engleski

Chlamydophilosis in laying hens : a case report

In the 40s and 50s years of the last century, chlamydiosis were often detected in turkeys, chickens, ducks and pigeons in all over the Europe and USA (GRATZL and KÖHLER, 1968 ; ANDERSEN et al., 1997.). Moreover, infection in humans were also reported, especially in those closely connected to infected birds (Andreson and Vanrompay, 2003). The cases of chlamydiosis in laying hens were reported (MALKINSON et al., 1987 ; ARZEY and ARZEY, 1990), but were often inapparent. Epidemiological and laboratory examination revealed that chickens are relatively resistant to chlamydiosis, especially older birds (Anderson and Vanrompay, 2003). In total 36, 000 of laying hens of light hybrids at the age of 25 weeks were collected from different farms and reared together in cages (batteries).. Out of them, 450 were raised before as free-range chickens, in close contact with other free-living birds and had very poor egg production (20%, instead of 94%). At the age of 28 weeks these 450 hens developed different respiratory symptoms (rhinitis with purulent exudates, sneezing, and conjunctivitis). The symptoms slowly started to spread to all birds in the facility and were followed by decreased egg production. The mortality was not elevated. Post mortal examination revealed sero hemorrhagic rhinitis and tracheitis, congestion of the lungs, catarrhal enteritis, perihepatitis, pericarditis and atrophy of the ovaries. Organs from 5 hens (liver, lungs and ovaries), together with 10 tracheal swabs and 4 faecal samples (10g) collected on 4 different parts of the batteries were subjected to bacteriological and mycological examination, which revealed the presence of Bacillus spp., Aspergillus fumigatus and Candida spp. in trachea, liver, and lungs, E. coli in faeces, while ovaries were negative. Embryo inoculation with tracheal material to chorioallantoic membrane or via allantoic route gave negative results, and ILT, pox and respiratory viruses were excluded. The diagnosis remained unknown, so another 28 so-called “ triple swabs” were taken (from conjunctiva, pharynx and cloaca) to detect the possible presence of specific antigen of C. psittaci by commercial ELISA kit (IDEIATM PCE Chlamydia, DAKO, United Kingdom), which revealed 22 positive samples (78.5%). After antimicrobial therapy with enrofloxacine for ten days (“ floksidin” , 10% solution, Intervet) via drinking water, together with vitamins, the symptoms disappeared, and the egg production increased up to 85%, but all hens with obvious clinical symptoms were euthanized. The identification of C. psittaci by PCR and determination of the serotype is still in progress.

C. psittaci; laying hens

nije evidentirano