The Basics of Feather Picking

Feather picking is a problem that has plagued and intrigued me for the last ten years. I wanted to speak about it because I wanted you to know that we can help many- perhaps 70% - of the birds that feather pick, but the journey is sometimes frustrating, time consuming, and expensive.

I also wanted you to know that the sharpest people in avian medicine are spending a lot of time on this problem and that there are a number of exciting new approaches.

Finally, I wanted you to know how you should best spend your time and money in working up this problem. I wanted you to get enough background information so that you can help determine what approach might yield the most information about your bird. I also want you to learn to be an accurate observer because your at-home observations are usually the most critical part of the process.

This presentation is going to be given in the same way that I discuss feather picking with my clients. The first step is to acquaint the owner with the most common causes of feather picking. The second step is the history and physical exam. Third, we collect some minimum data bits. The fourth phase is general management and record keeping recommendations. The last phase consists of specific tests and trials that might be used to diagnose and treat the feather picking.

We will explore each of these in some detail when we consider specific tests and trials used to diagnose the specific cause of feather picking. These categories are introduced now to get us thinking about what may be involved in this problem.

The history and physical examination helps us to assemble what we currently know about the problem.

The history is important because it gives us clues as to the cause of the problem. Try not to draw premature conclusions from the data. Inaccurate premature conclusions may blind us to the true cause of the feather picking. Questions we would like answered include the following:

2. What type of cage does the bird have? What toys? Is there exposure to heavy metals, especially zinc?

4. Does the bird live with any birds? Has he ever lived with any birds? What kind(s)?

17. From a personality standpoint, how would you characterize your bird? (You can choose more than one response.)

The physical examination involves visually inspecting, palpating, and asculting the bird. The purpose of the exam is to describe the disease patterns and to use the information to help 1) determine the etiology or cause of the disease and 2) give us a baseline from which to follow the progress (positive or negative).

You as the owner will play an important role in charting progress. Often we will attempt a trial treatment and we will evaluate the success of the treatment based on physical signs. If the bird's feathers become totally normal, we have a tremendous response to treatment. However, often we have only a partial response to treatment: 1) the bird may grow in more (but not 100%) of its feathers, 2) red ulcerated areas may heal, 3) the bird may be picking fewer feathers, 4) the bird may still look abnormal but may seem less itchy, or 5) there may be no change. These observations will greatly help us to know if we are on the right tract with our therapy. For this reason we want you to be very involved in seeing what we see on the physical exam.

As part of the initial exam, we minimally do the following diagnostics. These diagnostics are inexpensive, non-invasive, and often steer us towards an underlying cause.

We make impression smears of the skin. These will pick up hyperkeratosis, an inappropriate inflammatory response, abnormal bacteria, or an overgrowth of fungus. Depending on the findings, we may consider allergic, hormonal, or thyroid disease; in certain cases, the cytology may suggest general immunosuppression and may prompt us to look for diseases like aspergillosis. Additionally, cytology may suggest specific types of treatment approaches.

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1. This is a very general screen of the overall health of the bird. In my mind, abnormal cultures usually reflect either immuno-suppression or abnormal gastrointestinal function (versus a super infection by a specific pathogen). Because many diseases of the bird lead to abnormal gastrointestinal function, cultures are helpful but non-specific indicators of the overall health of the bird.

The following recommendations are general steps that will help with almost all types of feather picking. We can get started with these steps while we are trying to make an exact diagnosis of what is causing the feather picking. The record-keeping recommendation will help us start to journal our progress and may eventually provide the answer.

Bathing helps birds on many levels. Bathing removes bacteria, molds, and general allergens from the feathers and reduces their presentation to the immune system. Bathing also makes the feathers less sticky and less likely to retain there particles. It is still debated whether fungus such as malassezia or aspergillosis are primary pathogens of the skin or whether they are able to get a foothold due to inflammation brought on by an allergic or hormonal response. Nevertheless, cleaning the skin reduces the ability of these organisms to get a foothold and colonize the epidermis. Finally, bathing often helps birds with separation anxiety by giving them something to do during the critical first 30 minutes after the owner leaves the bird.

Do not expose birds to perfumes, cigarette smoke, incense, cleaning products, or aromatics of any sort. Owners may need to wash their hands before handling birds.

