Zoonotic diseases appeared to be a major hurdle to successful deer farming in Bangladesh

Abstract

Background and aim: Due to the diversified lifestyle and fancy ecology associated with Chitra deer (Axis axis), deer farming has become popular in Bangladesh. Diseases may be the common constrain of successful deer farming. This study aims to investigate the pathological, bacteriological, and nucleic acid based technologies to identify specific causes of morbidity and mortality of captive deer.

Materials and methods: Two deer farms and a park deer (designated as farm A, B, and C) entailing 87, 54, and 20 deer, respectively, showed illness and death constitute the study materials. A total of 42 deer died during this investigation. Following death, routine post-mortem examination, histopathology, impression smear staining, isolation, and identification of bacteria were carried out. Polymerase chain reaction (PCR) and reverse transcription PCR were carried out to safeguard the etiology.

Results: Clinically, farm A and B showed the acute phase of illness and park deer showed chronic illness. Case fatality rates were 90%, 92%, and 100% in farms A, B, and C deer, respectively. Pasteurella multocida and Streptococcus pneumoniae were identified from the visceral organs of farm A deer. Farm B deer was infected with Clostridium perfringens type A. Park deer was infected with Mycobacterium tuberculosis and hydatid cyst.

Conclusion: The infectivity in farm A deer was due to stress as induced by punishing weather. The infectivity in farm B deer was due to feeding a higher volume of protein in the diet. The park C deer may optate infection from companion man and animals living around. The diseases of captive deer identified mainly were zoonotic. It needs extensive veterinary services and specialized technologies to identify these diseases, monitor the infectivity and eliminate the public health important diseases at early onset.

Keywords: deer; enterotoxaemia; mycobacterium; pasteurella; zoonosis.

Figure-1

Farm A deer examined at necropsy showed massive hemorrhages in (a) heart (arrow) and (b) lung (arrow). (c) Multiple white necrotic foci were seen on the liver of Farm A deer (arrow).

Figure-2

Farm B deer examined at necropsy showed (a) severely congested and consolidated (hepatized) lung. (b) Liver appears degenerated and paler with capillary congestion. (c) Massive congestion and hemorrhages were seen in the myocardium. (d) Multifocal necrosis was seen in the kidneys, and the kidneys were soft, paler, and flabby (pulpy) in appearance.

Figure-3

Farm C deer investigated at necropsy showed granulomatous nodules in (a) lung (arrow) and (b) spleen (arrow). (c) Hydatid cyst was seen in the lung of a deer.

Figure-4

Histopathological examination of (a) heart showed Streptococcus spp. (diplococci) in inter-bundular tissues (arrow). (b) There were massive hemorrhages in lung (arrow, 10×) with copious exudate in the alveoli (circle, 10×). (c) Impression smear prepared from the lungs tissues and smears prepared from single colony of agar plate and stained with Gram’s iodine showed Streptococcus spp. (arrow).

Figure-5

Histopathological examination of (a) lung showed widespread congestion and hemorrhages with emphysema in lungs alveoli (H&E, 10×). (b) Section of heart stained with Gram’s iodine showed rod-shaped bacilli in the myocardium (100×). (c) Impression smears prepared from the kidney and liver of infected and dead deer and stained with Gram’s iodine showed the presence of Gram-positive rod (100×).

Figure-6

H&E staining of tissue section of (a) lung showed granulomatous reaction (arrow) consisting of inflammatory infiltration of macrophages, lymphocytes and fibroblasts. (b) Lung tissue section stained with acid-fast stain showed pink color bacilli in the granulomatous nodules (yellow arrow). (c) Brood capsule from the cysts of lung was examined under a microscope showed the future heads of the adult tapeworm (protoscolices) within brood capsules.