Detecting the brook floater,a freshwater mussel species at risk,using environmental DNA

1. The use of environmental DNA (eDNA) is a promising approach for the detection of aquatic species, including species at risk. One freshwater mussel species of interest in Atlantic Canada, the brook floater (Alasmidonta varicosa), is listed as being of Special Concern under the Species at Risk Act in Canada and as Vulnerable on the International Union for Conservation of Nature Red List. Further scientific data regarding species distribution and critical habitat is needed for the protection and conservation of this species.
2. The aim of this study was to design, optimize, and apply a species-specific quantitative polymerase chain reaction assay for the detection of brook floater from eDNA samples, and to assess temporal variability in brook floater eDNA quantities.
3. Through an eDNA survey performed in New Brunswick rivers in 2017 and 2018, brook floater DNA was found at a total of 16 out of 56 sites sampled. The amount of brook floater DNA detected at all 16 sites was always below the theoretical limit of detection of the assay, and, as such, results were classified as either ‘inconclusive’ or ‘suspected’.
4. The co-detection of eastern pearlshell (Margaritifera margaritifera), a more abundant freshwater mussel species in Atlantic Canada, was successfully used as a natural positive control.
5. Temporal variability in the amount of eDNA found in the water was also assessed at a site with a known brook floater population and minimal variability in eDNA quantities was observed from May to September.
6. These results provide researchers and managers with a new tool for the detection of the brook floater in support of conservation and monitoring efforts.

     

Asparaginase-associated pancreatitis in a dog

A dog with lymphosarcoma was evaluated for vomiting, lethargy, and abdominal pain 48 h after treatment with L-asparaginase. Based on drug administration, clinical signs, bloodwork, and elevated canine pancreatic lipase immunoreactivity, L-asparaginase-associated pancreatitis was diagnosed. This is an acknowledged toxicity; however, its pathophysiology and incidence rate in veterinary patients are unknown and sparsely documented.     

May-Hegglin anomaly in a dog

An 8-year-old female spayed Pug dog was presented for evaluation of cutaneous lesions occurring secondary to immunosuppressive treatment of presumed immune-mediated thrombocytopenia. Abnormal hematologic findings included persistent thrombocytopenia, macrothrombocytes, and variably shaped, often fusiform, blue cytoplasmic inclusions in neutrophils. May-Hegglin anomaly (MHA) was suspected based on the morphologic appearance of platelets and neutrophils. Examination of cells by transmission electron microscopy revealed normal platelet ultrastructure; neutrophil inclusions had features similar to those reported for inclusions in human MHA. Neutrophil function was within normal limits based on flow cytometric analysis. Thrombelastography indicated a prolonged clotting time (r), and PlateletMapping showed a lack of response to 2 μM ADP compared with a moderate response in the control dog. Immunocytochemical staining of blood smears using 2 commercially available antibodies against MYH9 protein (nonmuscle myosin heavy chain II) yielded negative results. However, genomic DNA sequencing analysis of the dog's MYH9 gene identified a single point mutation, resulting in substitution of lysine for glutamine at the 1841 amino acid position; this mutation is identical to one identified in people with MHA. To our knowledge, this is the first report of an MYH9 mutation in the dog. MHA-associated macrothrombocytopenia may be mistaken for immune-mediated thrombocytopenia.     

Plasma indicators of muscle damage in a model of nutritional myopathy in weaner sheep

SUMMARY Subclinical nutritional myopathy was induced in 5-month-old sheep by feeding them a diet low in vitamin E and selenium. Subsequently clinical myopathy was induced by dosing with protected polyunsaturated fatty acids. Plasma activities of creatine kinase (CK), pyruvate kinase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase and aldolase, enzymes of muscle origin, all remained above their reference ranges in clinically affected sheep, but fluctuated widely. Similar fluctuations occurred in subclinically affected animals, resulting in some activities being within the reference ranges and some above, at different times. Plasma malondialdehyde, an indicator of lipid peroxidation, proved of no diagnostic value. Terminal plasma CK activities were significantly correlated with microscopic damage in the vastus lateralis (VL), but not the vastus intermedius (VI) or the tensor fascia lata (TFL) muscles. AST was the most highly correlated with damage in VI and VL. In two clinically affected sheep successfully treated with an oral dose of α-tocopherol actetate all enzymes decreased steadily to within their reference ranges, at rates probably related to their plasma half-lives. These results suggest that measurement of plasma CK activity would be useful in monitoring recovery of treated sheep.     

