Experienced and professional animal trainer provide their insights in answering this question :
A. It sounds like allergy. You should take him to your local vet to get treatment. human anti-allergy drugs and shampoos are often not very effective in dogs.

How to Identify Common Pet Problems ?

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

Soothing shampoos (aloe or oatmeal based). Wiping off your dog`s paws and belly after a walk, to remove pollen and other potential allergens. Hydrocortisone cream is usually okay to apply for a few days directly on the rash. Just be sure your dog doesn`t lick and ingest it (an Elizabethan collar can help).
The most common reason for skin rashes in dogs is allergies. Allergies may be caused by your dog`s diet, by the environment and by parasites. A few flea bites on a dog that is allergic to flea saliva can trigger itching and scratching for weeks. A flea bite allergy is also known as `flea allergy dermatitis`.
Many dog rashes can be cured at home without veterinary treatment. Shampoos are a go-to for treating dog skin rashes at home. Those that contain colloidal oatmeal reduce skin redness, dryness, and itching. Over-the-counter medicated shampoos are also available to treat skin conditions that can cause rashes.
A rash can occur on any part of your dog`s body, but it pops up most often on the belly. A rash by itself is usually minor and often goes away on its own, but it can be a sign of a more serious situation. The cause of rashes on a dog can range from parasites to diabetes.
Dog hives are itchy, round welts that appear on a dog`s skin, causing the fur to stick up. They generally last up to one to two days and are usually caused by an allergic reaction to insect bites, although there are also several other possible causes.
Skin problems are fairly common in dogs just like in humans, and those skin problems may lead to a rash. Many rashes are minor, while others may be a sign of fleas, allergies, and infections. Rashes can be caused by heat, bacteria, yeast infections, and more.
You might notice that the skin is starting to become dry and showing dandruff, or your dog is beginning to scratch more than normal. It is best to wash your dog as soon as possible when symptoms start to worsen, in order to prevent excessive scratching which may lead to a skin infection.
Sugar-Free Plain Yogurt. Feeding your itchy dog plain, unsweetened yogurt may offer many health benefits. Some yeast infections and skin irritation can stem from your dog`s digestive system. This remedy is good for dogs who have certain types of rashes, hives, or allergies.
The initial allergy attack can last around two weeks until you find a new baseline, but that new baseline does not include immunity. Everyone is different though, and some people may not feel a difference until all the allergens are gone.
In many cases, the best treatment is to leave the rash alone. Your rash will likely clear up without complications in 2-3 weeks as long as you are not re-exposed to the allergen. Applying moisturizers will help the skin moisten and speed up the healing process.
Contagious infections include parasitic, bacterial, fungal and viral skin diseases. Canine scabies, mange, mites and lice all fall within this category, along with flea and tick infestations. Ringworm is a fungal skin infection and is more common in puppies than in adult dogs.
Scabies (Sarcoptic Mange)

Sarcoptic mange is caused by a microscopic mite called sarcoptes, which bites into your pet`s skin. This mite can be transferred through casual contact with your skin, causing a condition known as scabies in humans.

You can`t get rid of pet allergies. However, you can take OTC antihistamine pills, nasal corticosteroids and nasal antihistamines to treat your symptoms. For some people, allergy shots (immunotherapy) offer a long-term solution to managing pet allergies.
Allergy testing in dogs can be performed using two techniques: intradermal skin testing or RAST testing. Each method has its own pros and cons. While intradermal skin testing has long been regarded as the `gold standard` in determining the cause of atopic dermatitis, it is only performed by veterinary dermatologists.
Treatment of Bacterial Infection of the Skin in Dogs

Antibiotic treatment will last from 2 to 6 weeks. Your dog will need to continue taking the medication at least a week after the symptoms of infection have been resolved in order to ensure that bacteria don`t survive and develop resistance.

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.

While not a medical problem per se, stress has been linked to many skin problems in dogs. This can lead their fur to fall out, for them to excessively lick or bite themselves or even cause rashes if their anxiety is really heightened.
Always use cool to tepid water to wet the entire hair coat thoroughly before applying any shampoo. Water temperature is very important when bathing, as warm/hot water may irritate infected/inflamed skin, and cool water is much more soothing. Allow this to sit for 5+ minutes.
It`s probably best not to put Vaseline or any other petroleum-based product on your dog. When your dog is itchy, flaky, red, or bumpy, it`s always best to consult with your veterinarian first. There could be a more serious underlying issue happening, such as food allergies or a parasite infection.
Often in dogs with food sensitivities, proteins from animal or plant-based ingredients in the diet are the cause. Beef, corn, dairy, and wheat are some of the most problematic ingredients. It may seem counterintuitive, but it can take a long time for symptoms of food allergies to become apparent.
Yes, eggs are good for dogs with itchy skin. In fact, they are a very nutritious treat for your dog. Eggs are a source of protein that is full of fatty acids that work to keep your dog`s skin and coat healthy. It is also full of vitamins and minerals such as vitamin A and vitamin B, iron, selenium and folate.
While fish oil may be more beneficial when supplementing your dog`s diet, some plant-based products work well to soothe dog skin conditions when applied topically. Dr. Krause explains that coconut oil is also a good option for keeping your dog`s skin and coat in good shape.
Red or inflamed skin. Pus-filled lesions on the skin. Excessive licking, itching or chewing. Patchy fur with peeling, moist or crusty skin.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. My dog has red spots on his bottom what could it be ? I gave him foam fast relieve bottle .
ANSWER : A. Red spots on the body and rear may be cause by a number of things. Rashes can be caused by allergies, or even irritation if the redness is around the anus (such as with diarrhea or constipation). Rashes due to allergies may cause the area to be itchy or red and may be cause by environment or certain food ingredients. It is best NOT to give your pet any over the counter medications unless instructed by your vet as they may be the wrong treatment or even harmful if given to your dog. Stopping him from licking and chewing at the area with the use of an Elizabethan (cone) collar may help, and a trip to the vet is best if the redness continues for more than a day or worsens.

