The Itching Pet: Alternatives to Steroids
Excessive licking, chewing, and scratching can make a pet’s life miserable for month after month, even year after year. For rapid relief of itch and inflammation, nothing matches the corticosteroid hormones such as cortisone, hydrocortisone, prednisone, dexamethasone, and others.) There are some animals that seem unable to live with any degree of comfort without these medications. Unfortunately, these hormones have widespread and potentially dangerous actions throughout the body when they are used for inappropriately long periods and it is generally desirable to minimize the use of these hormones when possible to do so. Ideally, corticosteroids are used for a few really tough itch weeks and other forms of itch management are used for general itch maintenance.
See more detail on long-term corticosteroid use.
This is, of course, easier to write about than to actually do. When one's pet is scratching and chewing raw spots on his or her skin, practical advice is called for. The following list includes assorted non-steroidal methods for relieving itch and reducing the amount of corticosteroid hormones needed.
Histamine, a biological chemical, is the chief mediator of inflammation in humans hence the proliferation of antihistamines available for people both by prescription and over the counter. Histamine is not the major mediator of inflammation in the dog, thus these medications are not as reliable for dogs as they are for us.
The protocol recommended by this hospital is helpful to approximately 40% of dogs who try it. Four different antihistamines are used, one at a time, at least 2 weeks each, in hope of finding one that is acceptably effective. While the chance that an individual antihistamine will be helpful is small (about 15%), trying several antihistamines greatly increases the chance of finding one that works.
Antihistamines are not free of side effects; they are notorious for drowsiness in some individuals. Still, this is vastly preferable to the systemic disruption caused by the corticosteroid group.
Our hospital uses the following antihistamines in a typical antihistamine trial (click for more information):
In cats, antihistamines are substantially more reliable than in dogs so that the chances of a given antihistamine working are usually pretty good. For both cats and dogs, using antihistamines together with a corticosteroid hormone will decrease the amount of corticosteroid hormone needed to control the itching (i.e., less hormone is needed to get the job done if it is given with an antihistamine).
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Fatty Acid Supplementation
The discovery of anti-inflammatory properties of evening primrose oils and fish oils in humans has led to similar products on the market for our pets. These products are not analogous to the oil supplements that are recommended as food supplements to make a pet's coat shiny; instead; these are true anti-inflammatory drugs capable of relieving joint pain, cramps, and itchy skin.
The supplement alone is helpful in 10% to 25% of itchy dogs; we often recommend its use in combination with antihistamines to boost the efficacy of the protocol described above.
Cyclosporine is an immune system modulating drug originally developed for use in organ transplant patients, but which is also useful in other immune-mediated diseases. Since allergy is an immune-mediated condition, cyclosporine was investigated as an alternative to corticosteroids and found effective for most patients. Currently this medication is being marketed only for dogs and one dog in three will develop an upset stomach when starting the drug (though this resolves or is manageable with dose modification).
Topicals to Try
When using any dip on inflamed skin one should be aware that the use of cool water is considered much more soothing than warm water.
Colloidal Oatmeal Shampoos and Creme Rinse - At first, these products were only available for human use, as powdered soaks to pour into bath water.
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Once their value in itch management was determined, their use quickly spread to the veterinary field. Colloidal oatmeal actually pulls inflammatory toxis out of the skin, generally yielding 1 to 3 days of relief. The creme rinses are meant to yield longer acting relief. They are available plain or combined with local anesthetic forumlas to soothe itch.
Lime Sulfur Dip - This product kills parasites, ringworm fungi, and bacteria.
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It also dries moist, weeping skin lesions and helps dissolve surface skin proteins that are involved in itchiness. Many veterinary dermatologists recommend it regularly to control itch; however, it has several disadvantages. It smells terrible. The sulfur ingredient smells like rotten eggs and this is how your bathroom or bathing area will smell during the pet's bath. This dip can stain jewelry and clothing and will temporarily turn white fur yellow.
