Abstract In order to determine the actual prevalence of avian influenza viruses (AIVs) in wild birds in Bosnia and Herzegovina, extensive surveillance was carried out between October 2005 and April 2006. A total of 394 samples representing 41 bird species were examined for the presence of influenza A virus using virus isolation in embryonated chicken eggs, PCR, and nucleotide sequencing. AIV subtype H5N1 was detected in two mute swans (Cygnus olor). The isolates were determined to be highly pathogenic avian influenza (HPAI) virus and the hemagglutinin sequence was closely similar to A/Cygnus olor/Astrakhan/Ast05-2-10/2005 (H5N1). This is the first report of HPAI subtype H5N1 in Bosnia and Herzegovina.

The aim of the present study was to investigate the histopathological changes on the organs of the brown trout (Salmo trutta m. fario) inflicted by per oral cadmium and zinc poisoning in the 46- week experimental period. The fish were kept in well-oxygenated freshwater basins which were purposely set for the experiment. During the investigation, we set up two experimental basins along with the control one. We put 30 specimens of one-year-old brown trout of the average weight of 15 grams in each basin. According to Venugopal, peroral toxic doses for fish can not be determined precisely. Accurate lethal doses (LD50 and LD) can only be established for a number of laboratory animals. However, it is possible to calculate the approximate toxic doses for fish from peroral lethal doses for rats. The calculated values for cadmium chloride are 4,4 mg/kg and 11 mg/kg for zinc sulphate, respectively. In the experimental stage we soaked the fish food in solutions made in conformity with the aforementioned values of cadmium chloride and zink sulphate. As a result, the fish consumed the aforementioned toxic doses in the experimental stage, considering that the feeding regimen included the food ration of 2% body weight/day.

Important Findings In order to determine the prevalence of avian influenza viruses (AIV) in wild birds in Bosnia and Herzegovina (BIH), extensive surveillance was carried out between October 2005 and April 2006. A total of 394 samples representing 41 bird species were examined for the presence of influenza A virus. AIV subtype H5N1 was detected in 2 mute swans (Cygnus olor). The isolates were determined to be highly pathogenic avian influenza (HPAI) virus. This is the first report of HPAI subtype H5N1 in Bosnia and Herzegovina.

The aim of the present study was to investigate the histopathological changes on the kidneys of the brown trout (Salmo trutta m. Fario) inflicted by per os lead poisoning in the 46-week experimental period. The fish were kept in well-oxygenated freshwater basins. Approximately calculated toxic doses of lead-acetate for fish were 550 mg/kg. Following the experimental period, fish organs, in particular kidneys, were examined by light microscopy. Only fish with lesions observed in kidneys were further examined by electron microscopy. An accumulation of proteinaceous material in the glomeruli of the kidneys, and thickening of the basal membrane were observed histopathologically. This proteinaceous material was also observed in the lumina of the kidney tubules. Electron microscopic examination completely supported this finding. Furthermore, to the authors' previous knowledge, undocumented damage of the brush borders of the proximal kidney tubules was also observed.

This paper describes the occurence of listeriosis in silage fed domestic sheep of the Pramenka type. The aim was to investigate causes of death of animals with previously manifested nervous signs. According to the Law on Veterinary Medicine in Bosnia and Herzegovina, the brain of sheep showing nervous signs of illness must be examined with suspicion on Listeria monocytogenes infection. The disesase occured in  the region of Eastern Bosnia in February, 2009. The sheep affected were adult, gravid females. All sheep affected by disease shared similar clinical signs: dyspnea, increased heart rate, circling, staggering, torticollis and inappetence. No abortions of gravid sheep were noted. All simptoms were lasting for 3 to 4 days with lethal outcome and mortality of 5%. The administration of procaine benzylpenicillin showed no results. The necropsy of death sheep revealed encephalitis. Histopathologically, multifocal microabscesses containing mainly degenerated and viable neutrophils, perivascular accummulation of lymphocytes and plasma cells with some macrophages and neutrophils, and multifocal fibrinous microthrombi in the lumina of the blood vessels were observed in the brain tissue. Also, neuronal degeneration and small microglial accummulation were noted. Microbiologically, Listeria monocytogenes was isolated from the brain tissue. Key words: Listeria monocytogenes, encephalitis, microabscess, sheep, silage

