Age-related variations in hematologic and plasma biochemical test results in Beagles and Labrador Retrievers

OBJECTIVE: To investigate age-related variations in results of hematologic and plasma biochemical tests performed on dogs of 2 common breeds. DESIGN: Prospective cohort study. ANIMALS: 34 Beagles and 44 Labrador Retrievers. PROCEDURE: Blood samples were collected throughout the dogs' lives; 589 samples were collected from the Beagles and 964 samples were collected from the Labrador Retrievers (age at the time of sample collection ranged from 22 days to 15 years). White blood cell and RBC counts; hemoglobin concentration; Hct; mean cell volume; mean cell hemoglobin concentration; alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase activities; and calcium, phosphorus, cholesterol, urea, protein, and albumin concentrations were measured. RESULTS: For all tests, there were significant effects of age on test results. There was a significant interaction between age and breed for all tests except hemoglobin, albumin, and phosphorus concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that there were age-related changes in hematologic and plasma biochemical test results in these 2 breeds of dogs. Changes were most evident during the first year of life, reflecting growth and maturation of the puppies. In some instances, values for puppies diverged markedly from those for adults, necessitating the use of age-specific reference ranges for the interpretation of clinical data.     

An adenovirus linked to mortality and disease in long-tailed ducks (Clangula hyemalis) in Alaska

An adenovirus was isolated from intestinal samples of two long-tailed ducks (Clangula hyemalis) collected during a die-off in the Beaufort Sea off the north coast of Alaska in 2000. The virus was not neutralized by reference antiserum against known group I, II, or III avian adenoviruses and may represent a new serotype. The prevalence of the virus was determined in live-trapped long-tailed ducks at the mortality site and at a reference site 100 km away where no mortality was observed. Prevalence of adenovirus antibodies in serum samples at the mortality site was 86% compared to 10% at the reference site. Furthermore, 50% of cloacal swabs collected at the mortality site and only 7% of swabs from the reference site were positive for adenoviruses. In 2001, no mortality was observed at either of the study areas, and virus prevalence in both serum and cloacal samples was low, providing further evidence that the adenovirus was linked to the mortality event in 2000. The virus was used to infect long-tailed ducks under experimental conditions and resulted in lesions previously described for avian adenovirus infections and similar to those observed in long-tailed duck carcasses from the Beaufort Sea. The status of long-tailed ducks has recently become a concern in Alaska due to precipitous declines in breeding populations there since the mid-1970s. Our findings suggest that the newly isolated adenovirus is a disease agent and source of mortality in long-tailed ducks, and thus could be a contributing factor in population declines.     

Medical management of biological warfare and bioterrorism: place of the immunoprevention and the immunotherapy

Biological weapons are considered as mass destruction and terror weapons. Terrorism including bioterrorism is the major threat in the future conflicts for our nations. The aim of bioterrorism is more related to the potential disorganisation of the society than to the lethal effects of the agents used. The dramatic consequences cannot be discarded, especially if contagious agents such viral are used. The preparation of specific defence measures is a major challenge for our countries.

The knowledge acquired from the struggle against natural infectious diseases and recent events are essential to improve behaviours to face the biological weapon threats. The defence attitude is based on the anticipation of the threat, the management of the victims, and the restoration of the operational capabilities. This global defence attitude implies six important functions: (i) alert, (ii) detection and diagnosis, (iii) availability of pharmaceutical countermeasures such as vaccine, sera and anti-infectious medicine and products, (iv) medical management of victims, (v) training and information, (vi) research and development.

Passive and active immunoprevention and immuntherapy belong to the approaches discussed in the context of bioterrorism countermeasures. Further researches might be focused on these topics.     