Itchy skin can be the result of skin infection, excess oil accumulation, yeast infection, even parasitic infection. The list goes on. The shampoo products listed above can be used against any itchy skin disease but it should be noted that there are many other shampoo and creme rinse products that can be used against the specific skin diseases listed. If some other type of shampoo product has been prescribed to you for an itchy skin disease, it is important that you use it allowing at least a good 10 minutes of skin contact time before rinsing.
TEN MINUTES OF SKIN CONTACT IS THE MINIMUM REQUIREMENT FOR ANY MEDICATED SHAMPOO. PREMATURE RINSING WILL NOT ALLOW FOR THE THERAPEUTIC BENEFIT TO BE REALIZED.
Other Topical Products
Colloidal Oatmeal Sprays and Lotions - Same principle as above. These products pull inflammatory toxins out of the skin. Oatmeal products have become very popular and are available as shampoos, creme rinses, soaks, sprays, and lotions.
Humilac Spray - This moisturizer may be applied as a spray or mixed in water as a dip. It is helpful for dry skin but can also be used in combination with lime sulfur as lime sulfur is naturally drying to the skin.
Witch Hazel - This product has a cooling effect on the skin that is soothing for both animals and for people with sun burn. It is available as a spray or lotion.
Aloe Vera Gel - If possible, obtain 100% aloe vera gel from a health food store. Products containing aloe are much more available but are generally not as effective and not meant to be licked away by a pet. Aloe vera gel comes from the aloe vera succulent and contains enzymes which break down inflammatory proteins and enhance healing. Pure aloe vera gel is not harmful for pets who want to lick it off.
Topical Steroids? - It seems clear that taking steroids orally may be harmful to the body with chronic use but are topical cremes safe for long term use? We now know that topical steroids (cortisone cremes and related products) are absorbed through the skin and into the bloodstream but the hormonal side effects with topical use do seem blunted. For small irritated areas (hot spots), topicals can provide excellent relief without the systemic effects of hormones.
Respect the Steroid
Severe itching amounts to a reduction in life quality. It is important not to develop the mindset that corticosteroids should be avoided at all costs. This would not be fair to the itching pet. Steroids are valuable tools in the relief of pain and suffering and have an important place the therapy of the itchy pet. The goal is not to avoid steroid use if possible but to avoid long term dependence on steroids if possible. Despite all of the above management tricks, some pets will still require long term steroid use to achieve any reasonable comfort. There are monitoring protocols in place for such cases. It should also not be forgotten that underlying allergies and recurring skin infections can be addressed specifically and that as these conditions are managed, the itch is also managed.
Steroid hormones have many side effects and, as helpful as they are for allergic skin diseases, it is best to reserve them for only the most itchy episodes.
Everyone knows someone with hay fever. Airborne pollens, molds, dust particles, etc. are inhaled and soon the sneezing and sniffling begins.
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A simple way to think of atopy for pets would be simply saying that the pet inhales an airborne allergen but instead of sneezing and sniffling, the pet gets itchy skin. In fact, the situation is probably far more complex. The allergen is not only inhaled but is in contact with the skin and it is no longer considered accurate to think of atopy as an inhaled allergy. Exactly how we get from particles floating in the air to itching and scratching is not entirely understood but the important issue is that the allergen comes from the air.
Airborne particles (pollen, dander, etc.) are harmless to someone who is not allergic to them. Allergy develops in individuals who are genetically programmed to do so.
Breeds predisposed to develop atopy include: Dalmatian, Golden retriever, West Highland white terrier, Shar Pei, Labrador retriever, Cairn terrier, Lhasa Apso, Shih Tzu, Boxer, and Pug.
Features of Atopy
There are many reasons for pets to itch: parasites, allergy to flea bites, food allergy, secondary infection and the list goes on. The following findings in the history and examination of the patient might lead to a diagnosis of atopy.Atopy usually produces a seasonal itchiness though after several years, the duration of the itchy period extends. Finally, the pet is itchy nearly all year round.
