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FEATHER
PLUCKING
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Excellent
article by leading avian vet Neil Forbes
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Feather
plucking – not to mention other feather abnormalities – is a
massive subject. It is frequently a complicated, multi-factorial
problem, which may be resistant to therapy.
Although general advice can be given, which will on some occasions
result in a recovery, the majority of cases require detailed
investigations which may take some time, cost a considerable
sum of money, and will not lead to a recovery in all cases.
Past history
In tackling a feather abnormality or plucking case, a comprehensive
history needs to be established, including such factors as:
age of bird, species, duration of plucking, season of onset,
previous therapy, previous investigation, husbandry (housing,
daylight pattern, occupational therapy, feeding methods, nutrition,
concurrent illness, exact clinical signs, duration of isolation
etc.). |
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Picture
right : A badly plucked Grey is examined under anaesthetic
at the surgery. |
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Commitment
At the outset it is important to assess the owner's determination
and resolve to overcome the problem. Even if an owner
says yes, they want to fix it, if they are not prepared to follow
advice – whether this be medical, nutritional or behavioural
– the condition is unlikely to resolve. It is unlikely
there will be an instant fix, and the cure will involve considerable
time and commitment from themselves, together with a large amount
of 'psittacine understanding'.
If the case is to be investigated, then the following list of
causes are considered. As stated by Tracy Gwillim in a
recent issue, the key is to rule out all medical causes, prior
to accepting that there is a psychological problem. |
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Medical
causes of feather abnormalities/plucking/mutilation
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Allergies
(Typically food, but occasionally inspired). Some clinicians,
particularly in the US and Australia, believe that birds may
develop allergies which lead to plucking. Research work
in this field is ongoing, but all indications are that this
does occur at least in some birds.
Simply trying different foods is unlikely to resolve the problem.
If one suspects foods, then an exclusion diet should be used.
This means feeding the bird on a diet that comprises proteins
and carbohydrates it is not normally accustomed to, for a period
of at least six weeks.
All parrot owners will immediately realise that this is not
realistic for most birds, as changing a diet so radically is
not easy, and may even be stressful.
The better solution is an 'intradermal skin test'. This
procedure is similar to that performed on humans, and is currently
being developed for use in parrots by an international team
of avian experts, including Dr Pat MacWhirter from Australia,
as well as myself and Nigel Harcourt-Brown FRCVS from the UK.
It is hoped this allergy test will be available soon.
The initial indications are that basic foods such as millet,
sunflower, peanuts, as well as breathed-in allergens such as
canary feather dust and grain mill powder do certainly cause
allergies, amongst other things. |
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Ectoparasites
These are often blamed but rarely responsible; however
they must not be ruled out.
A white sheet should be hung around the cage at night.
In the morning the inside of the sheet should be studied
for mites or lice, often resembling moving grains of sand.
Some mites will not be seen in this way, and the avian
vet should also check the bird for signs of ectoparasites. |
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Picture
Right : Boredom and Loneliness will often lead to feather
plucking |
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Endoparasites
(This is, worms or protozoal parasites inhabiting the gut).
These frequently cause problems, especially in Cockatiels, and
should always be excluded in all species. The clinician
should perform a faecal examination in all cases, to exclude
these causes.
Environment
Excess tobacco smoke or too dry an environment (often triggered
by central heating), can lead to itching or poor quality feather
growth, leading to brittle feathers. These break, then
the bird plucks them. Those of us who do not smoke can
instantly tell the following morning when we smell our clothes
if we have been in a smoky environment the previous day.
At least we can take our clothes off and wash them – not so
the unfortunate parrot. No-one should ever smoke in the
same air space as any bird.
Most wild psittacines are accustomed to life in a rain forest,
where they would be rained on daily, so captive parrots will
usually benefit from a light, daily water spraying. An
inability to bathe is a common cause of feather plucking
The effect of a continuously dry environment may be premature
wear and tear on the plumage, leading to tatty feathers prior
to the subsequent moult. Poor nutrition during a moult
will have the same effect, leading to brittle non-durable feathers.
A parrot will often attempt to remove poor feathers. Low
light intensity will also cause plucking.
Excessive Daylight
This can be a problem leading to a tired, irritable bird.
We all know the effects of being chronically over-tired, irritable
and bad tempered, and in parrots this can lead to self-mutilation.
The bird should not be in a light environment for more that
12 hours a day. If it is in a lit room for longer, cover
it up. It is often best to cover a bird at night, only
removing the cover in the morning when you get up. That
way neither the bird nor the owner is over-tired as both get
the chance of a lie-in. The bird's cage should not be
left in direct sunlight.