Experimental studies of burns require the use of different animal models. The aim of this work was to establish experimental model of thermal injuries and to evaluate the effects of topical agents on healing of the burn wounds. Forty female Wistar rats were randomly classified in 4 groups and isolated for 2 weeks before the onset of experiment. Animals were primarily anaesthetized with pentobarbital-sodium and then shaved (skin area of their back with diameters 5 cm x 5 cm). A round metal stamp with contact area of 5 cm2 and total weight of 100 g was heated up to 80 degrees C and then applied without additional pressure on the depilated skin of the back for 14 seconds. This procedure produced a standardized burn wound. Induced burn wounds were immediately drowned in the 4 degrees C- water for 3 s in order to maintain microcirculation. After the inducement of thermal injures, all rats were treated with 1% silver sulfadiazine cream, herbal topical preparations or were not treated at all. Burn wounds were treated twice a day until the healing completion. The result of treatment application was a significant reduction of burn wound diameters. Herbal topical preparations expressed positive therapeutic effects on the parameters of burn wounds. The efficiency of silver sulfadiazine cream in burn wound healing was significantly more expressed in comparison to healing process in control group of animals (p < or = 0,001). We conclude that herbal topical preparations efficiently caused the completion of burn wound healing process without scar formation.

Gentamicin is still widely used in clinical practice in spite of its renal toxicity. The role of nitric oxide (NO) in that process is not completely elucidated. The aim of this study was to investigate the relationship between plasma level of NO and the histopathological changes of kidney in acute tubular necrosis (ATN) induced by gentamicin in rats. Study was carried out in Albino-Wistar rats, both sexes (n=16), average body weight 200-250 g. divided in two equal groups: control and gentamicin group. The control group was injected with 0.9% NaCl i.p. and gentamicin group was injected with gentamicin in the dose of 80 mg/kg/day i.p. in a period of 5 consecutive days. NO plasma level was determined by the production of nitrates and nitrites using classical colorimetrical Griess reaction. Kidney specimens were stained with hematoxylin-eosin (H-E) and Periodic acid-Schiff (PAS) stain. Semiquantitative histological analysis was used for the evaluation of the level of kidney damage. Both, the plasma NO level and the level of kidney damage were statistically higher in rats with gentamicin-induced ATN in comparison to the control group. In spite of that the correlation between plasma NO level and the level of kidney damage was not found. The rise of plasma level NO in gentamicin induced ATN in rats could possibly indicate on the role of NO in renal damage caused by gentamicin.

Experimental studies of burns require the use of different animal models with the aim to imitate and reproduce pathophysiological conditions. The aim of this work was to establish experimental model of thermal injury. New Zealand rabbits, weighted from 1.8 kg to 2.3 kg, were utilised during our study. Another, also utilized, animal types were laboratory Rattus rats, species Wistar, albino type, females with body weight of about 232 g. All animals were from our own litter (Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine in Sarajevo). During the experiment, animal were properly situated in adequate cages and rooms, at the controlled temperature (22 +/- 2 degrees C), and in the air with normal humidity level. All animals took food and water ad libitum. Rabbits received anesthesia--intravenous pentobarbital sodium in a dose of 60 mg/kg, and then, hair from the upper side of the each rabbit ear was removed and burns were caused by a metal seal in the same manner as in rats. Rats were primarily anesthesied by intraperitoneal pentobarbital sodium in a dose of 35 mg/kg, and then, their hair was removed from the scapula zone (5 cm x 5 cm). Burns were caused by contact with a round metal seal, heated at 80 degrees C in a water bath, during the period of 14 seconds together with contact thermometer control. Round metal seal (radius: 2.5 cm; weight: 100 g; surface: 5 cm2) was just placed on the rat skin without any additional pressure. In order to maintain the microcirculation in the burn wound and to reduce the conversion of partial-thickness skin burns to the burns of the full-thickness skin, all burn wounds were immediately sunk in the 4 degrees C water. Subsequent to that procedure, all animals were individually situated in the proper cages, and left to rest for 4 hours with a constant cautious monitoring of the wound development and animal general state.