مجله تحقیقات دامپزشکی ایران (دانشگاه شیراز)
سال:1389 | دوره: | شماره: |تعداد مقالات:14

Evaluation of the cardiovascular system of canine pediatrics requires awareness of the anatomical and physiological changes occurring from birth to six months of age. The aim of this study was to report electrocardiographic changes in the littermate mongrel dogs from birth to six months. Serial six-lead electrocardiograms were recorded from ten normal littermate mongrel dogs kept on right lateral recumbency, aged between birth and six months. Heart rate significantly decreased until the age of six months, reaching values of 99±5 beats per min. Age as well as body weight caused a gradual increase in duration of the P wave, P-R and Q-T intervals, S-T segment and also amplitude of the R and T waves. Sinus rhythm was commonplace in dogs under 18-week-old and sinus arrhythmia was found from 16 weeks of age. Sex only influenced the amplitude of the R and Q waves. Males had higher mean values of the R wave amplitude (0.991 ± 0.050) than females (0.740 ± 0.039), but females had higher mean values of the Q wave amplitude (0.256 ± 0.013) than males (0.217 ± 0.010). The mean electrical axis (±SD) of QRS waves in this study was 69.61° ± 21.47°. The possible dependence of the electrocardiographic alterations on age should be taken into consideration in practical veterinary medicine when working with dogs of different ages.

Ovine pulmonary adenocarcinoma (OPA) was studied in the lungs of 15 naturally-affected sheep (9 with classical and 6 atypical lesions) by transmission electron microscopy. Two lung samples from normal sheep were used to develop the ultrastructural criteria. Pathologic lesions consisted of focal-multifocal to coalescent nodules or masses in the cranioventral or diaphragmatic lobes. Ultrastructural characteristics of tumor cells in the alveoli and bronchioles allowed categorization of these cells into three groups; neoplastic alveolar type (AT) P cells in the alveoli contained numerous cytoplasmic lamellar bodies, well developed rough endoplasmic reticulum and glycogen particles; neoplastic clara cells in the bronchioles contained apical electron-dense granules and well-developed smooth endoplasmic reticulum; undifferentiated tumor cells in the alveoli and bronchioles lacked characteristic lamellar bodies or electron-dense granules. Neither complete virions nor viral inclusions were seen in the neoplastic cells. In the present study, there were no ultrastructural differences in the neoplastic cells between classical and atypical forms. It seems that type II pneumocytes and clara cells are the origin of the neoplasia in the alveoli and bronchioles, respectively.

Numerous techniques for injection into the distal sesamoid bursa (navicular bursa) have been described, especially in equine, but there are few specific descriptions regarding this practice being done in cattle. Five different techniques were compared for injection into the distal sesamoid bursa in cattle including distal plantar approach parallel with the coronary band, proximal plantar approach, distal plantar approach parallel with the sole, abaxial approach, and distal interphalangeal joint injection. The results revealed that the numbers of needle insertion until proper placement is significantly less in the DIPJ and the DPPS techniques compared to the others (P<0.05). Also, based on the times of contrast agent injection after the correct successful needle insertion, there were significant differences between DIPJ with DPPCB, PP30 and the Ab45 techniques (P<0.05). According to the absence of direct communication between the distal sesamoid bursa and distal interphalangeal joint, the placement of the needle through distal plantar approach parallel with the sole was suggested.

The objective of this study was to assess the etiology, diagnosis, treatment methods, surgical findings, postoperative results and necropsy findings of seventeen cases of thoracic trauma by evaluating medical records. A car accident, falling down, stabbing and bites were identified as the causes of trauma. Diagnosed pathologies in the cases included pneumothorax, hemothorax, pulmonary contusion, lung lobe collapse or eventration, rib fractures, etc. The treatment methods employed in these cases were medical therapy, thoracocentesis, tube thoracostomy, lateral intercostal thoracotomy, median sternotomy and thoracic wall revisions. Atelectasis, rupture, laceration or contusion of the lung lobes, pulmonary artery rupture, rib fracture and etc. were the surgical findings. Overall, seven dogs and four cats recovered completely. Two dogs were euthanized due to other pathologies including multisegmental lumbar fracture, paraplegia and postpneumonectomy syndrome. Three dogs and a cat died during treatment management. The necropsies revealed that the animals had pulmonary artery and tracheobronchial ruptures. The cat also had sudden onset cardiac arrest during surgery. In conclusion, cases with thoracic trauma should be assessed closely and managed with the necessary emergency and surgical procedures.

The objective of this study was to compare an indirect ELISA, based on a purified 60 kDa envelope glycoprotein (gp51SU), with a Pourquire indirect ELISA for the detection of antibodies to the bovine leukemia virus. For conducting this research, 340 serum samples were collected from two different breeds of cows (Sarabi and Holestin) in different herds. Commercial ELISA revealed positive results in 17 (7%) Holstein cows. An appropriate ELISA cut-off was determined by receiver operating curve (ROC) analysis in comparison with commercial indirect ELISA. Results showed a relative sensitivity and specificity of 97% and 92%, respectively, for a cut-off value of 0.34 in the domestic ELISA. In conclusion, the results of the present study showed that domestic developed kit can be used for diagnosis of bovine leukemia virus with appropriate sensitivity and specificity. In addition, a comparison of the results from a native breed, Sarabi, with Holstein showed that there was no significant (P>0.05) difference in the frequency of infection with BLV between the two breeds.

