Susan L. Clubb, DVM
Rainforest Clinic for Birds and Exotics, Inc., Loxahatchee, FL, USA
OVERVIEW OF ISSUE
Feather Damaging Behavior may be associated with a variety of clinical syndromes, however the most common causes are believed to be inflammatory skin disease, or psychological feather damaging behaviors.
The use of paired skin and feather biopsies is a useful diagnostic procedure for psittacine birds exhibiting feather damaging behavior. In this procedure a full thickness skin biopsy is obtained in an area where a bird is plucking feathers, preferable including a growing feather. A second skin biopsy is taken in an area of normal skin at a site where the bird is not plucking, again preferably containing a growing feather. By comparing these 2 sites the pathologist can make the determination as to whether there is an underlying inflammatory disease that may be causing the feather damaging behavior.
OBJECTIVES OF THE PRESENTATION
This presentation will assist practitioners in diagnosis and management of inflammatory Skin Disease in psittacine birds.
KEY ETIOLOGIC AND PATHOPHYSIOLOGIC AND CLINICAL DIAGNOSTIC POINTS
- Approximately 50% of parrots exhibiting feather damaging behavior have been diagnosed as inflammatory skin disease based on paired skin and feather biopsies.
- Species predilection varies, however this is diagnosis cannot be based on physical exam only.
- Allergic disorders are possibly involved in etiology of ISD.
Inflammatory skin disease (ISD) in parrots is a reflection of an underlying systemic inflammatory disease associated with Feather Damaging Behavior (FDB). (1,2,3) ISD is mostly likely analogous to hypersensitivity or allergic dermatitis in mammals. Feather damaging behavior (FDB) associated with ISD can begin in birds less that 1-year of age, or may take years to develop. ISD, like hypersensitivity disorders in humans or other animals, can be seasonal but is often a chronic, on-going problem. It cannot be cured; it must be managed possibly for the rest of the bird's life.
The incidence of inflammatory skin disease varies by species, however in a compilation of 412 cases by Garner, an overall prevalence of diagnosis of ISD was 51%. (Clubb, 2001, Clubb 2004, Garner, 2006)
The predominant clinical signs of ISD are pruritis and plucking or damaging the feathers. Some birds also have erythema or dry, flaky skin. The skin often has insufficient subcutaneous fatty tissue giving it a reddish color from muscle layers below. In severe cases, birds may mutilate the skin as well. A bird with inflammatory skin disease is often scratching while in the exam room. Clients may describe the bird as having severe episodes of obvious discomfort, often jumping, twitching or vocalizing as if irritated.
Onset of ISD may be very sudden possibly in response to the bird coming into contact with increasing or varying levels of antigen. Onset may also coincide with molting and may indicate follicular inflammation associated with the emergence of feathers. Birds may discontinue the behavior when moved to a new location, which may logically remove it from the offending allergens. Owners often report that they brought a FBD bird into their home and the behavior stopped. They may associate this change with improvements in diet or providing more toys while the response may actually be due to removal from the source of allergens. This response may be temporary as the bird becomes sensitized to new allergens in the new environment.
Inflammatory skin disease cannot be definitively diagnosed by physical exam. Diagnosis is based on paired skin biopsy as previously described. (Clubb, 2001, Garner, 2003) In this procedure, the bird is anesthetized and two growing feathers with a small section of skin surrounding each are biopsied for histopathology. One sample is taken from an area of skin where the bird is plucking, and another sample is taken from an area of skin where the bird is not plucking or cannot reach (usually the head or neck). Actively growing feathers are preferred because they are more reflective of current conditions in the follicle and helpful in diagnosis of other follicular abnormalities.
Inflammatory changes, typically perivascular inflammation is expected in affected areas and can be simply associated with the trauma of the scratching and plucking. If these inflammatory changes (lymphoplasmacytic perivasculitis) are noted in unaffected areas as well this indicates a systemic inflammatory process. If no abnormalities are found in either section, or inflammation exists only in the affected areas the FDB is most likely associated with psychogenic disorders by process of elimination.
