Evaluation of a serological test system for the diagnosis of natural Echinococcus granulosus infection in dogs using E. granulosus protoscolex and oncosphere antigens

Serum antibody responses in feral or domesticated dogs naturally infected with Echinococcus granulosus or/and other common helminths were examined in an enzyme-linked immunosorbent assay (ELISA) using antigens prepared from E. granulosus protoscoleces or oncospheres. The ELISA using the protoscolex antigen was optimised with serums from experimental dogs monospecifically infected with E. granulosus or other helminth parasites, and helminth-free dogs. Anti-protoscolex antibody was detected in 16 of 22 (72.7%) serums from feral dogs with E. granulosus burdens ranging from 300 to 302,600 worms per dog. Seven serums from feral dogs which did not harbour E. granulosus at autopsy but which originated from an endemic hydatid region were tested using protoscolex antigen, and 1 serum gave a positive reaction. One hundred and two serums from dogs known never to have been infected with E. granulosus all gave negative reactions to protoscolex antigen. The sensitivity of the ELISA test proved to be superior to that which has been achieved by arecoline purging as a method of diagnosis for E. granulosus infection in dogs. For use of the assay in hydatid control or eradication campaigns, its sensitivity can be increased by choosing a lower absorbance discrimination value above which serums are regarded as having positive reactions. However, this does introduce positive reactions of some serums from dogs infected with helminths other than E. granulosus. In further development of the assay, use of defined recombinant antigens may improve both sensitivity and specificity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunization of dogs with a Leishmania infantum-derived vaccine

A partially-purified extract of Leishmania infantum has been administered to healthy dogs. Post-immunization sera were found to neutralize the infectivity of L. infantum and to abate the development of L. major. Muramyl dipeptide and one of its derivates, murabutide, were the best adjuvants.     

The effects of high intensity exercise on the plasma concentration of lactate, potassium and other electrolytes

To study the effect of short term high intensity exercise on plasma lactate, potassium, sodium and chloride concentrations, five Thoroughbred horses were galloped on a treadmill at a 5 degree incline. Following a standardised warm-up period, they were galloped at 8, 10, or 12 metres/sec for 2 mins. One horse also galloped at 14 metres/sec for 1.5 mins. Sequential arterial and/or venous blood samples were collected during exercise and recovery. At 12 metres/sec, the effect of different recovery modes, ie, standing, walking or trotting, on the electrolytes was also examined. There was a progressive rise in plasma potassium concentration during galloping, with peak values occurring at the end of the exercise bout. In some cases, values above 10 mmol/litre were recorded at the highest workloads. Plasma lactate concentrations peaked during early recovery, with values up to 32 mmol/litre. A high correlation existed between peak potassium and lactate concentrations (venous r = 0.923, and arterial r = 0.989). Following exercise there was a rapid return to baseline plasma potassium concentrations, but by 12 mins recovery there was still an elevated lactate concentration, the extent depending on the intensity of the exercise bout and the recovery mode. There was a small rise in plasma sodium but no significant change in plasma chloride concentrations during exercise. However, when adjusted for the decrease in plasma volume, as determined from total plasma protein concentration, there was a decrease in circulating amounts of both electrolytes.     

Isoleucine requirement of broiler chicks as affected by the concentrations of leucine and valine in practical diets.

1. Chicks were fed on an isoleucine-deficient diet, with 6 added concentrations of isoleucine to determine their isoleucine requirement and an additional 6 treatments were devised to determine their isoleucine requirement when dietary leucine and valine contents were increased. 2. The diet deficient in isoleucine contained 5.6 g/kg isoleucine with leucine and valine contents of 20.1 and 10.3 g/kg, respectively. Supplementation with leucine and valine increased these to 24.7 and 12.6 g/kg, respectively. 3. The isoleucine requirement was not affected by dietary leucine and valine contents in a diet with 13.4 MJ of ME per kg. Analysis of variance and Least Significant Difference of means indicated an isoleucine requirement of 7.2 g/kg. Non-linear regression of the same data indicated an isoleucine requirement of 8.44 g/kg, based on weight gain, or 8.19 g/kg based on food efficiency. 4. Reasons for the failure to find an imbalancing effect of branched chain amino acids in practical diets are discussed.     

Bacterial endocarditis and inflammatory joint disease in the dog

The main clinical features of 12 cases of bacterial endocarditis were lameness, pyrexia, lethargy, anorexia and systolic cardiac murmurs. The lameness varied from generalised stiffness to an inability to stand and walk. Multiple joint involvement was typical. Two types of joint pathology were identified. A marked synovitis with granulation tissue sometimes covering the articular cartilage was present in some joints associated with the presence of bacterial organisms. Other joints proved sterile and showed a milder synovial pathology. In many dogs both an infective arthritis and a non-infective arthritis co-existed. Bilaterally symmetrical joint involvement was typical of the non-infective arthritis. The pathogenesis of the latter was likely to involve the deposition of circulating immune complexes (bacterial antigens, antibody and complement) in the synovium. The infective arthritis was presumed to be secondary to embolic disease, ie, the spread of infected emboli from the heart valve to the joints. Treatment was unsuccessful in all cases.     