Regional anesthesia

Organ toxicity from local anesthetic agents is rare. This makes these agents an attractive option in the high-risk patient. Complications associated with local anesthetics are related to overdosage. Overdosage with local anesthetic agents administered epidurally may cause motor paralysis and hind-limb weakness. Systemic signs of local anesthetic overdosage include changes in central nervous system activity (excitement or depression), muscle tremors, and hypotension. Because the dose required to produce these effects in the horse is high (12 mg/kg), this complication is uncommon. Few side effects and low cost justify the use of local anesthetic techniques in equine practice.     

Further investigation of lead exposure as a potential threatening process for a scavenging marsupial species

There is a growing recognition of the harmful effects of lead exposure on avian and mammalian scavengers. This can lead to both lethal and non-lethal effects which may negatively impact wildlife populations. Our objective was to assess medium-term lead exposure in wild Tasmanian devils (Sarcophilus harrisii). Frozen liver samples (n = 41), opportunistically collected in 2017–2022, were analysed using inductively coupled plasma mass spectrometry (ICP-MS) to determine liver lead concentrations. These results were then used to calculate the proportion of animals with elevated lead levels (>5 mg/kg dry weight) and examine the role of explanatory variables that may have influenced the results. The majority of samples analysed were from the south-east corner of Tasmania, within 50 km of Hobart. No Tasmanian devil samples were found to have elevated lead levels. The median liver lead concentration was 0.17 mg/kg (range 0.05–1.32 mg/kg). Female devils were found to have significantly higher liver lead concentrations than males (P = 0.013), which was likely related to lactation, but other variables (age, location, body mass) were not significant. These results suggest that wild Tasmanian devil populations currently show minimal medium-term evidence of exposure to lead pollution, although samples were concentrated in peri-urban areas. The results provide a baseline level which can be used to assess the impact of any future changes in lead use in Tasmania. Furthermore, these data can be used as a comparison for lead exposure studies in other mammalian scavengers, including other carnivorous marsupial species.     

A capillary electrophoresis laser-induced fluorescence method for analysis of potato glycoalkaloids based on a solution-phase immunoassay. 1. Separation and quantification of immunoassay products

Solution-phase immunoassays are typically faster and more precise than ELISAs. This research developed a solution-phase for the immunoassay of potato glycoalkaloids (GAs) based on quantification by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. Solanidine coupled to 4'-(aminomethyl)fluorescein and a polyclonal antibody solution were used as the immunoreagents. Unbound fluorescent solanidine was detected by CE-LIF (excitation 488 nm, emission 520 nm). Optimum resolution of immunoassay products was achieved with a buffer consisting of 50 mM phosphate, 10% (v/v) methanol, and 1.5 mM SDS, pH 7.5. A plot of signal vs log [GA] produced a sigmoidal curve typical of immunoassays. Analysis of extracts of sprouted Yukon Gold potato tubers and nonsprouted Yukon Gold tubers resulted in total [GA] of 98 microg/g (RSD 9%) and 55 microg/g (RSD 9%), respectively. The findings indicated that CE-LIF coupled with a solution-phase immunoassay can be used to quantify total GA in potatoes.     

Meningoencephalomyelitis in a foal due to Salmonella agona infection

CASE HISTORY: A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondary to dystocia.

CLINICAL FINDINGS: The foal developed a head tilt, seizures and watery diarrhoea during hospitalisation and died at 7 days of age. Histological examination of the brain and spinal cord revealed a suppurative meningoencephalomyelitis with vasculitis, and numerous intralesional, gram-negative bacilli. Similar microscopic lesions were noted in the lungs, renal medullary interstitium, and umbilicus. Bacilli in the brain, spinal cord and umbilicus were identified immunohistochemically as Salmonella group B. Salmonella agona was isolated in pure culture from the brain, lung, liver, kidney, and intestine.

CONCLUSION: This is the first report of meningoencephalomyelitis and septicaemia due to Salmonella infection in an equine neonate.     

Listeria monocytogenes gastroenteritis in sheep

Extract

Listeria monocytogenes is widely distributed in the environment of farm animals. It is found in soil, faeces and nasal secretions of healthy animals, water troughs and animal feeds. Under certain conditions it becomes pathogenic, causing serious disease in cattle and sheep. Most commonly it causes meningoencephalitis but, on occasion, septicaemic listeriosis results in abortion, and more recently it has been associated with gastroenteritis.