禽流感病毒对人类的威胁有多大

A型流感病毒的自然感染已在多种动物有所报道 ,包括人、猪、马、海洋哺乳动物和鸟类等动物。这种破坏性传染病有时发生于人类。尽管从哺乳动物中只分离到较少的HA和NA亚型组合病毒 ,但是在鸟类中分离到了大部分HA和NA亚型组合。     

Non-surgical management of rectal tears in two mares

Two mares presented with life-threatening rectal tears were successfully treated with intensive medical management. Although surgery has been regarded as mandatory for grade 3 or 4 rectal tears in the past, recent reports have indicated the value of medical management alone. The case reports presented in this article detail the use of antibiotics, flunixin meglumine, laxative diets and faecal softeners in the medical management of two mares presented with grade 3 rectal tears.     

First isolation and characterisation of Encephalitozoon cuniculi from a free-ranging rat (Rattus norvegicus)

The microsporidian species Encephalitozoon cuniculi can infect a wide variety of mammals including man. It is a common parasite in rabbits and several sporadic infections in laboratory rats have been described. Based on molecular data three E. cuniculi strains have been identified. Here we describe the first in vitro propagation of E. cuniculi, which was isolated from a free-ranging rat (Rattus norvegicus). The rat was one of three seropositive animals among 23 rats captured in the city of Zurich. The new isolate was further characterised as strain II ("mouse"-strain) based on the rDNA internal transcribed spacer sequence. Western blot analysis of this isolate revealed slight differences to other available strain II isolates originating from laboratory mice and farmed blue foxes. The new isolate caused disseminated infection in liver and lung upon oral inoculation of Brown Norway (BN) rats and was transmitted to sentinel rats. This rat-adapted isolate will be valuable to study the pathogenesis of Encephalitozoon infections in the rat model.     

Management of generalized gingival enlargement in a dog--case report and literature review

The present report describes treatment of a dog with generalized gingival enlargement and serves as a review of etiology and treatment options for this condition. The combined use of scalpel blade, electrosurgical equipment, and a 12-fluted bur on a high-speed handpiece with water irrigation allowed for accurate excision of excess gingival tissue and contouring of remaining gingiva. Surgery coupled with professional dental cleaning/periodontal therapy can decrease the recurrence of this condition. In addition, home oral hygiene is an important component of the treatment plan. The history of patients with gingival enlargement should be reviewed carefully, including drug history and previous medical conditions, in an attempt to elucidate a specific cause and thus allow for greater long-term success.     

Canine visceral leishmaniasis: relationships between clinical status, humoral immune response, haematology and Lutzomyia (Lutzomyia) longipalpis infectivity

The main source of Leishmania infantum infection in humans is a naturally infected dog. This study reports on the infectivity to phlebotomine sandflies (Lutzomyia longipalpis) of serologically positive mongrel dogs that differed in clinical status, haematology and humoral responses to immunoglobulin (Ig) G(T) (total anti-Leishmania IgG), IgG(1) and IgG(2) subclasses of antibody to crude antigen of L. infantum. Forty-five female L. longipalpis were allowed to feed directly on the ears of dogs classified as asymptomatic, oligosymptomatic or symptomatic before being dissected five days later. Promastigotes were detected in 88% of the dissected sandflies. The highest rate of infectivity to sandflies was found in symptomatic dogs, followed by oligosymptomatic and asymptomatic animals. The results suggest that dogs naturally infected with L. infantum with higher total IgG and IgG(2) concentrations and lower haematocrit levels were able to infect the highest proportion of L. longipalpis. No correlation was observed between anaemia and the intensity of clinical signs. Symptomatic dogs presented the highest infection rate and intensity of infection.     

Differential effects of phosphodiesterase inhibitors on platelet activating factor (PAF)- and adenosine diphosphate (ADP)-induced equine platelet aggregation

Compounds that activate adenylate cyclase, increasing intracellular cyclic adenosine monophosphate (cAMP), inhibit equine platelet aggregation. Cyclic AMP is broken down by phosphodiesterase (PDE) and, in the present study, the effects of theophylline, a nonselective PDE inhibitor, and selective inhibitors of PDE isoenzymes PDE3, PDE4 and PDE5, on equine platelet aggregation in response to platelet activating factor (PAF) and adenosine diphosphate (ADP) have been examined. Theophylline and the PDE3 inhibitors, trequinsin and quazinone, inhibited both PAF and ADP-induced aggregation in a concentration dependent manner. The inhibition of PAF-induced aggregation was, however, significantly greater than that of the response to ADP. The inhibitory effects of theophylline and the PDE3 inhibitors on ADP- but not PAF-, induced aggregation were reversed by addition of the calcium ionophore, A23187. Rolipram and zaprinast, inhibitors of PDE4 and PDE5, respectively, had no effect on either PAF- or ADP-induced aggregation. These results demonstrate that inhibition of aggregation caused by PAF or ADP can be achieved by selective inhibition of PDE3 but suggest that there may be agonist-specific differences in the intracellular signalling pathways that regulate equine platelet aggregation.     

Faecal calcium excretion does not decrease during long‐term feeding of a low‐calcium diet in adult dogs

According to a previous meta‐analysis, adult dogs do not notably increase calcium absorption from the gastrointestinal tract when calcium intake is decreased. This results in a negative calcium balance even with a moderate calcium reduction. In this study we wanted to verify (i) whether a negative calcium balance occurs at a calcium intake equivalent to NRC (2006) (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC) minimal requirements, and if so (ii) whether the negative calcium balance will persist for up to 6 months on a low‐calcium diet. After a pre‐feeding period of at least 18 weeks with calcium intake slightly exceeding maintenance requirements (200 mg/kg body weight^0.75), 12 dogs (6 Beagles, 6 Foxhound crossbreds) were fed a low‐calcium diet for 28 weeks. One dog was removed from the trial for reasons unrelated to the study at week 23. Calcium intake amounted to 60 mg/kg body weight^0.75 corresponding to the minimal requirement for maintenance in dogs (NRC, 2006 (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC)). Digestion trials were carried out at week 7, 14, 21 and 28 of the low calcium feeding period. At these time points, and at week 18 of the pre‐trial, blood samples were taken and analysed for calcium, ionised calcium, phosphorus, parathyroid hormone, vitamin D, serum crosslaps and bone alkaline phosphatase. Apparent calcium digestibility was negative throughout the study, suggesting a negative calcium balance. There was no systematic decrease in faecal calcium excretion. Serum calcium, ionised calcium and phosphorus remained within the reference range. Serum crosslaps increased continuously from baseline to week 28 of trial, with averages increasing from 0.102 ng/ml to 0.279 ng/ml, suggesting osteoclastic activity, indicative of calcium mobilisation from the skeleton. The study supports the theory of a lack of adaptation of intestinal calcium absorption from diets with relatively low calcium content in dogs. This agrees with clinical findings in dogs eating low‐calcium diet.