Survival and Complications After Large Colon Resection and End‐to‐End Anastomosis for Strangulating Large Colon Volvulus in Seventy‐Three Horses

Objective— To report complications and survival after large colon resection and end‐to‐end anastomosis in horses with strangulating large colon volvulus. Study Design— Retrospective case series. Animals— Horses (n=73) with strangulating large colon volvulus. Methods— Records (January 1995 to December 2005) of horses that had large colon resection and anastomosis for strangulating large colon volvulus were reviewed for complications. Follow‐up data were obtained by telephone questionnaire at least 1 year postoperatively. Cox proportional hazards model was used for multivariate association with survival time. Variables included admission date, age, temperature, heart rate, packed cell volume, total plasma protein concentration, white blood cell count, breed, and sex. Significance was set at P<.05. Results— The most common postoperative complication was diarrhea. None of the 9 variables of interest were significant for survival. Short‐term survival rate (to discharge) was 74%. Overall survival rates at 1, 2, and 3 years postoperatively were 67.8%, 66.0%, and 63.5%, respectively. Four horses died of colic in the first year after surgery. All horses surviving long‐term (>1 year) returned to their intended use (37 brood mares, 2 racehorses, and 1 show horse) with no chronic problems related to the surgical procedure. Conclusion— None of the variables examined were associated with survival. Outcomes were similar to other large studies of surgical colic in the horse. Self‐limiting diarrhea is common after large colon resection and the prognosis for survival after hospital discharge is favorable. Clinical Relevance— Horses that survive the early postoperative period and are discharged after large colon resection and anastomosis have a good chance for long‐term survival with minimal negative impact on quality of life and use.     

Effect of fertilizers on the yield and chemical composition of pure sown white clover and on soil nutrient status

The effects of three levels of potash, phosphate and lime fertilizers on the yield and mineral content of white clover ( Trifolium repens ) and on soil nutrient levels were studied in a field experiment over 7 years. The aim of the experiment was to define an optimum fertilizer programme for breeding nurseries and experimental fields.
Potash was the main factor limiting production: clover yield was negligible after 2 years where no potassium was applied. Phosphate increased yields after the third year, while liming had no significant effect on clover yield.
The soil potassium status improved with the repeated application of potash over the 7–year period, but no consistent pattern was discernible for the phosphate treatments. There was a slight increase in soil pH with liming.
Application of phosphate increased the phosphorous content of herbage, but had no effect on other plant constituents for the first 2 years. Subsequent applications increased the calcium and sodium contents. Potash reduced the content of all constituents other than potassium as the treatment levels increased. Lime had little effect on plant constituents other than calcium.     

Use of enzyme-linked immunoassays for antibody to types C and D botulinum toxins for investigations of botulism in cattle

The development of specific enzyme-linked immunosorbent assays (ELISA) for antibody to types C and D Clostridium botulinum toxins for investigation of botulism in cattle is described. Partially purified type C and D toxins were used as antigens to develop these ELISAs. Specificity of the ELISAs was evaluated on sera from 333 adult beef and dairy cattle from areas with no history or evidence of botulism in animals or water birds. The test was also evaluated on sera from 41 herds that included herds vaccinated against botulism, confirmed botulism cases and herds from areas where the disease is considered endemic. The ELISAs detected the presence of antibody to botulinum toxins in samples from vaccinated cattle and both convalescent and clinically normal animals from unvaccinated herds with outbreaks of botulism. Antibody was also found in unvaccinated animals from herds in which there had been no diagnosed botulism cases in areas where botulism was considered endemic. Sera from some unvaccinated cattle with high ELISA reactivity was shown to be protective for mice in botulinum toxin neutralisation tests. The use of these tests in investigations of botulism in cattle is discussed.     

Proliferative kidney disease in brown trout, Salmo trutta L., and Atlantic salmon, Salmo salar L., parr: histopathological and epidemiological observations

Abstract Proliferative kidney disease (PKD) has been described in cultivated rainbow trout but major outbreaks have not been recognized in other fish species. This paper describes light and electron microscope studies and presents epidemiological data of a disease condition in first summer Salmo salar parr and S. trutta , which is associated with an organism apparently identical to the aetiological agent of PKD. The pathology was found to be similar to that described for PKD in rainbow trout. The epidemiology in the brown trout suggests that exposure after May does not result in infection. The data from the outbreaks in two salmon hatcheries appear complex and suggest different susceptibilities to PKD among salmon originating from different sources.     

An appraisal of the extracellular toxins of Aeromonas salmonicida ssp. salmonicida

Abstract. Aeromonas salmonicida produces many extracellular enzymes, some of which are known to play an important role in pathogenesis and virulence, while the role of others is presently speculative. The latter group includes amylase, aryl-sulphatase, glucosidases, esterases and lysophospholipase. There are two enzymes which are known to be of prime importance in pathogenesis: a 70-kDa protease (caseinase) and a 25-kDa phospholipase (glycerophospholipid: cholesterol acyltransferase, GCAT). The protease causes extensive tissue liquefaction, activates the blood clotting system and is lethal for fish at 2·4 μg/g fish. It is inhibited by α2-macroglobulin but resistant to all the other serum protease inhibitors. Its role in vivo appears to be as a broad spectrum protease providing amino acids for in vivo growth. The GCAT is mainly present in a high molecular weight complex with LPS. The complex is extremely haemolytic for fish (but not mammalian) erythrocytes. It is the most lethal component of the exotoxins (lethal dose 45 ng/g fish). The complex with LPS confers enhanced toxicity to the GCAT and stability to heat and proteolytic degradation. In vitro , this toxin also has high leucocytolytic and cytolytic (RTG-2) activity. On injection into fish, it causes very little histopathology other than a marked degranulation of eosinophilic granular cells (EGCs) in the gills. Its precise mode of pathogenesis is uncertain and appears complex. The protease and the GCAT/LPS have an additive relationship in respect to lethal doses and mixtures of the two produce extensive liquefactive and haemorrhagic lesions typical of furuncles. The possible relationship of the GCAT/LPS to other less well characterized factors (cytotoxin, leucocytolysin, haemolysin, salmolysin) is discussed.     

Lack of relationship between virulence of Aeromonas salmonicida and the putative virulence factors: A-layer, extracellular proteases and extracellular haemolysins

Abstract The role of A-layer (A), protease (P) and haemolysin (H) as virulence factors of Aeromonas salmonicida, the aetiological agent of fish furunculosis, was a investigated using three strains of the bacterium. Strain MT004 lacked the A-Iayer (A⁻) and produced extracellular caseinase and gelatinase (P⁺) and haemolysin (T-lysin; H⁺). Strain MT028 was A⁻, P⁻ and H⁻, and strain MT048 was A⁺, P⁺ and H⁻. The pathology and LD50 produced in rainbow trout by cells or extracellular products (ECP) of each strain were determined. The ECP was produced by two different methods where the protease and haemolytic activities differed in relative levels, or when the protease of MT004 ECP was inhibited by the serine protease inhibitor PMSF. The results indicate that the presence of A-layer is not essential, at least for a moderate degree of virulence; that in vitro production of extracellular proteases is not a requisite of virulent strains; that presence of protease and haemolysin in ECP can be correlated with the development of certain lesions and a rapid time to death but cannot be correlated with the lethal toxicity of the ECP. The authors conclude that an as-yet unrecognized component of ECP is responsible for killing fish.