Necrotising fasciitis associated with Escherichia coli in a dog

CASE HISTORY: Lameness and limb pain associated with a laceration in the inner thigh of a Border Collie dog progressed over 4 days to extensive necrosis of the full-thickness of skin and subcutaneous (S/C) tissue. A successful outcome was achieved using surgical debridement and intensive supportive care, followed by limited local closure, axial pattern flap development, and free skin grafting.

CLINICAL FINDINGS: Clinical findings included severe pain, depression, pyrexia and hypoalbuminaemia, and full-thickness loss of skin from the caudal thigh to the hock. Histopathologically, debrided tissue showed extensive necrosis of the dermis, adipose and muscle tissues, and the presence of numerous Gram-negative rods. Escherichia coli was cultured from deep tissue samples.

DIAGNOSIS: Necrotising fasciitis (NF) associated with E. coli infection.

CLINICAL RELEVANCE: NF associated with E. coli has not been previously reported in dogs. The importance of early diagnosis and surgical debridement is noted and the relevant medical literature is reviewed.     

Salmonella monitoring programs in Australian feed mills: a retrospective analysis

The availability of safe, commercially prepared stock feed for production animals is an important step in ensuring animal health and welfare and the safety of food animal products for human consumption. Animal feed quality assurance programs include microbiological monitoring of raw materials, mill equipment and finished feed. Over a period of 16 years, 23,963 samples for Salmonella culture and serotyping were collected from 22 stock feed mills. A multivariable generalized linear mixed model (GLMM) was used to identify mill and sample type factors that increase the odds of detecting Salmonella. The odds of detecting a Salmonella positive sample was greatest in samples from raw materials and in mills that processed restricted animal material (RAM). The percentage of positive samples ranged from 7.2% in 2003 to 2.8% in 2017. Of the 1,069 positive samples, 976 were serotyped with 61 different Salmonella serotypes isolated. The serotype most frequently isolated from raw materials was S. Agona, (n = 108) whilst S. Anatum was the serotype most frequently isolated from equipment and finished feed (n = 156). The diversity of Salmonella serotypes differed between mills and different stages of the production line. Microbiological monitoring in the commercial preparation of animal feed in Australian stock feed mills guides the implementation of quality control measures and risk mitigation strategies thereby reducing the prevalence and diversity of potentially zoonotic bacteria such as Salmonella, enhancing food safety for both animal and consumer.     

Effects of two large doses of equine recombinant growth hormone on clinical, haematological and serum biochemical variables in adult horses

Objective To evaluate the clinical, haematological, and serum biochemical effects of two large doses of recombinant equine growth hormone.
Design Duplicated Latin square.
Sample population
Three Thoroughbred and three Standardbred mares aged between 12 and 17 years.
Procedure Two horses were randomly assigned into one of three groups. On each of three successive days, each horse pair received one of two dosages of growth hormone or a saline placebo so that by the end of the experiment all three horse pairs had received both dosages and the saline placebo. Dose rates selected were 50 μg/kg, and 100 μg/kg. A clinical examination was performed and a venous blood sample drawn for a complete blood count and serum biochemical analysis before administration of growth hormone and at 1, 2, 3, 4, 6, 8 and 24 h after injection. Data were analysed by a repeated measures analysis of variance assessing the effects of dose and time.
Results There was an effect of time on a number of clinical, haematological, and serum biochemical variables. There were significant effects of growth hormone on heart rate and serum glucose concentration but values for both variables remained within the reference range.
Conclusion The results of the present study suggest that equine recombinant growth hormone has a wide margin of safety and show that the single administration of up to five times the recommended dose rate has no significant effects on clinical, haematological, or serum biochemical variables.     