This is likely important for calcium uptake and may be necessary for appropriate thyroid metabolism. We may need to manage flicker associated with neon lights.

Admonishing a bird not to pick has never cured a single feather picking bird and can teach a bird to use feather picking as an attention getting device.

Treatment will depend on the extent and character of the wounds. Never apply salves to bird's feathers.

Set up a journal that is easy to use. The purpose of the journal is two-fold. First, by recording events associated with feather picking, we may get clues as to the cause. Record data such as the amount of feather picking, the time of day, activities surrounding the feather picking, and food eaten that day. Over a period of time patterns may become evident.

The other purpose of the journal is to determine if there is a response to therapy. Frequently, helpful treatments are discarded because they do not totally stop feather picking. Recording incremental changes like a decrease in the amount of feathers mutilated may help decide what is needed for a total cure.

The next phase of the process is to determine what tests or trials might be useful in defining or solving the problem. We use findings from the physical exam, the history, and the labs to direct us to the most likely cause of the feather picking, and then do tests to confirm or dispute our hypothesis.

Before elaborating on the specific tests and trials I would like to make a few brief comments about tests and trials. First, the lack of abnormal findings does not by default mean the problem is behavioral. It may mean that we as yet do not know how to test for the condition. Second, therapeutic trials can be a valuable diagnostic mode. A therapeutic trial means trying a drug and looking at response to treatment. This type of test is particularly valuable where an objective test has not been developed (e.g. allergies) or where it is difficult to develop (behavioral problems). This modality requires careful owner observation and the ability to differentiate partial response from no response. The weakness of this approach is that a positive response might be due to something other than the drug. Further, we sometimes attribute the curative effects of the drug to the wrong cause. An example of this is a positive response to metronidazole. Response may mean that the underlying problem was giardia, but it may also mean that the underlying cause was an overgrowth of bacteria or inflammatory bowel disease.

My final comment about tests is that some tests are more diagnostic than other tests. High levels of zinc generally correspond well with zinc intoxication, however other test results like aspergillosis serology can often be difficult to interpret. Understanding that tests may not be absolute does not mean that we should give up. In fact, this understanding of limitations of certain modalities will help to give us a better long lasting solution.

The following material looks at how we work up feather picking based on what we think is the most likely cause. We will look at infectious disease, allergies, endocrine/reproductive disease, toxins, parasites, hypothyroidism, primary skin infection, dietary deficiencies, systemic disease, and behavioral problems. We will discuss when we suspect each type of cause and which tests we do to rule in or rule out that particular etiology. Sometimes it seems clear which path to pursue; sometimes we simply start to systematically work thru the most likely causes.

1. Psittacine Beak and Feather Disease (PBFD). The species most susceptible to PBFD are old world birds. We suspect PBFD when we have abnormal feather development. Often feather development becomes increasingly abnormal with each molt. These birds usually do not aggressively pick feathers and are usually not pruritic (itchy). Lovebirds may have few or no feather lesions. The PBFD PCR identifies the organism in the blood and is a sensitive and specific test of this disease.

2. Proventricular Dilation Disease (PDD). PDD affects all avian species. Signs include weight loss, vomiting, passing whole seed in the droppings, and neurological deficits. Additionally, many birds with PDD pick their feathers. The cause of this is suspected to be either neurological or due to inadequate absorption of essential nutrients or fatty acids. Currently a specific test for this disease is being trialed at the University of Georgia. This test looks for the presence of viral DNA in blood and feces and looks at antibody response. While this test is in trial, we continue to screen for this disease with radiographs, crop biopsies, and serial CK isoenzymes.

3. Aspergillosis. Systemic Aspergillosis has also been implicated as a cause of feather picking. We suspect aspergillosis in birds with respiratory abnormalities or when a screening complete blood count (CBC) shows a high count and monocytosis, and protein electrophoresis shows abnormal globulin patterns. Aspergillosis can be an illusive disease to definitively diagnose. Specific tests include antigen or antibody levels. Some fungal granulomas can be confirmed by x-ray or endoscopy. Positive antigen or antibody results may indicate exposure, infection, or even an allergic reaction to the organism. Negative test results do not rule out infection as a negative bird may have an infection with a walled off granuloma or because it is not mounting an immune response. Treatment involves oral itraconazole, intratracheal arnphotericin B and/or nebulization with chlortrimizole.

