Observations on salpingitis, peritonitis and salpingoperitonitis in a layer breeder flock

A flock of 13,951 hens and 1379 cockerels was monitored from 26 to 58 weeks of age for the complex of salpingitis, peritonitis and salpingoperitonitis (sps). Two hundred and forty-three hens (78 per cent of the hens that died) were examined postmortem, and sps was recognised by gross examination for inflammatory exudate, in the body cavity or oviduct in 111 (46 per cent) of them. Salpingoperitonitis was the most common form, followed by salpingitis and then peritonitis. There were acute and chronic cases in all three conditions, but only in peritonitis were acute cases more common than chronic cases. Seventeen birds that had died of sps were cultured for aerobic bacteria within 12 hours of death. Escherichia coli was recovered from a variety of tissues from all of them, and other bacteria, including staphylococci, Mannheimia haemolytica and Streptococcus bovis, were isolated from a few carcases, either alone or together with E coli. Relatively few isolations of E coli were made from normal hens cultured 48, 72 and 96 hours after death.     

Age-related changes in serum insulin-like growth factor-I, insulin-like growth factor-I binding protein-3 and articular cartilage structure in Thoroughbred horses

REASONS FOR PERFORMING STUDY: Structural changes in articular cartilage associated with the ageing process require definition for investigators performing developmental and age-related studies, for which information is lacking. OBJECTIVES: To 1) determine the onset and end of puberty as defined by serum insulin like growth factor (IGF-I) and IGF-binding protein-3 (IGFBP-3) concentrations and 2) correlate articular-epiphyseal cartilage complex structural changes with the onset and end of puberty. METHODS: IGF-I and IGFBP-3 were measured in serum samples from normal female and male horses age 9-715 days to determine peak and steady-state values for horses transitioning through puberty. Osteochondral tissue sections were obtained from horses age 120-840 days (4-28 months) and examined histologically for cartilage canals and tidemark formation. RESULTS: In male and female horses, serum IGF-I/IGFBP-3 concentrations peaked at approximately 225 days, defining the onset of puberty. Cartilage canals were absent from articular cartilage just prior to this time point. IGF-I/IGFBP-3 concentrations declined to steady-state levels at approximately age 450 days, signalling exit from puberty and therefore the beginning of ageing. This time point correlated to initial formation of a tidemark in the osteochondral tissue sections. CONCLUSIONS: Horses may be considered pubescent at age 225-450 days, and post pubescent and ageing after age 450 days. POTENTIAL RELEVANCE: Defining the normal post natal to post pubescent concentrations for serum IGF-I and serum IGFBP-3 establishes subsets of animals for age-related studies and may be used to monitor horses for abnormally high IGF-I concentrations due to natural disease or subsequent to systemic growth hormone administration.     

Uses and effectiveness of pamidronate disodium for treatment of dogs and cats with hypercalcemia

Uncorrected hypercalcemia can cause clinical signs such as polyuria, polydipsia, vomiting, diarrhea, lethargy, and depression and contributes to the development of primary renal failure and soft tissue mineralization. Treatment of hypercalcemia includes diagnosis and treatment of the underlying disease process and some combination of excracellular fluid volume expansion by administration of fluids intravenously and administration of glococorticosteroids, salmon calcitonin, and furosemide. Bisphosphonates such as pamidronate disodium also may be safe and effective in the treatment of hypercalcemia. The purpose of our study was to characterize the efficacy and safety of pamidronate in the treatment of hypercalcemia attritutable to several different disease processes in the dog and cat. Seven dogs and 2 cats were administered pamidronate at a dose of 1.05-2.0 mg/kg IV for a variety of disease processes, including neoplasia (n = 4), calcipotriene toxicity (n = 3), nocardiosis (n = 1), and idiopathic hypercalcemia with chronic renal failure (n = 1). In all the animals, IV pamidronate administration rapidly decreased serum calcium concentrations without evident toxicosis. Two animals received pamidronate several times without obvious toxicosis. On the basis of the findings in our retrospective study, pamidronate may be a safe and effective drug with which to lower both serum total and ionized calcium concentrations in patients with hypercalcemia arising from a wide variety of underlying disease processes.     

Effects of iron modulation on growth and viability of Rhodococcus equi and expression of virulence-associated protein A

OBJECTIVE: To determine the importance of iron for in vitro growth of Rhodococcus equi, define potential iron sources in the environment and mechanisms by which R equi may obtain iron from the environment, and assess expression and immunogenicity of iron-regulated proteins. SAMPLE POPULATION: 10 virulent and 11 avirulent strains of R equi. PROCEDURE: In vitro growth rates and protein patterns of R equi propagated in media with normal, excess, or limited amounts of available iron were compared. Immunoblot analyses that used serum from foals naturally infected with R equi and monoclonal antibody against virulence-associated protein (Vap)A were conducted to determine immunogenicity and identity of expressed proteins. RESULTS: Excess iron did not alter growth of any R equi strains, whereas growth of all strains was significantly decreased in response to limited amounts of available iron. Virulent R equi were able to use iron from ferrated deferoxamine, bovine transferrin, and bovine lactoferrin. Only virulent R equi expressed an iron-regulated, immunogenic, surface-associated protein identified as VapA. CONCLUSIONS AND CLINICAL RELEVANCE: Iron is required for the growth and survival of R equi. Sources of iron for R equi, and mechanisms by which R equi acquire iron in vivo, may represent important virulence factors and novel targets for the development of therapeutic and immunoprophylactic strategies to control R equi infection in foals. Expression of VapA is substantially upregulated when there is a limited amount of available iron.     

Surveillance of amyloidosis and other diseases at necropsy in captive trumpeter swans (Cygnus buccinator).

