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.     

Procyanidin fractions from pine (Pinus pinaster) bark: radical scavenging power in solution, antioxidant activity in emulsion, and antiproliferative effect in melanoma cells

Pine (Pinus pinaster) bark is a rich source of procyanidin oligomers. From a total polyphenolic extract, we have generated fractions of different procyanidin composition. The mixtures, devoid of gallate esters, were active as free radical scavengers against ABTS(*+), DPPH, and HNTTM. Pine bark fractions were tested for antioxidant activity in solution (hydrogen donation and electron transfer) and emulsion (inhibition of lipid peroxidation) and compared with their galloylated counterparts from grape origin. While galloylation clearly influenced the free radical scavenging efficiency in solution, it did not seem to play a determinant role in protection against lipid peroxidation in emulsion. The fractions were very mild inhibitors of cell proliferation. Because gallate esters appear to interfere with crucial cell functions, gallate free pine procyanidins may be the innocuous chemopreventative agents of choice for many applications in food and skin protection.     

Experience and confidence of final year veterinary students in performing desexing surgeries

AIMS: To describe the level of experience and confidence of veterinary students in performing canine and feline desexing procedures at the end of their final clinical year.

METHOD: A cross-sectional survey was conducted with veterinary students at Massey University in November 2017 after completion of their final clinical year. The questions included career plans after graduation, number of assisted and unassisted desexing procedures performed, approximate time to complete desexing surgeries, level of confidence with different aspects of desexing surgeries, what aspects of their desexing surgery training were most helpful, and what could be done to improve training in desexing surgical skills in veterinary school.

RESULTS: The survey was completed by 70/95 (74%) students in their final clinical year. Among respondents, 55/70 (70%) had performed >2 unassisted feline neuters before graduation. However 38/70 (54%) students had never performed an unassisted feline spay, 31/70 (44%) had never performed an unassisted canine neuter, and 44/70 (63%) students had never performed an unassisted canine spay. The median reported times to complete a feline neuter, feline spay, canine neuter, and canine spay were 9, 40, 30 and 60 minutes, respectively. The median level of confidence for these procedures were 9, 6, 7 and 5 (on a scale from 1=least confident to 10=most confident), respectively. The reported time to complete procedures and the confidence in performing procedures did not change markedly with increasing total number of procedures performed. Students were most concerned about their ability to perform the desexing procedures in a reasonable amount of time and to prevent post-operative bleeding from occurring. Students were least concerned with their ability to manage post-operative pain in patients and to select the appropriate suture material. Free-text comments revealed that 62/70 (89%) students wanted more hands-on surgical experience prior to graduation.

CONCLUSION AND CLINICAL RELEVENCE: Many students are currently completing veterinary school with limited experience and low confidence with performing routine canine and feline desexing procedures. Further research is needed to identify the most effective ways for addressing this issue within the constraints of the veterinary curriculum and teaching hospital resources.     

Cross-sectional survey of pet ownership,veterinary service utilisation,and pet-related expenditures in New Zealand

ABSTRACT

Aims: To describe the demographics of and predictors for pet ownership, reasons for visiting a veterinarian, and pet-related expenditure in pet owners in New Zealand.

Methods: A cross-sectional online survey was conducted from 18–22 June 2015 using a permission-based panel of New Zealand residents aged ≥18 years. Questions included demographics of respondents, number of pets and reasons for owning or not owning pets, number of visits and reasons for visiting a veterinarian, and pet-related expenditure.

Results: Of the 1,572 respondents who completed the survey, 1,013 (64.4%) owned ≥1 pet. Of these, 443 owned dogs, 696 cats, 32 horses, 103 birds, 55 rabbits, and 159 owned fish. Companionship was the most common reason for getting dogs, cats, and birds; horses were mostly owned as a hobby, rabbits to provide fun for children, and fish as a source of relaxation. The majority of dog, cat, and rabbit owners considered their pets to be family members; horse owners almost equally considered their horses a hobby or a family member. The odds of pet ownership increased for respondents from a rural region, having a higher household income, having children and being female. Overall, 711/1,013 (70.2%) pet-owning respondents had taken ≥1 animal to the veterinarian in the previous year, with the most common reasons being for vaccination or annual check-ups or health issues. Respondents who considered their pets trusted companions, had a higher income, and owned dogs or cats compared with other species, were most likely to have taken their pet to a veterinarian. The greatest pet-related expenditure for all species was food. The median yearly veterinary expenditure was $200–499 by dog owners, $100–199 by cat owners, and <$100 by horse, bird, rabbit, and fish owners. The best source of information for pet-related issues was considered to be veterinarians by 724/1,001 (72.3%) owners, and the internet by 509/1,001 (50.8%) owners.

Conclusions: Among survey respondents, pet ownership was common and pets filled a variety of roles in the household. Pet owners reported spending considerable amounts of money on their pets each year, but some of them may be underutilising veterinary services despite veterinarians being considered as valuable sources of information about pet-related issues.     

Association of Reoviridae particles in an enteric syndrome of poults observed in turkey flocks during 1988

An enteric syndrome of turkey poults, characterized by enteritis, crop mycosis, intestinal changes (pale, thin-walled ballooning with watery contents), and rickets, occurred during 1988 in 74 turkey flocks from different farms belonging to 9 California turkey growers. The flocks ranged in size from 9,000 to 120,000 birds. Pools of intestine sections from 618 birds, representing 78 field cases, were examined. Histopathological examination of the intestines showed a mild to severe atrophy with a reduced depth of crypts, which was more prominent in the distal part of the small intestine. Viral isolation attempts with primary cell cultures of chicken embryo kidney cells were negative. Examination by electron microscopy of negatively stained intestinal specimens revealed the presence of Reoviridae particles of 58.8 to 80 nm in diameter. Enzyme-linked immunosorbent assay results on the intestinal pools for mammalian and group A avian rotaviruses were negative. A statistically significant relationship was found for the presence of Reoviridae particles in the intestines of 10-21-day-old birds. Of the 7 most common pathological conditions analyzed, 2, rickets and intestinal changes (thin-walled ballooning intestine with watery contents), showed a statistically significant association with the presence of Reoviridae particles.     

