It is a
sad fact that the majority of pet parrots are fed on
nutritionally deficient diets.
The majority of pet psittaciforms are given a seed-based
diet to eat. Seeds fall into two categories: sunflower
seed, peanuts and pine nuts, are large seeds that contain
a lot of oil. Small seeds such as safflower, hemp, millet
and canary seed contain mainly carbohydrate. Seeds are
high calorie, low in calcium with a poor Ca/P ratio,
low in most vitamins, have either low protein content
or a limiting essential amino acid, usually lysine or
methionine.
Seed based diets have
little to recommend them nutritionally but they are
easy to store and do not deteriorate visually. They
are also universally attractive diet to many parrots.
Seed is stored for an unspecified time and in unspecified
circumstances and is often seed that has failed to make
the grade as fit for human consumption. |
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The seed based
diet is almost never subjected to nutritional analysis
and if an analysis of a mixed seed diet is offered it
is usually book-based.
Although many
owners attempt to feed a varied diet, their birds usually
select an unbalanced seed-rich diet. Some Grey Parrots
eat nothing but sunflower seed. Also most birds are
offered far too much food further enabling the bird
to eat only the seeds that it wants. A Grey Parrot will
maintain its body weight on one tablespoonful of sunflower
seed per day.
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| The onset
of clinical signs of a dietary deficiency is based on
the lifestyle of the parrot: productive birds show more
dramatic signs more quickly.
As most parrot’s diets are deficient in several
vital nutrients the bird is usually presented with
a multitude of subtle problems and just because one
deficiency is more obvious, such as osteodystrophy
in a growing baby parrot, it does not mean that this
will be the only deficiency.
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Vitamin A deficiency causes
squamous metaplasia of the mucous membranes affecting
oropharynx, respiratory, reproductive and renal tracts.
The abnormal keratinisation blocks the ducts of the
glands causing abscesses in the salivary and mucus glands.
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| Carotenoids produce much of
the feather colour in parrots. In vitamin A deficient
birds the yellow, orange and red colours are much duller
and the green plumage (made of yellow carotenoid and
blue caused by scattered light) is affected too. |
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| Vitamin
A is formed in the bird by converting beta carotene
from a vegetable source: fresh vegetable such as carrot,
maize or sweet corn, green beans, celery, apricots,
etc.
Vitamin E deficiency is commonly seen and occurs
because storage of seed for long times allows the
oils to become rancid and the vitamin E to deteriorate.
Generalised weakness due to myopathy will occur and
is also worsened by selenium and sulphur containing
amino acid deficiency. This syndrome is commonly seen
in Cockatiels. |
Vitamin D3 is often deficient
in pet birds. Various vitamin D precursors are metabolised
within the skin by ultraviolet light to form Vitamin
D3. Glass tends to filter out u/v light form sunlight.
As the calcium to phosphorus ratio in most seeds is
poor (high phosphorus and low calcium) many parrots
become seriously depleted. In birds that are laying
eggs or still growing the problem is quickly seen as
egg-binding in the former and osteodystrophy with bony
deformity in the latter. Grey Parrots are very prone
to calcium deficiency, which manifests as convulsions
or the bird will suddenly fall off its perch. Their
ionised calcium (and often total calcium) level is low
as is their Vitamin D3.
In a study of hand-reared Grey Parrots,
44% of the birds had bent bones, mostly due to poor
feeding of the young birds and also importantly their
parents.
Calcium and vitamin D3 can be adequately supplemented
using a powder supplement such as Pet Chef at the manufacturer’s
recommended quantities, water soluble products are not
as good. Ideally vitamin D3 can be made by the bird
if it is allowed to be outside in the sunshine several
times a week. Sunshine can be replaced by full spectrum
lights available commercially for birds (don’t
use reptile or plant lights). These lights have a limited
life and their ultraviolet emission can fail before
their visible light goes. They also have to be situated
near the birds to have an effect on vitamin D levels
in the body.
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B vitamins are also deficient in a seed based diet
and although these vitamins are made in the gut the
birds do seem to get signs of deficiency that could
be due to deficiency: poor skin and feather quality,
dermatitis, and fatty liver problems. |
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| Vitamin
K deficiency is seen in Fig Parrots but is not usually
identified in other species. However if a broken blood
feather or bleeding claw continues bleeding it is worth
considering in any parrot. |
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| Most
seed based diets are deficient in some essential amino
acids. These are usually lysine and methionine. In productive
birds, moulting, egg-laying and growing birds, protein
deficiency is obvious. In adult non-productive birds
it is less so but these birds often have great difficulty
in responding to disease or injury. Feather plucking
parrots find it difficult to produce normal feathers,
which compounds their problems. |
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These amazons
show severe malnutrition in their feathers. Comparing
a normal secondary feather (right side) to the same
feather from a malnourished bird of the same species
(left side) it is easily seen that the pigmentation
is grossly abnormal and the feather is smaller than
it should be. Many times the feather barbs grow in a
deformed manner and the feathers are unable to form
an integral structure. Moult is delayed and this shows
as worn feathers.
Iodine is usually low in seed. This leads to
a lack of thyroxine, which controls the
basal metabolic rate and also initiates moulting.
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This Amazon parrot had been losing its feathers and
not growing new ones for several months. There was
no sign of infection. The bird was kept on the same
diet with Pet Chef added daily. The second picture
taken 6 weeks later shows rapid new feather growth.
The bird moulted completely over the next 3 months.