In dogs, atopy usually produces a seasonal itchiness though after several years, the duration of the itchy period extends. Ultimately, the dog is itchy nearly all year round in 80% of cases. In cats, unfortunately, seasonality is not nearly as reliable a feature.
Young age of onset
Seasonal itchiness due to atopy tends to begin early in a pet's life (between ages 1 and 3 years in 70% of dogs diagnosed with atopy). Food allergy tends to begin later, more like age 5 or 6 years in dogs. Age at which itching first manifests is not as reliable a sign in cats as in dogs.
Good response to steroids
Whether the patient is a dog or cat, itchiness due to atopy responds rapidly to cortisone-type medications (prednisone, DepoMedrol, dexamethasone, etc.) as does itching due to insect bite allergy. Food allergy is more variable in its response; it may or may not respond well.
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A few reactive blebs on an intradermal skin test
A positive intradermal skin test
Intradermal skin testing is generally done to put together a set of allergens to make allergy shots. Hair is clipped from an area of non-inflamed skin and small samples of different allergenic proteins are injected into the skin. An atopic patient should react to an allergen by showing swelling and redness in the injection area. In most cases, this kind of testing is done after a diagnosis of atopy has been made based on other factors. This is not generally done to diagnose atopy but is done as part of the preparation for hyposensitization (see below). Sometimes, however, a diagnosis is elusive. In such cases, seeing a field of positive and negative skin blebs (flaccid vesicles) helps build confidence that atopy is the cause of the patient's itching. There are blood tests that can also be helpful in preparing for hyposensitization but it is important not to consider them as tests “for atopy.” They are instead tests of antibody levels and are used to help pick allergens for serum.
Typical irritation pattern
Atopy is associated with irritation in certain parts of the body. In dogs these areas are:
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It should be noted that food allergy has a similar irritation pattern but a different history. Flea bite allergy, the most common form of allergic skin disease in pets, has a different irritation pattern.
In cats, the irritation pattern is not as characteristic. There are four common manifestations of atopy:
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Non-lesional fur mowing
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Eosinophilic granuloma complex
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Miliary dermatitis (small seed-like scabs)
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face and ear itching
Unfortunately, these same irritation patterns can be found in numerous other skin conditions and, in fact, up to 25% of atopic cats have multiple types of allergies.
While it would be nice to have a blood test that could tell us if a pet’s itching is due to atopy, it is important to realize that such a test does not exist. Atopy remains a clinical diagnosis, which means the diagnosis is made based on history and examination findings.
Before doing anything else, it is important to clear up secondary infections. Secondary infections involve bacteria (usually Staphylococcal) and/or yeast (Malassezia) at the site of the itchiest areas. These organisms live naturally in the skin but when the skin is irritated, they gain access to inner tissue layers and proliferate. Sometimes they generate further allergic response. These infections tend to be recurrent and are the usual cause of recurrence of itch symptoms in a patient previously controlled.
Making the Skin Less Reactive
Since it is unlikely that the patient is going to be able to avoid airborne allergens (pollens, for example, travel miles in the breeze), we are left with treating the patient. For short episodes of itching during the itchy season, cortisone-type medications are highly effective. When the pet becomes more chronically itchy, cortisones become less feasible because of their long-term side effects and other options must be considered.
These cortisone-type medications (prednisone, prednisolone, triamcinolone, dexamethasone etc.) tend to be useful as the first line of defense against itchy skin. A higher dose is used at first but this is quickly tapered down once the condition is controlled. Prednisone, for example, is given every other day so as to allow the pet one day of recovery from the prednisone's hormonal actions. An atopic dog will respond within days. For cats, long-acting cortisone-type injections are commonly used as cats are frequently not amenable to taking pills.
Side effects include:
- Excess thirst
- Excess hunger
- Excess urination (which can lead to house-breaking issues)
- Suppression of the immune-system/bringing out latent infection (especially urinary tract infection and upper respiratory infection.) Raising blood sugar/destabilizing a borderline diabetic (especially a problem for cats). In the short term, side effects can be controlled by adjusting dosage but in the long term, these medications are more problematic and if possible their use should be minimized.
