Ultrastructure of the gastrocnemius tendon and sheath from broilers infected with reovirus

Gastrocnemius tendon and sheath from male broilers infected with reovirus at 1 day of age were evaluated ultrastructurally at 1, 2, 3, 4, 5, 10, 15, and 20 weeks postinoculation (PI). Although virus particles were not identified, degenerative changes in sheath and tendon fibroblasts were characterized by cytoplasmic vacuolization, disruption of membranes, and loss of ribosomes from rough endoplasmic reticulum, mitochondrial degeneration, and cell disruption.     

Effects of Metomidate Hydrochloride Sedation on Blood Glucose and Marketability of Transported Threespot Gourami Trichogaster trichopterus

Abstract

Our objectives were to determine whether sedation with metomidate hydrochloride (hereafter, “metomidate”) during transportation of threespot gourami Trichogaster trichopterus would prevent an increase in blood glucose levels and improve fish marketability (i.e., based on appearance and behavior) in comparison with unsedated controls. Threespot gourami are obligate air-breathers that possess a labyrinth organ, enabling the fish to respire air above the water surface; these fish should be lightly sedated during transport. Fish were transported for approximately 24 h via truck and domestic airline. Blood was sampled at 0, 2, 6, and 12 h posttransportation, and appearance and behavior were observed at 0, 2, 4, 6, and 12 h and 7 d posttransportation. Metomidate concentrations tested were 0.0 (control), 0.1, 0.2, 0.3, and 0.4 mg/L. At the concentrations tested, metomidate neither inhibited elevations in blood glucose nor improved marketability. Fish that were transported with 0.3-mg/L metomidate were less marketable based on behavioral indices, and fish that were transported with 0.4-mg/L metomidate had higher glucose levels than control fish. Use of metomidate as a transport sedative for threespot gourami should be considered with caution and may be problematic at the concentrations tested; however, further research examining additional indices of stress may clarify metomidate use for this species.

Received February 16, 2011; accepted December 18, 2011.     

Outcomes of Heimlich valve drainage in dogs

Objective and design   Retrospective study of the outcomes of Heimlich valve drainage in dogs.
Procedure   Medical records of the past 3 years were retrospectively reviewed. Heimlich valve drainage was used in 34 dogs (median body weight 30 ± 5 kg): lobectomy (n = 15), pneumonectomy (n = 9), intrathoracic oesophageal surgery (n = 2), diaphragmatic hernia repair (n = 1), traumatic open pneumothorax (n = 2), bilobectomy (n = 2), ligation of the thoracic duct (n = 1), and chylothorax and pneumothorax (n = 1 each). Evacuation of air and/or fluid from the pleural cavity was performed with the Heimlich valve following thoracostomy tube insertion. During drainage, the dogs were closely monitored for possible respiratory failure. Termination of Heimlich valve drainage was controlled with underwater seal drainage and assessed with thoracic radiography.
Results   Negative intrathoracic pressure was provided in 29 dogs without any complications. Post pneumonectomy respiratory syncope and post lobectomy massive hemothorax, which did not originate from the Heimlich valve, were the only postoperative complications. Dysfunction of the valve diaphragm, open pneumothorax and intrathoracic localisation of an acute gastric dilatation–volvulus syndrome caused by a left-sided diaphragmatic hernia following pneumonectomy were the Heimlich valve drainage complications.
Conclusions   The Heimlich valve can be used as a continuous drainage device in dogs, but the complications reported here should be considered by veterinary practitioners.     

The ACVD task force on canine atopic dermatitis (V): biology and role of inflammatory cells in cutaneous allergic reactions.

Numerous inflammatory cells are thought to play a role in the pathogenesis of canine atopic dermatitis (AD) although, in the past, mast cells were considered the most important. However, evidence for this assumption is lacking. In this paper, we review the literature concerning the role of inflammatory cells in allergic reactions and conclude that a complex interplay exists between a wide variety of cell types. Thus, on the basis of the available evidence, the cells that appear to be the most important in the pathogenesis of canine AD are Langerhans' cells and dermal dendritic cells (both responsible for antigen processing and presentation), B-lymphocytes (responsible for reaginic antibody production), allergen-specific helper T-lymphocytes (responsible for cytokine production leading to activation of B-cells and other inflammatory cells) and mast cells (production of inflammatory mediators leading to inflammation).     

