Pharmacokinetics of carprofen and firocoxib for medication control in racing greyhounds

Animals used in sport should be treated as required to ensure animal welfare but any such use of medication should also be controlled to ensure integrity. Pharmacokinetic studies on groups of six greyhounds were performed to measure plasma and urine levels of carprofen and firocoxib to inform medication control advice. Using the standard methodology for medication control the Irrelevant Plasma Concentration was determined as 20 and 2 ng/mL for carprofen and firocoxib, respectively. The Irrelevant Urine Concentration was also determined as 0.3 and 2 ng/mL for carprofen and firocoxib, respectively. These Irrelevant Plasma and Urine Concentrations will allow laboratory Screening Limits, Detection Times and Withdrawal Time advice to be determined and publicised by regulators of greyhound racing. The Screening Limits will also inform Recommended Limits of Detection if meat-containing residues of these medications are fed to greyhounds.     

Piscirickettsia salmonis: a Gram-negative intracellular bacterial pathogen of fish

Piscirickettsia salmonis is the first Gram-negative, intracellular bacterial pathogen isolated from fish and is a significant cause of mortality in salmonid fish. Recent reports of P. salmonis or P. salmonis-like organisms from new fish hosts and geographic regions have increased the interest in the bacterium. In this review, the important characteristics of the bacterium including recent taxonomic changes, features of the disease caused by the bacterium including transmission, hosts, reservoirs, diagnostic procedures, and current approaches for prevention and treatment have been discussed. The reader is also directed to other reviews concerning the bacterium and the disease it causes (Fryer & Lannan 1994, 1996; Almendras & Fuentealba 1997; Lannan, Bartholomew & Fryer 1999; House & Fryer 2002; Mauel & Miller 2002).     

Loma salmonae (Protozoa: Microspora) infections in seawater reared coho salmon Oncorhynchus kisutch

Loma salmonae (Putz et al., 1965) infections were observed in five groups of coho salmon, Oncorhynchus kisutch, reared in seawater net-pens in Washington State, U.S.A. in 1984–1986. Ultrastructural characteristics, size of spores, tissues and host infected, and geographical location identified the microsporidium as Loma salmonae. Preserved spores measured 4.4×2.3 (4–5.6×2–2.4) μm and exhibited 14–17 turns of the polar filament. Infections were evident in the gills of some fish before seawater entry, but few parasites were observed and they caused little tissue damage. Infections observed in fish after transfer to seawater were associated with significant pathological changes in the gills. A mixed inflammatory infiltrate was associated with ruptured microsporidian xenomas within the vessels and interstitium of the primary lamellae. Microsporidian spores were dispersed throughout the lesions and were often seen inside phagocytes. The parasite was also observed in the heart, spleen, kidney and pseudobranchs; however, the inflammatory lesions were common only in the heart.

Monthly examination of fish after transfer to seawater showed peak prevalences (33–65%) of gill infections during the summer. Although moribund fish were often infected with other pathogens, the high prevalence of L. salmonae infections and the severity of the lesions it caused, suggested that this parasite significantly contributed to the recurrent summer mortalities observed at this net-pen site.     

Comparative evaluation of molecular diagnostic tests for Nucleospora salmonis and prevalence in migrating juvenile salmonids from the Snake River, USA

Nucleospora salmonis is an intranuclear microsporidian that primarily infects lymphoblast cells and contributes to chronic lymphoblastosis and a leukemia-like condition in a range of salmonid species. The primary goal of this study was to evaluate the prevalence of N. salmonis in out-migrating juvenile hatchery and wild Chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss from the Snake River in the U.S. Pacific Northwest. To achieve this goal, we first addressed the following concerns about current molecular diagnostic tests for N. salmonis: (1) nonspecific amplification patterns by the published nested polymerase chain reaction (nPCR) test, (2) incomplete validation of the published quantitative PCR (qPCR) test, and (3) whether N. salmonis can be detected reliably from nonlethal samples. Here, we present an optimized nPCR protocol that eliminates nonspecific amplification. During validation of the published qPCR test, our laboratory developed a second qPCR test that targeted a different gene sequence and used different probe chemistry for comparison purposes. We simultaneously evaluated the two different qPCR tests for N. salmonis and foundthat both assays were highly specific, sensitive, and repeatable. The nPCR and qPCR tests had good overall concordance when DNA samples derived from both apparently healthy and clinically diseased hatchery rainbow trout were tested. Finally, we demonstrated that gill snips were a suitable tissue for nonlethal detection of N. salmonis DNA in juvenile salmonids. Monitoring of juvenile salmonid fish in the Snake River over a 3-year period revealed low prevalence of N. salmonis in hatchery and wild Chinook salmon and wild steelhead but significantly higher prevalence in hatchery-derived steelhead. Routine monitoring of N. salmonis is not performed for all hatchery steelhead populations. At present, the possible contribution of this pathogen to delayed mortality of steelhead has not been determined.     

Residues of endosulfan in the tissues of lactating goats

SUMMARY: The sites of tissue accumulation in lactating goats of the organochlorine insecticide endosulfan were studied. Twelve lactating goats were dosed orally with endosulfan (1 mg/kg body weight per day) for 28 days. Groups of 3 animals were killed on days 1, 8, 15, and 21 after endosulfan treatment ended and their tissues examined for the presence of endosulfan. Total residues of α and β endosulfan and endosulfan sulphate (mg/kg) were detected in kidney (0.29), gastro-intestinal tract (0.20), liver (0.12), brain (0.06), muscle and spleen (0.04), lung and heart (0.01) and milk (0.02) on the flrst sampllng day but within 15 days, concentrations had fallen to < 0.01 mg/kg in all tissues except kidney (0.20). Endosulfan could not be detected in animals 21 days after dosing had ceased. The residue in milk could only be detected on day 1 of sampling. This study indicates that kidney rather than fatty tissue should be used to monitor the presence of endosulfan in animals intended for human consumption.     

Disease-husbandry associations in farmed crocodiles in Queensland and the Northern Territory

SUMMARY To investigate husbandry-disease associations in farmed crocodiles 7 farms in Queensland and the Northern Territory were visited and details of past and present farm design and husbandry practices were recorded. In addition pathological examination of 300 (mostly young) crocodiles was carried out (85 necropsied, one biopsied and 214 examined retrospectively). Mortality rate and occurrence of disease, especially opportunistic infections with bacteria and fungi, were highest during winter months and in farms located at greater latitudes. A difference in the presence and prevalence of disease between the initial establishment phase of Northern Territory crocodile farms (1984–87) and currently (1988–91) was apparent; parasitic infections are now relatively infrequent and bacterial septicaemias and mycoses less common as a result of some provision of artificial heating for juveniles. Gross and microscopic changes observed in visceral and periarticular gout, bacterial hepatitis/septicaemia, deep and superficial mycosis, pentastomiasis and other parasitic infections are described.     

Efficacy of praziquantel in the treatment of green sea turtles with spontaneous infection of cardiovascular flukes

Objective To assess the efficacy of praziquantel as a treatment for cardiovascular flukes in turtles.
Procedure Six green sea turtles ( Chelonia mydas ) spontaneously infected with cardiovascular flukes (Digenea: Spirorchiidae) were treated orally with praziquantel, and necropsied 3 or 7 days later to look for flukes in the heart and major blood vessels. Six similar animals were maintained as untreated controls.
Results Absence of flukes in treated, but not control turtles, indicated that a one day course of treatment at a dose rate of 3 times 50 mg/kg body weight is effective.
Conclusion This result should be of value for preventing disease in wild caught green turtles introduced into farms or aquaria.