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PostPosted: Tue Jan 08, 2013 7:25 pm 
Clever Cockerel
Clever Cockerel
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Joined: Sun Sep 27, 2009 10:09 am
Posts: 1513
Location: Murwillumbah, NSW
I recently had a broody sitting on some guinea eggs when I realised she had sour crop, yeasty smelling, very full and sloshy, I treated her with nystatin for a couple of days and it went down. A few days later after the keets had hatched I grabbed her again and found she had a badly impacted crop, it felt like a ball of plasticine, I spent the next 7-10days treating her with oil, probiotics etc but had no luck in shifting it.
Although she was very anaemic and obviously unwell she continued looking after the keets, so I decided to take her to the vets. The vet took a crop and poo sample and after examination diagnosed a megabacteria infection and after consulting an avian specialist prescibed fungilin, containing amphotercin B, a cheap drug costing approx $12 a bottle, and a course of baytril and probiotics.
Neither the vet or specialist held out much hope for her, thinking something else must be going on with her, but 10 days later I have a healthy broody with a functioning crop.
Below is the article by Dr Colin Walker the vet gave me to read.

By Dr. Colin Walker

Megabacteria are cigarette-shaped organisms about 20 times the size of most common bacteria,
which live in the digestive tract of some birds. First identified in Australian budgerigars in the
early 1990s, they have the potential to ulcerate the lining of the bird’s Glandular Stomach. This
leads to loss of blood and tissue fluid, predisposes the bird to secondary infection with other
organisms and interferes with normal digestion. Initially, as the ulceration begins, the birds
develop diarrhoea and become fluffed and quiet. As the disease progresses, the birds start to lose
weight and as the ulcers deepen and start to bleed the birds become anaemic. This means they
have trouble maintaining their normal blood pressure and, as a result, their feet become pale and
cold to the touch. In severe outbreaks, 50% or more of the birds can die.

Megabacteria infection is diagnosed usually by microscopic examination of a bird’s dropping.
However, our understanding of the disease that Megabacteria causes has changed since the
organism was first identified. What we used to believe was that if the organism was found in a
bird’s dropping, then this would be the cause of any digestive tract health problem it was
experiencing and that the bird should be immediately treated. We now realise that this is not
necessarily the case. We now know that although the organism can cause disease in its own right,
it is more often a secondary agent, only becoming involved after some other disease or poor
management practice has already weakened the birds, making them more vulnerable to disease
Also, recent work at the University of Melbourne has shown that the organism is not a bacterium
at all but rather a yeast and indeed the pattern of disease it causes is more typical of yeasts rather
than many bacteria. As a result of this recent work, the organism has been renamed and now
should be called by its correct name Avian Gastric Yeast. However, the term Megabacteria is so
entrenched that its use is likely to persist.

It seems that Megabacteria are now fairly endemic in our Australian budgerigar flocks, with
many young birds being passively exposed to the organism either directly from their parents or
other birds or droppings in the aviary from a young age. With ongoing good care, fortunately in
many cases this low-grade ongoing exposure does not cause disease but rather encourages the
development of a natural immunity to the organism. Disease comes when birds are exposed to a
level of organism to which the natural immunity they have developed is not strong enough to
protect them.

Typically, because of these factors, disease is seen most commonly in the post-weaning time.
Young birds have simply not been alive long enough to develop the strong natural immunity of
the adult and yet are under multiple stresses that are inherent in the weaning process such as
separation from their parents, establishing themselves in the new aviary, and learning to feed and
water themselves. Superimposed on this, any other stresses such as overcrowding, low hygiene,
poor nutrition or failure to provide good control of other diseases, in particular Coccidiosis,
during this time sets the stage for a massive outbreak and particularly high losses.

