Selected Metabolic and Hormonal Profiles during Maintenance of Spontaneous Ovarian Cysts in Dairy Cows

Information is lacking regarding the relationship between metabolic and hormonal profiles and the maintenance of spontaneous ovarian cyst disease in dairy cows. For this reason, the concentrations of non‐esterified fatty acids (NEFA), insulin‐like growth factor I (IGF‐I) and cortisol (C) were investigated during the spontaneous course of ovarian cyst disease in dairy cows (n = 6) between the 7th and 16th weeks post‐partum (PP). The control group consisted of normally cycling cows (n = 6). Blood samples were collected twice a day, and plasma was analysed using different techniques. Progesterone and 15‐ketodihydro‐PGF_2α plasma profiles were investigated to confirm the ovulatory or anovulatory conditions of the cows. Cortisol plasma levels were not significantly different among sampling times within each group or between the two groups. NEFA plasma levels were significantly higher in cycling cows compared to cystic cows at the 16th week PP (p < 0.01), but with rather low values, indicating by now sparse mobilization of fat stores. Insulin‐like growth factor I plasma concentrations were higher in cystic cows during the 8th, 10th, 11th (p < 0.01) and 16th week PP (p < 0.05), indicating that the presence of ovarian cysts coincides with increased IGF‐I levels. These results suggest no influence of cortisol and NEFA levels in cysts maintenance, while a possible involvement of IGF‐I can be suspected not only in the pathogenesis, as already known, but also in the maintenance of spontaneous cystic ovarian disease in cattle.     

Longevity of Mycobacterium bovis in brushtail possum (Trichosurus vulpecula) carcasses,and contact rates between possums and carcasses

Abstract

AIM: To determine, for a variety of environmental conditions, how long Mycobacterium bovis might remain viable inside the carcass of a brushtail possum (Trichosurus vulpecula) that died of bovine tuberculosis (Tb), and to measure the rate of contact between free-ranging possums and possum carcasses.

METHODS: Lesions of M. bovis were simulated by inoculating excised spleens weighing 0.5–1 g with 0.2 mL liquid culture containing approximately 5 x 10⁷ cfu M. bovis/mL. Simulated lesions were inserted into possum carcasses (n=48) at the peripheral lymph nodes. Carcasses were placed in the field at two sites (a tussock grassland and a podocarp-broadleaved forest site) and in two seasons (summer and winter) for up to 62 days. Survival rates of M. bovis were estimated by sampling the simulated lesions over time, and culturing the recovered lesion to determine if any viable M. bovis bacteria were present.

The time taken for a free-ranging possum to first encounter a dead possum in its home range was estimated by live-trapping possums and fitting them with proximity loggers (n=13). A ‘contact’ was recorded if these possums came within 40–50 cm of proximity loggers fitted to possum carcasses.

RESULTS: There were strong seasonal and site effects in the survival rate of M. bovis in possum carcasses. In the grassland habitat, no viable bacilli were cultured from any carcass after 3 days in summer, whereas in winter all samples were culture-positive for the first 20 days, and some were still positive after 27 days. The survival rates for forest habitat were intermediate between the results for grassland, and there were no culture-positive carcasses after 9 days in summer or 27 days in winter.

In summer, infected carcasses (n=6) were first encountered by possums a mean 1.9 (range 0.4–6.7) days after placement.

CONCLUSIONS: Possum carcasses were contacted by free-ranging possums within the period that viable M. bovis were shown to survive in a carcass. The risk of such infection is likely to be most significant in winter or in areas with microhabitats where the survival of M. bovis is high. However, the generally low survival rate of M. bovis in possum carcasses and the low frequency of possum-to-carcass contacts indicate this route of transmission alone could not maintain Tb in a possum population.     

Equine amnionitis and fetal loss: The case definition for an unrecognised cause of abortion in mares

A series of abortions occurred in mares in New South Wales during 2004 that involved similar and unusual findings on post mortem examination of aborted fetuses and fetal membranes. The term Equine Amnionitis and Fetal Loss (EAFL) was developed to describe the condition. This form of abortion had not been previously recognised in Australia. The pathology alone is not specific for EAFL and diagnosis requires demonstration of a combination of certain pathological and bacteriological features. The purpose of this paper is to describe patterns considered consistent with EAFL cases as a working case definition for use by veterinarians and veterinary pathologists in identifying future cases of EAFL. More detailed papers are in preparation to fully describe the epidemiological, histopathological, and microbiological aspects of EAFL.     

