Experienced and professional animal trainer provide their insights in answering this question :
A. You should use good quality flea treatment, ideally from your local vet. Also, please remember to de-flea your house using a special spray.

How to Identify Common Pet Problems ?

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

One of the more common causes of patchy dog hair loss and irritated red skin is demodicosis. This is especially common in puppies. Demodicosis (or “red mange”) is one of the skin problems in dogs that can be easily treated but requires a proper diagnosis.
Ticks, mites, fleas, lice, ticks and worms are all parasites that can cause dog hair loss. They all cause discomfort for your dog and if not treated, can cause your dog to lose hair. If you think your dog has any of these parasites, consult your vet to find the right treatment.
Folliculitis. Superficial bacterial folliculitis is an infection that causes sores, bumps, and scabs on the skin. These skin abnormalities are easier to see in shorthaired dogs. In longhaired dogs, the most obvious symptoms may be a dull coat and shedding with scaly skin underneath.
Allergies are a frequent trigger for hair loss in dogs. Like people, dogs can have an allergic reaction to foods, environmental triggers such as pollen, or to parasites like fleas or mites. Flea bites are behind most dog allergies, however.
In localized cases, it shows up as patches of hair loss and red, scaling skin. In generalized cases, the entire body may be covered with redness, infections, scaling, swelling, and crusts. Often the dog loses most, if not all, hair.
Topical Treatments May Help with Hair Loss in Dogs

Medicated dog shampoos might help with some hair loss or rejuvenation of your dog`s coat. There are also sprays, ointments, and dips for topical treatment of hair loss. Depending on the cause of your pet`s bald spots, this may be a useful strategy for treatment.

Mites are tiny spider-like creatures that can typically only be seen with a microscope, but sometimes they may be visible as tiny orange, black or white dots moving on your dog`s skin.
Ingredients in dog food like beef, lamb, chicken, eggs, or soy could cause allergic reactions. One of the major symptoms of allergies is itchy skin, which leads to scratching and associated hair loss. If the problem gets bad enough, you`ll likely see redness and inflammation, bald spots, or oozing skin.
Only riboflavin, biotin, folate, and vitamin B12 deficiencies have been associated with hair loss. Vitamin B2 (riboflavin) is a component of two important coenzymes: flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) [22].
Keep an eye out for dry or brittle fur, or even patches of hair loss; a simple tweak to your dog`s diet, like adding a fresh, high quality protein source, can improve the issue. Fats get a pretty bad rap (they should really fire their publicist), but healthy fats are essential for your dog`s skin and hair.
Chihuahuas are highly sensitive to food allergies and intolerances; often the symptoms of a food allergy are chronic ear infections, vomiting, diarrhea, and red, inflamed, and flaky skin. Hair loss and a dull, dry coat are also symptoms of food allergies in the Chihuahua breed.
APPLE CIDER VINEGAR

You can apply ACV directly to affected areas using a spray bottle, or if the issue is widespread, you can apply all over as a post-bath treatment. Allow the ACV to air dry. Do not use on pets with raw or otherwise damaged skin.

Pet MD Benzoyl Peroxide Medicated Shampoo is one of the few over-the-counter shampoos that may be effective in killing sarcoptic mites. It may also treat a number of other skin conditions, including rashes, dry skin, and yeast infections. There aren`t many problems with Pet MD Benzoyl Peroxide Medicated Shampoo.
Treatment of Demodicosis (Red Mange) in Dogs

Medicated baths, usually containing a pesticide known as Amitraz, are most commonly used to kill the mites. These are generally repeated approximately every two weeks for at least six treatments, or until no mites are found after two successive treatments.