Macaws, Amazons, conures, lories, and Eclectus parrots have a high incidence of ISD (Garner, 2006). ISD is not so common in cockatoos and African Grey Parrots, which seem to have a higher incidence of psychogenic FDB. Other disorders may also be diagnosed by paired skin biopsy including bacterial folliculitis or dermatitis, fungal dermatitis, follicular or feather dysplasia which may be associated with viral infections, hyperkeratosis which may be nutritional in origin and even dermal hemosiderosis. If characteristic feather dysplasia is present testing for psittacine circovirus is indicated
Bacterial and fungal secondary infections may actually be triggering effects as in dogs that have allergic dermatitis. Treatment of these secondary infections may enhance control efforts. (Hiller, 2004) Unfortunately, at this time allergy testing by skin tests or blood tests are not practical or available for birds. (Colombini et al, 1999)
KEY THERAPEUTIC POINTS FOR INFLAMMATORY SKIN DISEASE
- Reduce or control allergic response
- Provide optimum levels of nutrients which help to control inflammation
- Sooth skin inflammation
Therapy for inflammatory skin disease is based upon reduction or control of the allergic response with antihistamines, provision of a hypoallergenic diet if possible, elimination of allergens as much as possible and provision of optimum levels of specific nutrients that help to control inflammation, and enhance metabolism.(Hillier, 2004, Welle, 1999) I have found supplementation and balancing Omega 3 and Omega 6 fatty acids, which is often used in other species to reduce inflammation, is also clinically beneficial in birds. My goal in fatty acid supplementation is 50-250 mg/kg body weight of Omega 3 fatty acids with an omega3:omega 6 ratio of 1:2-1:6. When supplementing extruded diets I use a balance supplement of salmon oil and flax seed oil (high in omega 3 fatty acids) and safflower seed oil (high in Omega 6 fatty acids). If the bird is eating a primarily seed diet I supplement only with salmon oil and flax seed oil.
Due to concerns for adverse side effects, I have not initiated therapy with corticosteroids. Ideally in hypersensitive individuals, known allergens should be avoided as much as possible. Since we cannot test to determine which allergens should be avoided, we must try to simplify the diet and reduce exposure to items known to be allergenic in mammals.
Food allergies or sensitivity can be difficult to diagnose even in humans and dogs. The standard approach when dogs are suspected of having food allergies is to simplify the diet as much as possible, excluding foods, especially proteins, that are suspected to be allergenic. We have found that feeding an exclusion diet may consist of a simplified balanced formulated diet to be clinically beneficial. A natural colored pelleted or extruded parrot diet is a good place to start, and preferably as the only food for a period of time, although client compliance with this recommendation is often limited.
Suggested Supplemental Foods
Birds and owners love dietary variety and sharing at mealtime. In order to enhance compliance a list of foods that have relatively low antigenicity and do not contribute to skin inflammation was developed for owners to share with their birds. This was based on avian as well as human literature. (Surai, 2003, Periccone, 2003). Supplemental foods should be chosen from the following list. If the bird is begging for table foods at dinnertime, offer these foods. They can also be used for treats and to enrich the diet.
- Cooked or canned salmon
- Cooked chicken
- Spinach or kale
- Green peppers
- Green beans
- Cooked eggs
- Shelled Brazil nuts (raw unsalted)
- Spirulina--(If Marine algae)
- Olive oil
- Soybeans (roasted)
- Cottage cheese
- Sunflower seeds (shelled-limited quantity)
- Black beans
- Pinto beans
In the initial exclusion phase of dietary restrictions additional foods should not be given. After the first 2 months new foods should be added one item a week in order to detect items which the bird may be sensitive to.
KEY DRUGS, DOSAGES AND INDICATIONS
Chlorpheneramine--4 mg tablets
Loratidine syrup 5 mg/5 ml
Hydroxyzine hydrochloride--10 mg/5 ml
4 mg tab in 8 oz water
0.5 ml/100 gm BW
0.10-0.20 mg/kg-titrate dose to desired effect
SID in food or BID PO
SID or BID
PO or can use 2x dosage in favorite food
Birds affected with inflammatory skin disease often benefit from treatment with antihistamines. But antihistamines don't seem to work for all species or all individual birds. It is possible that in some birds, ISD may be mediated by some pathway other than histamine. Macaws seem to benefit most from anti-histamine therapy.
I often observe seasonal allergies in birds with inflammatory skin disease, especially in macaws. This is a reflection of systemic allergic disorders. Seasonal allergies may coincide with seasonal peaks in pollens, molds, or other allergens.
If antihistamines are used, I usually recommend chlorpheniramine maleate without other ingredients such as decongestants. (Chlorpheniramine Maleate 4 mg. Contact Pharmaceutical corporation, Hauppauge, NY 11788) This drug is difficult to find over the counter. It is conveniently administered in the drinking water at the rate of 1 tablet in 1 cup (8 oz) of bottled water. In my experience, water dosage is beneficial because the bird doses itself repeatedly during the day. Some individuals respond well to Loratidine syrup (Children's Claritin Syrup, 5 mg/5 ml, Schering Plough) which in the 24 hour formulation can be given orally once daily at the dosage of 0.5 ml/100 gm body weight. Dosage may need to be titrated to effect for individual birds. Overdosage can result in extreme lethargy or hyperactivity and agitation.