Book review

Ethical, Ethological and Legal Aspects of Intensive Farm Animal Management, by E. von Loeper, G. Martin, J. Müller, A. Nabholz, G. van Putten, H. H. Sambraus, G. M. Teutsch, J. Troxler, B., Tschanz, 1987. 158 pp. illustrated. Birkhäuser Verlag, Basel. DM 59. ISBN 3 7643 1930 5.     

Adenohypophyseal receptors for LHRH, pituitary content of gonadotropins and plasma concentrations of LH in cyclic, pregnant and postpartum beef cows

Adenohypophyseal concentrations of LHRH receptors, pituitary content of LH and FSH, and plasma concentrations of LH were determined in thirty Hereford, Angus or Hereford-Angus heifers that were randomly assigned by breed and weight to five periods including day 3 of the estrous cycle (CY), pregnant day 120 (P120), 200 (P200), 275 (P275), or day 2 postpartum (PP). Jugular blood samples were collected at 10-min intervals for 8 hr from all cows. Within 2 hr after completion of blood sampling, animals were slaughtered and the pituitary gland frozen at −196 C. LH pulse frequency/8 hr was reduced (P<.05) during gestation (.5, .2, and 1.5 ± .5/8 hr, for P120, P200, and P275, respectively) and PP (.5 ± .5/8 hr) compared to CY (7.8 ± .5/8 hr). Frequency of LH pulses/8 hr was not different (P>.1) among P120, P200 or PP periods but was different (P<.05) between P200 and P275. There were no differences in LH pulse height (P>.1) among periods; however, pulse amplitude was greatest (P<.05) at P120 (1.3 ± .2 ng/ml) and lowest between P200 and PP (.6 to .8 ± .2 ng/ml). Baseline concentrations of plasma LH did not differ (P>.1) among P and PP periods (.3 ± .1 ng/ml), but were lower (P<.05) than in CY animals (.7 ± .1 ng/ml). Concentration of adenohypophyseal LHRH receptors was approximately two-fold greater (P<.05) at P120 (25.85 ± 2.2 fmol/mg) than at all other periods (9.5 to 14.9 ± 2.2 fmol/mg). Pituitary content of LH was greatest at P120 (1.56 ± .11 ug/mg) and lowest (P<.05) at P275 and PP (0.46 to 0.52 ± .11 ug/mg). Pituitary content of FSH was greatest (P<.05) in P (12.7 to 17.0 ± 1.4 ug/mg) and PP (18.3 ± 1.4 ug/mg) vs CY (5.0 ± 1.4 ug/mg) cows and increased from P120 to PP (P<.05). Results indicate that physiological changes occurring during gestation may have an effect on subsequent function of the adenohypophysis in beef cows.     

Host range of avian influenza virus in free-living birds

Isolation of avian influenza virus (AIV) has been reported from 12 orders and 88 species of free-living birds. Most isolations are reported from species in the orders Anseriformes and Charadriiformes and it is recognized that species in Anseriformes represent important reservoirs of AIV. Morbidity and mortality among free-living birds attributable to AIV infection are rare, but differences in prevalence of AIV occur within and between avian species. Seasonal variation has been reported from free-living and sentinel ducks with peak AIV infection occurring in late summer and early fall. Prevalence of AIV is age-related, with highest isolation rates reported from juvenile birds. Differences in susceptibility to AIV infection among species have been demonstrated under experimental conditions. The dynamics and epidemiology of species-related variation in populations of free-living birds require further study.     

Type 2 diabetes mellitus with pancreatic β cell dysfunction in 3 horses confirmed with minimal model analysis

Reasons for performing study: Type 2 diabetes mellitus (T2DM) is diagnosed rarely in equine practice although it may be under‐recognised. A greater awareness of the condition and therapeutic considerations would be to the benefit of such cases presenting in practice. More investigation into the pharmacological management of these cases is needed. Objectives: Three cases of diabetes mellitus were investigated using a specific test for insulin sensitivity and pancreatic β cell function in order to define accurately and characterise the existence of T2DM in all 3 subjects. Methods: The insulin‐modified frequently sampled i.v. glucose tolerance test was performed in each case and the data so obtained were subject to minimal model analysis of insulin‐glucose dynamics. Cases were then monitored following treatment using a combination of dietary modification, metformin, glibenclamide and pergolide. Results: Marked insulin resistance was identified in each case and, furthermore, severe pancreatic β cell dysfunction was present therefore classifying each case as end stage T2DM. Treatment was nevertheless associated with restoration of normoglycaemia in all cases. Conclusions: T2DM in horses may be more common than generally considered. In some cases individuals may respond to therapy aimed at restoring insulin sensitivity and pancreatic function. Drugs used in other species for the treatment of T2DM have not yet been adequately tested in horses. Potential relevance: T2DM should be considered as an important differential diagnosis in mature to elderly horses and ponies suffering from weight loss, polydipsia and polyuria. Clinicians should be encouraged to offer treatment and management advice when such cases are encountered.