A survey on the efficacy of tulathromycin in the treatment of infectious pneumonia of small ruminants in Iran

Abstract

The principle aims of this study were to evaluate clinical, hematological, microbiological and macro and micro pathological effects of tulathromycin on small ruminants infectious pneumonia (IP) and to determine the side effects of the drug in the injected site. For this purpose, all ruminants (10 sheep and 9 goats) with signs of IP were assembled in the Khorasan-E-Razavi Province Veterinary Organization research centre. Also, all of these animals were free of internal parasite infestations and free of hydrated cysts in the lung tissue. Before tularthromycin injection, samples were taken as nasopharyngeal swabs for culturing Pasteurella spp. and Mycoplasma spp. and performing the Cell Blood Count (CBC) for blood. Each animal was injected at the dose of 2.5 mg/Kg subcutaneously. In 24-, 48- and 72-hours after injection, body temperature (BT), respiratory rate (RR), heart rate (HR), ruminal contraction rate (RCR), lung sounds (LS) and nasal discharges (ND) were recorded between 9-12 pm. Meanwhile on day 1 and day 3, the blood sampling was repeated and on day 3 nasopharyngeal swabs were repeated. Furthermore, 9 sheep and goats were killed on day 9 and the remainders were killed on the day 15 following injection and post-mortem inspections were conducted on lungs. From cases with lung lesions, a sample was taken for histopathological examination. The data showed that: A) The mean difference of BT, RR and HR of 0-, 24-, 48-, and 72-hrs after Tulathromycin injection was significantly different (p< 0.05). B) The mean difference of No. WBC and % neutrophils of 0-, 24-, 48-, 72-hrs was significant (p< 0.05). C) Pasteurella spp. was isolated from all sheep and goats before injection while this organism was cultured in only 2 of the animals on day 3 after tulathromycin injection (p< 0.05). D) Mycoplasma spp. was cultured from 57.9% of the small ruminants and the results were identical in the second culturing with the exception of one animal. Mycoplasma spp. was cultured from 57.9% of the small ruminants and the results were identical in the second culturing with the exception of one animal. E) 50% and 44.4% of the sheep and goats that were killed on the 9th and 15th days post-injection showed various pulmonary lesions including apical lob consolidation, apical lob consolidation plus adhesion, bronchopneumonia plus observed pleurisy. On the basis of this investigation Tulathromycin has not had any antibacterial effect on Mycoplasma spp.