فصلنامه آسیب شناسی درمانگاهی دامپزشکی
سال پانزدهم شماره 3 (پیاپی 59، پاییز 1400)

Pityriasis or dandruff is the presence of too many bran-like scales on the skin. According to the available information and based on previous studies, this complication exists in horse care and breeding centers in Tehran, Alborz and Golestan provinces with different frequencies. The aim of this study was to identify the causes of Pityriasis and its effective factors in horses of the mentioned provinces. The present study was performed on the population of horses in equestrian complexes of Tehran, Alborz and Golestan provinces. Based on history and clinical findings, horses with Pityriasis were identified and then the necessary samples were taken and sent to the relevant laboratories. In this study, 74 horses with Pityriasis were identified that mange (56.76%), insect bites hypersensitivity (24.32%) and ringworm (18.92%) were the most important causes of Pityriasis. Among possible affecting factors, breed, sex, age, insect control and density had no significant association but significant relationship (p<0.05) was recorded among season, sanitary conditions, type of accompanying lesion and animal bedding with Pityriasis. According to this study, mange is the most common cause of Pityriasis in horses in Tehran, Alborz and Golestan provinces. Pityriasis predominantly occurs in summer and the most common type of accompanying lesion is alopecia.

Studies have been conducted to find effective agents for nerve regeneration. The present study was conducted on sixteen adult male Syrian mice with the aim of assessment of the effects of tacrolimus on crushed sciatic nerve injury and its comparison with spontaneous repair. After exposure of the left sciatic nerve, crushing was performed using a 2 mm wide mosquito hemostatic forceps tip for 10 seconds. Animals were randomized into two groups of treatment group (Group I), and the control (Group II) with eight mice each. The treatment group received tacrolimus (5 mg/kg, q24h, SC) until the end of the study, and the control group received no therapeutic agents. Histopathological and immunohistochemical assessment was performed on second and fourth post-operative weeks, and suggested that perineurium formation did not show a significant difference between the study groups (p>0.05). At the end of the second week in the treatment group, the reduction of axon inflammation and swelling, and the increase in axonal count showed a significant difference with the control group (p<0.05).  At the end of the fourth week, the difference in inflammation severity between the groups was not significant (p>0.05) but the decrease in axonal swelling and increase in axonal count in the treatment group showed a significant difference with the control group (p<0.05).  Increase of glial fibrillary acidic protein (GFAP) expression showed significant difference between the treatment group and the control group at the end of the study (p<0.05). Based on the present results, the use of tacrolimus was responsible for reduction of inflammation in a two week period, and at the end of the fourth week, increase of axonal count and edema suppression caused regeneration of injured nerve.

The outbreak of calf pneumonia in herds occurs due to different pathogens. Vitamin D3 displays a regulatory effect on different cells, especially its pro-differential biological function and stimulates antimicrobial peptides. In the present study, the effects of vitamin D3 on the expression of antimicrobial peptides in experimental pasteurellosis in calves were assessed. Ten Holstein calves (2-4 months old) were randomly divided into two groups. Prepared Pasteurella multocida (3×109 CFU/mL) was inoculated in the trachea of all calves and Vitamin D3 was injected only in the treatment group following confirmation of pneumonia. Blood samples and broncho-alveolar lavage fluids were obtained from both groups at different time intervals and the peripheral blood mononuclear cells were isolated to evaluate the antimicrobial peptides gene expression. The expression of CD4, Cathelicidin, and Defensins genes was measured in vitro conditions following the addition of 10-6, 10-7 and 10-8 molar of vitamin D3. Defensins and CD4 gene expressions revealed a significant difference in the two groups, at the 48, 72, 96, and 120 hours after the challenge time, while the Cathelicidin gene was not expressed in both experimental groups. Surprisingly, increased expression of Cathelicidin, Defensins, and CD4 was observed at a concentration of 10-6 M of vitamin D3. According to the results of this study, vitamin D3 had positive effects on the immune system which was observed as significant improvement in the clinical symptoms of treated calves. The expression of lung-related Defensins and CD4 in vivo and in vitro approved the immunomodulatory effects of vitamin D3 but the gene expression of Cathelicidin is probably related to prescribing higher doses of vitamin D3.

