Hypokalaemic episodic polymyopathy in cats fed a vegetarian diet

A previously undocumented hypokalaemic condition with a cyclical nature, comprising acute bouts of polymyopathy followed by spontaneous recoveries, is described in the cat. Cats being fed a high protein vegetarian diet developed recurrent episodes of polymyopathy, characterised by ventroflexion of the head and neck, stiff forelimb gait, lateral head-resting and generalised muscle weakness. Plasma potassium concentrations (mean +/- standard deviation) were reduced from 3.28 +/- 0.33 mmol/l at the beginning of the experiment to 2.45 +/- 0.24 mmol/l during bouts of myopathy. This hypokalaemia was associated with increased creatine kinase activities indicative of muscle damage, and decreased urinary potassium concentrations, and was caused by insufficient dietary potassium. Cats that received the same diet supplemented with potassium did not develop hypokalaemic polymyopathy. Spontaneous recoveries of affected cats were not associated consistently with increases in plasma potassium concentrations. Plasma taurine concentrations decreased and glutamic acid increased markedly in all cats fed the experimental diet. There was no evidence of thiamin deficiency associated with the high glutamic acid intake. Veterinarians should be aware that hypokalaemic cats, and in particular those on potassium-deficient diets, may show cyclical disease with episodes of polymyopathy recurring after periods of spontaneous clinical recovery. This condition in cats may be a useful animal model for familial hypokalaemic periodic paralysis in humans.     

Pleuritis in the Dog Associated with Actinomyces-like Organisms

Abstract— The clinico-pathological and radiological features of two cases of effusive canine pleuritis are presented. In both instances Actinomyces-like organisms were encountered but attempts to culture them (using aerobic and anaerobic methods) were unsuccessful. In one case Salmonella dublin was obtained in cultures at all stages of the investigations. The zoonotic implications of these and simiIar cases are discussed.
Résumé— GL'auteur expose les caractéristiques clinico-pathologiques et radiologiques de la pleurite exsudative, observée chez deux chiens. Dans l'un et l'autre cas ont été décelés des organismes semblables à l'actinomycès, mais les tentatives de culture (en milieu aerobie et anaerobie) ont échoué. Dans l'un des cas, Salmonella dublin a été obtenue à tous les stades de l'investigation. L'auteur examine les aspects zoonotiques des deux cas étudiés et de cas semblables.
Zusammenfassung— Die klinisch-pathologischen und die radiologischen Befunde von zwei Fällen von Pleuritis exsudativa des Hundes werden dargestellt. In beiden Fällen wurden astinomy-cesähnliche Organismen gefunden, aber die Kulturversuche (mit aeroben und anaeroben Methoden) verliefen erfolglos. In einem Fall wurde Salmonella dublin in Kulturen aller Stadien der Untersuchung erhalten. Die zoonotische Bedeutung dieser und ähnlicher Fälle wird besprochen.     

Effect of lytic peptides on selected fish bacterial pathogens*

Abstract. Two synthetic lytic peptides, derivatives of the naturally occurring lytic peptide cecropin B, were tested for their effect on eight pathogenic fish bacteria. All bacteria were grown on tryptic soy agar at 30°C. Four levels (dilutions) of lytic peptides were incubated with viable cells in the log phase for 1 h. Standard plate counts were made after 24±2h with control plates (no toxin) representing 100% survival. Significant differences (P<0.05) in the toxicity of the two peptides were found for six out of eight bacterial pathogens. Peptide concentration or dilution level also caused significant difference (P<0.01) in bacterial counts. Peptide type by dilution level interactions were significant (P<0.01) for only two bacterial pathogens. The LD₅₀. in molar concentrations of the lytic peptides on the bacterial pathogens, ranged from approximately 10^?6 to 10^?9. The possible role of utilizing these peptides to enhance disease resistance in aquaculture is discussed.     

Epidermal hyperplasia of walleye, Stizostedion vitreum vitreum (Mitchill), associated with retrovirus-like type-C particles: prevalence, histologic and electron microscopic observations

Epidermal hyperplasia consisting of discrete translucent raised outgrowths of cells were observed on the skin of walleye, Stizostedion vitreum vitreum (Mitchill), during their spawning period in the spring. The cells constituting the hyperplastic growths were limited to the epidermal layer, and were associated with surface budded, 120-nm-diameter, retrovirus-like particles located in the expanded intercellular spaces. These tumour-like growths were distinct from the other virus-associated skin lesions of walleye including dermal sarcoma, lymphocystis disease and herpesvirus-associated hyperplasia. Lesions could be differentiated by careful observation in the field and comparison of portions of each growth by histologic and electron microscopic observations.     

STARRY SKY HEPATIC ULTRASONOGRAPHIC PATTERN IN HORSES

The starry sky hepatic pattern is an unusual ultrasonographic appearance of equine liver characterized by numerous small, hyperechoic foci, some of which cast an acoustic shadow, distributed randomly throughout the hepatic parenchyma. Our objectives were to describe the signalment, clinical signs, clinicopathological findings, primary disease process, and ultrasonographic findings of horses with this ultrasonographic pattern, as well as determine the associated gross and histologic changes. The starry sky pattern was identified in 18 adult horses of mixed gender and breed. The horses had various clinical signs, with weight loss and anorexia reported most commonly. Liver size and parenchymal echogenicity were normal in most horses. The hyperechoic foci frequently caused acoustic shadowing. Biliary dilation was noted rarely. The ultrasonographic pattern was the result of numerous fibrosing hepatic granulomas in all horses evaluated histologically. γ‐Glutamyltransferase was the most commonly elevated hepatic enzyme, though it was increased in fewer than half the horses. Fifteen horses had an additional disease that was identified as the apparent cause of clinical signs. Three horses had primary hepatic disease while 12 had diseases of other body systems. Therefore, the starry sky ultrasonographic pattern is likely incidental in most horses and not clinically significant. Improved recognition of this pattern and further investigation of affected horses may help refine the etiology and clinical significance of the granulomas.     

Follow-up of mercury levels in fish,human hair and urine in the Madeira and Tapajós basins,Amazon, Brazil

Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajós basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajós basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajós (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajós suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarém (low Tapajós) than in Alta Floresta (high Tapajbs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986–1994).