Experienced and professional animal trainer provide their insights in answering this question :
A. You should see your vet and report that. It can be allergy and secondary bacterial infection. But it should be confirmed by dermatological exam. Maybe some change in therapy is necessary.

How to Identify Common Pet Problems ?

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

Fleas, mites, and ticks can cause irritation, exposing your dog to bacteria, yeast, and fungal infections. Demodex mites, walking dandruff, flea allergy dermatitis, and sarcoptic mange (caused by the Sarcoptes scabiei mite) can all cause rashes on your dog`s skin, including her belly and groin area.
Steroids: Injectable or oral steroids such as cortisone or prednisone have many pros and cons in the treatment of allergies in pets. They are inexpensive and work quickly and effectively to reduce itching, and for short term use they are relatively safe.
Pets too can be affected by hives due to food, flea, or environmental allergies, occasionally with a contact allergy reaction or a possible vaccine reaction leading to the raised bumps!
If there are no cuts or open sores on the groin, you may also apply non-scented lotion or hydrocortisone cream to the affected area. Do not apply hydrogen peroxide or any other substance that will sting or irritate the skin. In some cases, applying oatmeal on the afflicted area also helps.
The skin that surrounds a dog`s vulva can develop rashes just like any other area of the body. Because the vulva touches the ground whenever a dog sits, it frequently comes in contact with irritants, allergens, and insects that may bite. Parasites or skin infections can also cause rashes around a dog`s vulva.
The most common clinical signs associated with pyoderma are papules or pustules that form on the skin. These lesions often look similar to pimples in humans. They are most often red and raised, with a white pus-filled center. Other signs include circular crusts, dry or flaky patches of skin, hair loss, and itching.
Though most reactions dogs may have to vaccinations will be short-lived and mild, more severe reactions requiring immediate attention may occur in a few rare cases. Anaphylaxis is a severe allergic reaction that may include hives, breathing difficulties, vomiting, facial swelling, itchiness and diarrhea.
Cytopoint is a small, painless injection that your veterinarian gives under your dog`s skin, similar to a vaccination. After the injection, the itch usually is reduced within a few days, and the effect lasts for 4 to 8 weeks. The injection can then be given again, as needed.
In mild cases, benzoyl peroxide alone may be sufficient to resolve canine acne; in more severe cases, long-term benzoyl peroxide may be used to decrease the likelihood of recurrence. “The most common treatment for canine acne is topical benzoyl peroxide.”
Many things can cause bumps on dogs` skin. Sometimes excessive scratching and chewing from allergies can cause small bumps to form on a dog`s skin — and these could indicate a skin infection. Other causes could be anything from acne, ringworm, or mange to various types of cysts and tumors.
Bathing routines for dogs with skin conditions

Bathing once a week will help to relieve pain and itching, and increase healing and recovery from both yeast and bacterial infections.

If your dog is focusing the licking on their rectum or groin, they may be experiencing anal sac, urinary tract, or reproductive organ infections. Your vet may first express your pet`s anal glands to rule out infection and impaction.
Signs of Heat Rash on a Dog

Red or pink blotches on low, fur areas (armpits, neck, tummy) Itchy or irritated skin. Persistent scratching and licking of affected skin. Boils, small pimples, pustules, bumps.

Irritation to the skin around the vulva, or vulvar fold dermatitis, is caused when there excessive skin or folds of skin around the peri-vulvar area. This can be due to obesity, breed conformation, or due to early neutering (juvenile vulva).
It is rare for humans to catch pyoderma from their dogs, though it is possible (e.g., Staphylococcus aureus). Staphylococcus pseudintermedius, the most common cause of canine pyoderma, does not lead to disease in humans.
This type of infection may impact a dog`s skin or upper respiratory tract, and can be treated using oral antibiotics such as cephalexin, erythromycin or clindamycin. Antibiotic ointments and shampoos can also work.
A prednisone overdose in dogs can cause itching, weakness, loss of hearing, depression, anxiety, increased blood pressure, heart problems, and seizures. That`s why it is very important to follow your veterinarian`s dosage instructions.
Most dogs on prednisone will have increased thirst and urination along with a voracious appetite that can lead to weight gain. Restlessness and panting may also occur. These signs can gradually improve as the dog adjusts to the medication and should cease after the drug is stopped.
Lumps and bumps are fairly common vaccine reactions in dogs. A small, firm bump may develop near the injection site following the vaccination. No need to worry – while the site may feel somewhat tender, this is simply a result of your dog`s immune system trying to resolve irritation in the area.
Skin issues often develop or get worse in dogs who`ve recently been vaccinated (or re-vaccinated). This includes problems like itching, redness, allergies, eczema, yeast infections, autoimmune diseases and so on.
What are the risks associated with Cytopoint? The most common side effects with Cytopoint (which may affect up to 1 in 1,000 animals) are allergic reactions with swelling of the face and itchy rash. Cytopoint must not be given to dogs weighing less than 3 kg.
What are the side effects of Cytopoint for dogs? The most common side effect in dogs is lethargy and it is self-limiting. Some dogs have experienced side effects such as vomiting, hyperexcitability, painful reaction at the injection site, and urinary incontinence after receiving the Cytopoint injection.
Any lump or bump, new or old, big or small, should always be evaluated by your veterinarian. It is sometimes helpful before your appointment to color the lump with a marker or draw a circle around it, especially if the lump is hard to find or your dog is very hairy.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

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.

