مجله تحقیقات دامپزشکی
سال هفتاد و پنجم شماره 3 (پاییز 1399)

Leptospirosis is a zoonotic disease with a worldwide spread, which is very important from two aspects, health concerns in human societies and economic losses due to abortion, stillbirth, birth of weak calves,  Milk-drop syndrome and mastitis and death. The prevalence of an infection at the herd or animal level is a key issue that determines whether the infection should be considered important and which measures and policies should be made and applied.

The aim of this search is a meta-analysis study of  the prevalence of leptospirosis and serovars of leptospira interrogans in Iran.

The search was carried out by relevant literature search from 1997 to 2017 and by keywords: Iran, leptospira, cattle, sheep, goats, buffaloes, camel, and their combination in data banks of Magiran, SID, Iranmedex, PubMed and Google scholar. In this study, 39 articles were finally accepted. For statistical analysis, prevalence rates were entered in the Comprehensive Meta Analysis (CMA) software.

The prevalence of leptospirosis in apparently healthy ruminants was 21.5% (95% CI: 17.8-25.8) and Grippotyphosa, Pomona and Canicola were the most prevalent.

According to the high prevalence of pomona in our results, using this serovar in produced vaccines inside the country, applying preventive methods to control infection in herd dogs and gaining a share of the health system budget can have a good effect on for leptospira control program.

Diagnosis of Cryptosporidium species based on morphological characteristics is very limited and has no taxonomic value alone, and therefore the use of molecular methods removes these limitations to some extent.

The aim of this study was to determine the predominant Cryptosporidium genotypes in calves with diarrhea.

Study were conducted in calves aged less than 3 months for a period of 2 years. During the study period, 160 dung samples were collected from neonatal calves and examined first microscopically and then by molecular techniques. Stools were analyzed for the presence of Cryptosporidium oocysts by Sheather's Sugar Flotation Solution followed by Ziel-Neelsen staining method. DNA of parasite was extracted and multiplex nested-PCR protocol basis on the 18srRNA were done to identify three cattle-adapted species (C. andersoni, C. bovis and C. ryanae) plus the zoonotic species C. parvum.

110 fecal samples were collected from livestock in Alborz province and 50 fecal samples were collected from livestock in Shahroud city. Of the 160 animals examined, 90 were female and 70 were male. In total, out of 160 animals examined, 85 cases (53.12%) had diarrhea, of which 55 cases (34.37%) were positive using Ziel-Neelsen staining. Since all positive cases were related to diarrhea samples and related to calves under one month old, a significant relationship was observed between diarrhea status and the presence of this parasite (p < /em><0.05). In terms of seasonal distribution, no difference was observed in the rate of diarrhea and positive parasitic cases. The presence of 305 bp band in all Ziel-Neelsen positive samples confirmed the presence of C. parvum in all samples.

Neonatal calves are more likely to be infected with Cryptosporidium parvum, as confirmed by the present study.

Health and welfare of dogs can be adversely affected by ectoparasite infestations and these infestations pose severe risks to human health due to close contact between dog and human.

This study was carried out to detemine the frequency of ectoparasite infestation in referred dogs to veterinary hospital of Ferdowsi University of Mashhad, Mashhad, Iran.

From April 2017 to April 2018, a total of 460 dogs were examined for ectoparasites. Age, gender, season, breed, keeping place, hair length, hair colour, pruritus, alopecia and distribution of parasites on different parts of the body of each examined dog were recorded in a questionnaire.

Out of 460 dogs examined, 99 (21.52%) were found to be infested with ectoparasites. Forty-eight  (10.43%) dogs were infested with Ctenocephalides canis and Pulex irritans. Rhipicephalus turanicus, Sarcoptes scabiei, Hippobosca longipennis and Rhipicephalus sanguineus were found on 14 (3.04%), 10 (2.17%), 10 (2.17%) and 9 (1.95%) dogs, respectively. Infestation with Wohlfahrtia magnifica, Demodex canis, Otodectes cynotis, Haemaphysalis erinacei and Linognathus setosus were observed in 9 (1.95%), 3 (0.65%), 2 (0.43%), 1 (0.21%) and 1 (0.21%) examined dogs, respectively. There was a statistically significant association between ectoparasite infestation and sex, keeping place and pruritus (p < /em><0.05). No statistical relationship was found between ectoparasite infestation and age, hair colour, hair length, season and alopecia (p < /em>>0.05).

