Anaesthetic complications in pigs undergoing MRI guided convection enhanced drug delivery to the brain: a case series

ObservationsA total of 13 intracerebral infusions were performed at approximately 1 month intervals in three NIH miniature pigs over the age range of 31–59 weeks. Pigs received azaperone and ketamine premedication to allow venous cannulation and propofol induction of anaesthesia. Anaesthesia was maintained with isoflurane throughout cranial surgery and MRI scanning. Physiological monitoring during surgery consisted of blood pressure, pulse, temperature and oxygen saturation monitoring, ECG and capnography. Analgesia consisted of meloxicam and morphine. However, during MRI scanning blood pressure and ECG monitoring had to be discontinued. Anaesthetized pigs underwent intermittent intraputamenal convection enhanced delivery (CED) of gadolinium with real-time magnetic resonance imaging. Progressive tachycardia was consistently observed in all pigs during CED with a mean ± SD maximum increase of 41 ± 22 beats minute^?1 from a baseline heart rate of 96 ± 9 minute^?1. The heart rate remained elevated until recovery. A mean reduction in body temperature of 2.8 ± 0.6 °C from the start of anaesthesia was also observed during the period of MRI scanning. All pigs recovered from anaesthesia smoothly and heart rates returned to normal during the recovery period.ConclusionsHypothermia is common in pigs undergoing this sedation and anaesthesia protocol. Convection enhanced delivery of drugs in healthy anaesthetized pigs may result in tachycardia.     

Imaging diagnosis--magnetic resonance imaging findings in a dog with sequential brain infarction

An adult greyhound was evaluated on three occasions for acute, intracranial neurologic signs. Based on magnetic resonance (MR) imaging, there were T2‐hyperintense and T1‐hypointense, noncontrast enhancing lesions in the cerebellum, and brain stem. Using diffusion‐weighted imaging (DWI), the lesions were characterized initially by restricted water diffusion. The presumptive diagnosis on each occasion was acute ischemic cerebrovascular accident leading to infarction. This allowed us to characterize the changes in appearance of infarcted neural tissue on the standard MR sequences over time, and to confirm that the DWI could be successfully used in low‐field imaging. © 2012 Veterinary Radiology & Ultrasound.     

A retrospective comparison of surgical removal and subsequent CO2 laser ablation versus topical administration of mitomycin C as therapy for equine corneolimbal squamous cell carcinoma

Objective To compare the complications and nonrecurrence rate following topical mitomycin C (MMC) therapy vs. CO₂ laser ablation for treating equine corneolimbal squamous cell carcinoma (SCC). Study design Retrospective study. Sample population Twenty‐five horses with corneolimbal SCC. Procedures Medical records of horses undergoing surgical tumor resection followed by either topical MMC therapy (0.04%) or CO₂ laser ablation between the years of 2004 and 2010 were reviewed. Recurrence and complications were compared between groups and within MMC subgroups defined by the time at which treatment was initiated relative to surgery. Results Therapy with topical MMC resulted in a nonrecurrence rate comparable to that achieved with CO₂ laser ablation (82.4% vs. 85.7%, respectively). Initiation of MMC following epithelialization of the surgical site a mean of 15 days postoperatively did not result in increased recurrence rates relative to treatment in the immediate postoperative period. Vision‐ or globe‐threatening complications tended to occur with greater frequency in horses receiving topical MMC in the immediate postoperative period (5 of 6 major complications) relative to following epithelialization of the surgical site (1 of 6 major complications). Conclusions Horses receiving adjunctive topical MMC therapy were no more likely to experience tumor recurrence than were horses undergoing CO₂ laser ablation in the horses in this study. Initiation of two to three rounds of MMC following epithelialization of the surgical site results in fewer major complications and achieves comparable disease resolution relative to treatment in the immediate postoperative period.     

