Why is my Chihuahua trembling, licking, and getting dark skin spots?

If Rico is licking that area then something is bothering him. It may be itchy. This could be a fungal or bacterial skin infection or even mites or a food allergy, and should be examined by a vet and treated. By licking the spots he will further irritate the skin and cause the problem to spread. I suggest you make an appointment with your veterinarian for an exam. Your vet will possibly want to do a skin scrape and will prescribe appropriate treatment (antibacterial or antifungal shampoo, ointment or tablets, or steroids or diet change). If he suspects a mite infection, then an acaricide will be applied (injection or tablet)

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly due to allergies. It really comes down to figuring out what is causing her allergies so that they can be treated or the specific allergen avoided. A secondary infection is likely and also needs to be addressed. 

There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. 

 Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). 

If not improved in 1-3 months then it is time to move on and check for food allergies by switching to a novel diet (new protein and new carbohydrate). If that does not seem to be the issue then you are left out having to check for environmental allergies which require blood and/or skin tests.

 Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!


She could have a skin infection, mites, fleas, ringworm, allergic dermatitis, etc. Your vet can do a skin scrape, cytology, or culture to help diagnose and then prescribe medications to treat the problem. She may need an antibiotic, anti-histamine, corticosteroid, or other medications depending on the cause. Make sure to treat her with a monthly flea medication like NexGard, Frontline, Advantage, or Revolution to prevent fleas.

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly due to allergies. It really comes down to figuring out what is causing his allergies so that they can be treated or the specific allergen avoided. A secondary infection is likely and also needs to be addressed. There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). If not improved in 1-3 months then it is time to move on and check for food allergies by switching to a novel diet (new protein and new carbohydrate). If that does not seem to be the issue then you are left out having to check for environmental allergies which require blood and/or skin tests. Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!

This presentation is likely to be due to a mild superficial bacterial infection (bacterial folliculitis) on the ventral abdomen. Nothing to be extremely worried about as it could be self limiting/resolving. Disinfection may be started at home with very diluted hibiscrub or betadine or salted water baths. Buster collar may be useful as well to avoid any licking/scratching (if any). If signs are not resolving, a check up, appropriate disinfection and possibly antibiotics (oral, topical or in a shampoo formulation) will be then needed to solve the problem. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!

I'm sorry to hear that Bella has been so itchy. In dogs, itching can be caused by a variety of different conditions, with the most common including underlying allergies, fleas, ringworm, or mange. When dogs scratch, they damage the outermost layers of the skin barrier, which can lead to the onset of a skin infection. Infections then causes further itching, creating a vicious cycle. The skin on Bella's neck and the inside of her knee do look as though it may be infected. Chronic inflammation, endocrine/hormonal disorders, and autoimmune conditions can all lead to the dark pigment change with the skin thickening that's visible in the pictures. (We call this lichenification and it resembles elephant skin.) The persistence of Bella's itching could certainly lead to such chronic inflammation. Regardless, it's really important that Bella is examined by a vet so that appropriate treatment can be started. Your vet may need to do some skin testing to check for microscopic evidence of infection, as well as checking for mange (caused by mites) or ringworm (a fungal infection). Then, based on those results, they'll be able to prescribe medications to help her feel better. I hope that she's on the mend soon!

It sounds like there are few things that could be going on with Belle. She could be in pain with the yelping. The hair loss and chewing could be due to fleas, mites, ringworm, or allergies. If she isn't up to date on her flea treatment, I can give you one for her. First, I would give her Capstar. It's a one time pill that starts killing fleas within 30 minutes. Then follow up with a spot on treatment, such as Advantage or Revolution. This is a treatment that has to be used once a month. You will also have to disinfect the environment. Wash her bedding in hot soapy water, and vacuum the furniture and carpet surfaces. You can use a spray to kill fleas in the house, such as Indorex, or a flea bomb would work well to kill the fleas in the home. If she is up to date on her flea treatment, I recommend taking her into the vet for an exam tomorrow. The vet can do blood tests, skin scrapings, and use a Wood's lamp to diagnose allergies, mites, and ringworm. Once the cause of the itching (chewing is a sign of itchiness) is found, the vet can prescribe the appropriate treatment. I hope this helps!