Q. My Cocker Spaniel keeps getting lumps on her body. She has some on the top of her head that feel soft with about six or so clumped together.
ANSWER : A. Lumps and bumps are very common in dogs. They can be caused by any number of things ranging from allergic reactions, to pockets of infection under the skin, to various tumors and cysts. If the bumps are spreading rapidly, or are very bothersome to your dog it is best to have a vet look at it to make sure it is not serious.

Allergic reaction bumps will often appear as small, red, itchy pockets of bumps anywhere on the body. These are usually treated with an allergy medication or over the counter antihistamine. Abscesses are pockets of infection under the skin that usually are one large bump, however in spreading infections may have other bumps appear. These are often painful or hot to the touch, and may ooze debris that is yellow or greenish in color. Abscesses are usually drained and then an antibiotic given to clear up the infection. Some tumors can also appear as small bumps that begin to spread and their type can be determined through biopsy of the site if other more common causes are ruled out.

Until you can have your vet look at the lumps, it is best to stop your dog from licking or chewing at them. Licking and chewing can cause cuts and scrapes to open, allowing bacteria and infection to spread over the affected area. An Elizabethan collar, or a T-shirt over the affected area can help prevent licking and chewing.

Q. My dog is almost 6 months and she has a bump right underneath where the ribs meet in that upside down V shape. What is it?
ANSWER : A. Bumps can be caused by a number of things including minor allergies to food or environment, cuts or skin infections causing swelling under the skin, or just normal puppy “acne” as your dog enters her “teenage” stage of life. If the bump is not bothersome, it may be best to monitor it for any signs of changing size, becoming bothersome, or if redness appears.

If the bump is red or itchy, it may be good to look into her diet for any common allergens such as wheat, corn, or soy, and to see if the bumps appear anywhere else on the body. If the food is not a culprit, then a daily allergy medication may also help. If the bump is red or hot to the touch, painful, growing quickly, or oozing debris it may indicate an abscess, or infection under the skin, which should be treated by your vet via draining and antibiotics. If your dog is bothered by the area, placing a T-shirt or Elizabethan (cone) collar on her to prevent licking and chewing and spreading infection is best until you can get into your vet.

Read Full Q/A … : Vetinfo

Q. My cat has a major rash on her back it looks like red bumps an some have even turned into scabs.
ANSWER : A. Skin disorders can be particularly vexing to diagnosis and treat. One of the most common causes of skin rashes in cats is allergic dermititis caused by the bites of fleas. Some cats are very sensitive to the bite(s) of fleas and will react with excessive itching, scratching, and scabby bumps particularly on the lower back and nape of neck. Finding fleas on your cat is a pretty good indicator that fleas are causing the skin irritation. Unfortunately, NOT finding fleas doesn’t rule out an allergy to fleas, as it takes only one bite from a flea to cause a reaction in sensitive cats. Moreover, there are many other possible causes for skin rashes in cats, including thyroid disease, fungal diseases, bacterial or viral infections, and irritation from chemicals in the enviroment (scented litter, fabric sheets, air freshners, floor and carpet cleaners, etc.).
A trip to the veterinarian is your first step in treating skin disorders. Your vet will examine your cat, checking for fleas and other external parasites and also looking at the distribution pattern of the rash which will help your vet to determine what might be causing the rash. If necessary, your vet may take hair or skin samples for analysis. Blood work may also be necessary if your vet suspects thyroid diseases or another metabolic disorder.

Q. Dog has itchy red bumps on groin area. Took him to the vet and was given steroid shot and cream. Skin scrapings were neg. Rash has returned.
ANSWER : A. You should see your vet and report that. It can be allergy and secondary bacterial infection. But it should be confirmed by dermatological exam. Maybe some change in therapy is necessary.

Read Full Q/A … : The Q&A wiki – Answers.com

Q. My dog likes to walk around trees and bushes. I noticed today a rash on his back in a straight line and his hair is gone in the area. Help?
ANSWER : A. If you live in a brushy or wooded area it is possible that your dog may have come into contact with an irritant such as poison oak or poison ivy. These can spread to people, so care should be taken when handling the area by using gloves and washing hands. You should also prevent your dog from licking or scratching at the area to prevent the spread of irritation. Topical ointments for pets can be used to treat oak/ivy infections.

Other causes such as allergies, cuts and scrapes, or even external parasites can cause redness as well. Ticks and fleas are common in wooded and brushy areas, so making sure your pet is on a preventative for these is important.

If the rash appears to have any cuts, scrapes, open sores, hair loss or spreads, then making an appointment with your vet is best. Your vet can take a sample of the area to look for any more serious infections causing the redness.

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. 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.