something or someone alone, I strongly suggest teaching your dog commands like “leave it”. Here is a link to a video in which I explain how to do it:

www.youtube.com/watch?v=R1TS5nA7z5Q

Another thing I suggest you use is a no-reward marker. This clearly communicates when your dog has done something wrong. No-reward markers have to be introduced during your training sessions. You should be doing at least three training sessions per day, that are something like 3-10 minutes long (working on different things each training session). If you are teaching your dog something BRAND NEW, do not use the no-reward marker, as you do not want to discourage your dog from performing behaviors for you. Use the no-reward marker for known behaviors only. Here is another helpful video about this:

www.youtube.com/watch?v=sdU5a6fXKlg

Lure each new behavior (as shown in the video) using high value treats. Let’s say you’re working on “down” which is a behavior your dog knows fairly well. Present the treat to your dog. Ask your dog to “down” (only ask once). If he does not go “down” immediately, say, “uh-oh” or “eh-eh” in a gentle tone, and then place the treat behind your back. This communicates to your dog that they did something to make the treat go away.

After you place the treat behind your back to show your pup “that was wrong” you need to communicate to your pup “let’s try again” by getting your pup to walk around for a second, and then start the behavior all over again. If your puppy is very young, chances are you haven’t taught him a solid “down” behavior yet. So, as I said, do not use this method until you have lured each new behavior as shown in the video.

This is the order in which you should teach behaviors: Lure using a high value treat as shown in the video. After a few successful food lures, lure with an empty hand. If the pup is successful with the empty hand lure, reward with lots of treats. If the pup is unsuccessful, then go back to food-luring a couple more times. After a few successful empty-hand lures, you can begin to add the cue. Say “sit”, then lure with an empty hand, and then reward. Once your pup understands the cue, begin to work on the no-reward marker.

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. 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 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. My 4 yr old male Catahoula Leopard Dog mix is a rescue. He’s become very possessive of me around larger dogs. How can I correct this behavior?
ANSWER : A. Sudden behavior changes can sometimes indicate an underlying health issue, so scheduling a checkup with your regular vet is always the first step. Once any health issues have been addressed, then you can address the behavioral ones. It is very common for dogs to become “possessive” of people or objects when around other dogs or people, and is called location guarding. Possession of objects or places can be a little easier to manage, however possession around other dogs can be treated as well. Working from a distance in a technique called BAT or Behavioral Adjustment Training may help. This technique involves your dog and another calm dog. Start off at a far distance and then move in until your dog becomes reactive or wary of the other dog. Move back a small amount and wait for your dog to become calm. If he shows calm behavior, reward with lots of praise, treats and love! If he becomes agitated or possessive, move back until he is calm, or stop the session completely and try again later. While this may take some time, it can help dogs learn that other dogs are not a threat to them or their people. Reading more information about BAT training or contacting a local trainer in your area can help with further advice and techniques!

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. My dog keep hacking like a cough or something in her throat, what can I do?
ANSWER : A. Hacking and coughing can be caused by a number of things ranging from foreign bodies such as twigs stuck in the mouth or throat, to infections or illnesses such as Bordetella or Kennel cough, common in dogs that frequent kennels, dog daycare or dog parks. In older dogs, heart and lung issues can also be indicated by a cough that does not go away.

If you think there may be a foreign object stuck in your dog’s throat, you can sweep a finger gently through the back of the mouth or throat if your dog will let you. If something feels stuck and is not easily moved by the finger, it is best to contact your vet to have the object safely removed. This usually requires sedation so that your dog does not become panicked or move, causing the object to become further stuck or cut the throat.

If your dog is showing other symptoms of illness in addition to the cough such as runny nose or eyes, fever, lethargy or changes in appetite, it may indicate a viral or bacterial illness such as kennel cough. These are usually treated with a cough medication in severe cases, plus rest and treatment of any additional symptoms until the condition improves. In bacterial causes, antibiotics may also be given to help your dog feel better.

If your dog has a constant cough that does not go away, or has had changes in ability to exercise, breathing, or appears to have swelling around the chest or abdomen, in may indicate a lung or heart issue. Your vet can thoroughly examine your dog for any signs of heart or lung problems and can then offer care as needed depending on the cause.