This is the first study conducted on dog ectoparasite infestation in Mashhad district, Northeast Iran. Fleas were the most common ectoparasites and although ectoparasite infestation rate was relatively low, high species diversity was observed. Some of these ectoparasites have zoonotic importance.

Replenishing fish oil with vegetable oils and using dietary supplements plays an important role in the metabolism of fats in aquatic animals. Corn oil is one of the vegetable oils that can be a good alternative to fish oil.

The aim of this study was to investigate the effects of replacing fish oil with corn oil and the use of dietary supplements L-carnitine and betaine on the metabolism of fats and blood indices of rainbow trout.

450 rainbow trout (9.12±0.26 g) were divided into four treatments (three replicates) and were fed with manual diet containing fish oil (1st treatment), corn oil (2nd treatment), fish oil with 500 mg/kg of food containing L-carnitine and betaine (3rd treatment) and corn oil with 500 mg/kg of food containing L-carnitine and betaine (4th treatment) for eight weeks. At the end of study, fatty acid profiles of the treatments were determined by gas chromatography (GC) and blood indices and their weights were also examined.

At the end of the experiment, the weight index did not show a significant difference. In the replacement of fish oil with corn oil, the levels of PUFA n-3, C18:3n3, C20:3n3, C20:5n3 and C22:6n3 fatty acids significantly decreased in fish carcasses and the PUFA n-6, C18:2n6, C20:2n6 and C20:4n6 increased significantly, but no significant difference was observed in total SFA and MUFA fatty acids. L-carnitine and betaine increased the EPA accumulation in fish oil and corn oil significantly, and the number of white blood cells in corn oil, L-carnitine and betaine fed fish (fourth treatment) were increased compared to fish oil treatment (first treatment), significantly (p < /em><0.05).

Considering the effect of corn oil, L-carnitine and betaine supplements on increasing the n-6 PUFA fatty acids, essential EPA and white blood cell counts, the use of corn oil and L-carnitine and betaine supplements in rainbow trout diet is recommended.

Nowadays, the tendency to use food packaging with antimicrobial activity of natural origin has increased. The use of edible and biodegradable films has been considered as an appropriate alternative to non-degradable plastic coatings.

In this study, the effect of coating with wheat starch and Pennyroyal (Mentha pulegium essential oil was investigated on microbial and physicochemical characteristics of rainbow trout fillet in cold conditions.

For this purpose, different treatments under the influence of starch, starch and Pennyroyal essential oil (1%), starch and Pennyroyal essential oil (2%) were prepared and physicochemical and microbial changes were evaluated at specified intervals (0, 4, 8, 12 and 16 days).

In the microbial test, the count of total bacterial and other bacteria by starch and starch + 1% and 2%, the essential oil was decreased in different days, also the difference between the control group and other treatments was significant (p < /em>≥0.05). The highest effect of pH reduction belonged to starch + 1% and 2% essential oil in different studied days. The level of pH was not different among different treatments on day 0 of storage. However, there was a significant difference between the control group and treatments on the fourth, eighth, twelfth, and sixteenth days of storage (p < /em>≥0.05). The results of the oxidative test showed that on the 16th day of storage, the lowest level of TBA was related to the treatment with starch + 2% essential oil and the highest value was related to the control group. In fact, the application of the coating layer delayed the oxidation process.

This study demonstrated antioxidant and antibacterial properties of the composition of edible starch and pennyroyal essential oil on the increased shelf-life of Rainbow trout fillet.

Dactylogyrus is one of the most common external parasites on  the gills of Cyprind fish. These parasites are highly host specific and many species only have a specific host.

Since there are reports of silver carp specific Dactylogyrus species isolated from big head carp and vice versa, the investigation of Dactylogyrids have been done in these two fish species.