Hydroxyzine hydrochloride solution--10 mg/5 ml, (Morton Grove Pharmaceuticals, Inc, Morton Grove, IL 60053) is another alternative for antihistamine therapy and as with chlorpheniramine it also has a mild sedative effect. This drug can also be administered directly orally (2 mg/kg, q 8 hrs) but such frequent oral dosage is unacceptable to most clients. I use 5 mg/kg BID or 10 mg/kg once daily added to soft food for more continuous dosing. Some clients can identify times of the day when plucking is more intense. Routine dosing of hydroxyzine at this time, or on a symptomatic basis can be a useful management tool.
Many tricyclic antidepressants such as Haloperidol (Haldol, McNeil) also exhibit potent antihistaminic effect and can be especially beneficial if the bird exhibits psychogenic behaviors as well as having inflammatory skin disease.
Bathing, even with only fresh water, helps to reduce skin inflammation. I recommend bathing the bird at least twice weekly. Soak the bird with tepid, fresh water. Ideally the bird should be allowed to dry in sunlight. A solution of Aloe Vera may be sprayed on the feathers and skin once or twice weekly, especially if the skin is very irritated (Aloe Vera Detoxifying Formula, Naturade, Inc, 14370 Myford Road, Irvine, CA, 92606- 1 oz contains 29.6 ml of aloe Vera Gel, 600 mg Aloe Vera Pulp). Aloe Vera Gel or solution is mixed 2 tsp in 8 oz water to spray on skin. To prevent build-up of aloe vera on feathers intermittent fresh water baths are recommended. Aloe vera may also be administered in drinking water at the rate of ¼ tsp in 1 cup water.
It is important to avoid getting oil supplements on the bird's feathers, because they can cause matting and discoloration. If feathers become soiled with oil, they can serve as a substrate for saprophytic fungi to grow on the feathers. (Clubb, 1998) If this occurs, a weekly misting of chlorhexidine solution (Nolvasan, Wyeth) diluted 1:10 in water can prevent the spread of the saprophytic fungi from infected feathers to new ones. Bathing with fresh water between chlorhexidine mistings will reduce build up on the feathers. Oil from the owner's hands and face, or oils from foods can also accumulate on feathers and be a substrate for feather fungus.
Improvement with therapy using exclusion diet, anti-histamines and anti-oxidants will be gradual. This is especially true if feathers are broken, chewed or otherwise damaged, rather than being plucked out in their entirety, because the bird must molt in order to replace the old feathers with new ones.
Therapy must be continued for at least 3-4 months prior to assessing effectiveness.
Taking photos of the bird is the best way to monitor its progress. Preferably these photos should be taken in the same place with the same lighting each time for ease of comparison. Monthly digital photos are ideal.
When managing chronic problems, is very important to give any therapy adequate time before stopping or changing treatment. Long term therapy is challenging so every attempt should be made to make it easy for the owner and palatable to the bird. As the inflammation resolves the bird will feel better and it's attitude and personality usually improve as well.
1. Clubb SL, Garner MM, Cray C. Detection of inflammatory skin disease in psittacine birds using paired skin biopsies. Proceedings of Association of Avian Veterinarians, Monterrey CA, 2001.
2. Clubb SL, MM Garner, C Cray, K Arheart, M Goodman. Diagnostic assessment of feather damaging behavior in African grey parrots (Psittacus erithacus) Proc. Assoc. Av. Vet. Annu. Meet. Pp 313-320. 2004.
3. Clubb SL, A Herron. Feather discoloration associated with saprophytic fungal growth, Proceedings of Association of Avian Veterinarians, 1998.
4. Garner MM. Techniques and trends in the characterization of inflammatory skin disease in feather picking birds., Proc Annu Conf Assoc Avian Vet, 2006.(In Press).
5. Garner MM. Avian noninfectious skin disorders, Proc Annu Conf Assoc Avian Vets., August 25, 2003. Pp21-24.
6. Hillier A. Practical symptomatic therapy for allergic dermatitis, Western Veterinary Conference, Las Vegas, NV, Feb 2004.
7. Surai PF. Natural Antioxidants in avian nutrition and reproduction, Nottingham University Press, Bath England, 2003
8. Perricone N. A Doctor's 28 day program for total body and face rejuvenation), Time Warner Book Group, New York, NY, March 2003.
9. Colombini S, Foil C, Hosgood G, Heatly J, Tully T. Intradermal skin testing in the avian patient. Proc Assoc Avian Vets., New Orleans, LA, pp 129-131, 1999.
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Susan L. Clubb, DVM
Rainforest Clinic for Birds & Exotics
Loxahatchee, FL, United States