Iranian Journal of Veterinary Research
Volume:21 Issue: 2, Spring 2020

Newcastle disease (ND) causes devastating economic losses in poultry industry.

This study evaluates the plausible effect of prior or post challenge vaccination with a live commercial vaccine on some pathogenic aspects of velogenic Newcastle disease virus (vNDV) infection in broilers with an emphasis on elucidating type I interferons (IFNs) response trends.

Chicks (n=250) were randomly allocated into 5 equal groups including negative control (NC), positive control (PC) (challenged with vNDV), and treatment (T1-T3) groups: (T1) only received Villegas-Glisson/University of Georgia (VG/GA) strain of NDV vaccine, (T2) vaccinated 24 h prior to vNDV challenge, and (T3) vaccinated 24 h post vNDV challenge. Samples from trachea, cloacal content, and serum were collected at different time points to evaluate virus shedding or IFNs levels.

Although clinical signs and lesions were not completely blocked by administration of vaccine prior to or post vNDV inoculation, the disease severity diminished as demonstrated by an increase in bird’s survival rate and median survival days (MSDs). Moreover, prior to or post challenge VG/GA live vaccine administration, modified viral shedding patterns by decreasing the vNDV shedding period especially from the gastrointestinal (GI) system. Strong early type I IFNs response was observed in the trachea and sera of chickens vaccinated prior to or post-infection (pi) as compared to birds that received vaccine or vNDV alone. In trachea, IFN-α response was more pronounced than IFN-β, while both IFNs showed a considerable change in serum.

It seems that vaccination after challenge with vNDV can improve bird’s health similar to prior administration and reduces virus shedding which may be due to type I IFNs production.

Analgesic and hemodynamic effects of ketamine in subanesthetic doses during surgical anesthesia and postoperative, are due to the action on the N-methyl-D-aspartate receptors (NMDAR).

To evaluate the intraoperative cardiorespiratory effects provided by ketamine compared to lidocaine, both administered epidurally, in bitches submitted to ovariohysterectomy.

Thirty-six dogs of different breeds were used in a randomized, prospective, and blinded clinical trial. Two groups were formed: GKET (ketamine 3 mg/kg, n=18) and GLIDO (lidocaine 4 mg/kg, n=18). Animals were premedicated with acepromazine 0.05 mg/kg intravenous. Anesthesia was induced with propofol 5 mg/kg intravenous. Anesthetic maintenance was performed with isoflurane in 100% oxygen. Every 5 min during surgery, heart rate (HR), respiratory rate (RR), esophageal temperature (°C), oxygen saturation (SPO2), end tidal carbon dioxide (ETCO2) and mean arterial pressure (MAP) were monitored.

Cardiorespiratory variables during anesthesia were within normal ranges. Heart rate was significantly higher at 5 (108 ± 12 vs 95 ± 11) and 10 (110 ± 11 vs 97 ± 11) min in GKET compared to GLIDO after the start of surgery (P=0.03 and P=0.01, respectively). Mean arterial pressure was higher in GKET, (100 ± 23, 105 ± 35, and 103 ± 35 mmHg) in comparison with GLIDO (66 ± 7, 74 ± 10, and 67 ± 9 mmHg) at 20, 25 and 30 min (P=0.01, P=0.004, and P=0.002, respectively). Mild hypothermia at 25 (36.5 ± 1.3°C) and 30 (36.5 ± 1.4°C) min in the GKET was recorded.

Epidural administration of ketamine provides better hemodynamic stability, compared to the use of epidural lidocaine.

The goat is a multi-purpose animal producing meat, milk, hide, fiber and manure, and hence plays a significant role in providing supplementary income and livelihood to the huge number of asset-poor ranchers and landless workers of rural India.

The present study is aimed to investigate the in vitro effects of prostaglandins E2 (PGE2) and F2α (PGF2α) on ovarian granulosa cells of a goat.

The healthy, slightly atretic and atretic antral follicles of goats with diameter ranging from 3-8 mm were cultured with PGE2 and PGF2α (1.0 μg/ml) along with control for 24 h. Histomorphological analysis was done in order to study the prostaglandins induced changes in granulosa cells of all the three categories of follicles. The acridine orange (AO) and methylene blue (MB) staining were used to study the apoptotic index in all the three categories of follicles and the collected data were analyzed by ANOVA with Duncan post Hoc test.