In general, allergic animals respond to certain environmental proteins as if they were pathogens. These animals mount an inappropriate immune response to inhalants (molds, pollens, dust), to certain foods or drugs, and/or to contact materials (wool, cotton). Some animals also seem to be sensitive to certain aromatics. It is this inappropriate immune response that results in the signs we call allergies. In dogs, these signs result in inflamed itchy skin often with secondary bacterial or yeast infections. The gastrointestinal (GI) tract may also respond to certain allergens. In cats, we may see itchy skin or we may see an asthmatic or GI response. I suspect old world psittacines may manifest allergies with itchy inflamed skin, while new world psittacines especially amazons and pionus may be more prone to respiratory signs.

In general, I suspect that allergies may be a problem if the bird seems very pruritic. These birds often scream or vocalize when they pick and often pick the leggings. Allergies are also suspected if the problem seems strongly seasonal, although some allergic animals pick year round, especially if they are allergic to food, dust, or dust mites. Allergies are also considered if the bird has hot spots or a super active epidermis, especially if overgrowth of bacteria or fungus is present. Finally, in my practice certain species, especially African Grays seem to be pruritic, have seasonal episodes of hot spots, and respond well to allergy medication. We diagnose allergies in the following 4 ways: response to therapy, elimination trials, biopsies, and inter-dermal skin tests.

1. Response to therapy means we try certain anti-allergy drugs and see if they reduce feather picking. Currently, I have best results with an antihistamine called hydroxyzine in combination with omega 3 and 6 fatty acids (these are anti-inflammatories). I am also investigating an antihistamine/anti-seratonin drug called cyproheptadine. Typically, a trial lasts 4 to 8 weeks. If we get consistent positive reproducible results, we can generally believe that allergies are involved in the feather picking. A lack of response may mean that the bird is not allergic or it may mean that is simply did not respond to that particular anti-inflammatory and that another drug might work. We are currently investigating whether histamines, seratonin, or lymphocytes mediate this response. When we understand this, we may be able to develop better drug trials. Additionally, the response may be mediated by different pathways in different species.

2. Elimination trials involve the elimination of potentially allergenic foods or substances from the diet or environment. A true elimination diet has limited protein sources (usually two). We try this diet for several months and look at the response. We can gradually add new foods and see if they trigger a reaction. An elimination diet requires a diligent owner and a cooperative bird. Several of my clients have methodically proceeded with elimination trials and have had excellent results. Foods often suspected of being allergenic include corn, wheat, and most processed foods. Interestingly, in human studies nuts including sunflower are not typically implicated as being highly allergenic. A number of my clients also associate the elimination of certain dyes with a decrease in skin problems.

Elimination trials can also include elimination or reduced exposure to environmental irritants such as aromatics, cigarette smoke, or feather dust from other birds in the household.

3. Skin biopsies are sometimes taken to see what kind of cells are involved in a lesion. When the pathologist concludes that the response is lymphocytic/plasmocytic, we make a tentative diagnosis of a hypersensitivity or allergic response.

4. Intra-dermal skin testing has been the standard to definitively diagnose inhalant allergies in dogs and people. This method involves injecting the allergen into the dermis of the skin and looking for a wheal to form indicating a hypersensitivity to the substance. After determining which agents cause a reaction, we make up an injectable suspension containing the agents (allergens). The patient receives injections from this suspension on a regular basis. This changes how the body responds to the allergens and reduces or eliminates the allergic signs.

We are just now investigating if this technique will work in birds. Dr. Tully of Louisiana State University and Drs. Gill and MacWhirter of Australia have both attempted to allergy test birds. I have tested 18 birds; my findings to date are more in harmony with the Australian veterinarians. This year we will all refine our work. The purpose is to determine if this is a viable tool for diagnosing allergies (I think it likely is) and to determine if allergy shots will work as a treatment tool. My findings suggest that birds may have a type 4 or delayed hypersensitivity reaction. This type of response is mediated by lymphocytes. If this is true, it will help us select what therapy may best mute the response.