81 silver carp and 82 big head carp were caught from 10 fish farms in Guilan province and after preparing wet mounts of body surface Dactylogyrus parasites divided and fixed by glycerin jelly. In order to perform morphometric assessments on captured images, Image J software was used for 7 point to point distances. Drawing of parasites was done by drawing tube and then compared by identification keys and parasites identified. For molecular investigation the genomic DNA was extracted from one parasite specimen and 28S rDNA region of Dactylogyrus specimens were amplified by related primers in PCR.

Sequences were deposited in GenBank with accession numbers MG825611 and MG825765 respectively for D. hypophthalmichthys and D. suchengtaii isolated from Hypophthalmichthys molitrix, and also MH023397 and MH023399 respectively for D. aristichthys and D. nobilis isolated from Hypophthalmichthys nobilis. The phylogenetic tree shows the genetic affinity of isolated parasites from these two fish.

It seems hybrid fish are sometimes produced accidentally in fish reproduction centers of Iran. Racial impurity of silver carp and big head carp is not only the reason of poorer breeding efficiency in fish farms but also these hybrid fish are hosts of more parasitic species.

Antimicrobial agents can alter physiological status and immunity system of the host, and use of hematological indices are the appropriate marker for monitoring them.

The present study intended assessment of changed hematological indices of rainbow trout challenged with streptococcosis/lactococcosis agents following oral administration of florfenicol.

The purchased fish (55±7.5 g) were examined through a randomized blocks design in the replicated 6 treatments consisting of without/with the infectious challenge of each pathogen separately and without/with medicated feeding in 15 mg/kg-1 BW for 10 consecutive days. Doses of Streptococcus iniae (2.87×107 CFU/ml) and Lactococcus garvieae (6.8×105 CFU/ml) equal to 30% of LD50 values were applied in the main experiment. At the end of trial, blood was sampled via caudal vein. Measurement of hematocrit and hemoglobin has been accomplished according to standard methods, and the number of blood cells was counted by hematocytometer.

Findings pointed out PVC%, Hb value and RBCs count of groups that received the drug were reduced significantly than control (p < /em><0.05). 10-day administration of flornfeicol in the mentioned dosage could cut down lymphocytes statistically (p < /em><0.05). On the other hand, monocytes, neutrophils, and other blood cells were enhanced following administration of therapeutical dosage (p < /em><0.05).

It seems that oral consumption of florfenicol could improve innate immunity, especially through enhancement of hematocytes. However, due to reduced frequency of blood lymphocytes, and as the problem of anemia in fish following drug consumption is still observed, it is recommended that in case of reduction of losses and improvement of clinical symptoms, the lowest FDA-suggested levels of the antibiotic for treatment should be used.

The use of natural immune stimulants is one of the most effective methods for strengthening immunity and preventing diseases in fish.

Due to the abundance of red algae (Laurencia caspica) in the Caspian Sea, the aim of this study was to investigate the effect of this algae on growth performance and blood indices of rainbow trout.

The present study was performed on 750 randomly selected rainbow trout (Oncorhynchus mykiss) in 5 experimental treatments including an algal extract-free diet (control), and diets supplemented with 0.5, 1, 1.5, and 2% of algal hydroalcoholic extract. During the experimental period, fish were sampled to measure growth performance and blood indices every two week for 8 weeks.

Growth indices were not affected by the algal extract at the end of eight weeks of feeding. There were no significant differences in fish survival at different treatments. Total counts of red blood cells, white blood cells, hematocrit percentage, hemoglobin concentration and neutrophil and monocyte percentages were affected by algal extract with significant increases compared to the control group (p < /em><0.05). Results of serum biochemistry showed that significantly increased total protein, albumin and globulin and also significantly reduced ALT, AST and ALP compared to the control in rainbow trout.

Based on the results of this study oral use of red algae (L. caspica) as an immune stimulant in rainbow trout (O. mykiss) was recommended.

Doxorubicin is one of the most widely used anticancer chemotherapeutic agents in small animal practice. The use of doxorubicin can cause cardiotoxicity, hepatotoxicity, neurotoxicity, and nephrotoxicity.

