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7) Pox
Causes and Clinical Signs
Pigeon pox is caused by a
virus infecting the bare skin around the eyes, on the beak, on the feet and internally
within the mouth and throat area. On occasions infection of a wound on a feathered
area of the body can occur.
The lesions are typically
scabby in appearance with pus often being present due to secondary bacterial
infection.
The internal form can be
so severe that feeding and breathing are affected to the point that death occurs.
Lesions typically occur 4 to 14 days after initial infection and may be present for
several weeks.
Diagnosis
This is based on the
clinical signs – the internal form affecting the mouth and throat may need a
laboratory diagnosis to confirm this condition.
The disease needs to be
differentiated from canker with which the mouth form could easily be confused, and from
Candida infection caused by a fungal infection of the mouth.
Treatment
As with paramyxo this
condition is due to a virus and no specific treatment is available. Antibiotics may
be used under veterinary direction to combat secondary infections and multi vitamins may
be of benefit in some birds during the recovery phase.
Prevention
As no specific treatment
is available the prevention of the disease by vaccination is very important.
All birds over six weeks
old should be vaccinated and vaccination should be done in all birds at the same
time. Annual re-vaccination should be done between the 30th September and the 31st
December each year. If birds are vaccinated at any other time of the year it is
important that they are withheld from racing for a period of six weeks after
vaccination.
Vaccination of young
birds in Spring would be advised in lofts where pigeon pox is endemic.
The pox virus is very
resistant and will remain infective for many months. It can be transmitted by biting
flies and other insects. As a result good loft hygiene is important in the control
of the disease.
8) Mycoplasma
Causes and Clinical Signs
Mycoplasma infection is
endemic in the pigeon population and the majority of pigeons will be affected by the
organism. The Mycoplasma organism is bacteria-like in many of its properties and for
diagnostic purposes it can be cultured on a special media in the laboratory. Stress
conditions favour the developments of the clinical disease in birds. The principle
clinical finding is one of catarrh and initially there is a clear nasal discharge which in
time becomes thicker due to the presence of pus. Affected birds may breath through
open beaks and clear rattles and wheezes may be detected when the bird is examined.
The disease appears to lower the bird’s resistant to other disease and chronic
infection can markedly affect performance due to respiratory problems.
Internally the air sacs
can be seen to be affected and secondary bacterial infections can occur at this site.
Diagnosis
The clinical presence of
catarrh together with respiratory sounds are highly suggestive of this condition.
Reduced performance in an otherwise healthy bird may also suggest that Mycoplasma is
present. Post mortem examination shows typical signs in the respiratory system and the
organism can be cultured in the laboratory.
Treatment
Suitable antibiotic
medication with Enrofloxacin, Tilmicosin, Tetracyclines, Tylosin or Tylamulin is effective
against uncomplicated cases of Mycoplasmosis. These antibiotics may be prescribed by
a veterinary surgeon where their use is indicated by the presence of disease.
Prevention
The disease spreads
rapidly from pigeon to pigeon. Prevention is very difficult as birds mix with birds from
other lofts during the racing and show season. Eradication for any length of time is
hence virtually impossible. The organism is easily killed by most disinfectants used
to clean lofts.
In lofts where the
disease is known or suspected to be clinically present strategic use of suitable
antibiotics at times of stress may be recommended by a veterinary surgeon, e.g. when young
birds are being raised and at the end of the racing season.
9) Salmonellosis
Causes and Clinical Signs
Salmonellosis is caused
by a bacterial infection and a number of different strains of Salmonella are capable of
causing disease in pigeons.
The disease is
particularly severe in young birds and can be introduced into a loft by an apparently
healthy carrier bird that can excrete the organism in faeces or saliva but which shows no
clinical signs of disease itself. Young birds can be affected from crop milk or
affected faeces. Salmonellae most commonly affect the intestinal tract.
Affected birds have enteritis which may be blood stained, they are depressed, rapidly
become dehydrated and emaciated and death quickly follows if they are not treated.
