Subcuticular urate accumulation in an American lobster (Homarus americanus).

An unusually "lumpy" lobster, Homarus americanus, was presented to the Atlantic Veterinary College Lobster Science Centre for evaluation. The lobster was weak with numerous pale, raised, and flat areas (diameter, 3-15 mm) on the exoskeleton, some of which were ulcerated. On postmortem examination, the pale areas corresponded to accumulations of viscous to free-flowing white material, which was found in only the subcuticular connective tissues. No internal organs were affected. Direct light examination of nonstained impression smears of the material showed abundant crystals resembling uric acid, amorphous urates, and sodium urate, which were readily soluble in 1 M potassium hydroxide. Wright-Giemsa stained imprints showed numerous fine, rounded, nonstaining granules free in the background and within individual round cells. Fourier-transformed infrared spectroscopy confirmed the presence of urates or mixed urate salts. Hemolymph plasma urea (1.7 mmol/liter) and uric acid (287 µmol/liter) concentrations were slightly higher than those seen with 36-hour emersion. Histologic sections showed aggregates of vacuolated mononuclear cells in the loose subcuticular connective tissue occasionally infiltrating between underlying muscle fibers. Grossly visible urate deposits are occasionally documented in land crabs and rarely reported in the blue crab; none, however, are associated with deformation of the cuticle. Possible etiologies include increased uric acid intake or production or decreased excretion. Anecdotal reports of similarly affected lobsters have been received but are intermittent and undocumented.

Response of American lobsters Homarus americanus to infection with a field isolate of Aerococcus viridans var. homari (Gaffkemia): survival and haematology.

American lobsters Homarus americanus were inoculated with a field isolate of the Gram-positive bacterium Aerococcus viridans var. homari, causative agent of gaffkemia, at 1 x 10(6), 1 x 10(4) or 1 x 10(2) colony forming units (CFU) kg(-1) or with sterile 3% NaCl and maintained at 10 or 15 degrees C until they died or were euthanised. Progression of disease in individual animals was monitored daily by total haemocyte count (THC) and haemolymph culture. Post-mortem examinations were performed on all lobsters. Effects of both ambient temperature and infective dose on survival time were observed. Marked bacteraemia occurred in all mortalities. Haemocytopenia (THC < 10 x 10(9) cells l(-1)) preceded death in most, but not all, mortalities.

Differences in electrophoresis patterns between plasma albumins of the cockatiel (Nymphicus hollandicus) and the chicken (Gallus gallus domesticus).

Unique migration patterns for chicken and cockatiel albumins were detected when electrophoresis was performed using cellulose acetate and agarose gel support media. Cockatiel albumin migrated to a position equivalent to chicken alpha globulins, while the migration of cockatiel prealbumin was similar to that of chicken albumin. A chicken prealbumin band was not detected. Cockatiel and chicken albumins purified by affinity chromatography had similar migration patterns when electrophoresis was performed under denaturing conditions [sodium dodecyl sulphate (SDS) ] in 7% polyacrylamide gel (PAGE). The molecular weights of both albumins were similar, and were estimated to be approximately 66,000 Da when compared to known molecular weight markers. The different migration patterns were attributed to variations in conformation and surface charge distribution of albumin molecules between the two species. The experimental and clinical consequences of these findings are briefly discussed.

Ascites and hepatic cirrhosis in a cockatiel (Nymphicus hollandicus).

A mature, female cockatiel (Nymphicus hollandicus) was examined because of respiratory difficulties. Clinical and laboratory findings included ascites and evidence of hepatic disease (i.e., increased plasma bile acid concentrations, aspartate aminotransferase, and alkaline phosphatase activities). Plasma protein electrophoresis results were consistent with chronic-active inflammation. The albumin-to-globulin (A:G) ratio, calculated from plasma electrophoresis, was 0.3. Postmortem examination revealed severe hepatic fibrosis and a diffuse, interstitial, granulomatous lipid pneumonia.