Prostaglandins E2 revealed positive while PGF2α showed a negative effect on the rescue of apoptosis in granulosa cells. The PGE2 treated follicles revealed a reduction in the attributes of apoptosis in granulosa cells while PGF2α showed an increased in the apoptotic characteristics.

The present study depicted that granulosa cell viability in vitro is dependent on the continuous supply of survival and growth factors and prostaglandin of E series synthesis is a crucial step in the suppression of granulosa cell apoptosis while that of F series induces apoptosis.

Maedi-Visna (MV) is a progressive lymphoproliferative viral disease that affects multiple organs of small ruminants, including sheep and goats. The disease occurs primarily in the lung tissue and causes interstitial pneumonia.

The aim of present study was to investigate the prevalence of ovine MV infection in Iranian sheep population through macroscopic, histopathological, serological, and molecular assays, as well as transmission electron microscopy (TEM).

Lung and blood samples of one-hundred female sheep (≤ 2 years old) referred to the Kermanshah slaughterhouse with respiratory symptoms were collected for histopathological and molecular evaluations. Corresponding serum samples were also collected for serological examination.

Histopathological study showed the Maedi-like pulmonary lesions in 85% of the affected lungs, which included the interstitial pneumonia, smooth muscle hypertrophy of alveolar septa and around the blood vessels, interstitial lymphoplasmacytic infiltration and lymphofollicular hyperplasia. Specific antibodies against MV virus were detected in 7% of serum samples. Long terminal repeat (LTR) region of MV provirus was amplified in three (3%) DNA samples, extracted from the suspected lungs. Sequencing analysis of polymerase chain reaction (PCR)-positive samples confirmed the presence of MV provirus in the genome. No amplification was observed, neither in the DNA samples extracted from the blood samples of suspected sheep nor the control group. Transmission electron microscopy also confirmed the presence of MV virions inside the cytoplasmic membrane of MV-infected macrophages.

Although histopathology can provide a preliminary estimation of Maedi in populations, definitive diagnosis of the disease needs to be approved by more sensitive techniques such as serological examinations and molecular analysis.

Avian influenza (AI) caused by AI virus subtype H9N2 is a prevalent viral disease with enormous economic losses in poultry farms through significant respiratory and gastrointestinal manifestations. The degree of protection obtained from a vaccine strongly depends on the level of antigenic similarity between challenge and vaccine virus.

The study aimed at investigating the possible effects of continuous antigenic changes occurring in circulating Iranian viruses since 1998 on the commercial vaccines outcome by using vaccine seeds from earlier outbreaks for inhibiting viral replication in target organs of broilers challenged with the recent isolate.

Ninety broilers at one day of age were randomly allocated into 5 groups and vaccinated with autogenous or commercial vaccines (A or B). Two remaining groups consisted of challenged without vaccination and intact birds. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed on the trachea and faecal samples of challenged chickens with recent H9N2 virus to determine viral load. Moreover, humoral antibodies titers were evaluated by hemagglutination inhibition (HI) assay.

There was no significant difference in H9N2 viral load in the trachea among vaccinated groups on 5 days post challenge (DPC), but on 15 DPC, the autogenous vaccine significantly lowered viral load compared to commercial vaccines (P≤0.05). No significant differences in faecal swab’s viral load was observed between autogenous and commercial vaccine A, and both of them significantly inhibited viral load compared to unvaccinated group (P≤0.05). In addition, the autogenous vaccine elicited the highest HI titer.

Inactivated vaccines that use isolates from previous outbreaks are no longer able to induce proper immunity against recent H9N2 viruses. It seems the time to change vaccine strains to more recent isolates that have better antigenic similarity with current circulating H9N2 viruses in the region has come.

Research has demonstrated that certain nutrients can reverse infertility.

The present study, “Impact of Omega-3 fatty acids preconception intake on some fertility parameters of female rats and foetuses quality” was conducted to further investigate this subject.

Subjects were thirty-four female and twelve male adult Albino rats, weighing 172-181 g. Initially, 12 male rats were assigned to treatment groups 1, 2, 3, and 4, and 24 females were assigned to treatment groups 5, 6, 7, and 8. The treatment protocol was administered orally as follow: groups 1 and 5 (controls), 0.3 ml distilled water (as placebo); groups 2 and 6, 250 mg/kg Omega-3 fatty acids (O3FA); groups 3 and 7, 25 mg/kg cyclophosphamide (CPP, negative control); and groups 4 and 8, 25 mg/kg CPP + 250 mg/kg of O3FA for 28 days. Thereafter, they were cohabitated (1:2 male to female ratio) into mating groups 1 to 7 until mating was confirmed. Ten pregnant rats (5 of which were administered 500 mg/kg O3FA on days 15 and 16 of gestation) were used for abortifacient effect experiment.