It is possible for
Salmonellae to enter the blood stream and a generalised infection will result. On
post mortem examination the organism can be recovered from various body organs.
In addition to the two
forms of Salmonella recorded above cases are seen where the organism localises in one or
more joints. Affected joints are swollen and painful and movement of the joint is
lost due to the pain involved. If the organism localised in the brain nervous signs
will be seen depending upon the area of brain involved.
Diagnosis
Laboratory testing is
required to confirm a diagnosis of Salmonellosis. Positive cases must be reported to
the Department of the Environment, Food and Rural Affairs (DEFRA) under the Zoonosis
order. The disease needs to be differentiated from other causes of diarrhoea
(viruses, other bacteria, parasites etc) injury to the joint and other causes of nervous
signs including Paramyxo-virus and poisoning.
Where dead birds are
available for post mortem examination cultures from the birds should determine whether or
not the organism is present. In live birds faecal and mouth swabs may detect
the organism but as birds can be intermittent excreters a single negative result does not
definitely preclude the presence of Salmonella.
Note:
Most strains of
Salmonella can cause disease in man. This can be very serious in the young, old and
debilitated. Strict personal hygiene after handling birds and loft equipment and
before eating /smoking is therefore essential.
Prevention.
Isolate newly introduced
birds and if there is any doubt have faeces and mouth swabs cultured for
Salmonella.
Good loft hygiene will
reduce spread within the loft and where a loft is known to be affected then an eradication
and control programme, which will depend upon conditions in the loft and facilities etc.,
needs to be agreed with the attending veterinary surgeon.
10) Worms
Causes and Clinical Signs.
Worms are intestinal
parasites that can affect birds of all ages but due to some degree of resistance in older
birds the more extreme clinical signs are more commonly seen in the younger birds.
In mild infestations
clinical signs may not be obvious. Weight gain in young birds may be adversely
affected and in more severe infestations diarrhoea, depression and loss of condition, even
emaciation, may be obvious, as may anaemia.
Two types of worms affect
pigeons, Roundworms and Tapeworms. Both large and small Roundworms will inhabit the
bird’s intestine and these worms pass their eggs into the gut and these are voided by
the pigeon in its faeces. In the environment these eggs develop and are then
ingested by the other pigeons.
Tapeworms require
‘intermediate hosts’ and these include snails, slugs and insects. Within
these creatures the eggs develop and when swallowed by a pigeon another mature Tapeworm
can develop.
Diagnosis.
In the live bird worm egg
counts on faeces are a reliable indication of the level of infestation. Visual and
microscopic examination of gut contents can identify worms post mortem.
Treatment.
Either water or food
medication is available to treat for roundworms, treatment for Tapeworms is not as
easy.
We recommend that all
birds in a loft are wormed at the end of the racing season and again before pairing and at
other times when egg counts show worming to be necessary.
Prevention.
Regular removal of faeces
from the loft (every other day) is recommended as is the control of insects that may be
intermediate hosts of the Tapeworm.
A programme of regular
worm egg counts should be started and birds treated when the counts show this to be
necessary.
Routine treatment of
birds after the flying season and before pairing will help reduce the worm burden for
young birds.
11) Haemophillus.
Cause and Clinical Signs.
Birds infected with
Haemophillus bacteria suffer from a severe conjunctivitis, which affects both eyes.
In this condition the eyelids are markedly swollen and there is purulent discharge.
Affected birds often show
respiratory signs due to infection of the upper respiratory tract.
The disease spreads by
direct contact and droplet infection from one bird to another.
Diagnosis.
Diagnosis is on clinical
signs and laboratory culture from the eyes or nasal discharge.
Treatment.
As this is a bacterial
infection a suitable antibiotic such as a Tetracycline can be prescribed by a veterinary
surgeon once the disease has been confirmed.
Prevention.
Isolation of suspect
infected birds together with a correct diagnosis and suitable treatment is necessary to
prevent the rapid spread of this condition in a loft once an infected bird is present.
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