Differences in blood supply to the cerebral cortex between sheep and calves during slaughter

Using methylene blue boli, injected via an intracardiac catheter, the blood supply to the brain in two one- to 10-day-old calves and three adult sheep was studied during and after severance of the common carotid arteries and jugular veins. Passage of dye through cerebral vessels could not be observed in the exposed cerebrum of sheep after bilateral severance of major blood vessels. When vessels were severed on one side only, the passage of dye was noted for at least 53 seconds. In calves, after bilateral severance, sequential boli of dye could be detected passing through the cerebral vessels for more than 100 seconds. These results provide an explanation and support for the belief that there are major differences in the onset of insensibility between sheep and calves subsequent to severance of the common carotid arteries and jugular veins. The differences in blood supply to the brain which were demonstrated could be accounted for by differences in the blood supply to the brain by the vertebral artery in sheep and cattle. The effects of slaughter on the blood supply to the eye are discussed as a possible explanation of the disparity between results of studies in this general field which have used retinal responses in their investigations and those which have not.     

The experimental transmission of various mycoplasmas of feline origin to domestic cats (Felis catus)

Mycoplasma felis and M. gatae recovered from domestic cats, M. arginini from a cheetah, an unidentified glucose-fermenting mycoplasma from a lion, and M. pulmonis from a rat were inoculated into specific pathogen free (SPF) kittens by the oral, ocular and nasal routes. During the 21-day experimental period a persistent infection was established in a proportion of the kittens challenged with M. felis, M. gatae and M. arginini. The mycoplasma isolated from the lion created a transitory infection in one kitten, but M. pulmonis could not be recovered even 24 hr after inoculation. None of the organisms investigated showed any pathological effect. The implications of this work in relation to the host-specificity and pathogenicity of the feline mycoplasmas are discussed. Résumé. On a inoculé à des chatons axéniques par les voies orales, oculaires et nasales, un Myco-plasmafelis et un M. gatae recueillis de chats domestiques, un M. arginini recueilli d'un guépard, un mycoplasme non identifié à glucose fermentant recueilli d'un lion et un M. pulmonis recueilli d'un rat. Durant la période expérimentale de 21 jours, on a établi une infection persistante dans une proportion des chatons soumis aux tests de Mycoplasma felis, de M. gatae et de M. agrinini. Le mycoplasma isolé recueilli du lion a créé une infection transitoire chez un chaton, mais le M. pulmonis n'a pu être recueilli, même 24 heures après l'inoculation. Aucun des organismes sous investigation n'a montré d'effets pathologiques. On a discuté des implications de ce travail en relation avec la spécifité d'hôtes et la pathogénicité de mycoplasmes félins. Zusammenfassung. Mycoplasma felis und M. gatae von Hauskatzen erlangt, M. arginini von einem Tschita, ein unidentifiziertes Glukose-fermentierendes Mycoplasma von einem Löwen, und M. pulmonis von einer Ratte wurden in keimfreie (SPF) junge Katzen geimpft, auf oralem, Augen- und Nasenweg. Während der 21 tägigen Versuchsperiode wurde eine anhaltende Infektion in den Katzen festgestellt, die dem M. felis, M. gatae und dem M. agrinini ausgesetzt waren. Das Mycoplasma von dem Löwen abgesondert, verursachte eine vorübergehende Infektion eines Kätzchens, aber M. pulmonis konnte selbst 24 Stunden nach der Impfung nicht gefunden werden. Keines der untersuchten Organismen zeigte irgendwelche pathologischen Effekte. Die Folgerungen dieser Arbeit im Verhältnis zu der Gast-Spezifität und Pathogenizität des Katzen-mycoplasmas sind diskutiert.     

Detection and survival of group A rotavirus in a piggery

Samples of dust, faeces and effluent were collected from a piggery and examined for group A rotavirus, using a commercial ELISA test, electron microscopy and inoculation of MA-104 cells. Rotavirus antigen was demonstrated in samples collected from farrowing and weaner rooms but not from fattener and sow houses. Rotavirus antigen was also detected in samples collected from a weaner room which had been free of piglets for three months. A cytopathic porcine rotavirus (British isolate SW20/21) was kept at room temperature for four months; it survived with titres reduced by 2 log10. These observations suggest that the environment of commercial piggeries is an important source of rotaviral infection for young piglets.     

