Feather Plucking

Introduction

Feather-plucking is a common presenting sign in birds. Underlying causes are often multifactorial, so diagnosis and treatment of several of the contributing factors may be necessary to produce resolution of clinical signs. It is best to rule out medical causes before diagnosing the feather-plucking as behavioral in origin, therefore a thorough work-up is indicated including a detailed history, physical and dermatological exam. Referral may be considered.

Individual tests such as; haemotology, biochemistry, heavy-metal testing, sexing, skin acetates, pulp cytology and faecal staining should all be performed in the initial work up to guide diagnosis. Additional tests that should be considered are; Chlamydophila testing, circovirus testing, coeloscopy, radiography, skin biopsy, crop biopsy and faecal flotation (for Giardia and helminths).

The causes of feather-plucking can be divided up into four categories:

1. Infectious, contagious or transmissible causes
2. Non-infectious and metabolic cause
3. Environmental causes
4. Psychological causes

Infectious, Contagious or Transmissible Causes

• Psittacine Beak and Feather Disease (PBFD)
• Budgerigar fledgling disease (BFD)
• Ectoparasites (e.g. Dermanyssus gallinae)
• Endoparasites (e.g. Giardia sp.)
• Chlamydiosis
• Fungal dermatitis

Diagnosis

PCR should be performed to diagnose PBFD and BFD.

Ectoparasites can be identified by performing a physical examination during the day and night, a faecal exam is required to diagnose endoparasites.

PCR/ELISA (antigen/antibody) is used to identify chlamydiosis.

Skin scraping followed by microscopic examination and culture is necessary to diagnose fungal dermatitis. Stained impression smears, culture and sensitivity should be performed if bacterial infection is suspected.

Haematology and biochemistry, thyroid stimulation test, biopsy and histopathology, improving the diet and monitoring the response to therapy also help to confirm or eliminate differential diagnoses.

Treatment

Treatment is dependent on the individual underlying infection.

Non-Infectious and Metabolic Causes

• Bacterial dermatitis
• Pulpitis or folliculitis
• Allergy
• Hepatitis
• Hypothyroidism
• Skin neoplasia
• Follicular cysts
• Post-traumatic injury, or arthritic or scar tissue pain
• Nutritional deficiency (e.g. hypovitaminosis A; B vitamin deficiencies) and essential amino acid deficiencies (e.g. lysine))

Diagnosis

This should be based on a combination of history, clinical signs and the results of preliminary and secondary test results as mentioned above.

Treatment

Treatment is dependant on the individual underlying cause.

Environmental Causes

• Over-tiredness
• Poor bathing
• Inappropriate cage position and exposure to cooking or tobacco fumes
• Boredom and inadequate environmental enrichment

Diagnosis

This type of feather-plucking is caused by the environment provided for the bird. Therefore a detailed history may provide clues as to the origin of this behavior. Like psychological causes of feather-plucking, it is a diagnosis of exclusion, with all infectious aetiologies ruled out before confirming it as the diagnosis. The bird should appear clinically normal in all other aspects, unless fumes have caused skin irritation.

Treatment

Over-tiredness should be treated by imposing strict 'bed-times', and providing the bird with a 'roost cage' in a quiet room. The bird should be placed in the 'roost cage' and covered at the same time each night, allowing for a peaceful night's sleep.

Poor bathing should be addressed by misting or bathing the bird daily with water. This should be done even if the bird appears to dislike water, as bathing is essential for feather maintenance.

The cage should be positioned away from any irritant fumes and potential predators. In addition it should be placed against a wall so that it is less exposed.

Boredom and inadequate environmental enrichment should be addressed by providing toys for the bird (under rotation) and by encouraging independent play.

Psychological Causes

• Sexual frustration
• Attention seeking
• Boredom and separation anxiety
• Overcrowding
• Environmental change or poor routine
• Excessive preening
• Secondary to untidy feather or wing clipping

Diagnosis

The psychological plucker presents as a clinically normal bird in all respects except for its plumage. Bacterial, fungal, parasitic, viral, chlamydial and metabolic aetiologies for feather plucking should be ruled out. The feathers on the head are totally normal (if head feathers are affected disease is most likely caused by a circovirus, bacterial or yeast infection). It is most common in hand-reared birds and plucking is often only done in the presence of the owner.

Reproductive hormonal pressure aka sexual frustration is the most common cause of psychological feather-plucking. It often begins when young birds that bonded to their owner mature, which can occur earlier than what is thought to be the natural reproductive age. Hormonal influences cause the young bird try to gain dominanceover the other members of the flock. This relates to behavior in the wild which would result in the bird obtaining a mate, holding territory and having access to enough food, which in turn would allow it to reproduce. Captive birds mature more quickly than wild birds, because the owner is providing it with food etc and giving it attention, resulting in a close bond between the two. However, the ‘mate’/owner does not responding in the appropriate manner to the sexually mature bird. ‘Displacement behaviour’ such as feather picking, screaming or aggression develops as a response to this.

Treatment

For birds suffering from reproductive hormonal pressure, treatment with progesterones is reported, however significant side-effects such as obesity, polyuria/polydipsia, diabetes mellitus and hepatic lipidosis can occur. Human chorionic gonadotrophin (HCG) may be an effective short-term treatment particularly in African grey parrots and Cockatoo hens.

Occasional success is seen with Tranquillisers (haloperidol) and psychotropic agents (clomipramine and Prozac).

All the medications should be used in combination with behavior and environmental management. Petting and cuddling should be decreased or stopped entirely. The cage should be placed below chest height and moved away from busy areas of the house. These actions assert dominance over the bird and reduce anxiety respectively. The cage should be covered up earlier in the day to shorten day length.

Surgical removal of the oviduct may provide the best long-term solution in female birds. The picking may become a compulsive habit, in these cases compulsive behavior management and anti-compulsive medication (as mentioned below) may be indicated.

Attention seeking should be discouraged by the owner by ignoring the bird when it is feather plucking, and then fussing it when it has stopped. Gradually the bird should learn not to feather pluck.

Boredom and separation anxiety should be managed by providing various bird toys and encouraging independent play. Ideally the bird should be tired out by activities such as bathing and play prior to the owner leaving the house. Leaving on a radio or television may also help with separation anxiety.

Overcrowding should clearly be managed by reducing the number of birds per cage, or providing the bird with a larger cage.

Environmental change and poor routine should be managed by imposing a strict routine, including set 'bed-times'. Environmental change should be minimised where possible.

Over-preening is considered a type of obsessive-compulsive behavior. To counteract this, the bird should be encouraged to play independently and any objects it may be scared of should be removed. The cage may also require re-positioning. As for attention-seeking, the behavior should not be encouraged. Anti-compulsive medication may be used.

Feather Plucking Learning Resources
Flashcards Test your knowledge using flashcard type questions	Avian Medicine Q&A 04

References

Forbes NA & Altman RB (1998) Self-Assessment Colour Review Avian Medicine Manson Publishing Ltd

Chitty, J (2003) Feather plucking in psittacine birds 1. Presentation and medical investigation In Practice 2003 25: 484-493

Chitty, J (2003) Feather plucking in psittacine birds 2. Social, environmental and behavioural considerations In Practice 2003 25: 550-55

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