Survey of field outbreaks of avian infectious laryngotracheitis in England and Wales.

Field outbreaks of infectious laryngotracheitis in commercial chicken flocks in England and Wales between 1985 and 1988 were investigated. Material from 49 outbreaks was submitted to Liverpool University, and virus was isolated from 17 of them. The results of a questionnaire on each outbreak are described. Generally, the disease was of moderate severity, and mainly affected laying flocks; it occurred in birds of a wide age range but most of the outbreaks were in birds between 10 and 20 weeks of age. The disease was not seen more frequently at any particular time of the year, and there was no evidence of a common source of infection. Three of the affected flocks had recently been moved and were beginning to lay; these stresses may have caused the re-excretion of latent virus.     

Lymphocyte populations in the synovial membranes of dogs with rheumatoid arthritis.

Lymphocyte populations in the synovial membranes of dogs with canine rheumatoid arthritis (CRA) were investigated by immunohistochemical staining techniques. T-lymphocytes were the predominant cell type distributed throughout the supporting layer of the synovial membranes. B-lymphocytes expressing IgG were seen far more commonly than those expressing either IgA or IgM. Synovial membrane biopsies from normal and osteoarthritic joints did not have the marked cellular infiltrates seen in joints with CRA. The synovial immunohistopathological features in dogs with CRA are similar to those seen in human rheumatoid arthritis.     

Placental transfer of specific antibodies during ovine congenital toxoplasmosis

The passage of non-Toxoplasma antibodies from dam to fetus through damaged placenta was studied in sheep inoculated with Toxoplasma gondii. Six ewes were inoculated with chicken globulins and Leptospira bacterins 2 months before oral inoculation with Toxoplasma gondii oocysts. Ewes were euthanatized between 42 and 62 days after T gondii inoculation. Antibody titers against chicken globulins, Leptospira spp, Haemonchus contortus, Sarcocystis spp, and T gondii were measured in the maternal and fetal sera. All ewes became infected with T gondii and had grossly visible necrotic foci in the placentas, and T gondii antibodies were found in the fetuses and the ewes. Appreciable amounts of antibodies to Haemonchus contortus, Sarcocystis sp, Leptospira spp, and chicken globulins did not cross the placental barrier. Seemingly, serologic examination of the fetus was reliable for the diagnosis of ovine congential toxoplasmosis.     

The Effect of Storage on Ammonia Concentration in Canine Packed Red Blood Cells.

Objective: To determine the effect of storage on ammonia concentration in canine packed red blood cell (pRBC) units.
Design: In vitro and in vivo study.
Setting: University Veterinary Teaching Hospital.
Interventions: Ammonia concentration was measured in 7 units of canine pRBC prepared in citrate-phosphate-dextrose (CPD) and Adsol^a on Days 1 and 35 of storage. Ammonia was measured in 4 additional units of canine pRBC on Days 0, 7, 14, 21, 28, and 35. Plasma ammonia was also determined in 5 anemic dogs receiving pRBC.
Measurements and Main Results: Ammonia concentration increased from 73 ± 15 mmol/L (mean ± SD) on Day 1 to 800 ± 275 mmpl/L on Day (p<0.001). When measured every 7 days in 4 units of canine pRBC, ammonia concentration increased from 23 ± 8 mmol/L on Day 0 to 179 ± 13 mmol/L (Day 7), 276 ± 56 mmol/L (Day 14). 383 ± 47 mmol/L (Day21), 466 ± 30 mmol/L (Day 28), and 562 ± 27 mmol/L (Day 35) (p<0.05 for all comparisons). In a preliminary study, plasma ammonia concentration measured in blood samples from 5 anemic dogs without primary liver disease immediately before and after transfusion with 5–10 ml/kg of stored pRBC remained in the normal reference range.
Conclusions: The ammonia concentration in stored canine pRBC increased markedly with time. In this preliminary study, ammonia concentrations in dogs without primary liver disease did not increase above the reference range after transfusion with pRBC.