Number of implantation sites (IM), implantation index (IMI), percentage of pregnant females (PPF), life foetal number, foetal weight, foetal crown-rump length (FCRL), corpora luteal number (CLN) and fertility index (FI) in O3FA-treated female rats and their foetuses significantly increased (P<0.05) compared with negative control. No noticeable abortifacient effect occurred.

Preconception intake of O3FA may have impacted female fertility positively.

Peripheral blood mononuclear cells (PBMCs), commonly referred to as lymphocytes and monocytes, representing cells of the innate and adaptive immune systems.

To find out whether changes in PBMCs’ mRNA expression of pattern recognition receptors (PRRs) are associated with puerperal metritis in Holstein cows.

‏ Peripheral blood mononuclear cells were collected from 20 cows with puerperal metritis and 20 cows without metritis at 10 days postpartum. Expression of toll-like receptors 2 and 4 (TLR2 and TLR4), and cluster of differentiation 14 (CD14) genes were assessed in PBMCs using a quantitative real time-polymerase chain reaction (qRT-PCR) technique. The data was normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a reference gene, and 2-∆∆Ct methodology was used for relative quantification.

The results of the present study demonstrated that the expression of TLR4 (P=0.04) and CD14 (P=0.008) was significantly greater in cows with puerperal metritis compared to the control group. However, the expression of TLR2 (P=0.06) was not significantly different between cows with puerperal metritis and healthy cows.

This study suggests that puerperal metritis significantly increases the expression of TLR4 and CD14 genes in the PBMCs which contributes to the proper stimulation of inflammation and uterine clearance of bacteria soon after calving.

Toxoplasmosis causes economic losses due to abortion, neonatal death and reproductive diseases in infected sheep. Erzurum is one of the most important cities in Turkey where sheep farming is done.

The aim of this study was to evaluate seroprevalence of Toxoplasma gondii and related risk factors in sheep brought to the slaughterhouse in Erzurum province of Eastern Anatolia region, Turkey.

Nine-hundred and sixty sheep brought to slaughterhouse from Erzurum center and districts were used in this study. The data on age, breed, abortion history of sheep and whether or not they had contact with cats were recorded. The presence of T. gondii antibodies was determined by enzyme-linked immunosorbent assay (ELISA) kit in blood samples taken from sheep just before slaughter.

According to the study results, 44 (4.58%) of 960 sheep were found to be seropositive. Seroprevalence was found to be highest in the ≥2<3 age group with 5.29% (P>0.05), and it was more common in Akkaraman breed compared to Morkaraman breed (P<0.01). It was determined that 43 (97.73%) of the 44 seropositive sheep had contact with cats (P<0.01) and 12 of them (27.27%) had abort history.

The study results identify the presence of T. gondii in the sheep from Erzurum province of Eastern Anatolia region, Turkey.

Staphylococci are the most common cause of pyoderma in dogs.

The purpose of the present study was to investigate clinical, bacteriological and histopathological aspects of bacterial skin infections in a population of Iranian domestic dogs with first-time pyoderma.

The study animals were 61 clinical cases of Iranian domestic dogs with first-time pyoderma. The diagnosis of pyoderma was based on the history, the presence of variable gross cutaneous lesions, positive findings on microscopic examination of surface cytology and histopathological findings.

Detection of pyoderma amongst adult dogs was significantly higher than puppies (P=0.001). Large breed dogs were presented more frequently for pyoderma in comparison to small breeds (P=0.002). Bacterial species were recovered from 43 of the 61 (70.49%) studied animals. No isolates were recovered from 18 studied dogs. The most frequently recovered bacterial genus was Staphylococcus (32/43 isolates, 74.41%) including: S. epidermidis (22/43 isolates, 51.16%), S. aureus (7/43 isolates, 16.27%), and S. pseudintermedius (3/43 isolates, 6.97%). Staphylococci species resistance was most commonly seen against amoxicillin (94.11%), penicillin (83.35%), and ampicillin (76.47%). Resistant to cephalexin and cefoxitin was 5.88% and 2.94%, respectively. A total of 27 of the staphylococci isolated (84.37%) were resistant to at least one antimicrobial agent and 19 isolates (59.37%) were resistant to three or more antimicrobial drugs.