Staphylococcal mastitis is one of the most important diseases in industrial livestock and Staphylococci capable of producing biofilm, micro and macro abscesses, are considered to be the cause of malignant mastitis which result in culling of dairy cattle. The ability of these bacteria to produce biofilm depends on the presence of ica operon genes (icaA, icaB, icaC, icaD and icaR) and also some environmental factors. In the present study, the pattern of antibiotic resistance and the presence of operon ica virulence genes in Staphylococcus aureus isolated from bovine mastitis was investigated. According to the findings of microbiological and simplex PCR tests, it was determined that in the farms tested in East Azerbaijan province, Staphylococcal mastitis has a relatively high prevalence and among the relevant isolates, a relatively high percentage of them contain a variety of operon ica virulence genes that encode the ability to produce biofilm. Also, the results of antibiotic susceptibility testing performed on these isolates showed that they were more resistant to most of the antibiotics tested. Due to the high presence of ica operon genes, especially genes such as icaA and icaD, which result in production of stronger and excessive biofilm as well as increased resistance to various antibiotics, the results of the present study therefore indicate an unfavorable prognosis regarding the success of antibiotic treatment of staphylococcal mastitis in livestock farms in the region.

Avian infectious bronchitis (IB) is an acute and highly contagious disease of the upper-respiratory tract caused by the infectious bronchitis virus (IBV). The virus is a member of the Coronaviridae family and has numerous serotypes and strains. Rapid replication combined with high mutation rate and recombination are the main causes of the observed high diversity.Feed conversion and average daily gain are affected in broilers, and infection is often followed by secondary bacterial infections. In layers, IBV causes a reduction in egg production.Today, IB is one of the most economically important diseases in the poultry industry. Transcriptional profiles of trachea tissue of the infected group (IBV) were studied with control group to evaluate changes in transcriptome profile at the early stages of infection. After the challenge of SPF chickens with IBV IS-1494 like (GI-23, the trachea tissue was used for RNA extraction, and changes in the transcriptome were investigated by Illumina RNA-seq technique. Up-regulated and down-regulated differentially expressed genes (DEGs) in the transcriptome of trachea were identified. Gene ontology category, KEGG pathway were analyzed to identify relationships among differentially expressed genes. In general, the numbers of up-regulated genes were higher than of down-regulated genes in experimental group. In the experimental group, a more severe immune response occurred; an important up-regulated genes in this group’s was Toll-like receptor signaling pathway, apoptotic pathway, MAPK signaling pathway. Results of this study could provide a general overview of transcriptome changes in the trachea at the early stage of infection with avian infectious bronchitis (IBV) virus.

Ewes have seasonal estrous cycle so Estrus synchronization is a valuable way to manage ewes reproduction . Due to the existing conditions and some problems in preparation of PMSG in Iran, we should looking for an alternative method , Therefore, in this study Comparison of estrus synchronization and fertility in Afshar sheep out of breeding season was done with these methods.- Group1 CIDR+PMSG. -Group2 CIDR+HMG. -Group3 CIDR+HMG+Estradiol.200 non-pregnant Afshar ewes are divided randomly in 4 different groups (n=50). Estrus was synchronized in all groups by using Abu Reihan progesterone CIDR for 12 days. At the CIDR removal, in group1 any treatment were not received ,in group2 they were received PMSG(500 UI),in group3 they were received HMG (1 vial) and finally in last group they were received HMG(a vial) + Estradiol(0.1 mL). The results of Incidence of estrus and fertility symptoms in the groups were analyzed. P value between the first and Second group was not significant(P value <0.05), which seams there is no significant difference between these two groups.The results from the occurrence of estrus and fertility in ewes were analyzed. Therefore, to replace PMSG , using HMG in estrus synchronization of ewes can be a good way.

In March 2020, three 5-15 day old mixed breed lambs were referred to the University of Tehran Veterinary Hospital. The farmer complained of 20% mortality rate (42 heads) in 4-17 day old lambs of his flock that they were exclusively breastfed. In observation and clinical examination, recumbency, depression, weakness, 40 ° C temperature ,abomasal dilation with fluid, tachypnea, tachycardia and hyperemia of the mucosa were recorded. After clinical examination, the lambs were examined by hematology and then necropsied under sterile conditions. In hematologic examination, normocytic-normochromic anemia, leukopenia, lymphopenia, left shift, the presence of schistocytes, keratocytes, myelocytes and metamyelocytes were observed. In necropsy, there were abomasal petechiae hemorrhages, coffee grain-like blood masses in the contents of the abomasum and pale kidneys. The direct gram smear from the abomasum had a large number of positive gram rods. All organs were subjected to aerobic and anaerobic bacterial cultures. Clostridium perfringens type A and non-pathogenic E coli were isolated from the abomasum and intestine of patients. The highest antibiotic susceptibility of Clostridium perfringens A isolate was to ceftiofur and ceftriaxone antibiotics. This study showed that Clostridium perfringens A may be involved in the pathogenesis of abomasitis in lambs. . . . . . .