Estimating the level of disease risk and biosecurity on commercial poultry farms in New Zealand

ABSTRACT

Aims: To collect baseline data on the contact risk pathways and biosecurity practices of commercial poultry farms in New Zealand, investigate the relationship between the farm-level disease contact risks and biosecurity practices, and identify important poultry health concerns of producers.

Methods: A cross-sectional survey of all registered New Zealand commercial poultry operations was conducted in 2016 collecting information on farm demographics, biosecurity practices, and contact risk pathways. Survey responses were used to generate an unweighted subjective disease risk score based on eight risk criteria and a subjective biosecurity score based on the frequency with which producers reported implementing seven biosecurity measures. Producer opinions towards poultry health issues were also determined.

Results: Responses to the survey response were obtained from 120/414 (29.0%) producers, including 57/157 (36.3%) broiler, 33/169 (19.5%) layer, 24/55 (44%) breeder, and 6/32 (19%) other poultry production types. Median disease risk scores differed between production types (p?<?0.001) and were lowest for breeder enterprises. The greatest risk for layer and broiler enterprises was from the potential movement of employees between sheds, and for breeder enterprises was the on- and off-farm movement of goods and services. Median biosecurity scores also differed between production types (p?<?0.001), and were highest for breeder and broiler enterprises. Across all sectors there was no statistical correlation between biosecurity scores and disease risk scores. Producers showed a high level of concern over effectively managing biosecurity measures.

Conclusions: The uptake of biosecurity measures in the commercial poultry farms surveyed was highly variable, with some having very low scores despite significant potential disease contact risks. This may be related to the low prevalence or absence of many important infectious poultry diseases in New Zealand leading farmers to believe there is a limited need to maintain good biosecurity as well as farmer uncertainty around the efficacy of different biosecurity measures. Further research is needed to understand barriers towards biosecurity adoption including evaluating the cost-effectiveness of biosecurity interventions.     

Successful treatment of a pancreatic pseudocyst by omentalisation in a dog

CASE HISTORY A 3-year-old male Labrador retriever was presented with a history of dietary indiscretion followed by vomiting and abdominal pain.

CLINICAL FINDINGS AND TREATMENT: Abdominal ultrasonography revealed the presence of a fluid-filled cystic structure in the region of the pancreas. Flocculent, dark fluid was drained from the cystic structure during exploratory celiotomy prior to resection of the lateral cystic wall. Omentum was sutured into the cystic cavity to provide drainage and enhance immune response. A jejunostomy feeding tube was placed. Post-surgical care consisted of antibiotic therapy. The dog was clinically normal at 1 and 7 months post-operatively and the pancreas appeared normal on final ultrasonographic examination.

CLINICAL RELEVANCE: This case describes the use of omentum to provide physiological drainage of a pancreatic pseudocyst. This surgical technique may help clinicians manage patients with this condition in the future.     

Clinical efficacy of diclofenac sodium and flunixin meglumine as adjuncts to antibacterial treatment of respiratory disease of calves

Objective To compare the efficacy of the non-steroidal antiinflammatory drugs, diclofenac sodium and flunixin meglumine as adjuncts to the antibiotic treatment of bovine respiratory disease (BRD). Procedure We randomly allocated 80 Holstein calves with BRD to three groups. All the calves received a dose of 2.5 mg/kg tulathromycin by single subcutaneous injection and two of the groups received, in addition, either 2.5 mg/kg diclofenac sodium as a single intramuscular injection (diclofenac group, n = 30) or 2.2 mg/kg flunixin meglumine as an intravenous injection on the first three consecutive days after tulathromycin administration (flunixin group, n = 30). All calves were given a clinical score prior to initial treatment (day 0) and after treatment (days 1, 2, 3, 7 and 14) by observing appetite, demeanour, rectal temperature, the rate and type of respiration, presence or absence of coughing, and nasal discharge. Results During the first 48 h, improvement of adverse signs of respiratory disease, such as pyrexia and elevated respiratory rate, and of a high clinical index score was significant in the two adjunct groups compared with the calves receiving antibiotic alone. The reduction in pyrexia was greatest in the diclofenac group. There were no statically significant differences between treatment groups with regard to eventual perceived recovery from respiratory disease in 14 days. Conclusion In this trial, a single intramuscular dose of diclofenac sodium was equally effective as three intravenous injections of flunixin meglumine given on consecutive days as adjunctive therapy for BRD.     