Some interesting notes in my study: the group consisted of 18 old world psittacines (cockatoos, African greys, and cockatiels). All 18 responded to aspergillosis. Half of the birds (9) responded to dust and 8 responded to dust mites. This is another good reason to encourage daily bathing.

A likely significant cause of feather picking centers around endocrine or reproductive disease. Spaying and neutering birds and hormonal injections seem in many cases to cause a cessation of symptoms.' Typically, birds do not breed based on a monthly rhythm; instead they breed because a variety of stimuli are present. The importance of the specific stimuli vary depending on the species but can include a nesting site, increased availability of food, weight gain, appropriate temperature, an increase or decrease in daylight hours, and ascendancy in the flock. Many of our birds, instead of cycling in and out of breeding condition, are constantly in breeding condition. This seems in some species to lead to picking. Other conditions such as follicular cysts may lead birds to be constantly in the prophase of breeding and may be associated with mutilation.

We suspect hormonal involvement when picking coexists with breedy type of behavior, with some seasonal picking, when birds pick their leggings, and with certain cases of mutilation. Specific tests that can be helpful include estradiol and androstenedione (University of Tennessee Endocrine lab). Breeding readiness and follicular cysts can also be suggested by radiographs and confirmed by endoscopy.

Drugs that have seemingly been helpful in reducing feather picking associated with reproductive behavior include the following:

1. Depo-Provera (medroxyprogesterone acetate) is synthetic progesterone sometimes used for birth control in humans. This drug is not used much anymore in birds because of its many side effects.

2. HCG (human chorionic gonadatropin) is widely used and seems to have little in the way of side effects. Practitioners report variable results with HCG. In my hands, it is very effective with certain birds. To get a good effect, I seem to need to use HCG on a weekly or biweekly basis.

3. Lupron (a synthetic analog of gonadotropin-releasing hormone) works by obliterating blood levels of estrogen or testosterone for weeks to months. This drug is currently in its trial stages and shows some promise for mutilators.

Other drugs which may have some effects on reproductive behavior and which may help feather picking associated with endocrine activity include a zona pellucida vaccine currently being investigated by Dr. Ritchie, and cyproheptadine (an anti-seratonin drug) which may make some birds less likely to breed because they perceive that there are inadequate food supplies. Further, melatonin which affects the pineal gland and then ultimately the adrenal gland seems to help many birds. Metatonin may be working by decreasing estrogen or testosterone or it may simply have a calming or sedating effect. Fluoxetine (prozac), which has prolactin effects, has not been useful in my hands for feather picking. However, in combination with HCG, it has worked to stop chronic egg laying in cockatiels. Perhaps prozac may be useful when used in combination with some other drug.

In addition to actual drug therapies, it may be useful to decrease the environmental triggers for reproductive behavior. Where appropriate remove perceived nesting areas, decrease daylight hours, feed a limited diet consisting of dry food only, and minimize if possible masturbation by the bird. It is also appropriate to use behavioral training to demote the bird to a lower status level.

The primary toxin associated with feather picking is zinc. We suspect zinc as a potential cause if there is environmental exposure to this heavy metal or if the bird shows neurological or gastrointestinal signs (esp. GI stasis and a mildly enlarged proventriculus). A blood test will give us accurate blood levels of zinc. Various chealators including CaEdta and DMSA are effective at removing excess zinc from the body.

In psittacines, the ectoparasites (external parasite) primarily associated with feather picking are biting lice. These lice are approximately ¼ inch long and are easily visualized by owners. In every case where I have diagnosed lice, the owner had seen the parasite and was coming to me for confirmation. Endoparasites (internal parasites) can also cause feather picking. The most common endoparasite associated with feather picking is giardia. The mechanism by which this causes feather picking is unclear, it may be an allergic response or it may be due to malabsorbtion of certain essential nutrients. We screen all birds for giardia, but do not consider this parasite to be a major cause of feather picking.

For a number of years we have suspected that birds might suffer from hypothyroidism. In dogs, the same individuals that have skin allergies are more likely to be hypothyroid as the same immune process causes each of these diseases. Additionally, hypothyroidism makes the skin more likely to develop secondary bacterial and fungal infections. We screen for hypothyroidism if skin cytology reveals persistent bacterial and fungal overgrowth, if the bird has overall poor feather quality, if the bird is obese, or if the bird seems to have a delayed molt.

