فصلنامه آسیب شناسی درمانگاهی دامپزشکی
سال دهم شماره 4 (پیاپی 40، زمستان 1395)

Escherichia coli is one of the most important causes of infection in avian species. To reduce the losses caused by this organism, antimicrobials are widely used in the poultry industry. The aim of this study was to compare pulse and continues administration of doxycycline on the clinical signs, lesions and selected biochemical parameters in colibacillosis infected broilers. The study was performed in a colibacillosis infected broiler farm with two similar houses. In the first group Doxycycline was administrated continuously for 4 days and in the second group it was administrated by pulse method for 4 days and 8 hours daily. After treatment, 20 blood samples were taken from each group, and the amounts of ALT, AST, ALP, total protein and creatinine was evaluated by biochemical tests. Differentiated white blood cell counts were also recorded along with gross lesions and clinical signs. Results indicated that there was a significant difference between the two methods concerning the amounts of AST (p<0.05). Although the amounts of ALT, ALP and creatinine in the continuous group were lower than pulse group, but it was not statistically significant. In the continuous group, WBCs and lymphocytes decreased significantly (p<0.05) while hematocrit, heterophils and eosinophil increased significantly (p<0.05). It was demonstrated that the pulse administration of doxycycline had better outcome in treatment of colibacillosis in comparison to continuous administration.
Conflict of interest: None declared.

Zonisamide is one of the most effective medications for epilepsy, which has teratogenic properties; and is widely administrated in patients. The present study aimed to evaluate the teratogenic effects of zonisamide on newborn rats’ skeletal system during fetal period. Therefore, 12 mature male rats were mated with 36 female rats and the female rats became pregnant. The pregnant rats were randomly divided into two equal groups of treatment and control.. The treatment group received 200 mg/kg zonisamide on days 9, 10, and 11 of pregnancy via gavage. The control group also received the same amount of normal saline solution on the same days of pregnancy via gavage. Length and weight of the newborn rats were measured using caliper and digital weigh. Then, the newborns were evaluated in terms of apparent anomalies under the stereomicroscope. Eventually, Alizarin Red staining was conducted in order to study bones. Data were analyzed using T-test. The mean length of arm, ulna, radius, thigh, tibia, and fibula was significantly different between the two groups. Alizarin Red results suggested that the treatment group had anomalies such as scoliosis, wavy rib, imperfectly formed bones of the skull. The results of the study indicated that administration of zonissamide during pregnancy causes fetal growth disorders and retards fetal growth therefore it is considered as a risk factor for fetal development in this species.
Conflict of interest: None declared.

Paratuberculosis or Johne's disease is chronic infectious granulomatous enteritis of ruminants, which has a worldwide occurrence. It is caused by Mycobacterium avium subspecies paratuberculosis and the most common symptoms of disease in goats are cachexia, anorexia and severe disability. The aim of this study was to survey seroprevalence of Mycobacterium avium paratuberculosis in goats of Khuzestan province and its correlation with host and environmental determinants. In this study sera samples were collected randomly from 368 goats in Ahvaz, Hendijan, Izeh, Shushtar, Dezful and Susangerd cities and were tested by ELISA. Apparent and real seroprevalence of Mycobacterium avium subspecies paratuberculosis were 7.07% (95% CI: 4.47-9.67 percent) and 13.8% (95% CI: 10.3-17.3 percent), respectively. This study showed that infection increased with age and odds of infection between the age, based on year and disease is 1.08 (95% CI: 0.86-1.35) (p>0.05). Relative frequency of positive samples in females was more than males and the odds of infection in female goats was 1.19 (95% CI: 0.4-3.59) times the males (p>0.05). The odds of infection in goats with history of diarrhea was 4.38 (95% CI: 1.92-9.96) times more than goats without this history (p<0.001). The seroprevalence in Ahvaz, Dezful, Izeh, Shushtar, Hendijan and Susangerd was 8.06% 5%, 4.92%, 13.33%, 2.67% and 5% respectively (p>0.05). This study confirms that Mycobacterium avium subspecies paratuberculosis exists in goats of Khuzestan province and preventive and control measures should be considered by health authorities.
Conflict of interest: None declared.

