Flagellate infections with Lories, Lorikeets (Subfamily Loriinae) and Hangingparrots (Genus Loriculus spp.).

by Jos Hubers, The Netherlands. Article taken from the Internationaal lori journaal.

When considering bird diseases, we usually think of the mould Candida albicans or bacterial diseases caused by E.coli or Salmonella.

A disease which is, comparatively unknown, but nevertheless quite frequent is a protozolasis caused by the flagellate microbes, which are single-celled organisms driven by whip-shaped flagella.

It is often found in pigeons, termed 'the yellow disease', referring to the discoloration in the throat.

Bengalese finches are known to carry the disease but these birds do not exhibited the symptoms.

Other birds such as the Australian waxbills are also susceptible to this disease.

Flagellates are also found in the intestines of parrots and lorikeets although not all birds are infected by the same flagellate.

Most infected waxbills suffer from Cochlosoma and Trichomonas, parrots from Giardia, while Trichomonas infections are usually found with lorikeets.

The symptoms depend on the variety of flagellate.

In my description I will restrict myself to our main 'target group'.

At first sight, the symptoms may lead to confusion for they strongly resemble the complications arising with crop inflammation which is caused by Candida or non-flagellate bacteria.

I have observed different symptoms:

  • 1. Vomiting or tendency to vomit. The way the bird behaves is comparable to the regurgitation of food for the young or the partner. Some droplets of nectar may appear at the tip of the beak which the bird later swallows. Especially in the early stages, the birds suffers only from the inclination to vomit. In this phase, the bird does not loose weight; nor does it show other signs of illness.
  • 2. Crop stasis. Sometimes the food can remain in the crop. The bird does not eat anymore as food is unable to pass through the crop. It is possible that this is due to flagellate infections although other conditions can produce the same symptoms.

I treated a bird with crop stasis in the following way:I massaged the crop while holding the bird upside down to attempt to remove the crop contents. This did not work and after it remained for more than two days. I dosed with 2ml of physiological saline (9g salt to 1 litre water) into the crop using a crop needle. After massaging the crop again I managed to get some crop contents out which I examined under the microscope. I expected to find Candida but there were in fact many Flagellates.Shortly afterwards, I fed the bird with 1ml of nectar containing the medicine (Ronidazole). Within a day the crop had completely resolved. My lory recovered well from its digestive disorder and soon started to take its usual quantity of food. In my opinion, these experiences clearly indicate that the presence of flagellates may very well lead to crop stasis.

  • 3. No specific Symptoms. To make things more difficult some birds just sit looking ill, with no specific symptoms. Further examination and analysis of crop samples are necessary to determine if Flagellates are involved. Sometimes I examined samples but did not find Flagellates. These were birds which were vomiting. After giving the medicine the vomiting ceased and the birds recovered.The lining of the crop is highly folded enabling the Flagellates to be missed if only one sample is examined.


Taking a smear of the crop and using a microscope with a magnification of 100x to 400x enables us to see the flagellates. These disease carriers do not take long to die off and the diagnosis of flagellates should be carried out within an hour of taking the smear.


The most common medicines for treatment of Flagellates are ronidazole (also known as Ronitrol) and metronidazole (Emtryl). One should take great care in dosing metronidazole. Metronidazole has no effect in very low doses, but a dose that is too high may result in poisoning and, even worse, a dead bird. Considering these dangers, it is far better to use ronidazole (2.5%). Previously 10% was available but this is no longer manufactured. Ronidazole has to be dissolved in water but since the birds belonging to our 'target group' are not seedeaters and take very watery food the dose has to be adjusted.The dose-measuring spoon is normally supplied with ronidazole.A level spoon of ronidazole has to be mixed with 4 litres of nectar. Obviously the amount of ronidazole required has to be in exact proportion to the quantity of nectar used. However, contrary to the metronidazole, the bird will suffer no ill effects from a small overdose of ronidazole. This course of treatment has to be given for 10 days.  

Birds which have suffered from a previous infection should go on a treatment (7 days) twice a year. Flagellates may survive the treatment in the folds of the crop wall and eventually cause another infection.If newly purchased birds have yet not been tested (this applies particularly to imported birds), one would be well-advised to subject them to a preventative course of treatment against a possible infection caused by flagellate microbes.

It is advisable to give all birds a preventative treatment twice a year to avoid problems with Flagellates in your collection.Ronidazole is available in capsules and in powder form. Capsules are to be dissolved in water and are therefore very suitable for seed-eaters. Ronidazole which is sold in powder form is much cheaper and since it will not deteriorate for 3 to 4 years, a group of bird fanciers should consider the possibility of buying large quantities.


This disease is more widespread than most people are inclined to believe. Most of us will remember the case of the imported Iris Lories, Trichoglossus iris, in Holland: all birds died of an infection caused by flagellates. There are plenty of other sad examples. Recently a lory-keeper saw several of his lories and hanging parrots die without knowing anything about the exact cause of the deadly disease. Fortunately, after the pathogens had been detected, he still managed to save a few ill birds thanks to an effective treatment.

My birds go on a cure twice a year; this is merely a precautionary measure. They do not seem to become resistant to flagellates with normal use.


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