Chronic respiratory disease (crd), Biology

Chronic respiratory disease (CRD)

Infection with Mycoplasma gallisepticum is characterized by slow onset; CRD is seen in chickens, turkeys, and other birds. Ducks from multispecies mixed populations may be infected. It is now rare in commercial poultry. The route of infection is via the conjunctiva or upper respiratory tract with an incubation period of 6-10 days. Transmission is generally by direct contact with birds, exudates, aerosols, airborne dust and feathers, it may also be transovarian. Recovered birds remain infected for life; subsequent stress may cause recurrence of disease.

The infectious agent survives for short periods although prolonged survival was reported in egg yolk and allantoic fluid, and in lyophilized material as well as on hair and feathers. Intercurrent infections with respiratory viruses (IB, ND, and ILT), E. coli, Pasteurella spp. Hemophilus and extreme environmental conditions are predisposing factors for clinical disease.

Symptoms and lesions: Clinically, the birds show coughing, nasal and ocular discharge, and thereafter the batches undergo poor productivity, unable to pickup bodyweight, leg weakness, reduced hatchability and hatching of weaklings. The classical picture presents airsacculitis with caseous plugs on lungs, air sacs; pericarditis, catarrhal inflammation of nasal passages, sinuses, trachea and bronchi. Occasionally arthritis, tenosynovitis and salpingitis in chickens are also noticed.

Diagnosis: History, lesions, isolation and identification of organisms, demonstration of specific DNA by PCR are normally used for diagnosis of Mycoplasmosis. Culture requires inoculation in specific pathogen-free embryos or more commonly in Mycoplasma broth followed by plating out on Mycoplasma agar containing sterols and horse serum. Serum agglutination is the standard screening test used to detect suspect flocks.

Prevention and control: Mycoplasma infection is important for trade in birds or hatching eggs. Purchase of uninfected chicks, all-in/all-out production systems, biosecurity, and culling of infected birds with routine serological monitoring are the means of disease control.

Posted Date: 9/18/2012 8:39:27 AM | Location : United States







Related Discussions:- Chronic respiratory disease (crd), Assignment Help, Ask Question on Chronic respiratory disease (crd), Get Answer, Expert's Help, Chronic respiratory disease (crd) Discussions

Write discussion on Chronic respiratory disease (crd)
Your posts are moderated
Related Questions
Describe the clinical significance and symptoms of edema. How does edema (in its different forms listed in your text) appear on medical imaging examinations? Discuss any specific c

In order to define growth limit logistic equation was given by Verhulst. In a given ecosystem, the maximum population that can exit is called carrying capacity (k).  The factors wh

Sporadic exertional  rhabdomyolysis (azoturia, tying up in horses) Azoturia is a metabolic condition of horses that is characterized by reluctance to move and poor performance.

Obturator - Ovule An obturator is an outgrowth of the placenta or funicle or integument or style near the micropyle. It is presumed to guide the pollen tube to the micropyle.

Explain Properties related to protein-protein interactions? Properties related to protein-protein interactions include dough formation, one of the important functional properti

Terminal process of diseased stage This is the last stage in the process of disease. In this stage, the disease process is halted either temporarily or permanently. There are t

Question 1 Explain the essential elements of Pharmaceutical Manufacturing Question 2 What is pharmacokinetics? Briefly describe the different pharmacokinetic processes that d

Infectious proteins are present in: 1.Gemini viruses 2.Prions 3.Viroids 4.Satellite viruses Prions

ALCOHOLISM - Continual heavy consuming of alcohol is called alcoholism or drinking . Word alcohol is refered to C 2 H 5 OH or ethyl alcohol or ethanol or grain alcohol.

Water of Estuaries The water of estuaries is turbid because of the great number of particulates in suspension in the water. The turbidity is minimum near the mouth and increas