Caraway is one of the medicinal plants used for digestion problems, however, it has been reported that the long term use of this plant in large doses might cause hyperthyroidism symptoms such as leanness, hair loss, severe sweating and tremulousness. Therefore, the aim of this study was to evaluate the effect of hydroalcoholic extract of caraway on the level of thyroid hormones and morphologic changes of thyroid gland in rats. For this purpose, 60 rats were divided into 5 experimental and control groups. Experimental groups were orally given 100, 400, 800 and 1600 mg/kg of extract for 45 days by gavage. The same volume of saline was given to the control group. Blood samples were taken before and after the experiments for the measurement of hormones. The rats were dissected under deep anesthesia and their thyroid glands were removed, processed and stained with H&E. Results show that T3 and T4 were increased and TSH was decreased significantly at high doses compared to those in the control group, but no change was observed in the structure of the gland and the size of follicles. It seems that caraway can temporally increase thyroid hormones and cause hyperthyroidism, but further studies are required to clarify the issue.

A total of 200 moribund rainbow trout with clinical signs of a hyperacute haemorrhagic septicemia were collected from rainbow trout farms in Fars, Kohkiloyeh-Boyer Ahmad and Charmohal-Bakhtiari provinces in the south and southwest of Iran during summer 2002 to winter 2008 for detection of Lactococcus garvieae, the causative agent of lactococcosis. Fish kidney samples were cultured aseptically onto brain heart infusion agar plates and incubated at 25°C for 48 h. using conventional biochemical tests, L. garvieae was detected from 32 fish (16% of total fish samples). Additionally, isolates were confirmed as L. garvieae using a specific PCR assay based on 16S rDNA gene by producing a single band of 1107 bp. Partial analysis of 16S rDNA revealed 100% sequence similarity for all Iranian isolates and there was a close genetic relationship among these isolates and those previously reported from mullet in Taiwan (AF352166) and yellowtail in Japan (AB267897) based on GenBank data. Results of antibiogram tests on L. garvieae isolates showed a high susceptibility to erythromycin, enrofloxacin, chloramphenicol and clarithromycin. In pathogenicity tests, immersion of fish in a bacterial suspension of 6 ´ 105 colony forming unit/ml of L. garvieae in challenge experiments showed 60% mortality during 14 days post-infection. Experimentally, infected fish showed typical blackening of skin haemorrhages, exophthalmia and wide haemorrhages on viscera. The present study provides useful molecular and biochemical information for L. garvieae isolates in Iran compared with those from different hosts and geographic locations.

This study was conducted to investigate the correlation between lipid-lowering and bone-protective effects of eicosapentaenoic acid on steroid-induced bone changes in rats. Twenty-one male 10-week-old Wistar rats were divided into 3 groups (n = 7 each) and treated with 0.9% NaCl SC (group 1) or methylprednisolone 7 mg/kg SC once a week (group 2) or methylprednisolone 7 mg/kg SC once a week + eicosapentaenoic acid 160 mg/kg, PO daily (group 3), for 6 weeks. At the end of the experiment, serum total cholesterol and triglycerides concentrations were determined using enzymatic colorimetric assays and bone histomorphometric analyses were performed on cancellous bone of femoral epiphysis and metaphysis using a photomicroscope and a digital camera. Histomorphometric parameters demonstrated a significant bone loss due to methylprednisolone administration, which was partly restored by eicosapentaenoic acid. A strong inverse correlation was observed between the serum total cholesterol concentration and epiphyseal trabecular width and metaphyseal trabecular osteoid width (R = -0.82, P = 0.04 and R = -0.86, P = 0.01, respectively). Serum triglycerides concentration was also strongly and inversely correlated with the above mentioned parameters (R = -0.88, P = 0.02 for epiphyseal trabecular width and R = -0.81, P = 0.02 for metaphyseal trabecular osteoid width). The correlation between the lipid-lowering and bone-protective effects of eicosapentaenoic acid may be helpful in the clarification of its effects on bone and lipid metabolism.

Heartworm infection is one of the most important parasitic diseases in dogs and an increasing number of cases are reported each year by necropsy in Ahvaz. This study was conducted to determine the prevalence of Dirofilaria immitis infection and to investigate the risk factors related to heartworm disease in urban dogs in this area. Blood samples were collected from 100 dogs from Feb 2007 to Feb 2008. All samples were examined by modified Knott test, direct smear and antigen detection (Immunochromatographic antigen rapid canine D. immitis Ag Test Kit) technique to detect circulating microfilaria and adult antigen of D. immitis, respectively. Of the total 100 dogs, 1% were positive by direct smear, 5% were positive by modified Knott test and 6% were positive by antigen detection. In addition, 1% of positive dogs were determined to have occult D. immitis infections. Dirofilaria immitis was the only canine filarial parasite present in this study. From these three methods, modified Knott test, due to microfilarial identification on concentrated blood had the highest validity. The difference between outdoor and indoor dogs was found significant (P = 0.033), whereas no statistically significant differences were observed between different age groups, sexes and breeds (P>0.05). The highest heartworm prevalence by modified Knott test was observed in older than 6-year-old dogs (8.3%) followed by 3–6 years (2.7%) and the 6-month to 3 years (3.5%) age groups. The infection was more prevalent in males and short haired breeds. Our results suggest that heartworm treatment and preventive care should be considered in urban dogs of Ahvaz, Iran.

