Age-related and non-age-related changes in 100 surveyed horse brains

Brains from 100 horses, aged 2-25 years, were systematically examined by histopathology at 46 different neuroanatomical sites. The horses were sourced from a slaughterhouse (group A, n = 57), from a kennel that collected dead animals, and from 2 diagnostic laboratories (group B, n = 43). All horses from group A and 26 horses from group B were examined by a veterinarian in the period before death. None of the horses were known to exhibit clinical signs suggestive of neurologic disease. Among the main changes identified were vacuolation in the neuropil (n = 73), neurons (n = 32), white matter (n = 31), and focal perivascular lymphoid cell infiltrates (n = 35). Spheroids were frequently seen (n = 91), and 10 horses each had more than 10 spheroids in the cuneate or gracile nucleus. Statistically significant age-related changes noted included intraneuronal (n = 97) and glial or extracellular lipofuscin deposition (n = 41), hemosiderin deposition around blood vessels (n = 60), and calcium depositions (n = 24). One horse had low-grade nonsuppurative meningoencephalitis; Alzheimer type II cells were detected in the brains of 2 horses. Hyalinized vessel walls in the cerebellum were observed in 1 horse. It was concluded that some histopathologic changes are a frequent feature in equine brains, which has implications for the pathologists involved in equine neurology and disease surveillance.     

Original Study: Comparison of three intraosseous access techniques in cats

Objective – To compare the placement feasibility and amount of bone trauma induced by 3 intraosseous (IO) access techniques in cats: an automatic impact penetration device (A), an automatic rotary insertion device (B), and a manual IO needle (C). Design – Prospective ex vivo study. Setting – University. Animals – Eighteen adult mixed breed feline cadavers. Interventions – Cadavers provided 72 total IO insertion locations divided equally between the right and left humerus and tibia. The 3 IO techniques were randomly allocated to these locations. Time to successful insertion, ease of insertion, and success rate were recorded. Each insertion site was analyzed for the number of bone fragments and defect diameter by computed tomography. Measurements and Main Results – Device B had lower time of insertion (P=0.01) compared with devices A and C. Device B had better ease of insertion scores (P<0.01) compared with devices A and C. No differences were detected between insertion sites (tibia versus humerus). No differences in the number of bone fragments, defect diameter, or success rate were detected among devices (P=0.06, 0.31, and 0.14, respectively). Conclusions – All 3 IO access methods evaluated yield acceptable results. Device B is significantly faster and easier to place in cat cadavers when compared with other methods.     

Pharmacokinetics of cefotaxime in the domestic cat

Cefotaxime was administered as single IV or IM dose for the purpose of examining its pharmacokinetics in healthy cats. The mean predicted plasma concentration of cefotaxime in 6 cats at 0 time after a single IV dosage of 10 mg/kg of body weight was 88.9 micrograms/ml. The mean plasma concentrations decreased to 10.8 micrograms/ml at 2 hours, 3.7 micrograms/ml at 3 hours, and 0.5 microgram/ml at 6 hours. The half-life was 0.98 +/- 0.25 hour (mean +/- SD), and the total body clearance was determined to be 2.76 +/- 1.25 ml/min/kg. After a single IM injection of 10 mg/kg of body weight, the mean maximum observed plasma concentration was 36.2 micrograms/ml at 0.75 hour. The mean absorption half-life was 0.24 hour. In 2 animals, the bioavailability of an IM injection was 98.2% and 93.0%.     

How commercial fishing effort is managed

Wild capture fisheries produce 90 million tonnes of food each year and have the potential to provide sustainable livelihoods for nearly 40 million people around the world ( http://www.fao.org/3/a-i5555e.pdf ). After decades of overfishing since industrialization, many global fish stocks have recovered, a change brought about through effective management. We provide a synthetic overview of three approaches that managers use to sustain stocks: regulating catch and fishing mortality, regulating effort and regulating spatial access. Within each of these approaches, we describe common restrictions, how they alter incentives to change fishing behaviour, and the resultant ecological, economic and community‐level outcomes. For each approach, we present prominent case‐studies that illustrate behaviour and the corresponding performance. These case‐studies show that sustaining target stocks requires a hard limit on fishing mortality under most conditions, but that additional measures are required to generate economic benefits. Different systems for allocation allow stakeholder communities to strike a locally acceptable balance between profitability and employment.     

Oesophageal compliance in naturally occurring canine megaoesophagus

SUMMARY The passive blomechanical property of oesophageal compliance (OC) was measured in 8 naturally occurring cases of canine megaoesophagus, 8 matched control and 7 vagotomised control dogs. Of the 8 dogs with megaoesophagus, 6 had congenital Idiopathic megaoesophagus and 2 had secondary megaoesophagus attributable to generalised skeletal muscle disease. Stepwise distension of the whole oesophagus was employed for measurement of OC at the 4.0 and 8.0 mL/kg Injected volume steps within the control volume range (0 to 12.0 mL/kg). At both Injected volume steps OC was higher In megaoesophagus dogs than in either matched control or vagotomised control dogs (P / 0.01 In both cases), and no significant difference was observed In OC between matched control and vagotomised control dogs. No correlation was demonstrated between OC and the estimated duration of clinical signs of dogs with megaoesophagus. These findings suggest that In most cases of canine megaoesophagus the viscoelastic properties of the oesophageal wall are significantly altered, that In such cases the disorder is unlikely to be purely dynamic and that processes other than the duration of oesophageal dilatation are responsible for the alteration in oesophageal wall blomechanical properties. The relevance of these findings to current concepts on pathophysiological mechanisms underlying the evolution and resolution of various forms of canine megaoesophagus Is discussed.