فصلنامه دامپزشکی ایران
سال نوزدهم شماره 80 (پاییز 1402)

The hypothesis of this study was to investigate how Japanese quail chicks in post-hatching period can response to delayed feeding through their growth performance and gastrointestinal tract development. One hundred and twenty as hatch Japanese quail chicks were randomly assigned to 12 pens. Four replicate groups of 10 chicks were randomly assigned to each of the three treatments. Experimental treatments included; chicks early feeding (EF) for 3h, and delayed feeding (DF) for 24 and 48h after hatching. After that, all birds were fed a mash diet ad-libitum until 15 days of age. At 1, 3, 6, 9, 12, and 15d of ages, one bird of each replicate (four birds of each treatment) was randomly selected, weighted and euthanized. Samples from the middle part of jejunum dissected free and fixed in 10% formaldehyde solution. Sections were stained with Hematoxylin and Eosin, Alcian blue-van Gieson and Periodic acid-Schiff stain. Morphometric indices were included villus height (VH), crypt depth (CD), villus width (VW), tunica muscular thickness (MT) and villus surface area (VSA). Birds subjected to treatments showed no significant differences in feed intake and residual yolk weight. In the EF birds the 15d live body weight and weight gain during the 1-15d of ages were significantly higher, but feed conversion ratio (FCR) was significantly lower than DF birds. Similarly, in the EF birds, the VH and VSA were significantly higher than DF birds. In conclusion, delayed access to feed after hatch has adverse effects on Japanese quail chick growth and gastrointestinal tract development.

Mastitis is a well-recognized and costly disease of dairy cattle. Mycoplasma bovis is one of the most important causal agents of mastitis in dairy cows. In respect to the importance of mastitis caused by Mycoplasma, the objective of the present study was to evaluate of presence of M. bovis in bulk milk of dairy cattle farms of Hamedan province, Iran. For this purpose, a total of 125 bovine bulk tank milk samples were collected from 31 dairy farms of Hamedan, Iran. After that, California Mastitis Test (CMT) and Somatic Cell Count (SCC) were done on the milk samples. Then using DNA extraction kit, the total DNA was extracted from each sample. The PCR followed by nested PCR (nPCR) was performed for specific detection of M. bovis. Based on PCR for genus detection, totally, 19 out of 125 (15.2%) bulk tank milk samples were contaminated with Mycoplasma spp. In addition, 11 samples (8.8 %) were contaminated by M. bovis based on nested PCR results. Moreover, the results showed that 26 of 125 bulk milk samples (20.8 %) and 102 of 125 bulk milk samples (81.6 %) have high rate score by CMT and SCC, respectively. Statistical analysis showed a positive correlation between CMT and SCC results. In the present study, the presence of M. bovis in the bulk tank milk samples suggests that more hygiene practices are required to avoid transmitting this pathogen among dairy cow herds of Hamadan region. According to the presence of Mycoplasma in bulk tanks of this region, the present study suggested that the frequency of Mycoplasma contamination in individual cows be determined.

Intraosseous infusion is considered a useful technique for administration of medications and fluids in emergency situations when peripheral intravascular access is unsuccessful. The purpose of this study was to compare the effectiveness of intraosseous (IO) versus intravenous (IV) administration of oxytetracycline for delivery of antibiotic to the central circulation in dogs. Four intact mongrel dogs weighing 15-20 Kg of both sexes between 1 to 3 years old received 20 mg/kg oxytetracycline intravenously. The animals were allowed to recover, and, after a two-week timeout period, each dog received the same antibiotic and dose as before through a femoral Jamshidi bone marrow needle. Blood samples were taken for antibiotic assay immediately before and 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 24 hours after injections using high-performance liquid chromatography (HPLC). Analysis of variance revealed statistically significant differences between serum oxytetracycline levels comparing intraosseous and intravenous administration at all assay intervals. Serum levels of oxytetracycline after IV administration were significantly higher than those after IO injection at all time intervals but decreased significantly at 24 hours after injection. Peak oxytetracycline serum concentrations were achieved in IV (7.69±1.25 µg/ml) and IO (4.20±0.09 µg/ml) routs after 0.5 and 2.5 hours, respectively. However, Oxytetracycline levels were above therapeutic concentration by both intravenous and intraosseous routes. No side effects were observed in relation with the intraosseous administration of the drug. Thus, IO route appears to be practical and effective for the rapid delivery of oxytetracycline in dogs. In conclusion, oxytetracycline may be administered intraosseously when intravenous access is not possible.