The purpose of this study was to characterize the incidence and diagnostic features of amyloidosis and other diseases found at necropsy in captive trumpeter swans (Cygnus buccinator). A search of Iowa State University's Department of Veterinary Pathology and Veterinary Diagnostic Laboratory databases yielded 31 trumpeter swan (C. buccinator) necropsy cases from captive swans in protected habitats. Eleven of the 31 birds had amyloid deposition most commonly in the spleen (8 of 11), liver (7 of 11), and kidney (6 of 11) and less often in the pancreas (2 of 11) and adrenal gland (2 of 11). Amyloid deposition effaced normal tissue with adjacent necrosis and hemorrhage in severe cases. Amyloidosis was most often diagnosed in February and March. Other disease diagnoses in the trumpeter swans included aspergillosis (5 of 31, 16%); bacterial infection (5 of 31, 16%); lead toxicosis (3 of 31, 10%); gout (2 of 31, 6%); parasitic infection (2 of 31, 6%); vitamin E deficiency (1 of 31, 3%); trauma (1 of 31, 3%); and ventricular foreign body (1 of 31, 3%). Histopathologic, toxicologic, and microbiologic analyses did not define an etiologic diagnosis in the deaths of 9 trumpeter swans. In these cases, necropsy lesions included emaciation (5 of 9), enteritis (1 of 9), pulmonary hemorrhage (1 of 9), and no lesions (3 of 9). The number of trumpeter swan case submissions was greatest in January and February. This study provides a reference for veterinary diagnosticians concerning incidence and diagnostic features of amyloidosis and other diseases in captive trumpeter swans of the midwestern United States.     

Improved methods for quantifying potential nutrient interception by riparian buffers

Efforts to quantify the effects of riparian buffers on watershed nutrient discharges have been confounded by a commonly used analysis, which estimates buffer potential as the percentage of forest or wetland within a fixed distance of streams. Effective landscape metrics must instead be developed based on a clear conceptual model and quantified at the appropriate spatial scale. We develop new metrics for riparian buffers in two stages of increasing functional specificity to ask: (1) Which riparian metrics are more distinct from measures of whole watershed land cover? (2) Do functional riparian metrics provide different information than fixed-distance metrics? (3) How do these patterns vary within and among different physiographic settings? Using publicly available geographic data, we studied 503 watersheds in four different physiographic provinces of the Chesapeake Bay Drainage. In addition to traditional fixed-distance measures, we calculated mean buffer width, gap frequency, and measures of variation in buffer width using both “unconstrained” metrics and “flow-path” metrics constrained by surface topography. There were distinct patterns of relationship between watershed and near-stream land cover in each physiographic province and strong correlations with watershed land cover confounded fixed-distance metrics. Flow-path metrics were more independent of watershed land cover than either fixed-distance or unconstrained measures, but both functional metrics provided greater detail, interpretability, and flexibility than the fixed-distance approach. Potential applications of the new metrics include exploring the potential for land cover patterns to influence water quality, accounting for buffers in statistical nutrient models, quantifying spatial patterns for process-based modeling, and targeting management actions such as buffer restoration.     

Inhibition of appressorial adhesion of Pyricularia oryzae to barley leaves by fungicides

The effects of rice blast fungicides known to inhibit melanisation or penetration on the adhesion of Pyricularia oryzae to the leaf surface of barley were investigated. Adhering appressoria were counted after shaking inoculated leaves vigorously with water. On untreated leaves, appressoria began to adhere at the time when appressorial melanisation was initiated. The number of adhering appressoria then increased gradually, and most were melanised. On chlobenthiazone-treated leaves, appressoria were not melanised and were easily detached from the surface. Similar results were obtained with tricyclazole. However, after treatment with tetrachlorophthalide or pentachlorobenzyl alcohol, which are also known to prevent penetration of P. oryzae, melanised appressoria still remained after shaking in water. It is suggested that appressorial melanisation in P. oryzae is involved in appressorial adhesion. The antipenetrant action of the melanin biosynthesis inhibitors chlobenthiazone and tricyclazole may be ascribed to the lack of adhesive intensity necessary to support the mechanical shearing of the cuticle of rice plants.     

Comparative study of serological methods for the detection of antibodies to porcine reproductive and respiratory syndrome virus.

A comparison was made of serological diagnostic methods used for the detection of antibodies against porcine reproductive and respiratory syndrome (PRRS) virus. In the "phase I" PRRS test panel comparison, a panel of sera collected from 135 pigs of various ages, from North American herds with and without PRRS histories, were sent to 4 different laboratories and tested by an indirect immunofluorescent assay (IFA), an immunoperoxidase monolayer assay (IPMA) and an indirect enzyme-linked immunosorbent assay (iELISA). In the "phase II" PRRS test panel comparison, a panel of 382 sera collected from pigs of various ages, PRRS histories, and from various locations in North America and France, were divided into 2 panels (A & B) and sent to 3 Canadian laboratories and tested by the IFA and iELISA. In the phase I comparison, agreement between the IFA of laboratory 4 and the iELISA and IPMA of laboratory 3 was excellent (kappa values of 95% and 98%, respectively). This contrasted with the poor agreement between these laboratories and the IFA results of laboratories 1 and 2 in the phase I trial. In the phase II comparison, the results demonstrated good agreement between various tests both within and between laboratories. The overall performance of the iELISA was superior in the combination of sensitivity (96.1%) and specificity (100%) relative to the reference classification of the serum samples and repeatability (kappa value 98%). The iELISA is technically superior to IFA and IPMA, time efficient, cost effective and suitable for testing of a large number of samples over a short period of time. Thus, the iELISA may be a better alternative to IFA or IPMA for routine detection of PRRS viral antibodies in swine sera.