This study was carried out to evaluate the effects of ascorbic acid on doxorubicin hepatotoxicity in mice.

Twenty-four Balb/c mice were randomly divided into four groups. Group one received normal saline, group two received 100 mg/kg ascorbic acid, group three received 8 mg/kg doxorubicin and group four received ascorbic acid and doxorubicin intraperitoneally, with the same doses of groups 2 and 3. Twenty-one days after injection, the mice were euthanized. The activities of ALP, ALT, AST enzymes and total bilirubin levels in the serum samples were measured. Liver samples were evaluated histopathologically.

The activities of ALP, ALT, AST, and total bilirubin levels and histopathologic scores of hepatotoxicity were significantly lower in the group that received ascorbic acid + doxorubicin in comparison to those of the doxorubicin group.

Ascorbic acid may be useful in the prevention of doxorubicin hepatotoxicity in mice. Further studies are recommended for evaluation of the use of ascorbic acid in small animals.

Nowadays, due to widespread usage of anti-pain drugs, more attention is being paid to tramadol, although it has only been recognized  rather recently in veterinary medicine. Therefore, evaluation of its effects on various organs is a principal issue.

The aim of present study was to investigate cardiac function change following administration of tramadol using electrocardiography and echocardiography.

Five healthy dogs aged 3-5 years and weighting 20-26 kg were selected for study. To check the health of animals, clinical and laboratory examinations were performed. Then animals were kept for 2 weeks and vaccination and anti parasite therapy were prescribed for them. This study was conducted in 3 stages and ECG and echocardiography were recorded: before tramadol injection, immediately after injection and one hour after that. Parametric data analysis of variance with repeated measure was conducted using SPSS version 20.

Along evaluated parameters, only left ventricular volume in end-diastole and end-systole, time interval between the Q wave to aortic valve closure, stroke volume and ejection fraction showed significant difference between the three stages.

In conclusion, tramadol shows remarkable anti-pain effects with low cardiac side-effects in comparison to other opioid drugs. However, more studies are needed due to the importance of this subject.

Thoracoscopy is a minimally invasive method used in diagnosis and treatment of many disorders in animals, however, its application in smaller species is limited in literature which can be contributed to the challenges faced while performing a minimally invasive procedure in smaller mammals.

Evaluating the feasibility and ideal port placement considering heart as the target organ in rabbit. Also, the impact of ventilation protocol on rate of mortality was evaluated.

Twenty New Zealand white rabbits were used in this experiment. Approaches used for the introduction of the camera were Para-xiphoid and intercostal space, the optimal spot for insertion of the second trocar relative to the camera was also evaluated, lung damage and rate of mortality were assessed under two different mechanical ventilation modes of pressure-controlled and volume-controlled.

Surgical view gained through the para-xiphoid approach is rather panoramic and spatial than the direct intercostal view, maneuver on the heart with an instrument is easier when the 5th intercostal space is used for the second trocar. With the help of PCV, lungs sustain less damage and atelectasis can be avoided till the end of the procedure and therefore, less mortality is experienced.

Using the Para-xiphoid approach and the correct ventilation protocol provides sufficient working space under good vison, which makes the rabbit thoracoscopic heart model a practical model that can be used in many cardiac experiments.

Regarding the economic values of meat, adulteration in meat products is probable.

This study was carried out to evaluate the histological method for the quantitative detection of meat in Kabab Loghme and cooked sausage model.

Five Kabab samples (containing 70 % meat) and cooked sausage (30, 50, 70 and 90% meat), were prepared. Then, each sample was divided into three parts and one piece was taken from each part and fixed in 10% neutral-buffered formalin. The samples were routinely processed for light microscopy and embedded in paraffin. The paraffin-embedded blocks were cut into 6 μm sections and stained using hematoxylin and eosin (H & E) for histological study.

The histometrical analysis indicated that the estimated percentages for the added meat in kabab did not show significant difference with the real related percentages. On the other hand, the amount of meat was difficult to estimate especially in cooked sausage.

The findings of the present research suggest the histological technique as a complementary method for quantitative evaluations of meat in raw meat products. However, the quantitative evaluation of meat in raw meat products was more convenient than in processed ones.