Omega 3 Fatty Acid Supplements
These products are NOT analogous to adding oil to the pet's food. Instead, these special fatty acids act as medications, disrupting the production of inflammatory chemicals within the skin. By using these supplements, it may be possible to postpone the need for steroids/cortisones or reduce the dose of steroid needed to control symptoms. It takes a good 6 weeks to build up enough omega 3 fatty acids in the body to see a difference.
These are far less harmful than prednisone but only 10-20% of dogs will respond to any given antihistamine. Fortunately, there are numerous antihistamines to try and often it is possible to find one that works by trying a different one sequentially. In contrast to dogs, cats are far more responsive to antihistamines; the downside is having to give a cat medication twice daily. Antihistamines and omega 3 fatty acids synergize with each other so it is a good idea to use omega 3 fatty acids in conjunction with antihistamines.
Cyclosporine is a modulator of the immune response that has been very helpful in organ transplant patients both human and non-human. It has been found to be as reliably effective in atopic dermatitis in the dog as steroids and does not carry the unpleasant side effect profile that steroids do. It is used mostly in dogs but can also be used in cats. For more details on this medication click here.
This is a new drug still under development. It addresses mast cells, the cells that carry the
inflammatory biochemicals of allergy. It is currently available on a very limited basis through its manufacturer as part of clinical research.
Reducing Allergin Exposure
The following are some general tips for minimizing allergen exposure.
Bathing the pet weekly to remove allergens from the fur may be helpful in reducing allergen exposure. There are also many therapeutic shampoos that can be used to restore the skin’s natural barrier or to assist in general itch relief. For more details, see our section on Itch Relief.
- Avoid stuffed toys and wash bedding regularly to minimizes dust mite exposure. Also, remove the pet from the area when vacuuming or dusting.
- Use air-conditioning and/or an air filter system.
- Keep the pet away from the lawn while it is being mowed.
- Minimize houseplants.
Just as people have allergy shots, so can pets; however, the process is not without difficulty and you should not expect hyposensitization to end all itchy skin concerns.
Allergy shots require approximately 6 to 12 months to begin working.
25% of atopic dogs will not respond (these are usually the animals allergic to multiple allergens).
25% will require prednisone or a similar steroid at least at some times.
You will most likely have to give the allergy shots yourself.
In hyposensitization the patient is injected with small amounts of allergens on a regular basis. As time passes, the amounts of allergens increase and injections are given at longer intervals. The selection of allergens is made based on the results of an intradermal skin test (as described above), an in vitro test (a blood test) or a combination of the results of both tests.
Is your Pet a Candidate for Skin Testing?
Testing is best done during your pet's non-itchy season (if there is one) so that the skin responses of the test will not be clouded by active inflammation. The test involves injections of small amounts of allergen extracts into the skin. Reactions noted are compared to reactions produced by two controls: pure histamine (very inflammatory) and pure saline (very non-inflammatory).
In order for skin testing to be performed, medications must be discontinued well in advance. How long in advance depends on the medication and on the policies of the veterinary dermatology practice that will be doing the test. Oral steroids, for example, commonly require a full month of discontinuance, which can be problematic if the pet is highly dependent on medication for life quality.
In Vitro Testing
In vitro testing does not always require withdrawal of medications nor does it require referral to a specialist. There is no hair clipping and sedation is rarely necessary. Blood is simply drawn and checked for antibodies against common allergens for that geographic region. A profile is reported and allergens can be selected accordingly. It is important to remember that these results do not necessarily imply that the patient is allergic to substances reported; this is simply a test for antibodies. Antibody elevations are common with levels changing based on an assortment of factors (whether the pet has parasites at the time of the test, how common the substances being tested are, how long medications have been used prior to the test etc.) and interpretation of the profile is part of the “art of veterinary practice.”
For more details on what is involved, see our page on allergen-specific immunotherapy (allergy shots).