In birds, the T4 test to confirm hypothyroidism has not been especially sensitive. In the distant past, almost all avian tests reported undetectably low levels of circulating thyroxine This did not mean that all birds were hypothyroid. It meant we did not have a reliable test. A new test methodology offered by Auburn University offers a significantly more sensitive measurement. Additionally, we may be able to confirm these T4 tests by doing a TSH stimulation test.

Birds that are actually hypothyroid can be treated with oral thyroid supplements. We typically periodically recheck thyroid levels while on the supplement to be sure that replacement levels are adequate. Further, we do not wish to have replacement levels that are too high. Birds that are hyperthyroid suffer a variety of ills including possible cardiac disease.

Another cautionary note about thyroid testing is that thyroid function may be different in birds than in mammals. Some of the birds that I have tested seem to have seasonally wide fluctuations in thyroid levels. I am beginning to wonder if thyroid function may in some species (especially Amazons) decrease during breeding periods and then increase after the breeding season ushering in the molt.

Feather folliculitis and/or skin inflammation is usually secondary to other processes (viral, allergic, hormonal, hyperthyroidism). However, it may occasionally be a primary infection. Skin cytology and biopsies (feather follicles and skin) may be helpful in determining if the problem is a fungal overgrowth, bacterial infection, or a generalized inflammatory response.

We suspect that dietary deficiencies may be causal if the owner describes a diet with significant inadequacies or if the feathers or epithelium suggest gross deficiencies. Although dietary problems are less common than in the past, some feather picking still stems from an inadequate diet. Additionally, there may be some species-specific nutritional needs that are not being met (e.g. increased selenium needs for African species). We also find that many birds that pick seem to have low calcium levels. It is a reasonable idea to be sure that all feather picking birds have adequate UV light sources and perhaps some extra emphasis on calcium rich foods in the diet. Some investigators think that extra methionine might also be helpful.

Systemic disease is usually not a primary cause of feather picking. However, in my practice I can specifically recall a macaw with cystic kidneys, and African grey with heart disease, and a pionus with an aspergillosis granuloma who picked feathers in a tightly localized region directly over the diseased organs. While this is not common, if the bird seems systematically ill (decreased vocalization, lethargic, fluffed) or has systemic signs (heart murmur, polyuric, polydypsic, etc.), it is important to systematically look at the bird's organ function. Tests that are usually helpful for this are the CBC, chemistry profile, and x-rays. Endoscopy may also be helpful.

I have long had a strong bias against behavior as the cause for feather picking. This is due to two factors. First, it seemed that veterinarians were doing a poor job of eliminating other disorders before they concluded that the problem was behavioral. Typically a feather picking work-up consisted of a CBC, chemistry profile, giardia check, and gram stain. If no disorder was discovered, it was concluded that the problem was behavioral. However, as we have seen, those specific tests rarely uncover much about feather picking and there have been few specific tests that diagnose allergic or hormonal disorders. Thus, concluding that the problem is behavioral based on negative findings on a chemistry profile is at best premature. At worst, it might keep us from finding the real cause of the problem.

The second reason that I chafed at a behavioral diagnosis was that we couldn't, in a thoughtful reproducible way, determine how to help those birds whose feather picking was truly caused by behavioral issues. However, Dr. Kenneth Welle, with some truly original work, has adapted to birds Karen Overall's behavioral scheme for dogs and cats. What is excellent about this work is that by categorizing behavior we can select the most appropriate therapies, tailor behavioral modification strategies, and quantify results.

To detail what this means, I will use a client's cat as an example. The cat has an insatiable need for the owner’s attention, sprays when he is anxious, follows the owner constantly when she is at home, and wails at her bedroom door for ½ hour ever night. We hypothesized that this cat had separation anxiety, chose a drug (clomipramine) that is effective for this problem, and instituted behavioral modification strategies to reward independent behavior and ignore anxious behavior. We set up a timetable for how long to continue the trial and used discreet criteria (time cat was willing to spend alone, amount of spraying, length of time cat wailed at the door) to measure progress. This is what we hope to do with birds with this approach.

The following analytical scheme picks out certain behaviors (signs) that point to a specific type of disorder (the behavioral diagnosis). Making a specific behavioral diagnosis helps us to clarify the underlying causes and develop well-targeted solutions. This list should expand as we become more sophisticated with these concepts.