The objective of the present study was to study the comparative effect of administering selenium nanoparticles and sodium selenite in pregnant ewes on the blood serum levels of thyroxin in newly born lambs. For this purpose, twenty, four-month pregnant ewes within the same age were used. During the 21 days leading up to birth, supplementation of selenium nanoparticles (Se NPs) with dosages of 0.05 and 0.10 mg/kg B.W. were respectively fed to treatment groups 1 and 2. And supplementation with sodium selenite with dosage of 0.1 mg/kg B.W. was fed to treatment group 3. At the same time the control group was fed distilled water in equal volume. The ewes were monitored under accurate laboratory and clinical examination until the time of delivery. Neonatal lamb serum thyroxin level was measured at the day zero (birth day) and also at the 7th day. The results indicated that serum thyroxin level of neonatal lambs of treated groups 1 and 3, decreased significantly at 7 days' age in comparison to the birth day (p values less than 0.006 and 0.001, respectively). Results also showed that serum thyroxin level of group 2 offspring lambs on the day 0 was significantly less than that in group 1 (p=0.003). It was concluded that the physiological function of selenium nanoparticles was dose dependent, and the 0.05 mg/kg B.W. dosage of Se NPs induced similar effects like 0.1 mg/Kg B.W. of sodium selenite, which resulted in increasing serum level of thyroxin at the day of birth.  Conflict of interest: None declared.

Cadmium is a metal widely dispersed in the environment. The main sources of this metal are industrial compounds and phosphate fertilizers. This metal is absorbed by plants and accumulates and accumulates in tissues like liver and kidney and causes anemia, hypertension, destruction of testicular tissue and bone complications. Considering the numerous side effects of cadmium, it is necessary to determine the amount of cadmium in milk in different areas in order to reduce milk contamination. In this study, a total of 400 milk samples were obtained from industrial and traditional farms from northern, southern, eastern and western areas of the city of Tabriz. All samples were frozen at -21°C and the concentration of cadmium in milk was measured by atomic flame spectrophotometry. The average values of cadmium in western, southern, northern and eastern areas of Tabriz were respectively 0/006 ± 0/0005 ppm, 0/0005 ± 0/004 ppm, 0/0004± 0/0059 ppm and 0/0002 ± 0/0037 ppm. Statistical comparison of cadmium concentrations in different areas indicated a significant difference (p<0/05). Also, a statistically significant relationship between the mean values of cadmium and daily milk production wasn't observed. Since the permitted levels of cadmium in raw milk according to Codex 2000 (Review Committee on Food Additives Geneva) is 0.01 ppm, therefore it is concluded that cadmium levels in the four regions studied is lower than the limit. Conflict of interest: None declared.

Salmonellosis is one of the most important zoonotic diseases. Antimicrobial therapy is an important tool in reducing both the incidence and mortality associated with Salmonella infections, but the indiscriminate use of antibiotics in poultry farms can lead to the emergence of resistance and inefficacy of antimicrobials. Moreover, transmission of the resistant strains to humans through food chain could be a menace to public health. This study was conducted to determine serogroup and antibiotic resistancepatterns of Salmonella isolates recovered from 25 broiler chicken farms in Ahvaz. All isolates were examined for serogroup using commercial antiserum, and for resistance to the most commonly used antibiotics in poultry (enrofloxacin, florfenicol, fosfomycin, lincospectin, sultrim and doxycycline) and humans (gentamicin, amoxiclav, ciprofloxacin, cefalexin, cefotaxime and ceftriaxone) by Kirby-Bauer disc diffusion method. The Salmonella isolates belonged to serogroups B (two isolates), C (three isolates) and D (45 isolates). Out of 50 isolates, 24 (48%) were resistant to one or more antibiotics. All isolates were sensitive to florfenicol, sultrim, cephalexin and ceftriaxone. The highest and lowest rates of resistance were observed against lincospectin (36%) and amoxiclav (2%), respectively. The high prevalence of resistant salmonellae among broilers indicates that the administration of antimicrobial drugs has to be made with more caution.
Conflict of interest: None declared

Creatine is one of the most common supplements for improvement of athletic performance which is used by athletes. The most important debate about creatine consumption is its adverse effect on kidneys due to increased protein load. This study was performed to evaluate the protective effects of aerobic exercise on renal tissue injury following consumption of creatine monohydrate in the rat. For this purpose, 30 male Wistar rats were randomly divided into 3 groups of 10 animals each. Group 1, as control, received only standard food. Group 2 received 5 g/kg b.w. creatine monohydrate supplement daily for 8 weeks through gavage and group 3 received creatine monohydrate supplementation in the same manner30 minutes before aerobic exercise. Aerobic exercise was performed 5 times per week on treadmill at speed of 10-25m/min for 10-30 minutes with the slope of 5 degrees. At the end of 8 weeks, water intake and urinary excretion of rats were measured and blood samples were collected for measurement of serum renal function biomarkers including urea, uric acid and creatinine. Finally, the rats were euthanized for renal histopathology. In group 3, by doing regular aerobic exercise, water intake and urinary excretion rates were significantly (p<0.05) increased compared to group 2 and serum biomarkers of kidney injury decreased significantly (p<0.05). In group 3, microscopic studies showed a significant (p<0.05) reduction of glomerulo-tubular and renal interstitial damages compared to group 2. The results showed that regular aerobic exercise can ameliorate kidney tissue damage following creatine monohydrate supplementation in rats. Conflict of interest: None declared.