Salmonellosis in poultry, Biology


Salmonellosis in poultry

A wide variety of serovars are prevalent among chicken, turkeys, ducks and geese. The poultry is an important reservoir of salmonellae. The common diseases in poultry are pullorum disease or bacillary white diarrhoea due to infection with S. Pullorum, fowl typhoid due to S. Gallinarum, and fowl paratyphoid due to other serotypes. S. Gallinarum and S. Pullorum are considered to be identical in all respects except pathogenicity. Serologically both are identical.


Pullorum disease: The adult birds are symptomless carriers. The infection persists in ovaries. Some of the eggs laid by birds with infected ovaries carry the organisms in yolk. These infected eggs when hatched constitute the source of infection to other chicks in the incubator and hatcher. The faeces of infected chicks contaminate the environment thus spreading infection to other chicks. Some young chicks which survive infection may remain as symptom less carriers.In young chicks the disease is acute, septicaemic and highly fatal. When the disease is less acute the chicks appear sluggish; there is loss of appetite and thirst, drooping wings and ruffled feathers. Some chicks show nervous symptoms. Diarrhoea is generally present and vents of chicks are covered with whitish faeces. The duration of illness is 2 to 3 days. The disease in adult birds is of chronic type. The affected birds may not show any symptoms except lowered egg production. The lesions of dead chicks show congested spleen and yellowish liver streaked with haemorrhages. In adult hens the ovary is pedunculated and misshapen ovules are found detached in abdominal cavity. Adult birds died of acute disease show congested level with necrotic areas. Spleens and kidneys are also enlarged and congested.


Diagnosis: It can be arrived at by the history of disease in a flock, symptoms of ailing birds and lesions. A final diagnosis depends upon the isolation and identification of causal organisms. The diagnosis in carrier birds is made by various modifications of bacterial agglutination like tube-agglutination test and rapid whole blood test.


Control: To control the disease, serological tests like rapid whole blood test should be applied to detect carrier birds. The carrier birds as well as the survivors should be slaughtered. Incubators and hatchers should be fumigated with formaldehyde. In India, Salmonella Pullorum coloured antigen is used to identify the prevalence of the disease in young chicks and usually salmonella free chicks are distributed for commercial rearing.
 

Fowl typhoid: The infection of fowl typhoid also passes from hen to chick like pullorum disease. The common route of infection is by ingestion. The disease is of varying severity among growing birds. A high proportion of birds become carriers. They excrete S. Gallinarum intermittently in faeces. The disease in chicks is indistinguishable from pullorum disease. It is common among young stocks and adult birds causing a mortality up to 50% in acute outbreaks. The birds are listless and show diarrhoea with greenish faeces and purple discolouration of comb and wattles. The liver is congested and enlarged with multiple necrotic areas. Spleen also shows similar lesions. The small intestine may show catarrhal inflammation with petechial haemorrhages.


Diagnosis: The causal organism can be isolated from heart blood and visceral organs. The tube-agglutination test and whole blood rapid agglutination test can be used for detecting fowl typhoid in living birds.


Control: The measures to control the disease are similar to those used in pullorum disease. Vaccines have been developed using avirulent variants and rough variants such as 9R. Cross protection using S. Enteritidis has been reported.

Posted Date: 9/17/2012 7:46:13 AM | Location : United States







Related Discussions:- Salmonellosis in poultry, Assignment Help, Ask Question on Salmonellosis in poultry, Get Answer, Expert's Help, Salmonellosis in poultry Discussions

Write discussion on Salmonellosis in poultry
Your posts are moderated
Related Questions
Q. What are the two major divisions of the chordate phylum? Chordates are divided into vertebrates and protochordates (urochordates and cephalochordates). Q. What are the d

Q. Explain Shannon-Wiener index? This diversity measure is based on information theory of measure of order (or disorder) within a particular system. For our uses, this order co

Q. Example of Trial Balance columns? Start by extending all of Micro Train's revenue and expense account balances in the Adjusted Trial Balance columns to the Income Statement

Define need of vitamin C during pregnancy period? Vitamin C deficiency has not been shown to affect the course or outcome of pregnancy in humans, although low plasma levels hav

write a comprehensive note on vitamins?

Q. What is the difference between carriers of HIV and AIDS patients? A person be able to be a carrier of the HIV without necessarily being affected by the immunodeficiency synd

Question 1 What is megalobastic anemia? Discuss briefly its lab diagnosis. How would you differentiate megaloblastic anemia from other anemias? Question 2 What is hemog

MENSTRUAL CYCLE - It occurs only in Primates. Start at the age of 13 yrs. upto menopouse. During this period, generally one egg is released every 28 dyas or so alternately f

What is dichogamy? Dichogamy is the phenomenon of the maturation of female reproductive structures of the plant in a dissimilar period to the maturation of the male reproductiv

How do you determine net atp production after complete oxidation to CO2 and H2O using mitochondrial ?-oxidation, the TCA cycle, the mitochondrial electron transport chain and oxida