The effect of pseudorabies (Aujeszky''s) virus infection on young mature boars and boar fertility.

This study was designed to determine the effects of experimental inoculation with pseudorabies virus on the reproductive tracts of young adult boars. Pseudorabies virus was inoculated intranasally into 12 boars and intrapreputially into four boars. All animals seroconverted after nasal or preputial inoculation. Semen abnormalities were observed 21 days postinoculation with partial recovery by 50 days postinoculation. Virus was isolated from the preputial sheath of two intrapreputially inoculated boars 12 days postinoculation. It was concluded that pseudorabies virus infection can be established via preputial inoculation and that decreased spermatogenesis and infertility can result.     

Impact of supplement withdrawal and wheat middling inclusion on bone metabolism, bone strength, and the incidence of bone fractures occurring at slaughter in pigs

The objective of this study was to determine if supplement withdrawal (omission of dietary vitamin and trace mineral premixes and 2/3 of inorganic P) 28-d preslaughter and the feeding of wheat middlings (dietary concentrations of 5, 15, or 30% from weaning to 16 kg, 16 to 28 kg, and 28 kg to slaughter, respectively) affect bone metabolism, bone strength, bone density, and the incidence of bone fractures at slaughter in pigs. Crossbred barrows (n = 64) were assigned to a 2 x 2 factorial arrangement of treatments (with or without supplement withdrawal, and with or without wheat middlings). Serum was collected on d 0, 14, and 27 of the preslaughter withdrawal period to determine changes in the concentrations of osteocalcin, an indicator of bone formation, and pyridinoline, an indicator of bone resorption. The serum osteocalcin and pyridinoline concentrations on d 14 and 27 were analyzed as change from the d-0 concentration. At slaughter, radiographs of the lumbar vertebrae and of the right and left femurs were taken to determine the incidence of bone fractures. Third metacarpal bones were analyzed for bone mineral density, peak load, ultimate shear stress, and percent ash. Supplement withdrawal increased (P < 0.05) serum osteocalcin and pyridinoline concentrations, indicating an increase in osteoblast activity and bone resorption. Supplement withdrawal decreased (P < 0.01) bone mineral density, peak load, ultimate shear stress, and percent ash of the metacarpal bones. Dietary wheat middling inclusion did not alter bone quality. Neither supplement withdrawal nor wheat middling inclusion affected the incidence of bone fractures at slaughter. The results of this study indicate that removing inorganic P, vitamin premix, and trace mineral premix for 28 d preslaughter increases bone turnover and decreases bone quality.     

Detection of Oocyst‐Associated Toxoplasmosis in Swine from Southern Chile

Pork has been traditionally considered an important source of human Toxoplasma gondii infection. Pigs, as other meat‐producing animals, can become infected by the ingestion of oocysts that are shed in the environment by infected cats or by the consumption of cysts present in tissues of infected mammals, commonly small rodents. The objective of this study was to investigate the level of T. gondii infection in swine from southern Chile that can be associated with the ingestion of oocysts and therefore exposure to a contaminated environment. A total of 340 serum samples from swine were obtained from three commercial slaughterhouses located in the Araucania and Los Rios Regions from southern Chile. Study animals originated from local farms, mainly small commercial producers, and the meat is sold locally. Overall, 8.8% (30/340) of the samples showed T. gondii‐specific IgG antibodies. Of these sero‐positive animals, 80% (24/30) were also positive for antibodies specific against the oocyst stage of the parasite, indicating that animals had been infected recently by the ingestion of oocysts. The observed results suggest a high level of environmental contamination with oocysts on the farms of origin. In addition to the food safety problems associated with the consumption of meat from infected animals, the high level of environmental contamination on the farm represents a direct health risk for people living and/or working on these farms. Consequently, there is a need to develop on‐farm monitoring programmes and identify risk reduction strategies (food storage, water purification, rodent control and contact with cats) that are appropriate and cost‐effective for informal and outdoor type of farms.