Is it contagious? Yes. Sarcoptic mange is highly contagious to other dogs and humans. Since the mite may be found in areas where infected dogs or foxes frequent, keep your dog away from these areas to help prevent infection.
Oatmeal is an age-old remedy for our dry, itchy skin that happens to be safe for use on our canine friends too! In fact, most doggy hypoallergenic shampoos include oatmeal as an active ingredient to soothe and fight irritation. Start by grinding plain oatmeal into a powder to sprinkle in your dog`s warm bath.
Alopecia can result from a variety of medical conditions, including skin infections, hormonal diseases, and infestations with fleas or mites. Many causes of alopecia are treatable. If the hair follicle has not been permanently damaged or destroyed, the hair will grow back over time.
If your cat has had an allergic reaction to a flea bite that has caused baldness a vet may administer an injection or other treatment to help reduce the allergic reaction and help calm the area. Hair will usually grow back once the inflammation resolves.
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).
You may notice a very fine rash or just the itching at first. Over time the skin becomes very red, there is hair loss and flaking skin. Areas where hair is thinner (ears, elbows, ankles, belly) tend to be the most severely affected. However, some dogs may have a different pattern or no symptoms at all.
The Sarcopetes scabiei mange mite gets transmitted to humans on close contact with infected domestic animals, leading to intense pruritis and irritation due to the hypersensitivity reactions for the mites and their products [1].
Endocrine diseases such as hypothyroidism (low thyroid hormone), Cushing`s disease (high cortisol), or reactions to rabies and corticosteroid injections can also cause alopecia. Additionally, an established yeast infection on the skin weakens the immune system and causes digestive issues, inflammation, and itching.
Thyroid medication and hormone therapy can reverse hair loss in hormonal and endocrine disorders. Vitamin E, Vitamin A and fish oil supplements may be recommended for pets with certain conditions or a predisposition to dry skin or skin infections.
The main difference between dust mite allergy and other causes of itchy skin (dermatitis, dry skin, fleas) is that with dust mite allergy your dog will also have sneezing, runny eyes and nose, a cough, and possible wheezing.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. My cat is excessively scrstching herself., to the point she has sores. She is strictly an indoor cat. Did have flees been treated for 2 months
ANSWER : A. For every flea you see on your pet, there are 100 more in the environment. Get your pet on a good topical or oral flea control through your vet. In flea control, you get what you pay for. Consider asking your vet for a dose of Capstar. It helps get the problem under control by killing the fleas on the pet starting in five minutes but only lasts for 24 hours.

You need to treat your home environment. If you use a pest control service, tell them you are having a flea problem and they can adjust their treatment. Use a premise spray that also contains an IGR, insect growth regulator. This keeps eggs and larvae from maturing into adults and helps break the life cycle. Also, vacuum EVERY DAY, throwing out the bag or emptying the canister every time into an outside receptacle and spraying the contents with insecticide to kill the fleas you’ve vacuumed up.

Treat your yard too, since fleas are opportunistic and will hop a ride into your home on your pant leg without you knowing it. Concentrate on areas under bushes, in the shade. Fleas are less likely to be located in open sunny areas where it gets hot.

If chemicals are a problem, you can use borax. Sprinkle it into rugs, into corners and under furniture, use a broom to work it into the fibers and let it sit for hours, days even. It won’t hurt you or your pet to have it present. Then vacuum it up, reapply as needed. Food grade diatomaceous earth can be gotten from a health food store and worked into the rugs and corners in the same way as borax. These treatments aren’t as fast and effective as chemical insecticides but they can help.

You might want to consider boarding your pet for the day at your vet, to give you the opportunity to flea bomb your house without having to worry about your pet being exposed. They can bathe your pet and give a dose of Capstar while you treat your home.

Be patient, you may have to repeat these steps multiple times 10-14 days apart to help break the flea life cycle.

Skin problems can have a variety of causes, sometimes more than one. It is important to have the problem checked by your vet to determine if there is a medical cause for your pet’s skin issues and treat accordingly.

In pets of all ages, fleas, food allergies and exposure to chemical irritants such as cleaners and soaps can be a cause. Any one of these may not be enough to trigger the breakouts, depending on how sensitive your pet is, but a combination can be enough to start the itch-scratch cycle. Finding out the cause and eliminating it is the best course of action. With flea allergies, if your pet is sensitive enough, a single bite can cause them to break out scratch enough to tear their skin.

Check for fleas with a flea comb. Look for fleas and/or tiny black granules, like coarse black pepper. This is flea feces, consisting of digested, dried blood. You may find tiny white particles, like salt, which are the flea eggs. Applying a good topical monthly flea treatment and aggressively treating your house and yard will help break the flea life cycle.

If you use plastic bowls, this is a possible cause for hair loss, though this tends to be on the chin, where their skin touches the bowl while they eat. If you suspect this to be the culprit, try changing the bowls to glass, metal or ceramic.

Food allergies are often caused by sensitivity to a protein in the food. Hill’s Science Diet offers some non-prescription options for sensitive skin as well as prescription hypoallergenic foods for more severe cases. Royal Canin carries limited protein diets that may also offer some relief. Your vet can recommend a specific diet that will help.

