I have a 6-year-old, 11-pound Shih Tzu, whom i love dearly. All she does day and night is bite and lick her body, and scratch until she bleeds. I put a baby’s undershirt on her and it helps a little, but she still chews herself.
I have been to many veterinarians and veterinary dermatologists, who are all stumped.
Can you possibly help with some advice? Thank you.
I am so sorry to hear about your sweet girl. Itchy skin is probably one of the most common problems we see and one of the most frustrating to treat.
There are several possibilities for the itching:
- Infection (such as mange mites, ringworm, or a bacterial or fungal infection)
- Allergies (which can be contact, inhalant/environmental, dietary or flea-bite allergies)
- Hormonal imbalance (such as low thyroid levels or Cushing’s disease)
- Immune-mediated disorders
The first step is always to try to find the underlying cause. This process can take some time and requires patience as you work through each of the possible causes with your veterinarian to determine which one is the problem.
Allergies are probably the most common reasons we see dogs with chronic itching. If the allergy is to flea bites, it is important to keep your dog on flea control all year round. However, your dog may also need something to treat the allergy and help with the itching while the fleas are getting under control. It only takes one or two flea bites for an allergic dog to start scratching like crazy, so even with excellent flea control on board, she may still have occasional outbreaks throughout the year.
Dietary allergies are a nice diagnosis because we have a lot of control over what our pets eat. To determine if this is the cause, your dog will need to be placed on a limited ingredient (a single protein source and a single carbohydrate source), hypoallergenic diet for at least two to three months. During this period of time, she cannot eat any other foods, treats, chews or flavored medications. At the end of the dietary trial, there is a change to the old diet to see if her symptoms flare up again, which confirms a food allergy. If this is the case, you can then go through the process of figuring out which exact ingredient is the culprit.
Environmental or inhalant allergies are the most challenging. There are allergy tests (either a blood test or skin test) that can determine which allergens your dog reacts to in the area where you live. A vial of small pieces of these allergens is created specifically for your dog. She will then be given a series of injections to desensitize her system to these allergens. During this process, dogs often have worse symptoms because they are being injected with small particles of what they are allergic to.
It usually takes approximately one to two years of injections to determine if your dog is going to respond. There is only a 60 percent reported improvement rate, and your dog may still have some symptoms after this treatment. This means there’s a 40 percent chance your dog will be no better than when you started.
The alternative to allergy testing and injections are long-term medications. These medications often have effects on dogs’ immune systems and can have some detrimental long-term side effects. Medications to control symptoms include steroids such as prednisone, cyclosporine and antihistamines.
There are also alternative treatments, supplements and topical therapies that can help reduce the amount of stronger medications that need to be used. These include fish oil (omega-3 fatty acids are anti-inflammatory if given in adequate doses) and hydrocortisone-based shampoos, sprays and conditioners.
In addition to all of these, it is very common for dogs to develop secondary bacterial or fungal infections because of the scratching, and these contribute to the itchiness. If the infections are not also addressed, a vicious cycle of itching and infection occurs that is never resolved.
Infections of the skin are particularly difficult because it can take three to four weeks for your dog’s body to make new skin. If the infection is not treated for long enough, the bacteria repopulate and the itching starts again. In addition, there is a risk of the development of resistant bacterial infections. Sometimes, a bacterial culture and sensitivity must be performed to determine if there is resistance so the correct antibiotic treatment can be chosen.
– Dr. Hoag
PHOTO: Joel Sowers