Metabolic/systemic disorders
These have often been blamed for feather plucking and on occasions
are responsible for it – in particular with an under-active
thyroid gland, especially in cockatiels. However, any
form of liver disease can lead to itchy skin and hence plucking.
Chlamydiosis (psittacosis) is almost certainly the commonest
cause of psittacine liver disease. Septicaemia and air
sacculitis may cause feather plucking, due to pain caused from
internal adhesions or general soreness.
Lead and Zinc
Low level, chronic toxicity (acquired from the environment)
will cause feather plucking. This is now recognised as
a far commoner cause of general low grade illness and plucking
than was previously realised. In the US it has been shown
that there is no safe form of cage wire other than stainless
steel.
With the passage of time – sometimes even with a new cage –
a pet parrot that habitually chews or sucks the bars of a standard
commercial parrot cage will gradually pick up significant levels
of zinc. It is my belief that all plucking birds should
be screened for zinc and lead.
Psittacosis
(Chlamydiosis or Parrot Fever) This is a significant cause
of feather plucking, and should always be excluded. Diagnosis
in itself may not be a simple matter and treatment will be long
winded (typically taking at least 45 days), and on occasions
not effective.
Testing for chlamydiosis is not straightforward and no one test
is wholly accurate, but it must always be excluded as a cause
of liver disease, which in turn may cause feather plucking.
Infectious dermatitis/folliculitis
These are infections of the feather roots, or the follicles
from which the feathers grow. Cause and effect may be
difficult to differentiate – for example, the bird itching at
its feathers or skin because they are infected, or is the infection
present as a consequence of the plucking and physical trauma
of plucking. This is an uncommon cause of plucking, but
the feather follicles should be examined for any signs of swelling
or discharge by the vet.
Polyomavirus
('Budgerigar Fledgling Disease') and Circovirus (Psittacine
Beak and Feather Disease)
These do cause the development of abnormal feathers, poor plumage
and plucking, although the pattern of feather abnormalities
is typically different from a normal feather plucking 'pattern
picker'.
These viruses should be excluded where relevant. With
Psittacine Beak and Feather Disease, apart from feather dystrophy
(that is, abnormal feather development), one of the first signs
is the loss of the grey powder down (especially typical of Greys
and Cockatoos) from the beak. This is a result of the
powder down feathers being affected, resulting in a beak that
is black and shiny.
Malnutrition
This is the single most significant medical cause of feather
plucking in pet birds. It is reported that between 75
– 90% of all sick birds are suffering from primary nutritional
deficiencies. This is a very poor reflection on our parrot
nutrition, and is an issue that should be addressed. Malnutrition
may be caused by dietary deficiency, a digestive abnormality
or a lack of access to unfiltered natural light. Feather
plucking birds on a predominately sunflower seed based diet
must be converted onto a better diet and receive vitamin A supplementation
in the interim.
There is no value in placing vitamin powder on top of seed diets.
Sweetcorn, apricots and other highly coloured vegetables are
excellent sources of vitamin A. Vitamins may be given
mixed with soft food, or with some treat, for example toast
and honey, or alternatively dissolved in water (Daily Essentials1).
If in doubt, it is essential to look into providing a better
diet and ways of achieving the change, even though this is not
always an easy task. It is important that birds are not
forced onto a new diet unless they are healthy at the time,
or the stress of change may precipitate clinical disease.
Diet options are a wet/chopped, mixed 'sprouted seed/vegetable/rice
mix' or a pelleted diet.
Neoplasia
Feather plucking will often occur over the site of a skin cancer.
There is circumstantial evidence that the trauma of chronic
feather plucking can lead to such tumours, although the plucking
may commence because of the tumour. In such cases the
growths are most often on the underneath of the wing.
Only when all the medical causes have been excluded, and standard
environmental changes have failed to lead to an improvement,
can psychological causes by considered.
Many of the psychological causes of plucking have been mentioned
by Tracy Gwillim, but will include:
Attention Seeking, Boredom, Over-crowding, Environmental Change,
Stress, Excessive Preening, Nest Building, Feather Clipping,
Trauma, Sexual Frustration, Lack of Behavioural Training, Incorrect
Flock Status, Situation, etc etc.
It is my belief that feather plucking cases cannot be tackled
alone by a behaviourist without the previous assistance of an
experienced avian vet.
Likewise however, after the medical aspects of a case have been
addressed, often a vet is not in a position to perform a house
visit and follow up amended training procedures on a weekly
basis, so these may well be performed by an experienced behaviourist. |
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This
Blue and Gold macaw (left) stopped pulling out it's feathers
once it was given a healthy diet and stimulating environment |
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