If there is no relief or not enough, consider getting your pet checked by a veterinary dermatologist and having allergy testing done.

Q. Fleas? First noticed scabs & small lumps under chin & neck. Used hydrocotizone spray, flea collar, spray, baths…Is licking, has hair loss & swelling
ANSWER : A. If you are currently treating for fleas with a flea prevention treatment, several things could be happening. It could be that your pet is experiencing a flea-bite allergy, even if the fleas themselves are gone, which is very common. This causes small, red, itchy bumps to appear on the body where fleas have previously bitten the area. If your pet is allowed to scratch or chew at these spots, it could lead to a bacterial infection under the skin which can become red, painful, hot to the touch or even cause the hair to be lost in the affected area. Making an appointment with your vet can determine if this is the case and treatment usually involves allergy medications and any antibiotics or anti-fungals needed to clear up a secondary infection.

Another cause of skin changes, swelling and hair loss are hormonal imbalances. Thyroid problems, adrenal gland problems and other hormone produces in the body can cause changes to appear on the coat and skin in affected animals. You may also notice other signs such as changes in appetite, thirst, urination or even in your pet’s weight. A set of blood tests from your vet can determine if this is the case. Most of these conditions are treated successfully with the addition of a daily medication to balance the hormones.

Q. Our cat developed a flea allergy in the form of red sores above the eyes Our vet gave him an antibiotic shot and a flea collar but they remain.
ANSWER : A. I’m so sorry to hear! Flea allergies are tough to deal with! Unfortunately when a pet has an allergy to fleas, the problem lies in the flea bite. The actual allergy lies in the flea saliva, so what we really need to prevent is the flea biting our pet! I would recommend a product that can kill the flea before they even have a chance to bite your pet! A couple of really great products on the market right now are Frontline Plus and Revolution. Both are liquid topical products that you place on the skin of your pet once a month. They work by using the skins oils to spread themselves around the body and rest in the hair follicles. Each has a slightly different mechanism of use, but they both work to kill the flea before it actually has a chance to do harm to your cat. Flea collars simply are not as effective. I would also recommend treating your home environment, such as the area where the cat sleeps and the carpets inside your home. Flea eggs and larva can live for a very long time in these environments and unless we treat all of these areas, the problem will remain. I hope this was helpful! Good luck and I hope your kitty feels better!

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. Year 3 my dog loses patches of hair on back, stomach and neck. Vet has tested, but has not found anything. Patches are a red and scaly by hair lin
ANSWER : A. Skin problems can have a variety of causes, sometimes more than one. It is important to have the problem checked by your vet to determine if there is a medical cause for your pet’s skin issues and treat accordingly.

In pets of all ages, fleas, food allergies and exposure to chemical irritants such as cleaners and soaps can be a cause. Any one of these may not be enough to trigger the breakouts, depending on how sensitive your pet is, but a combination can be enough to start the itch-scratch cycle. Finding out the cause and eliminating it is the best course of action. With flea allergies, if your pet is sensitive enough, a single bite can cause them to break out scratch enough to tear their skin.

Check for fleas with a flea comb. Look for fleas and/or tiny black granules, like coarse black pepper. This is flea feces, consisting of digested, dried blood. You may find tiny white particles, like salt, which are the flea eggs. Applying a good topical monthly flea treatment and aggressively treating your house and yard will help break the flea life cycle.

If you use plastic bowls, this is a possible cause for hair loss, though this tends to be on the chin, where their skin touches the bowl while they eat. If you suspect this to be the culprit, try changing the bowls to glass, metal or ceramic.

Food allergies are often caused by sensitivity to a protein in the food. Hill’s Science Diet offers some non-prescription options for sensitive skin as well as prescription hypoallergenic foods for more severe cases. Royal Canin carries limited protein diets that may also offer some relief. Your vet can recommend a specific diet that will help.

If there is no relief or not enough, consider getting your pet checked by a veterinary dermatologist and having allergy testing done.

Q. Hi I have a female Shepherd mix, she is itching and losing fur on her side and legs? Current on flea meds no fleas
ANSWER : A. Skin problems can have a variety of causes, sometimes more than one. It is important to have the problem checked by your vet to determine if there is a medical cause for your pet’s skin issues and treat accordingly.

