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This article was published in 1954
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
Hexamitiasis—A Disease of Turkeys
H. M. WARE, B.V.Sc., Inspector of Stock, Narrandera.
The running of poultry, especially turkeys, is becoming increasingly popular in Australia. With an increasing poultry population disease problems are also increasing. Unfortunately knowledge of diseases which affect poultry in this country is strictly limited outside Glenfield and a few practitioners who specialise exclusively in poultry work.
HEXAMITIASIS, a disease caused by a one-celled protozoan parasite, Hexamita meleagridis, is one of those diseases which is becoming more prevalent and consequently of more economic importance at the present time. Hinshaw and Rosenwald (1), two American workers, state that this is a disease attacking poults from hatching up to 10 weeks or more; the heaviest losses being in those 3 to 8 weeks old. At such ages mortality is stated to be as great as 75 to 90 per cent. In poults older than 8 weeks, heavy losses seldom occur unless the resistance of the birds has been lowered by other infections or by environmental factors.
Until recently, very few outbreaks of the disease had been reported in New South Wales. The writer was fortunate to have the opportunity to investigate an outbreak of Hexamitiasis in turkeys and the following case report is submitted in the hope that it will be of interest to others having to deal with large numbers of turkeys.
The outbreak occurred on a property in the Murrumbidgee Irrigation Area of New South Wales. This property, primarily a citrus orchard, ran about 800 turkeys. These birds were fed a ration of half mixed grain and oats. During the day the birds had the run of the orchard and consequently had ample green feed. The ration was a properly balanced one.
Investigations into the mortality in the birds was commenced on 10th March, 1953; the owner advising that about 12 birds, aged from 14 to 16 weeks, had died since 7th March, 1953. The most prominent symptoms at this time were progressive weakness and rapid death. Up to 10th March the only poults affected were part of a late hatching introduced from a breeding establishment in South Australia. The affected birds were out on the range for approximately two weeks before the loss of condition was noted. The weather at this time was extremely hot, and small birds particularly were noted to huddle together a good deal and to be eating considerably less than normal. Droppings were copious and frothy.
About two weeks prior to the onset of symptoms these turkeys were vaccinated against Fowl Pox. In fact, birds vaccinated on Saturday, 28th February, 1933, and running on the ground became sick on Saturday, 7th March; while birds vaccinated on Thursday, 5th March, became sick on 12th March. The youngest of the birds vaccinated were approximately 11 weeks old, but practically all birds were over 12 weeks old when they exhibited symptoms of disease. All birds had been raised on wire from day-olds. August September hatched birds were not affected.
On 12th March, 1953, another visit was made to this property when it was found that mortality was increasing and the disease apparently was spreading to other birds. The owner had isolated about 90 showing symptoms; the most prominent of which were rapid loss of condition, reddening of the breast and frothy diarrhoea with a good deal of mucus.
In all, autopsies were held on three birds found dead, while sick birds were killed for examination. The latter showed one very small area of necrosis in the liver, and the duodenum and jejunum bloated in parts. The caeca, one of which was considerably enlarged, contained a large amount of very frothy material. Otherwise the organs appears to be normal. No significant changes were noted in the birds found dead except that the caeca were filled with this frothy material. The writer formed the opinion that the mortality was due to Hexamitiasis or Coccidiosis or a non-specific Enteritis.
On the evening of 12th March, three (3) live turkeys, together with one killed immediately prior to despatch, were forwarded to Glenfield Veterinary Research Station for examination. After diagnosis from these birds the owner was advised verbally by Glenfield that Hexamita had been found. Treatment as recommended by Hínshaw & Rosenwald (1) was conmmenced immediately, This consisted of giving the birds a mixture of 3 per cent, by weight of dried whey in a 1:2000 copper sulphate solution in place of the usual drinking water. At first glucose was substituted for dried whey, the latter being unprocurable at the time.
On the 16th March another visit was made to this property, when it was found that only one bird had died since 12th March, the isolated birds were eating much more feed and there was considerably less diarrhoea. Six (6) more birds were selected and railed to Glenfield.
The birds, dead and alive, were received at Glenfield in the following order — on 13th March one dead turkey, on 14th March one dead and two live turkeys and on 17th March six live turkeys. The report written on 26th March on the examination of these birds was as follows:
"Post-mortem examination of the first dead turkey revealed slight congestion of the mucous membrane of the duodenum but there were no other visible lesions. Smears were negative.
"Of the turkeys received on 14th March, the dead bird was decomposed and not satisfactory for examination. Of the live birds one was very depressed and died shortly after being received. Post-mortem examination revealed catarrhal enteritis, particularly in the duodenum and jejunum. An excessive amount of clear mucus was present. The mucous membrane of the caeca and rectum was congested. Smears from the duodenum failed to reveal any protozoa morphologically resembling Hexamita meleagridis. By staining smears with giemsa the protozoa were seen to resemble the classical description of Hexamita; having eight flagellae. The other live turkey was depressed and showed frothy diarrhoea. Smears taken from the Bursa of Fabricius revealed numerous protozoa resembling Hexamita. This turkey was killed and postmortem examination revealed congestion and thickening of the mucous membrane of the duodenum and congestion of the mucous membrane of the rectum. Caecal smears revealed the presence of Hexamita.
"Of the six live turkeys received on the 17th March three died shortly after arrival. The other birds were depressed and showed diarrhoea. Post-mortem examination of all dead birds revealed catarrhal enteritis; most marked in the duodenum and jejunum. In one bird there were small diphtheritic deposits scattered over the mucous membrane of the small intestine. Small intestinal smears revealed numerous Hexamita. The caeca of two birds showed congestion and haemorrhage of the mucous membrane, particularly in the region of the caecal tonsils. Hexamita were present in caecal smears.
"On the 18th March one of the live birds had died and the others were still slightly depressed. Smears from the two remaining live birds, taken from the Bursa of Fabricius, were positive for Hexamita. Post-mortem examination of the dead bird again revealed catarrhal enteritis and congestion of the caecal tonsils. However, no Hexamita were visible in smears; probably due to the fact that considerable time had elapsed since the death of the bird. The two live birds now (26th March) appear fully recovered from the infection, but smears from the Bursa of Fabricius are still positive for Hexamita."
In all about 40 turkeys died on this farm from Hexamitiasis. It is possible that without treatment a much higher percentage would have succumbed. There appears very little doubt that lowered resistance due to vaccination against Fowl Pox was responsible for the sudden onset of the infection.
It is of interest to note that the writer visited this farm again on the 21st July, 1953. The owner reported that a number of birds were showing a frothy diarrhoea. Smears taken from the Bursa of Fabricius were examined, but protozoa were not seen. It is possible that they may have been there, but not observed owing to the writer's inexperience. On 26th July the owner sent five live gobblers (which had been exhibiting frothy diarrhoea) to Glenfield. Examination of scrapings from cloacal mucosa in wet smears revealed the presence of a small number of Hexamita meleagridis in one gobbler only. This bird had lesions of Fowl Pox on head and neck at the time; being a "carrier" five months after infection.
ACKNOWLEDGMENT :
The writer wishes to express thanks to the Chief, Division of Animal Industry, Department of Agriculture, N.S.W. for permission to make use of information contained in departmental files.
REFERENCE: (1) California Agricultural Experiment Station and Extension Service Manual 3. Turkey Diseases. W. R. Hinshaw and A. S. Rosenwald.