1. Feather picking occurs when owner is not present. Separation anxiety is the disorder most commonly associated with this sign. Separation anxiety is an important issue for animals whose early life centers around a flock. Birds that have been rehomed or improperly socialized are especially at risk. Behavioral modification strategies center around rewarding independent play, teaching self-calming strategies, and not rewarding anxious behavior. Since most animals with separation anxiety act out most in the first half hour after the owner leaves, you may wish to bathe the bird just before leaving, leave him a special toy, or meal feed - giving the meal just as you leave. Drugs often useful on treating separation anxiety are clomipramine and fluoxetine (prozac).

2. Feather picking occurs when owner is present but is not paying attention to the bird. Attention-seeking behavior is the disorder most commonly associated with this sign. Owners frequently reinforce the feather picking by immediately speaking to the bird and telling him not to pick. Appropriate behavioral modification would be to ignore the behavior, act like you simply do not notice, or actually leave the room when the bird is picking. If the feather picking is an attention-seeking device, count on the behavior to significantly worsen when you first begin to ignore the behavior. The bird will conclude that you simply did not see and may amplify the behavior. Count on 200-300 episodes of ignoring the behavior before the bird gives up.

In addition to ignoring behavior you do not want, you should reward independent behavior and teach the bird other appropriate means to demand attention (tricks, vocalizations, etc). Neutral room work to reinforce commands or to teach tricks is often useful. Such work teaches the bird how to earn good attention. Further, five to ten minutes of your undivided attention is enough to satisfy many birds. At this time, there is not a drug that is specific for attention-seeking behavior.

3. The bird interrupts other behaviors to feather pick. Obsessive/compulsive disorder (OCD) is the behavioral disorder most commonly associated with this sign. OCD in animals manifests itself by stereotypic behavior such as cribbing in horses, incessant tail chasing in dogs, wool chewing in cats, and certain kinds of feather picking in birds. Some researchers feel that stereotypic behavior distracts the animal from its anxieties; others feel that it is simply a visual manifestation of anxiety. Another school of thought is that stereotypic behaviors are self-stimulator and result in endorphin release. Finally, some researchers feel that it is a manifestation of aberrant neuronal activity and may be hereditary.

Drugs that have been used to deal with OCD include the tricyclic antidepressants (esp. clomipramine), the ssri's (esp. fluoxetine or prozac), haloperidol and naltrexone. Both pruritic birds and OCD birds will interrupt satisfying behavior to pick. Before we can decide that a bird has OCD, we need to rule out pruritic conditions like allergies.

4. The feather picking bird exhibits signs of excessive fear or stress. Fear, phobias, or panic may be displaced and translated into picking behavior. Recall that fear can be an adaptive appropriate response. A bird’s high level of vigilance and instant flight response is highly protective. In a wild situation, the bird will dissipate fear-induced adrenaline by flying for a quarter of a mile. In our lives, these birds may displace this energy by picking their feathers. A large part of our socialization efforts are intended to get the bird to tolerate stimuli that in the wild should provoke fear.

To behaviorally treat these birds we must remember not to reward the feather picking with attention. We should remove objects that generate fear and/or gradually habituate them to these objects or circumstances. We should teach the birds self-calming techniques. Teaching birds to fly may also help to build confidence. Patterning a variety of behaviors also prepares the bird to deal with life with assurance. Finally, give them environmental prompts, such as a raised cage or a partially covered cage, that enhance security.

Drugs that may have some application in treating fearful of phobic behavior include diazepam, haloperidol, clomipramine, and fluoxetine.

A bird stressed by a medical problem may occasionally be mistaken for a fearful or phobic bird. It is a good idea to rule out systemic illness in these birds.

' It is wise to consider that some treatments that seem to be effective may be working in ways we don't understand. For instance, antihistamines may not be treating allergies, but might instead simply be calming birds. Likewise, hormonal preparations may be working by decreasing estrogen or testosterone, or may in fact work by increasing endogenous steroids and thus be treating allergies. At this point, our understanding of the physiology is still under development.

This article was originally presented at the 1999 PBR Convention, and was subsequently published in the Pet Bird Report, Issue 45, November, 1999.