A better understanding of this microbial population is critical for clarification of the pathophysiology of bacterial skin diseases.

Bovine tuberculosis (bTB) is a chronic disease of cattle with high economic importance in livestock farming caused by Mycobacterium bovis and bears a zoonotic potential. There are some non-tuberculous mycobacteria (NTM) which cause disease similar to bTB and interfere with diagnosis of bTB. Non-tuberculous mycobacteria are saprophytic in nature but some of them may cause pulmonary infections, mastitis, lesions in respiratory tract and lymph nodes of cattle, due to which they are being recognized worldwide and interfere with the diagnosis of bTB.

The aim of the study was to detect NTM species from cattle and buffaloes with respiratory distress using biochemical test and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis (PRA).

A total of 50 trans-tracheal washes were collected from cattle (n=41) and buffaloes (n=9) with respiratory distress. The samples were inoculated on Middlebrook 7H10 media after proper decontamination with 4% NaOH. The isolate obtained was identified by biochemical testing. Extracted DNA from samples and isolate was subjected to PRA which involved hsp65 gene amplification (439 bp) and RFLP analysis of amplified product.

Out of 50 trans-tracheal washes only one isolate of Mycobacterium kansasii (n=1) (2%) was obtained which was confirmed by biochemical testing and PRA. Mycobacterium kansasii (n=4) (8%), Mycobacterium intracellulare (n=1) (2%), and Mycobacterium vaccae (n=1) (2%) were identified by PRA.

The study emphasizes the importance of NTM in animals. Polymerase chain reaction-restriction fragment length polymorphism analysis is a more reliable and rapid method for identification of NTM than conventional methods.

Genetic analysis of canine parvovirus type 2 (CPV-2) variants circulating in South Eastern Nigeria was investigated. The original strain of CPV-2 emerged in 1978, mutated later to CPV-2a and has continued to be evolved.

To genetically characterize CPV-2 strains detected in dogs in South Eastern Nigeria and to phylogenetically group the viruses with existing sequencing data.

A total number of 82 rectal swabs were collected and stored in virus transport medium (VTM) from suspected cases of CPV-2 within the study area and were tested with polymerase chain reaction (PCR).

Seventy-nine samples (96.3%) were positive for CPV-2 and sequence analysis of partial VP2 gene of 20 amplicons revealed circulation of CPV-2a (n=4) and CPV-2c (n=16) in the region. The obtained strains clustered together. However, the group was further divided into two clear clusters comprising of 2a and 2c strains. The vaccine strain and the CPV-2 reference strains from USA formed a monophyletic cluster.

Canine parvovirus types 2a and 2c are co-circulating in South Eastern region of Nigeria and therefore, there is an urgent need for an improved vaccine to cover for the emerging strain (CPV-2c) in Nigeria.

Leptospirosis is a zoonotic bacterial infection that is common worldwide, with a wide spectrum of clinical signs. It commonly infects the kidneys and the liver but can damage a number of organ systems.

An 18-month-old boxer dog was referred because of reluctance to walk and sickness. Findings/treatment and outcome: His clinical presentation, including swollen and inflamed joints fulfilled the requirements for a diagnosis of immune-mediated polyarthritis (IMPA). Shortly after, unexpected icterus developed and laboratory signs of hepatic and renal failure were observed. A diagnosis of leptospirosis was reached after observing typical clinical signs, along with a positive microagglutination test. Since the diagnostic molecular test for Leptospira from joint fluids came back negative and also the localization of Leptospira in multiple joints in association with inflammation has never been described in canine patients, an immune-mediated complication seemed most likely. The dog quickly recovered after the administration of ampicillin for 5 days, followed by a two week course of doxycicline.

In human medicine, this case would be considered as a reactive arthritis (ReA), which is mistakenly cited in the current veterinary literature for cases associated with chronic infections. In humans, ReA is described as inflammatory arthritis not directly caused by culture-proven infection of joint tissue but by infection at another site due to a complex interplay of host antimicrobial factors. This case presentation reports for the very first time, a case of canine leptospirosis mimicking an IMPA and fitting the description of ReA in human medicine.