Measurement of superoxide dismutase, diamine oxidase and caeruloplasmin oxidase in the blood of thoroughbreds

Methods were developed for the measurement of superoxide dismutase (SOD), diamine oxidase (DAO) and caeruloplasmin oxidase in the blood of thoroughbred horses. These enzymes were measured in 178 normal thoroughbreds stabled throughout the United Kingdom. The relationships between the activities of SOD, DAO and caeruloplasmin oxidase and the blood concentrations of their associated trace metals (copper, zinc and manganese) were studied in 52 of the thoroughbreds. Trace metals were measured by electrothermal atomic absorption spectrophotometry. No relationships were found between the activities of erythrocyte SOD and serum/whole blood copper, zinc and manganese, or serum DAO and serum copper or zinc concentrations. Caeruloplasmin oxidase in equine blood was found to be correlated to serum copper concentration, r = 0.695 (P less than 0.001) over the normal range. Samples from thoroughbreds with trace metal deficiency or toxicity were not available for study. The observed normal ranges for the activity of these enzymes are as follows: SOD: 50 to 200 units per ml whole blood between 5 and 95 percentiles; DAO: 0.1 to 28.5 units per litre (means = 14.8, SD 7.1) and caeruloplasmin oxidase; 11.6 to 35.8 units per ml (means = 23.7, SD 6.0). For numerical simplicity, the activity of DAO is given in units per litre, compared to units per ml for caeruloplasmin oxidase and SOD.     

Isolation of Leptospira interrogans serovars tarassovi and pomona from dogs

Extract

This communication reports the isolation of Leptospira inter-rogans serovars tarassovi and pomona from dogs in New Zealand.     

Successful treatment of a pancreatic pseudocyst by omentalisation in a dog

CASE HISTORY A 3-year-old male Labrador retriever was presented with a history of dietary indiscretion followed by vomiting and abdominal pain.

CLINICAL FINDINGS AND TREATMENT: Abdominal ultrasonography revealed the presence of a fluid-filled cystic structure in the region of the pancreas. Flocculent, dark fluid was drained from the cystic structure during exploratory celiotomy prior to resection of the lateral cystic wall. Omentum was sutured into the cystic cavity to provide drainage and enhance immune response. A jejunostomy feeding tube was placed. Post-surgical care consisted of antibiotic therapy. The dog was clinically normal at 1 and 7 months post-operatively and the pancreas appeared normal on final ultrasonographic examination.

CLINICAL RELEVANCE: This case describes the use of omentum to provide physiological drainage of a pancreatic pseudocyst. This surgical technique may help clinicians manage patients with this condition in the future.     

Reduction in the mRNA expression of sVEGFR1 and sVEGFR2 is associated with the selection of dominant follicle in cows

The vascular endothelial growth factor (VEGF) is essential for follicular development by promoting follicular angiogenesis, as well as for the proliferation and survival of granulosa cells. The biological effects of VEGF are regulated by two membrane receptors, VEGFR1 and VEGFR2, and two soluble receptors, sVEGFR1 and sVEGFR2, which play an antagonistic role. Thus, the objective of this study was to identify the mRNA expression pattern of total VEGF, VEGFR1, VEGFR2, sVEGFR1 and sVEGFR2 in bovine preselected follicles (PRF) and post‐selected follicles (POF). The mRNA expression of these five genes in both granulosa cells (GC) and theca cells (TC) was compared between follicles classified as PRF and POF based on their diameter and on their ratio of estradiol/progesterone (E2/P4). Results showed a lower expression of mRNA of sVEGFR1 and sVEGFR2 in POF than in PRF (p < .05). Regarding the mRNA expression of total VEGF, VEGFR1 and VEGFR2, there was no difference between POF and PRF follicles (p > .05). Our results showed that the mRNA expression of VEGFR2 and sVEGFR1 was more abundant than the expression of VEGFR1 and sVEGFR2, while GC was the main source of mRNA for total VEGF. On the other hand, TC was the follicular compartment where the receptors were most expressed. Our results suggest that non‐dominant follicles maintain a greater concentration of the mRNA expression of both membrane and soluble VEGF receptors. On the other hand, follicular dominance is related to a reduction in the mRNA expression of sVEGFR1 and sVEGFR2, which may favour VEGF binding with VEGFR2 and, hence, improve the follicular health and development.     

Seizures during medetomindine sedation and local anaesthesia in two dogs undergoing skin biopsy

Each of two dogs presented for multiple skin biopsies were sedated with intravenous medetomidine and lignocaine was injected subcutaneously to provide local anaesthesia for skin biopsy. One dog had a seizure during skin biopsy and again immediately following reversal of medetomidine with atipamezole. The other dog developed seizures 2 h following skin biopsy at which time the medetomidine was reversed with atipamezole. Both dogs were neurologically normal with no history of seizures prior to the procedure and remained neurologically normal for 14 weeks and 9 months, respectively, following the procedure. A drug interaction between the α₂-adrenergic agonist medetomidine and lignocaine is suspected and highlights the potential for seizures following the subcutaneous administration of relatively large doses of lignocaine under medetomidine sedation.