Q. My Pug’s nose is red and he doesn’t have a yeast infection. He is taking medicine for that. It seems to get worse when he goes outside. Any ideas?
ANSWER : A. Redness or irritation can be caused by a number of things including yeast infections as you mentioned, but can also be caused by allergies to the environment, or even cold or hot weather. Dogs with short fur can often get sunburns on the skin, and the cold may also irritate or cause redness when outdoors. Allergies to pollens or other outdoor allergens may also cause redness on the body or nose. An allergy medication from your vet is usually all that is needed to clear this up.

If the redness is happening just when outside, it may also be that your dog is digging or nosing around in something that is irritating. It may be a good idea to watch your dog a few times while he is outside to see if there is anything he enjoys exploring. The redness could just be irritation from that.

However, if you are concerned about the redness, it is always a good idea to bring it up with your veterinarian to make sure there is not a more serious cause behind it.

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. I have a Collie shepper and she develope a rash and redness all over what I Can do for
ANSWER : A. It sounds like allergy. You should take him to your local vet to get treatment. human anti-allergy drugs and shampoos are often not very effective in dogs.

Q. My 5 yr old border collie has always had slightly blood shot eyes –usually noted in evenings–now has increased red eyes (on sclera)
ANSWER : A. While this could be an intensified allergic reaction (since you mentioned that he’s always had red eyes) I strongly recommend you get this checked out. Red eyes are considered a veterinary emergency, mainly because they could be indicative of glaucoma, which is a very painful an serious condition that can result in loss of sight. It’s definitely possible that it’s not something serious, but the first job is to make sure it isn’t.

Read Full Q/A … : Causes of Limping in Dogs

Q. My dog itchs all the time a codozon shot helps but don’t cure it after a bath she turns red and still itchs I changed dog food that didn’t help no fle
ANSWER : A. Do you live in a region where fleas are prevalent. Where I live the fleas are truly horrible, and I see many animals developing a flea allergy. This usually presents as relentless itching especially at the base of the tail, although it can be all over the body. Often on exam I won’t find a single flea, just red bumps, hair loss and itching. In response, I will start animals on an oral steroid such as prednisone (I think your doctor has administered an injectable steroid), while at the same time bathing the animal and starting on an oral flea preventative such as Comforts which I then re dose at 3 weeks instead of 4. Additionally, the environment needs to be decontaminated- flea bombing the house, vacuuming often and washing bedding on hot. The flea life cycle is short, however, so this needs to be one frequently as they will just continue to hatch in your home. Most importantly, I tell my clients, that any steroid (oral or injectable) does not fix the problem, but rather suppress your dogs reaction to it thereby making them more comfortable. Just the steroid alone changes nothing except giving them a brief break from their symptoms.

Now that I have spoken in depth about flea allergy, there is a potential that it is something else. Food allergies are slow to develop, and slow to change. If you wanted to eliminate a potential food allergy I would switch to a novel protein, limited ingredient diet. For example, lamb as the protein source if your previous food was always chicken or beef, and in a formula with very limited ingredients such as lamb, rice and veggies. A pet store should be able to help you with this. While on this diet they cannot have any additional treats for 1 month, to see if you have eliminated the allergy. From an Eastern Medical perspective, I also recommend novel proteins that are “cool”, such as fish, lamb, or duck while avoiding “warm” foods such as beef, chicken, pork.

Finally, all animals with allergies should be on an Omega 3 supplement. Given regularly, this can help reduce overall inflammation in the body both in the skin, joints, and other tissues. Good for allergies, arthritis and overall health. My dogs are on fish oils, but one of my dogs who is allergic to fish gets flax oil instead. I would be happy to consult with you further, but I hope this helps to some degree.

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. Our dog was diagnosed with pancreatic cancer low blood suger not making red blood cells white gums taking steroids his gums are red now is this write
ANSWER : A. I am sorry to hear your dog is so unwell. Gums r should be a gentle pink color but red can be an indication of infections or shock developing. If he is uncomfortable, his heart rate is elevated or pounding or his ears/feet feel warm I would be concerned that his condition could be worsening. If he is bright, alert with a cool damp nose and willing to drink a normal amount of water you can monitor his signs and repeat bloods next week to assess progress but otherwise I would recommend assessing his as an emergency