Hoof disorders, locomotion ability and lying times of cubicle-housed compared to pasture-based dairy cows

Forty six spring-calving Holstein–Friesians (12 primiparous, 34 pluriparous) were block-paired (expected calving date, parity, body condition score and genetic merit) and allocated to either a PASTURE or HOUSED system for a full production cycle (− 40 to 305 days relative to calving). Both hind claws were inspected on six occasions (− 40, 10, 35, 85, 120 and 210 days relative to calving) to determine the severity of 5 disorders (sole and white line area haemorrhages, white line disease, heel horn erosion, digital dermatitis and other lesions). Six aspects of locomotion ability (tracking, spine curvature, speed, head bobbing, general symmetry and abduction/adduction) were assessed from 1 (normal) to 5 (abnormal) every 2 weeks. Throughout the study records of clinical lameness were kept for all animals. Lying times of 26 block-paired cows (PASTURE n = 13, HOUSED n = 13) were recorded automatically every 5 min for 48 h at 33, 83 and 193 days post-calving. Data were analysed using mixed models for repeated measures, logistic regression and survival analysis, as appropriate. The severity of hoof disorders was lower for PASTURE compared to HOUSED cows from 85 days post-calving onwards (P < 0.05). HOUSED cows had a greater hazard ratio (P < 0.01) of presenting an abnormal (i.e. scoring ≥ 3) tracking (2.8), spine curvature (2.3), head bobbing (3.6), general symmetry (3.0), abduction/adduction (4.2) and for the average (3.9) of all locomotion aspects investigated (i.e. abnormal locomotion). Furthermore, HOUSED cows had a greater odds ratio (6.5, P < 0.01) of clinical lameness from day 180 post-calving onwards. Mean total lying times per 48 h period were shorter (P < 0.001) for HOUSED compared to PASTURE cows (18.1 h, SE 0.71 vs. 20.5 h, SE 0.73). In summary, from day 85 post-calving to the end of the production cycle PASTURE cows had less severe hoof disorders, better locomotion ability and reduced likelihood of clinical lameness compared to similar cows in a HOUSED system. The PASTURE system also facilitated longer, undisrupted lying times that have beneficial implications for lameness. A PASTURE system therefore improved cow welfare in terms of lameness compared to a HOUSED system.     

Stable Isotope Probing Identifies Novel m-Xylene Degraders in Soil Microcosms from Contaminated and Uncontaminated Sites

Toxicity of contaminated soils cannot be assessed only by chemical analyses, therefore bioassays are increasingly used. Widely accepted ecotoxicological methods include organisms from all levels of the food-chain but plant-based ones are usually restricted to germination and growth tests. In our study the toxicity of heavy metal contaminated soil samples were examined not only by germination and bacterial tests of their extracts but also by the measurement of physiological parameters of two plant species (cucumber and wheat) that were grown directly on the contaminated substrate. Changes in chlorophyll concentration, stomatal conductance, fluorescence characteristics, and malondialdehyde (MDA) level (showing oxidative damage to lipids in leaves) undoubtedly indicated the mobilisation and toxic effect of contaminants. The results showed that the sensitivity of plant physiological parameters was higher than that of the extract-based ecotoxicological tests. Whereas these latter could not reveal the toxic effect of the highly contaminated soils the plants have reacted in a more complex way and their physiological parameters have changed significantly in all cases validating their use in such studies. The applied measurements also allow quicker and more reliable testing even under field conditions (stomatal conductance) or the detection of a more complex response if detailed analyses is needed (MDA, fluorescence imaging) thus underlining the importance of plant-based methods.     

Methodological considerations in reserve system selection: A case study of Malagasy lemurs

Although data quality and weighting decisions impact the outputs of reserve selection algorithms, these factors have not been closely studied. We examine these methodological issues in the use of reserve selection algorithms by comparing: (1) quality of input data and (2) use of different weighting methods for prioritizing among species. In 2003, the government of Madagascar, a global biodiversity hotspot, committed to tripling the size of its protected area network to protect 10% of the country’s total land area. We apply the Zonation reserve selection algorithm to distribution data for 52 lemur species to identify priority areas for the expansion of Madagascar’s reserve network. We assess the similarity of the areas selected, as well as the proportions of lemur ranges protected in the resulting areas when different forms of input data were used: extent of occurrence versus refined extent of occurrence. Low overlap between the areas selected suggests that refined extent of occurrence data are highly desirable, and to best protect lemur species, we recommend refining extent of occurrence ranges using habitat and altitude limitations. Reserve areas were also selected for protection based on three different species weighting schemes, resulting in marked variation in proportional representation of species among the IUCN Red List of Threatened Species extinction risk categories. This result demonstrates that assignment of species weights influences whether a reserve network prioritizes maximizing overall species protection or maximizing protection of the most threatened species.     