Many parrots will moult excessively within a few weeks
of going onto a vitamin and mineral supplement. Usually
these birds have not had a complete moult for several
years due to lack of nutrients. |
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• poor integument quality: flaky beaks and
scaly skin plus softening of the claws and beak allowing
overgrowth
• poor plumage, both in form and colour
• delayed or incomplete moult
• convulsions or muscular weakness
• lethargy and inability to fly
• lipomata
• upper respiratory tract disease plus conjunctivitis
• reduced resistance to disease
• inability to breed: lack of libido, egg-binding,
infertile eggs, deformed baby birds
Most birds have specific feeding times and do not
usually need to eat outside them. They feed in the
morning and in the evening. Parrots are vegetarian
birds. They should be fed a balanced vegetarian diet
and the diet should be in a form where it is difficult
for the bird to be selective. The food should be fed
in a quantity where the bird is kept slightly hungry
and especially where it is keen to eat its next meal.
Parrots (and other birds) are similar to many humans;
they will eat a favourite food when they aren’t
hungry and will continue to do so. Unfortunately many
people see this as a reason to feed the bird large
quantities of this particular food.
A balanced vegetarian diet can be made from a mixture
of fruit, vegetables and pulses. Pulses is a term
used for peas and beans. The pulse mixture that I
use consist of equal parts of mung beans, black-eyed
beans, chick peas and marrowfat peas with half a part
of soya beans.
I take equal quantities of apple and raw carrot
and chop them into bean sized lumps in a food processor.
To this I add an equal quantity of pulses that have
been soaked for 24 hours and then thoroughly washed
and drained. It is also possible to gently cook the
pulses rather than soak them. I then chop the whole
mixture into pieces about 2-3mm in size. I add a suitable
vitamin and mineral supplement (Pet Chef) and mix
into the food. Please always use supplements at the
recommended rate and dose: if it says daily on the
packet, using the supplement once weekly will produce
a deficient bird.
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This
is a low calorie well-balanced food and is suitable
to feed throughout life to the larger parrots. It is
also suitable for the birds whilst rearing their chicks.
This diet is too low in calories for small parrots such
as conures and parakeets or during the winter if the
parrots are kept outside without heat in the UK. These
birds should have some seed added to their diet. Macaws
seem to need more oil in their diet and they should
have some large nuts such as walnuts and brazil nuts
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Birds always tend
to eat selectively. It is possible to prevent this by
being careful about the amount of food that is fed each
day. The birds should be fed twice daily. The apples/carrots/pulses
mixture is fed in the morning. If it is finished, then
later in the day extra food can be provided in the form
of more mixture if the birds are breeding or seeds and
nuts in birds that require them, especially in cold
weather when the nights are short.
I recommend a powder form of vitamin and mineral supplement,
such as Pet Chef can supply.
There are a number of water-soluble products that are
sold to supplement vitamins and minerals, especially
calcium. Even when the manufacturer’s instructions
are followed these products do not prevent deficiency.
They should not be used or relied upon.
All parrots should be provided with grit.
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The grit sold
for pigeons is suitable. Parrots start to take it as
soon as they are weaned. Oyster-shell grit is useful
as a source of calcium. Parrots only need a small amount
of grit so it may seem as if they are not taking it.
Radiography usually shows there is grit in the gizzard.
Birds are able to manage without grit but I have seen
a lack of grit cause various severe problems, even life-threatening
problems in parrots.
The big drawback with this fresh vegetarian diet is
that it can ferment if left for a long time in hot temperatures.
Pelleted diets are less prone to this. All-in-one pelleted
diets are also the most convenient and suitable way
of feeding single pet birds. There are a number on the
market in Europe and the USA. Initially owner and parrot
acceptance may be low, primarily because many birds
do not like them. The client must be educated and they
must persevere. Do not attempt to force an ill bird
to change diet and do not force the bird to eat the
new diet by starving it. Young adventurous birds will
often make the change quickly; older birds do not. It
is possible to introduce the pellets into the normal
diet and slowly change the quantity being offered. Over
a few weeks the bird will end up eating 100% pelleted
food. However it takes a ‘good’ owner to
make this work. If the owner is sure that the bird will
not eat its new diet then it is best for the vet to
take control.
I admit the bird and
tell the owners that I am going to keep it for a week.
I then place a small quantity of the pellets in its
food bowl. If possible I weigh the bird. I watch its
droppings to see if the faecal portion disappears. Its
gut is then empty and if it is not eating the pellets
it has to be fed. I usually use a baby bird food made
by the manufacturers of the pellets and give this two
to four times daily by crop tube. The amount of supplementary
feeding depends on weight loss of the bird. Weight loss
is not common and the bird usually requires feeding
only twice daily. It is rare for the bird not to be
eating the pellets by day five.
I tell the owners that the pellets are to replace the
seed-based diet but that the bird still needs some fruit
and vegetables and it can have its treats - pizza crusts,
chips, nuts in small quantities. The pellets must remain
as 80% of the diet.
Treatment of chronic vitamin deficiencies
is by dietary change. However owners should be made
aware that full improvement will take a year. For
acute problems, such as grey parrots with convulsions
more aggressive treatment is required. I tend to avoid
using injectable multi-vitamin supplements. In my
experience they are a dangerous.
Convulsant grey parrots or birds that are egg-bound
should be given subcutaneous 10% Calcium borogluconate
and be fed a baby bird food (10 mls for a grey parrot)
with added calcium (Nutrobal, VetArk UK) by crop tube.
The bird should then be put somewhere quiet and warm.
Most birds lay their egg within a few hours.
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