The Acidic Probe LysoSensor™ is not Useful for Acrosome Evaluation of Cryopreserved Ram Spermatozoa

To try new acrosomal probes for assessing ram spermatozoa, we compared the LysoSensor^? probe, which labels acidic organelles, with the frequently used peanut agglutinin acrosomal probe (PNA‐PE; phycoerythrin as fluorescent moiety). The previous microscopic observations showed a lack of relationship of LysoSensor^? with acrosomal status. Semen was obtained from five rams and frozen in four pools. Each pool was analysed carrying out a triple staining propidium ioide/PNA‐PE/LysoSensor^? Green DND‐189 to test acrosome labelling, and a double staining SYBR‐14/PI, to assess sperm viability. Stained samples were analysed by flow cytometry. All measurements were replicated. Data were processed using agreement and repeatability tests. LysoSensor^? labelling did not agree with PNA (mean of differences: 30.8%; coefficient of agreement: 22.6%), confirming microscopic observations. Nevertheless, when LysoSensor^? was compared with SYBR‐14/PI, the agreement was high (mean of differences: ?0.05%; coefficient of agreement: 5.07%). Repeatability of both methods was high and similar. LysoSensor^? did not seem to specifically stain the acrosome, but it may accumulate in the cytoplasm and label viable spermatozoa. Therefore, LysoSensor^? might not be used as an acrosomal probe in ram spermatozoa, but it could be used in other kind of studies, taking advantage of its pH sensitivity.     

Microbial origin of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L.

The aetiological agents of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L., were studied. Four Vibrio strains were isolated from larvae of S. aurata affected by this disease, and all strains reproduced the disease in healthy larvae under controlled infection experiments, producing a significant increase of the mortality rates compared to the control (non-inoculated larvae). Several enzymatic properties, which can act as .virulence factors, were demonstrated both in the extracellular products (ECPs) and In live cells of the strains tested. Histopathological examinations of the infected fish larvae revealed important changes of the anterior intestine and liver characterized by a marked hyperthrophy of the intestinal epithelium and hepatocytes, and by a separation of the mucosal and submucosal layers in the digestive tube. These histological alterations were associated with the constant presence of cocobacillar bacteria in the anterior intestine and in the liver. However, the precise pathogenic mechanisms of the strains tested have not been completely elucidated yet.     

Isolation of Canine Mammary Cells With Stem Cell Properties and Tumour-Initiating Potential

Recent data suggest that mammary carcinogenesis may be driven by cancer stem cells (CSCs) derived from mutated adult stem cells, which have acquired aberrant cell self-renewal or by progenitor cells that have acquired the capacity for cell self-renewal. Spontaneous mammary cancers in cats and dogs are important models for the understanding of human breast cancer and may represent alternative species model systems that can significantly contribute to the study of human oncogenesis. With the goal of identifying markers for isolating human breast CSCs, we have generated a canine model system to isolate and characterize normal and CSCs from dog mammary gland. Insight into the hierarchical organization of canine tumours may contribute to the development of universal concepts in oncogenesis by CSCs. Cells with stem cell properties were isolated from normal and tumoural canine breast tissue and propagated as mammospheres and tumourspheres in long-term non-adherent culture conditions. We showed that cells obtained from spheres that display self-renewing properties, have multi-lineage differentiation potential, could generate complex branched tubular structures in vitro and form tumours in NOD/SCID mice. We analysed these cells for the expression of human stem and CSC markers and are currently investigating the tumour-initiating properties of these cells and the hierarchical organization of normal and neoplastic canine mammary tissue.