Avian pox virus infection in a mourning dove

An adult mourning dove (Zenaidura macroura) was presented with dyspnea, poor body condition, and poor flight endurance. Nodular lesions were visible on the cere, both feet, and skin covering the pectoral region. Histopathological examination revealed epithelial hyperplasia with eosinophilic intracytoplasmic inclusion bodies consistent with Avipoxvirus infection.     

Are the concepts of andragogy and pedagogy relevant to veterinary undergraduate teaching?

Knowles and colleagues have described teaching methods as being either teacher centered, with dependent learning (pedagogy), or learner centered, with independent learning underpinned by the learners' experience and intrinsic motivation (andragogy). This paper argues that both models can be recognized within veterinary undergraduate programs. Veterinary students enter the program with a high level of intrinsic motivation and are prepared to invest considerably in comprehending the material that is presented to them. While this should result in learners whose behavior fits the assumptions underlying andragogy, information overload, poor communication of the relevance of material, teaching by transmission, and examination by memorization often confine learning to the dependent learning characteristic of pedagogical approaches. Students' experience and practical ability should develop as they progress through the program. Drawing upon experience provides opportunities for both fleshing out and putting in context the declarative knowledge from the didactic components of the curriculum. Where this is achieved (either in the clinical or preclinical curriculum), students' motivation and interest is stimulated, resulting in andragogical responses of enhanced motivation and engagement with the subject. Pedagogy and andragogy can, however, be complementary, rather than antithetical. Students enter a new subject with minimal experience and little knowledge about it, so a pedagogical methodology may be the most efficient way of initiating understanding. However, as understanding develops, an andragogical method becomes more appropriate, progressively developing students' independence of learning. The cycle may repeat itself during the program, with the balance changing along with changes in knowledge, goals, experience, and context.     

Evaluation of a canine D-dimer point-of-care test kit for use in samples obtained from dogs with disseminated intravascular coagulation, thromboembolic disease, and hemorrhage

OBJECTIVE: To evaluate a canine D-dimer point-of-care (cD-d POC) test kit for use in healthy dogs and dogs with disseminated intravascular coagulation (DIC), thromboembolic disease (TED), and hemorrhage. ANIMALS: 12 healthy dogs, 18 dogs with DIC, 23 dogs with TED (19 acute and 4 chronic), and 18 dogs with hemorrhage. PROCEDURE: The cD-d POC, canine D-dimer ELISA (cD-d ELISA), human D-dimer latex agglutination (hD-d LA), and fibrin degradation product (FDP) tests were performed on citrated plasma. RESULTS: All healthy dogs had negative cD-d POC test results and mean cD-d ELISA value of 0.2 U/mL. All dogs with DIC had positive cD-d POC test results and mean cD-d ELISA value of 44 U/mL. Dogs with acuteTED had a mean cD-d ELISA value of 34 U/mL, and 17 of 19 had positive cD-d POC test results. Mean cD-d ELISA value in dogs with hemorrhage was 14 units/mL, and 15 of 18 had positive cD-d POC test results. The cD-d ELISA values in dogs with hemorrhage were significantly higher than those of healthy dogs but lower than those of dogs with DIC and acute TED. The cD-d POC, cD-d ELISA, and hD-d LA tests were comparable in differentiating healthy dogs from dogs with DIC, acute TED, or hemorrhage and appeared to be superior to measurement of FDPs. CONCLUSIONS AND CLINICAL RELEVANCE: The cD-d POC test kit can be quickly and easily used and reliably detects dogs with DIC or acute TED. Positive results may also be seen in dogs with internal hemorrhage.