Mycoplasmosis of the poultry
The mycoplasmosis in poultry is a chronic disease-like disease in turkeys and chickens caused by mycoplasma is caused ( mycoplasmosis ). In this case, economic losses occur primarily in the rearing of young animals due to insufficient weight gain and qualitative deficiencies in the meat. In addition, there is a slow decrease in the laying activity of the animals in laying hens. The disease is a factor disease because its occurrence is favored by inadequate hygienic conditions and the occurrence of accompanying infections with other germs such as Escherichia coli can often be observed.
Mycoplasma synoviae , Mycoplasma gallisepticum , Mycoplasma meleagridis and Mycoplasma iowae are of particular economic importance . A total of 24 different mycoplasma species have been described in poultry. The previously assumed high host specificity turned out to be incorrect. In addition to turkeys , M. meleagridis has been found in wild birds of prey and M. synoviae has been found in poultry in city pigeons and sparrows.
Clinical picture
The incubation period for chickens is 10 to 30 days, for turkeys it is given as six days to 17 weeks. Chicks most commonly get sick between four and eight weeks of age. The disease mostly occurs during the winter months. The mortality is up to 30 percent.
Chicken chicks have conjunctivitis as well as nasal and eye discharge at the onset of the disease. Some animals also show respiratory symptoms with sniffing and smacking breath noises and clear beak breathing. The feed intake often decreases, the animals have unkempt plumage. The disease develops slowly. Particularly with fast-growing broiler chicks , the different growth rates of the animals in the herd are noticeable. Most deaths occur in fattening herds.
In laying hens , too , the respiratory symptoms described above initially dominate. Here, however, the emaciation of the animals is less important, the decrease in laying performance by 5 to 20 percent is much more noticeable. As the disease progresses, secondary bacterial infections in the area of the lower eye sockets ( infraorbital sinus ) cause bulging swellings, which give the animals an owl-like appearance.
In turkey chicks , the disease begins with increased secretion around the eyes and nose. The animals try to get rid of these deposits by shaking their heads. Similar to chickens, the lower eye sockets are later swollen. This form of mycoplasmosis is known as infectious sinusitis .
In breeding turkeys, late embryonic mortality after infection with M. meleagridis or M. iowae is probably the most important.
Verification procedure
Isolation with subsequent cultivation and polymerase chain reaction are available for direct detection of the pathogen . The serological examination serves to indirectly detect the pathogen in the herd.
treatment
The antibiotics tylosin , erythromycin , spiramycin and tiamulin have proven effective for treatment . Additional antibiotics may be necessary to suppress accompanying infections. Much more effective is the prevention of the disease through hygiene measures and targeted merging of infected animals. Attempts are made to specifically cultivate mycoplasma-free stocks. In addition, active immunization is possible through a vaccination administered into the nasal cavity .