Experienced and professional animal trainer provide their insights in answering this question :
A. Patchy skin can be caused by parasites, hormonal disorders, or allergies. A physical exam is necessary for a proper diagnosis. I recommend taking her to a veterinary dermatologist. The appointment will likely be more expensive up front, but you’ll also be more likely to get the right answer now quickly. In the meantime, if you don’t have your dog on flea and tick prevention, start that. Revolution is a good one that covers many parasites.

How to Identify Common Pet Problems ?

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

Hair loss on the outer ear (pattern baldness) has been reported in Dachshunds, Chihuahuas, Italian Greyhounds, and Whippets and is thought to be hereditary. The hair coat begins to thin when a dog is less than 1 year old, and complete hair loss on the outer ear may occur by 8 to 9 years of age.
Ringworm fungus, pests like mange mites, and bacteria can all lead to infections that may ultimately cause bald spots on your dog. Along with hair loss around the ears, eyes, mouth, and elsewhere, signs your dog may have mites include oily skin, thickened skin, itching, and inflammation.
There is no treatment for this disorder, but its symptoms are purely aesthetic and should not cause your dog any further issues. In some cases, dogs can also suffer from a form of temporary alopecia after clipping.
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.
Ear mites are tiny animals and are a fairly common parasite in both cats and dogs. They look like tiny white dots, but can barely be seen with the naked eye. Ear mites live on the skin of the ear canal and feed off ear wax and skin oils.
Dog ear mites and yeast infections have similar symptoms such as itching, discharge, and redness. However, a distinctive characteristic of ear mites is the presence of dark granules resembling coffee grounds in your dog`s ears, which are not present in yeast infections.
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.
Fur issues can happen to either type of Chihuahua; however with a long haired Chihuahua it may be more noticeable. One of the most common fur issues with this breed involves a loss of hair that is not easily explained by normal shedding. This can happen at any age and for a variety of reasons.
At about 4-8 months your chihuahua`s fur may start to thin, fall out or shed heavily. This may be more noticeable in a long-haired chihuahua. They are also growing fast and may start to look a bit stringy and gangly.
To best support your dog and healthy hair growth, feed a diet that`s rich in animal protein. The amino acids and fatty acids present in animal protein play an important role in hair growth and can be extremely beneficial if you want to help you rest regrow his coat. Plus, look for a blend that`s full of antioxidants.
If your dog`s hair loss is caused by a vitamin deficiency, supplementing their diet might be a good dog hair loss home remedy. Vitamins E and A, as well as fish oil, can help pets with dry skin or even some infections.
“There are many topical, oral, and systemic agents,” Dr. Miller notes, “and most—such as ivermectin—are highly effective. Even one old-time remedy—baby oil—can do the job. A few drops put into an affected ear several times a day for a month or so will usually smother the mites.”
Unfortunately you will always need to treat ear mites in your cat because they will not go away on their own. If treating ear mites in cats is delayed for too long you run the risk of chronic ear infections.
A diagnosis is made by observing the mite. This is usually straightforward and may be done either by examination of the pet`s ears with an otoscope or by microscopic examination of discharge from the ear. If the ears are very sore, the pet may need to be sedated to allow the ears to be properly examined and treated.
Dogs will usually pick up ear mites from another pet. It can be another dog or cat, and mites can pass very quickly between animals. They can only live in the environment for a limited time and with such a small window of time at their disposal, they`re quick find an unsuspecting dog to claim as their host.
Signs That Your Dog May Have A Yeast Ear Infection

Red or brown waxy discharge in the ear. Itching, scratching & pawing at the ear. A cheesy or musty smell coming from the ear. Red or irritated ear.

Medicated shampoos and dips are often used to treat demodicosis. Prescription medications to kill the mites may be required. In cases where secondary bacterial infections are present, antibiotics may also be prescribed. Skin scrapings are taken at monthly intervals to monitor the number of mites on the dog.
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].
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.

Dental disease affects more than 80% of chihuahuas before two years of age. Due to their small heads, they experience teeth overcrowding. It makes it easy for food to be trapped between the teeth resulting in plaque.
A dog can acquire alopecia from a parasitic infestation of fleas, lice, mosquitoes, or mange mites such as Demodex or Sarcoptes. Spider bites or insect stings can wreak havoc on the skin, too.
If your dog has been clipped and the hair is failing to grow back, it may be due to a hormonal deficiency or imbalance. In order to diagnose this, blood samples are necessary to measure concentrations of various hormones. If your dog is losing hair in spots then it may have a bacterial infection or ringworm or mange.
It can be caused by many different conditions including fleas, skin allergies and hormonal problems. It`s important to have your dog seen by your vet if they start losing fur, especially because in some cases, it can be very irritating and painful.
If you shave a single coated Chihuahua the hair will grow back again without changing it. That, however, is not true of double coats. If you shave a double-coated Chihuahua it can ruin the coat.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. One of my pet’s ears seems very irritated. What I can use to clean it with?
ANSWER : A. Ear Irritation can be caused by a number of things ranging from allergies, ear infections or even mites. Dirty ears can also cause irritation and problems. Knowing the type of problem is best for figuring out how to treat it.