In the present study, aflatoxin M1 (AFM1) in bulk milk (n=72) and aflatoxin B1 (AFB1) in concurrent rations (TMRs; n=48) and feed ingredients (n=230) were assessed in 12 dairy farms in winter and summer. Bulk milk was sampled on days 1, 15 and 30 of the study. Feeds were sampled at days 1 and 30. Aflatoxin was measured using ELISA kits (detection ranges: 1-81 ngkg−1 for milk, 1.25-101.25 ngkg−1 for feeds). AFM1 was identified in all milk samples (range: 2.03 to >81 ngkg−1; median: 70 ngkg−1). Overall, 76% of milk samples (n=55/72) had AFM1 levels <81 ngkg−1 (Iranian limit:100 ngkg-1). Contaminations >81 ngkg−1 (n=17/72; 24%) were more frequent in winter (n=15/36 vs. 2/36). Sixty-nine percent of winter (n=25/36) and 31% of summer samples (n=11/36) had contaminations above the median. The chance of contaminations above the median was higher in winter (OR=5.33, P=0.007). All TMRs and ingredients had higher contaminations in summer. Seventy percent of summer and 30% of winter TMRs had contaminations above median (716 ngkg-1). The chance of TMR contamination above median was higher in summer (OR=5.57, P=0.002). The lower AFM1 levels in summer could be due to reduced hepatic AFB1 metabolism and lower dry matter intake induced by heat stress. Grain mix (rs=0.90; P=0.001), corn silage (rs=0.66; P=0.001) and wet beet pulp (rs=0.68; P=0.005) were the most prominent contaminants of TMRs. Due to the limitations of the diagnostic kit and different year-round nutritional conditions, higher or lower AFM1 contaminations are probable. With the current nutritional practices, higher summer contamination may happen if heat stress is efficiently controlled.

Neospora caninum is a causative agent of abortion, stillbirth, and birth of weak neonates in wild and domestic mammalian species. The purpose of this seroprevalence study was to detect N. caninum in goats and farm dogs at the central Zagros region. This high altitude region is a mountainous, semi-humid and cold region with average rainfall. For this purpose, blood samples were obtained from 384 goats and 30 farm dogs and the existence of antibodies against N. caninum was determined using the commercial indirect ELISA method. The goats were divided into three age groups: less than one and a half years (54 heads), two to three years (163 heads), and more than three years (167 heads), with positive cases confirmed in 12, 40, and 50 heads, respectively. The seroprevalence of N. caninum was determined to be 26.56% which the highest rate was belonged to the age group of more than 3 years compared to other age groups. In the last thirty years, Neosporosis has been one of the causes of abortion in ruminants and in the present study, it was found that out of 5 female goats with a history of abortion, 3 had antibodies against Neospora caninum. In addition, 43.3 percent of farm dogs carried antibody against Neospora caninum, which may explain the role of domestic carnivores in Neosporosis epidemiology.

Pro-inflammatory cytokines may contribute to physiological, e.g., tissue reconstruction and vascularization, or pathological, e.g., inflammation or some metabolic disturbances, processes during pregnancy establishment. The current study aimed to investigate IL-6 plasma levels at 30 and 45 days post-insemination (dpi) in pregnant and non-pregnant dairy cows. The cows were examined for pregnancy diagnosis at 30 and 45 dpi. Cows (n=71) were assigned into four groups: Non-pregnant at 30 dpi (n=16), pregnant at 30 dpi (n=36), non-pregnant at 45 dpi (n=11), and pregnant at 45 dpi (n=8). Blood samples were collected at 30 and 45 dpi for IL-6 assay. Results showed high levels of plasma IL-6 at 30 dpi either cow-conceived or not. Cows with healthy embryos at 45 dpi had lower concentrations of IL-6 than cows with late embryonic death. The plasma IL-6 concentrations showed different patterns of changes in dairy cows during the first two months of pregnancy.