In pets of all ages, fleas, food allergies and exposure to chemical irritants such as cleaners and soaps can be a cause. Any one of these may not be enough to trigger the breakouts, depending on how sensitive your pet is, but a combination can be enough to start the itch-scratch cycle. Finding out the cause and eliminating it is the best course of action. With flea allergies, if your pet is sensitive enough, a single bite can cause them to break out scratch enough to tear their skin.

Check for fleas with a flea comb. Look for fleas and/or tiny black granules, like coarse black pepper. This is flea feces, consisting of digested, dried blood. You may find tiny white particles, like salt, which are the flea eggs. Applying a good topical monthly flea treatment and aggressively treating your house and yard will help break the flea life cycle.

If you use plastic bowls, this is a possible cause for hair loss, though this tends to be on the chin, where their skin touches the bowl while they eat. If you suspect this to be the culprit, try changing the bowls to glass, metal or ceramic.

Food allergies are often caused by sensitivity to a protein in the food. Hill’s Science Diet offers some non-prescription options for sensitive skin as well as prescription hypoallergenic foods for more severe cases. Royal Canin carries limited protein diets that may also offer some relief. Your vet can recommend a specific diet that will help.

If there is no relief or not enough, consider getting your pet checked by a veterinary dermatologist and having allergy testing done.

Read Full Q/A … : Leerburg

Q. For the past few months my dog has slowly licked most all of his hair off his legs and lower belly. The skin is now dotted with red sore spots.
ANSWER : A. Skin problems can have a variety of causes, sometimes more than one. It is important to have the problem checked by your vet to determine if there is a medical cause for your pet’s skin issues and treat accordingly.

In pets of all ages, fleas, food allergies and exposure to chemical irritants such as cleaners and soaps can be a cause. Any one of these may not be enough to trigger the breakouts, depending on how sensitive your pet is, but a combination can be enough to start the itch-scratch cycle. Finding out the cause and eliminating it is the best course of action. With flea allergies, if your pet is sensitive enough, a single bite can cause them to break out scratch enough to tear their skin.

Check for fleas with a flea comb. Look for fleas and/or tiny black granules, like coarse black pepper. This is flea feces, consisting of digested, dried blood. You may find tiny white particles, like salt, which are the flea eggs. Applying a good topical monthly flea treatment and aggressively treating your house and yard will help break the flea life cycle.

If you use plastic bowls, this is a possible cause for hair loss, though this tends to be on the chin, where their skin touches the bowl while they eat. If you suspect this to be the culprit, try changing the bowls to glass, metal or ceramic.

Food allergies are often caused by sensitivity to a protein in the food. Hill’s Science Diet offers some non-prescription options for sensitive skin as well as prescription hypoallergenic foods for more severe cases. Royal Canin carries limited protein diets that may also offer some relief. Your vet can recommend a specific diet that will help.

Q. My dogs skin has become red the vet said its an allergy to fleas yet he has none could it be an allergic reaction to my new carpet.
ANSWER : A. Skin problems can have a variety of causes, sometimes more than one. It is important to have the problem checked by your vet to determine if there is a medical cause for your pet’s skin issues and treat accordingly.

In pets of all ages, fleas, food allergies and exposure to chemical irritants such as cleaners and soaps can be a cause. Any one of these may not be enough to trigger the breakouts, depending on how sensitive your pet is, but a combination can be enough to start the itch-scratch cycle. Finding out the cause and eliminating it is the best course of action. With flea allergies, if your pet is sensitive enough, a single bite can cause them to break out scratch enough to tear their skin.

Check for fleas with a flea comb. Look for fleas and/or tiny black granules, like coarse black pepper. This is flea feces, consisting of digested, dried blood. You may find tiny white particles, like salt, which are the flea eggs. Applying a good topical monthly flea treatment and aggressively treating your house and yard will help break the flea life cycle.

If you use plastic bowls, this is a possible cause for hair loss, though this tends to be on the chin, where their skin touches the bowl while they eat. If you suspect this to be the culprit, try changing the bowls to glass, metal or ceramic.

Food allergies are often caused by sensitivity to a protein in the food. Hill’s Science Diet offers some non-prescription options for sensitive skin as well as prescription hypoallergenic foods for more severe cases. Royal Canin carries limited protein diets that may also offer some relief. Your vet can recommend a specific diet that will help.

If there is no relief or not enough, consider getting your pet checked by a veterinary dermatologist and having allergy testing done.