For plain dirty ears that do not have any odor, redness or leakage of discharge/debris, a simple over the counter canine ear cleaner can be used. Gently soak some cotton balls or a washcloth with the cleaner, and then use these to wipe out the flap of the ear and opening to the ear. Do NOT use Q-tips as these can become stuck or lodged in the curve of the ear canal and may cause injury to the ear drum.

If the ear is bright red or itchy without any dirt or debris in it, it may indicate an allergy. Sometimes an allergy medication can help provide relief in this situation. Your vet can give you the correct dosages of an over the counter allergy medication to use, or may recommend one specifically for dogs.

For infections and mites, changes to the ear such as bad smell or lots of debris and discharge, flecks of black or brown debris, or scabs and sores in the ear may be present. In these cases, it is best to have your vet take a sample of the ear debris to test for mites or infection. Your vet can then give you an ointment that is placed and left in the ear between ear cleanings. Most vets will then recommend cleaning the ears twice daily and then leaving in the ointment after for a period of ten days.

Ear mites ARE contagious to other pets, so if your dog does have them, it is best to treat any other pets in the house at the same time to prevent the mites from spreading around continuously.

Q. My dog is having ear problems. I have had her at two vets and they can not seem to find the cause. Can you help?
ANSWER : A. For a pet with chronic ear issues I would recommend checking her thyroid levels. Hypothyroidism can be a cause of chronic ear infections.

Then I would recommend having a bacterial culture of the ear debris to ensure the appropriate antibiotic is chosen to completely rid the bacteria in there. If there is resistant bacteria, the ear will appear to get better at first but then once ear meds are stopped they will thrive again and cause a re-emergency of the ear infection. Also longer treatment may be needed, for example instead of 7-10 days, perhaps 14 days continuously.

If all else fails, I would recommend a skull radiographs to look for signs of a narrow ear canal and/or an inner ear infection which will require not only topical antibiotic ointments put into the ear, but also oral antibiotics.
Most ear infections are caused by moisture in the ears, narrow ear canals, hypothyroidism or skin allergies. Each one has to be gone through systematically.

Q. 11y.o. Chihuahua. She is missing a little hair on her ears and it looks like the skin is patchy. Also on her leg joints. What can we do.
ANSWER : A. Patchy skin can be caused by parasites, hormonal disorders, or allergies. A physical exam is necessary for a proper diagnosis. I recommend taking her to a veterinary dermatologist. The appointment will likely be more expensive up front, but you’ll also be more likely to get the right answer now quickly. In the meantime, if you don’t have your dog on flea and tick prevention, start that. Revolution is a good one that covers many parasites.

Q. I have two problems with my 16 yrs old dog: he’s constipated and has a ear ache. What can I use to relieve these?
ANSWER : A. Constipation is a common problem in dogs that can be due to a number of things. However it is a good idea to make sure the constipation is not actually diarrhea, as some dogs can strain after a bowel movement, making it look like such. If constipation is present, adding a little pumpkin puree or plain yogurt to the diet can help make digestion easier and make stools easier to pass. However if symptoms do not resolve after a few days, it is best to speak with your vet.

For ear aches, it is best to have your vet examine the ear as many things including allergies, ear infections, mites and more can cause ear problems. If the ear is just dirty, then cleaning the ear gently with cotton balls or a clean washcloth and a dog ear cleaning solution can help. Do not use Q-tips as a dog’s ear has a 90-degree turn in it and placing Q-tips in the ear can cause damage to the canal or inner ear. However if the problem persists or cleaning does not help, it is best to seek care.

Q. Dog has dry ears and it itches him. Any recommended soothing lotions??
ANSWER : A. I will answer this question as if you are speaking of the inside of the ears (not the external). Most dogs ears aren’t dry unless they have other skin issues such as skin allergies, which can be seasonal or year around and caused by many different things, such as foods, environment, dust, grass, pollen, and products (shampoos, perfumes, etc). Check in the ears for waxy build up. The ears should be clean of any wax and dry. If they have build up, I would take a cotton ball, and soak half of it in a dog ear cleaning solution. This solution should be made specifically for dogs, and your local vet would most likely sell the appropriate brand.

I would address any possible skin allergies, if they do not have any other skin issues, then looking inside the ears and cleaning with a good ear cleaner (should be alcohol free—because alcohol is very drying) If the ear scratching continues regularly then bring him/her into the vet to have a proper ear exam.

Q. Russian blue mix cat – usually velvet soft coat but hair on back hind qtrs. is thinning, remaining hair seems less velvety than normal
ANSWER : A. Changes in coat appearance can be caused by a number of things. In older cats, hair loss or changes in coat and skin confirmation may indicate a metabolic issue such as thyroid problems. Cats can begin to lose hair and may also show other changes such as weight changes or appetite changes. Blood work is usually done to check for this, and most pets do very well with a daily medication treatment.

Hair loss can also be caused by mites on the skin, external parasites or even skin and fungal infections. These may cause red bumps or sores to appear on the skin in addition to the hair loss and coat changes. Your vet can take a skin scraping of the area to check for mites and infections, and a preventive flea treatment can remove any external parasites. If an infection or mites are present, your vet can also prescribe an antibiotic or topical cream to treat.

After any treatment it may take a month or two for completely bald patches to grow back in. This is normal as the skin and follicles need some time to heal prior to beginning the hair growth cycle again.

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. 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.