Antibiotics are widely used to treat infectious diseases in humans and animals. However, the indiscriminate use of antibiotics contributes to the emergence of antibiotic-resistant bacteria, making infections more difficult to treat. In this study, we randomly collected thirty-six rainbow trout fish from various retail stores in Kerman city, located in the southeast of Iran. Skin samples were obtained from each fish using a swab, and Escherichia coli (E. coli) isolates were identified and screened for antimicrobial resistance (AMR) phenotypes, as well as related genes, using microbiological culturing, disc diffusion, and conventional PCR methods. Our findings showed that the prevalence of phenotypic resistance against the tested antibiotics was high, with erythromycin (88.57%), florfenicol (77.14%), oxytetracycline (74.28%), trimethoprim-sulphamethoxazole (71.42%), trimethoprim (65.71%), chloramphenicol (62.85%), flumequine (60%), ciprofloxacin (54.28%), and tetracycline (54.28%) having the highest resistance rates. Moreover, 8.57% of the E. coli isolates were found to be ESBL-producing strains, and 74.28% of the isolates were multi-drug resistant (MDR). The highest frequencies of antibiotic resistance genes were 5.71 % for blaTEM, 14.28% for qnrA, 17.14% for sul1, and 20% for sul2. E. coli is a mesophilic bacteria and is not naturally present in fish. Fishes have mostly psychrophilic bacteria in their microflora. The origin of E. coli on the skin of fish is water contaminated with human and animal feces, so the antibiotic resistance of this bacterium has an indirect relationship with aquaculture. Our study showed that E. coli isolates from the skin of rainbow trout has a high level of antibiotic resistance, which may be a risk to public health. Therefore, it is very important to control the use of antibiotics in fish farming to reduce the selection pressure to emergence and spread of antibiotic-resistant bacteria.

In the present study, Oreochromis niloticus juveniles were exposed to 10, 20, and 30% (96h LC50) of ammonia for two weeks. After this period, the fish were anesthetized and blood samples were taken from the caudal peduncle with a heparin-coated syringe to evaluate blood parameters. The 0.5 cm samples of the kidney tissue were taken, fixed in 10% formalin buffer, and after dehydration with alcohol, clarification with xylol, blocking with paraffin and cutting 4-6 microns thick with a microtome. Finally, the stained slides were studied with a light microscope. The results showed an enlarged Bowman's capsule, hyaline accumulation, epithelial detachment, increased melanomacrophage centers, necrotic glomeruli, and tubules in the kidneys after ammonia exposure. In the studies of blood serum factors with the increase of ammonia, cholesterol and BUN compared to the control and other groups. As the ammonia concentration increased, the severity of the lesions also increased. Therefore, ammonia causes changes in the structure and activity of some factors of the kidneys, which must be controlled by creating the appropriate ammonia and management conditions in the aquatic environment.