The interdigital pouch is an invagination of the skin which locates between the digits in several species of the artiodactyla. It secretes pheromones that play important biological functions in the conspecific chemical communication.

This study has been carried out in order to determine the anatomical and radiological structure of the interdigital pouch in native goats.

Eighty interdigital pouches (40 forefeet and 40 hind feet) of 10 female and 10 male, one to three-years-old, healthy native goats in slaughterhouses of Chaharmahal va Bakhtiari were selected. After dissection, topography of each pouch was determined in the feet. For radiologic studies, contrast urografin media were injected into the pouch and then radiographs and photographs were obtained. Different parts of each pouch were identified and measured between the two limbs in both sexes. Data were analyzed by t-test.

In native goats, the pouch, which was observed in all feet,  was a primitive type and located in the space between two hooves at the level of pastern joint. The pouch represents an equilateral triangle with an apex next to the first phalanx and the base near the second phalanx. The best radiographic view for pouch in native goats was dorsopalmar or dorsoplantar. Detection of the pouch in the forelimb was more than that of the hindlimb. Except for the base of pouch, the means of the other parts in male were significantly higher than females. It is difficult or impossible to define the exact radiological and topographical limits of the pouch in goat, due to the absence of secretion, excretory duct and orifice and also the dispersion of structure.

Based on this study, it can be concluded that although the interdigital pouch has only been reported in sheep, deer, moufflon and antelope, it was also found in native goats, but it is not common.

Infectious diseases widely occur through bacteria such as Salmonella spp. in different hosts such as domestic animals and human.

The aim of this study was to isolate Salmonella Typhimurium bacteria from poultry feces and in vitro assessment of antimicrobial effects of 9 species of Zagros native medicinal plants.

Ethanol extracts of jooshir, shallots, Iranian eremurus, artichokes, sheng, amaranth, sorrel, oregano and harmel were extracted through rotary vacuum system. Furthermore, 12 strains of Salmonella Typhimurium were isolated from poultry feces in Sistan region. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined through micro dilution method. Sensitivity of different strains to antibiotics was tested through standard Kirby-Bauer diffusion disk methods.

Salmonella Typhimurium strains are resistant to Penicillin (100%), Ampicillin (100%), Tetracycline (16.6%), Amikacin (8.3%) and Oxacillin (75.0%). Results of the antimicrobial assay have shown that extracts of amaranth, jooshir and artichokes had the highest MIC against Salmonella Typhimurium.

Results of the current study showed that according to the antibiotic resistance of Salmonella Typhimurium isolated from poultry, antibiotic treatment, in particular with penicillin, ampicillin and oxacillin with the bacterium resistance of 75 to 100% would not be effective. In contrast, using plant ethanol extracts especially jooshir, amaranth and artichokes could be recommended as an alternative to conventional antibiotic treatments.

Major histocompatibility complex (MHC) is a group of genes which codes for binding of antigenic peptides and presenting them to T cells. MHC molecules polymorphism is associated with presenting different antigens, immune and autoimmune responses. One of the most important dog MHC genes is DRB1. The association between this gene and its alleles with Atopic Dermatitis has been reported.

In this study, the association between canine Atopic Dermatitis and DLA-DRB1 alleles has been evaluated using HRM (High Resolution Melting) genotyping method.

Blood samples were collected from 20 dogs with Atopic Dermatitis and 20 healthy dogs. Frequency of different DRB1 genotypes, as well as heterozygosity and homozygosity of alleles were analyzed using HRM. Their associations with Atopic Dermatitis were evaluated by statistical analysis.

Based on the HRM analysis, genotypes were grouped in 9 types (A-I). Statistical analysis showed that the presence of type D allele in the exon II of DLA-DRB1 gene increases the risk of Atopic Dermatitis (Odd ratio=0.206 and p < /em>=0.064). A significantly increased risk of Atopic Dermatitis in heterozygous samples was also observed (Odd=0.158 and p < /em>=0.090).

The results of this study showed that some alleles of DLA-DRB1 gene can play a role in the sensitivity or resistance to Atopic Dermatitis in dogs.