Comparison between Cloprostenol-induced and Spontaneous Oestrus Fertility in Dairy Cows

A short calving to conception interval is of main importance to achieve high economic efficiency in dairy cow industry. In order to reduce this interval, several hormonal treatments have been put on the market, in which cloprostenol, a synthetic analogue of prostaglandin F2alpha (PGF2alpha). The aim of this study was to compare fertility of cloprostenol-induced oestrus to that of spontaneous oestrus in dairy cows. In a group of 525 cows, 280 (treated group) were administered 0.5 mg cloprostenol i.m. after transrectal corpus luteum (CL) detection, and inseminated at detected oestrus during the following week. The other 245 cows (control group) were inseminated during spontaneous oestrus. Whey progesterone concentrations were checked at treatment and at insemination in order to remove from the study cows whose P4 levels indicate a non-functional CL, or a lack of luteolysis respectively. Moreover, cows that were not inseminated due to genital problems were also excluded from this study. Conception (59% vs 54.5%) and calving rates (93.7% vs 93%) were not significantly different between the two groups.     

Splanchnic nitrogen metabolism by growing beef steers fed diets containing sorghum grain flaked at different densities

The objective of this study was to determine effects of processing method, dry-rolled (DR) vs steam-flaked (SF), and degree of processing (flake density, FD) of SF sorghum grain on splanchnic (gut and liver) N metabolism by growing steers. Diets contained 77% sorghum grain either DR or SF at densities of 437, 360, and 283 g/L (SF34, SF28, and SF22, respectively). Eight crossbred steers (340 kg initial BW), implanted with indwelling catheters into portal, hepatic, and mesenteric veins and the mesenteric artery, were used in a randomized complete block design. Blood flows and net output or uptake of ammonia N, urea N (UN), and alpha-amino N (AAN) were measured across portal-drained viscera, hepatic, and splanchnic tissues. Plasma arterial, portal, and hepatic concentrations of individual amino acids were also measured. Decreasing FD linearly increased (P = .04) net absorption of AAN (51, 73, and 78 g/d for SF34, SF28, and SF22, respectively) and transfer (cycling) of blood UN to the gut (49, 48 and 64 g/d; P = .02). Net UN cycling averaged 38% of N intake across all diets. Hepatic uptake of AAN or UN synthesis, and splanchnic output of AAN and UN, were not altered by FD. Lowering FD linearly increased (P < or = .02) portal-arterial concentration differences for blood AAN and UN and plasma arterial concentrations for alanine. Steers fed SF compared to DR tended to have greater (P = .11) blood UN cycling (percentage of hepatic synthesis; 64 vs 50%) and decreased (P = .03) net splanchnic UN output (30 vs 50 g/d), but other net fluxes of N were not altered across splanchnic tissues. Steam-flaking compared to dry-rolling tended to decrease (P = .12) portal, but not hepatic, blood flow and increased (P < .01) hepatic-arterial concentration differences for blood UN. Except for a decrease (P = .01) in hepatic-arterial concentration differences of glutamine, plasma amino acid concentrations were not altered by feeding SF vs DR sorghum. Processing method (steam-flaking vs dry-rolling) or increasing the degree of processing (by decreasing FD) of SF sorghum grain resulted in greater transfer of blood UN to the gut. Reducing FD also linearly increased the absorption of AAN by growing steers, which explains (in part) published responses of superior performance by steers fed SF grains.     

Vaginal isolation of beta‐haemolytic Streptococcus from bitches with and without neonatal deaths in the litters

The aim of the study was to identify beta‐haemolytic streptococci in the vagina of bitches who had delivered healthy litters and bitches who had delivered litters in which neonatal deaths occurred. Fifty‐one bitches divided into two groups were used. Group 1 (G1) included 28 bitches that had delivered healthy litters and group 2 (G2) included 23 bitches that had delivered puppies who died in the neonatal period. Two vaginal samples were taken, one in proestrus and the other at the end of gestation (EG). Beta‐haemolytic Streptococcus (BS) was isolated from 16 bitches (57%) in G1 and from 21 bitches (91%) in G2. The bacteriological cultures, serological tests (Streptex^®) and PCR assay allowed identification of Streptococcus canis and Streptococcus dysgalactiae in G1 and G2. Ultramicroscopic studies allowed the observation of M Protein and capsules in strains of S. dysgalactiae and S. canis in G1 and G2. The S. canis strains isolated from G2 showed thicker capsules than S. canis strains isolated from G1 (234 ± 24.2 vs 151.23 ± 28.93 nm; p < .001.). No differences were observed in capsule thickness between strains of S. dysgalactiae isolated from G1 and G2 (210 ± 13.54 vs 211.66 ± 19.67 nm; p > .70). All strains of beta‐haemolytic Streptococcus isolated were penicillin sensitive. Penicillin was administered from EG to 5 days post‐partum in 10 G2 females with isolation of BS (G2A). Saline solution was administered in eleven G2 females with isolation of BS (G2B). Ninety per cent of the puppies survived in G2A and 25% survived in G2B. Our results suggest BS is involved in canine neonatal deaths.