Vaccination is the most important preventive measure to protect companion animals against infectious diseases. The aim of the present study was evaluation and comparison the effects of vaccination with two dogs' multivalent vaccines on selective immune indices. twenty healthy 4-month-old dogs of mixed breed and both sexes were randomly divided into two groups. The first and second group of the dogs were vaccinated with polyvalent Biocan (Group A) and Hipradog (Group B) vaccines on days 0 and 28, respectively. Blood was taken from the dogs of both groups on days 0, 28 and 35; The collected sera were assessed for lysozyme, complement, bactericidal activities, and total serum immunoglobulin. The type of vaccine and time had a significant effect on the amount of complement, but their interaction had no significant effect. Also, time had a significant effect on the amount of lysozyme, but the type of vaccine and the interaction between vaccine and time did not have a significant effect on this index. Regarding the bactericidal activity, the type of vaccine, time, and their interaction had no significant effect on the anti-Salmonella and anti-Staphylococcal activity. Vaccine type, time and the interaction between vaccine and time had a significant effect on the immunoglobulin trend changes based on the ELISA method.  The results obtained in the present study indicated that there is no significant difference between these two polyvalent vaccines in terms of antimicrobial properties; however, the Hipradog vaccine in comparison with Biocan vaccine, stimulates the production of more complement, lysozyme, and immunoglobulin, so it is recommended to use the Hipradog vaccine for dog's vaccination.

The objective of the present study was to investigate the effects of in ovo injection of nanocurcumin on intestinal histomorphology and some serum components of the hatched chicks. The chicken eggs were injected with 1, 10, 100, 1000, and 10000 ppm of nanocurcumin, and the other two groups were used as control and injected control (saline). At the end of the experiment, blood and tissue samples were collected for biochemical and histological examination. For histological examination, small intestine was sampled and routine histological methods containing fixation, dehydration, clearing and paraffin embedding were used. Sections were stained with hematoxylin & eosin for light microscopy evaluation. Blood biochemical parameters were analyzed by an automatic analyzer. Results indicated that in ovo injection of saline significantly reduced albumin, globulin, total protein and AST (aspartat aminotransferase) compared to the control group, so that injection of nanocurcumin corrected the reduction of these factors. Uric acid was increased by injection of 1, 10 and 100 ppm nanocurcumin compared to the other groups. Blood glucose levels decreased slightly with increasing the dose of nanocurcumin, and in the 1000 ppm nanocurcumin group, the levels were significantly lower than those of the control. In ovo injection of 1000 ppm nanocurcumin significantly increased the villi height and villus height/crypt depth ratio compared to the saline and 1 ppm nanocurcumin groups. Although the primary purpose of this study was to evaluate the effects of in ovo administration of nanocurcumin, it was demonstrated that the use of saline in the in ovo injection was inappropriate. In conclusion, in ovo injection of nanocurcumin corrected saline-altered serum factors, lowered blood sugar, and increased the intestinal absorption surface.

A 3-year-old Lori-Bakhtiari ram with a history of a mass on the penis was referred to the veterinary teaching hospital of Shiraz University. The owner reported that the presence of the mass prevents the penis from returning to the prepuce. On physical examination, a 3.5cm × 2cm × 2cm mass on the penis was observed. After preparation, the mass was removed and its both sides were sutured. At this time, penis was simply returned into the prepuce and no recurrence was observed until seven months follow-up. No complication was noted in days after surgery. The removed mass was examined histopathologically. Microscopically, the mass was diagnosed to be a fibropapilloma. Although penile fibropapillomas have been described in bull and horse, to the best of authors' knowledge, no report was published about incidence of penile fibropapilloma in ram. Vaccines and immunization are crucial strategies to prevent and reduce the recurrence rate.

An 8-year-old crossbred thoroughbred chestnut stallion was suspected to an autoimmune mediated skin disease based on history, clinical observations, microbiological and clinicopathologically findings. The clinical signs disappeared completely after five weeks of treatment with PO prednisolone. However, approximately eight months later, the lesions recurred in a more severe form. There was no improvement despite the repeating previous treatment by horse's owner; therefore, oral azathioprine was added to prednisolone after skin biopsy. A significant therapeutic effect was observed by this combination, however; the use of azathioprine was discontinued after fifteen days due to diarrhea, while prednisolone continued for another week. After improvement of the symptoms, oral prednisolone was also stopped with a decreasing trend. Vesiculobullous to pustular lesions with acantholytic characteristic of the stratum corneum and stratum granulosum of epidermis were the histopathological findings, characteristics of pemphigus foliaceus. This is the first reported case of recurrent pemphigus foliaceus in Iran.