The purpose of this preliminary study was to determine the prevalence of raw milk contamination with Listeria monocytogenes. In this study, 100 bulk tank milk samples were collected randomly and delivered to Pegah Pasteurization Factory in Mashhad. For isolation and identification of L. monocytogenes, the samples were first enriched using cold enrichment method in Listeria enrichment broth, followed by plating onto supplemented Oxford agar. For final identification of suspected colonies a multiplex-PCR assay, using two pair of primers was employed. The prs primers are specific for putative phophoribosyl pyrophosphate synthetase (prs) gene of Listeria spp. and the LM lip1 primers are specific for prf A gene of its monocytogenes serovar. Using this method, the contamination of raw milk with L. monocytogenes was determined to be 4% and the sensitivity of the primers was 3.5 × 103 cfu ml-1, and the specificity was determined to be 100%. Considering the high specificity and sensitivity of the employed multiplex-PCR assay, it is recommended to use this method for the identification of suspected colonies of Listeria spp. and L. monocytogenes.

Aspartic proteases are a relatively small group of enzymes which express in various nematodes including Onchocerca volvulus. An estimation of the gene copy number corresponding to the OV7A clone, which contains a cDNA insert encoding approximately two-thirds of the entire coding sequence of aspartic protease of O. volvulus, was made by slot blot analysis in a closely related species O. gibsoni genome. Nylon membrane was loaded with serial dilutions of genomic DNA alongside the OV7A plasmid DNA before hybridizing the membrane to that 32P-labeled cDNA insert. To prepare the initial probe, OV7A cDNA insert was amplified using gene-specific primers. By comparing the signal intensity of slot blot hybridization of known amounts of genomic DNA and plasmid DNA containing the cDNA insert under similar conditions, the abundance of sequence homologues to the 32P-labeled cDNA insert in the genome was calculated. For confirmation, southern blot analysis was performed by digesting genomic DNA with a panel of different restriction enzymes. Hybridizing patterns of the same probe revealed a single band except when predicted internal restriction sites were affected. It was confirmed that Onchocerca contains a single copy of the gene corresponding to this cDNA insert per haploid genome.

In this study, to increase information about the relationship between caprine and ovine isolates of Pasteurella multocida, 16S rRNA gene sequencing of 9 goats (5) and sheep (4) isolates were investigated. Also, capsular type and toxA gene presentation was studied in this paper. All isolates, except one, belong to capsular type A, and toxA+ strain distributed among strains were isolated from both species. Comparison of the 16S rRNA gene sequence showed the role of goat as a reservoir for P. multocida to sheep independent of toxA genes transmission.

Megaesophagus (esophageal dilatation) is a neuromuscular disease. In this disorder, the esophagus is abnormally stretched and air is collected with food in it. Two male dogs aged 4 and 6-year-old, German shepherd breeds and weighing 18.4 and 23.2 kg were presented to the Veterinary Hospital of Shahid Chamran University with complaints of regurgitation, dehydration, anorexia, depression, dysphagia, myoclonus, hypersalivation, gurgling sound during swallowing and fatigue in the past month. They were not vaccinated against distemper and other viral diseases. Physical examination revealed a relatively thin body condition. A plain radiograph of the chest revealed advanced megaesophagus with aspiration pneumonia. Rapid antigenic test (immunochromatography assay) was positive for canine distemper. CBC was abnormal (leucopenia, lymphopenia and neutropenia). Supportive treatments were administered for them. We advised the dogs be placed in a vertical position for 15 min after the meal. Only one dog was sent back home in good health four weeks later and the disease did not relapse for more than six months. The second dog had a symptom of megaesophagus and did not respond to supportive treatments completely. A possible relationship between megaesophagus and canine distemper infection has been reported in the present survey. 

The intracellular parasite Neospora caninum is prevalent in several countries and is increasingly recognized as an important cause of abortion and stillbirth in cattle. For characterizeing the tachyzoite antigens of Neospora caninum in aborted cows, sera were obtained from 116 cows which were aborted in the third semester of the pregnancy period and had antibodies to Neospora caninum in ELISA. To obtain the protein content of Neospora, purified tachyzoites were lysed, electrophoretically separated and blotted to nitrocelloluse membrane for immunostaining. Minimum 9 and maximum 13 protein bands ranging from 10 to 90 kDa were observed after immunostaining. It seems that, in almost all of the cows, two protein bands with a molecular weight of 45 and 41 kDa, have a prominent reaction in Western blotting. According to our findings, these two protein bands are the most important antigens observed after Western blotting, in seropositive aborted cows.