Around the time the organism was first being identified, Dr Fillipich of Queensland University
trialled an extensive range of antimicrobial agents to see which were effective against
Megabacteria. He found only one, an antiyeast/antifungal drug called Amphotericin B. In
Australia, this is available under several brand names. There used to be a Squibb product called
Fungilin, which contained Amphotericin B as a thick orange syrup. Birds would not drink this
but it was useful in crop tubing individual birds. Unfortunately, Squibb no longer manufacture
this product. Vetafarm, an Australian company based in Wagga, produces a water-soluble yellow
Amphotericin B-based powder called Megabac S. This is not always available but at the time of
writing can be purchased through their web site. Being water soluble, it is useful where large
numbers of birds need to be treated. Squibb also produces Amphotericin B in tablets, called
Fungilin lozenges. Although designed for human use, they can be adapted for use in birds under
veterinary advice. Usually a tablet is crushed into 6 ml of water and 0.25 ml of this solution is
given to sick birds daily. The tablet is not easy to dissolve, however, it eventually forms a yellow
suspension that will flow through a crop needle. Alternatively, one tablet can be dissolved into
80 ml of water and provided ad lib to unwell birds. The usual suggested treatment time is at least
10 days. Do, however, remember that budgies are not obligate drinkers. Unlike other birds, such
as pigeons, which will rush to a drinker if deprived of water for only a few hours, budgies can go
without water for 20 days and still look basically normal on the perch. This means that just
because medicated water is in front of them, there is no guarantee that they are getting the drug.
Another group of therapeutic agents which may help in managing Megabacteria, which initially
might seem a little bit strange, are the acids. Stress disrupts the normal bowel bacteria, in the
process interfering with their lactic acid production. This lactic acid keeps the pH of the healthy
bird’s bowel on the weakly acidic side, in the process helping to protect it from disease. With
stress, this innate protective mechanism can be lost. It is thought that by lowering (ie acidifying)
gastric pH, an intestinal and stomach environment is created that not only makes it difficult for
Megabacteria to establish in uninfected birds but also makes it difficult for Megabacteria to
multiply in birds that are already infected. Usually, either citric acid (a white crystalline powder)
at a dose of 1 teaspoon (3 g) to 4.5 – 6 litres or apple cider vinegar (acetic acid) 5 – 10 ml to 1
litre, are used. Being natural nutrients, at the above doses, there is no risk of a toxic reaction and
so they can be used fairly freely. Their use also helps ensure that droppings passed build up an
acidic dressing in the aviary, helping to inhibit Megabacterial survival in the environment.
Probiotics are also thought to be of use through promoting healthy generally and by helping lower
digestive tract pH through the production of lactic acid.

So, what should you do if your veterinarian tells you that your birds have Megabacteria? The
correct answer depends on whether the birds are unwell and if so, how many are affected. Being
a stress-based disease, only part of the answer involves the use of medication.
If all of the birds appear clinically normal, the appropriate thing to do is simply provide ongoing
good care. With ongoing good management practices and the maintenance of a good aviary
environment, the organism is unlikely to cause disease and the low-grade ongoing exposure is
likely to strengthen the birds developing immunity.
If small numbers of birds occasionally become unwell (and the majority of aviaries fit into this
group), a three-point plan is followed:

1. Megabacteria exposure to further birds is reduced by separation of the unwell birds and a
super thorough clean of the aviary. Unwell birds are treated with Amphotericin B
(usually Fungilin lozenge solution, 0.25 ml daily for at least 10 days via crop tube).
There may also benefit in treating severely unwell birds with a broad-spectrum antibiotic
to control any secondary bacterial infection. Baytril 0.5 drop twice daily per bird is a
good choice.

2. Aviary management and environment are reviewed to identify any predisposing stresses
that may have triggered the outbreak. To be thorough, this should involve a veterinary
health profile to screen for any other concurrent health problems.

3. Ongoing good care is provided so that the majority of birds are best placed to resist the
disease. Acids or probiotics can be placed in the water, mixed freshly each day, until a
period without new birds becoming unwell occurs.

If large numbers of birds become unwell, then the same basic procedure is followed. It may no
longer however be practical to crop tube individual unwell birds with Amphotericin B, and so
water-based medications containing Amphotericin B (Fungilin lozenge or Megabac S) may need
to be used. In aviaries with severe ongoing problems, the regular use of acids or probiotics, eg 2
days per week, may decrease the chance of severe disease outbreaks.


PostPosted: Tue Jan 08, 2013 9:16 pm 
Champion Bird
Champion Bird
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Joined: Sun Oct 02, 2011 11:06 pm
Posts: 886
Location: Sunshine Coast, QLD
Get the crop and faecal material tested again. It is uncommon to clear the infection first time despite clinical improvement. It may take 3 or more treatments and a considerable percentage are uncureable. It is not uncommon that this pops up in birds with immunosuppression for other reasons and it is extremely uncommon in poultry so I'd be watchful of leukosis or mareks in the background somewhere. Good luck.


Breeder of Exotic waterfowl, wild type Muscovy, Dutch bantams, Phoenix and Yokohama Fowls.

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