Positive Effects of Melatonin Treatment on the Reproductive Performance of Young Border Leicester Rams Mated to Merino Ewes in Spring: Preliminary Observations

Poor reproductive performance of Merino ewe flocks when mated to Border Leicester rams during spring may be due to seasonality of the Border Leicester breed. Two approaches were taken to test this assumption. Six young (12 months old) or six mixed‐age (12, 24 and ≥36 months old) Border Leicester rams were either treated or not treated with melatonin implants (2 × 2 design) 6 weeks before the four groups of rams were each put with approximately 300 Merino ewes for an 8‐week mating period. Implants were inserted in early September (experiment 1). The second approach was to yard or not yard ewes and mixed‐age rams on several occasions during the first 3 weeks of the mating period (experiment 2). Pregnancy rate and twinning percentage were assessed by ultrasonography. In experiment 1, melatonin treatment in young rams increased (p < 0.001) pregnancy rate from 5.0% to 92.6%, but mixed‐age rams did not respond (90.7% vs 89.5% for melatonin and non‐melatonin treatments, respectively). Twinning rate was similar (p > 0.05) for ewes mated to either melatonin or non‐melatonin‐treated young rams (36.8% vs 40.0%, respectively), whereas melatonin significantly improved (p < 0.05) twinning rate in those ewes mated to mixed‐age rams (49.1% vs 36.1%). After 6 weeks of melatonin treatment, scrotal circumference was greater (p < 0.05) in both young and mixed‐aged rams than in untreated counterparts. In experiment 2, yarding of ewes and rams overnight on several occasions early in the mating period reduced (p < 0.001) pregnancy rate compared with non‐yarded counterparts (89.5% vs 65.5%). Twinning rate was not affected (37.7% vs 36.1%, respectively). In summary, melatonin treatment of Border Leicester rams significantly improved flock reproductive performance in spring due to improved pregnancy rates with young rams and improved litter size with mixed‐age rams.     

The Effect of Oxidative Stress on Thawed Bulk‐Sorted Red Deer Sperm

The aims of this study were to assess the effects of the sex‐sorting process on post‐thaw sperm quality as well as on induced oxidative stress damage (H₂O₂ 0 mm  = H000; H₂O₂ 50 mm  = H050; H₂O₂ 100 mm  = H100) and the protective action of reduced glutathione (GSH) and Trolox, when comparing sorted (BSS) and non‐sorted (NS) red deer spermatozoa incubated at 37°C. Sperm samples from three stags were collected by electroejaculation and frozen. Immediately after thawing, sperm motility was higher (p < 0.05) for NS (59% ± 3.3) than BSS (36.9% ± 5.8) sperm. Furthermore, the percentage of apoptotic sperm was higher (p < 0.05) for BSS (21.6% ± 5.0) than NS sperm (14.6% ± 1.2). The presence of H₂O₂ increased DNA damage in NS (H000 = 4.1% ± 0.9; H050 = 9.3% ± 0.7; and H100 = 10.9% ± 2.3), but not in BSS sperm. However, in the presence of oxidant, GSH addition improved (p < 0.05) sperm motility in both groups of sperm samples as compared to their controls (NS: 44.5 ± 4.8 vs 21.1 ± 3.9 and BSS: 33.3 ± 8.1 vs 8.9 ± 1.8). These results demonstrate that the sperm‐sorting process induces sublethal effects, albeit selecting a sperm population with a chromatin more resistant to oxidative stress than that in non‐sorted sperm. Moreover, addition of GSH at 1 mm may be a good choice for maintaining the quality of stressed sperm samples, unlike Trolox, which inhibited sperm motility.     

Incidence of alcohol-related deaths in the veterinary profession in England and Wales, 1993-2005

It has recently been shown that the proportional mortality ratio for suicide by veterinarians is one of the highest of all occupational groups. The reasons for this alarming statistic are unclear although it has been postulated that alcohol or drug misuse may be significant risk factors which contribute towards the high incidence of suicide within the profession. However, there have been few studies on alcohol misuse by veterinarians and so the aim of this study was to investigate the incidence of alcohol-related deaths in the veterinary profession in England and Wales between 1993 and 2005. The proportional mortality ratio for alcohol-related deaths for veterinarians was not significantly higher than the general population during this time period. Future studies should focus on establishing the incidence of sub-lethal alcohol misuse within the veterinary profession.