A survey for BVDV antibodies in cattle farms in Slovakia and genetic typing of BVDV isolates from imported animals

A serological survey for bovine viral diarrhoea virus (BVDV) antibodies on a collection of 1295 serum samples obtained from 6-12 months old cattle originating from 45 farms in Slovakia was carried out. On 13 farms more than 90% of the examined animals were seropositive, on 14 farms 71-90% seroprevalence was observed, on 13 farms only 50-70% animals were found to be positive for BVDV antibodies, while the remaining 5 farms showed fewer than 50% seropositive animals. The average incidence of BVDV antibodies (around 70%) was similar as determined 30 years ago. Of 84 serum samples from seronegative animals originating from 14 farms in which 70-98% seropositivity was observed, six were positive in Ag-BVDV ELISA indicating persistently infected (PI) cattle. On a farm to which animals were imported from abroad, a BVD outbreak was observed. Of 110 animals tested, four were positive in Ag-ELISA indicating the presence of PI cattle on this farm. Genetic typing of two isolates from imported animals performed by RT-PCR (324/326 primers from 5'-UTR), sequencing of PCR products and computer-assisted phylogenetic analysis revealed that they belong to BVDV-1 h group.     

Liquid chromatography-mass spectrometry (LC-MS) investigation of the thiobarbituric acid reactive substances (TBARS) reaction

The thiobarbituric acid reactive substances (TBARS) assay is a commonly used method for the detection of lipid peroxidation. Malondialdehyde is formed as a result of lipid peroxidation and reacts with thiobarbituric acid to form a pink pigment that has an absorption maximum at 532 nm. Other compounds also react with thiobarbituric acid to form colored species that can interfere with this assay, but little is known about these interfering species. This is the first investigation using LC-MS and MS-MS to study the structures of the pink adduct as well as a common unstable yellow interference compound, which absorbs at 455 nm. Also, the presence of barbituric acid impurities in the thiobarbituric acid reagent was found to produce 1:1:1 thiobarbituric acid/malondialdehyde/barbituric acid and 2:1 barbituric acid/malondialdehyde adducts that absorbed at 513 and 490 nm, respectively, indicating that thiobarbituric acid should be purified before use.     

Time-dependent changes in plasma concentrations of 3-methylindole and blood concentrations of 3-methyleneindolenine-adduct in feedlot cattle

OBJECTIVE: To describe time-dependent changes in plasma concentrations of 3-methylindole (3MI) and blood concentrations of 3-methyleneindolenine (3MEIN)-adduct in feedlot cattle. ANIMALS: 64 yearling steers. PROCEDURES: Steers were assigned to 2 groups (32 steers/group). During the first 8 weeks, blood samples were collected from group 1 before the morning ration was fed, whereas samples from group 2 were collected 2 to 3 hours after the ration was fed. Blood samples were collected from all steers approximately 4 times/wk for 3 weeks and 3 times/wk for the subsequent 5 weeks. Samples were collected at the same time for all steers for an additional 10 weeks. Plasma samples were analyzed for 3MI concentrations. Blood samples collected from cattle in group 2 during the first 8 weeks were analyzed for 3MEIN-adduct concentrations. RESULTS: Mean blood concentration of 3MEIN-adduct increased to a maximum value on day 33 (0.80 U/microg of protein) and then decreased to a minimum on day 54 0.40 U/microg of protein). Plasma 3MI concentrations initially decreased and remained low until after day 54. Group-1 cattle had lower plasma 3MI concentrations, compared with concentrations for group-2 cattle. Blood 3MEIN-adduct concentrations and plasma 3MI concentrations were not associated with deleterious effects on weight gains. CONCLUSIONS AND CLINICAL RELEVANCE: Blood 3MEIN-adduct concentrations peaked during the period of greatest risk for development of bovine respiratory disease complex. Conversely, plasma 3MI concentrations decreased during the same period. Animal-to-animal variation in metabolic capacity to convert 3MI to 3MEIN may be of more importance than differences in plasma 3MI concentration.     

Potentially hazardous sulfur conditions on beef cattle ranches in the United States

OBJECTIVE: To analyze the sulfur content of water and forage samples from a geographically diverse sample of beef cow-calf operations in the United States and to estimate frequency and distribution of premises where forage and water resources could result in consumption of hazardous amounts of sulfur by cattle. DESIGN: Cross-sectional study. SAMPLE POPULATION: 709 forage samples from 678 beef cow-calf operations and individual water samples from 498 operations in 23 states. PROCEDURE: Sulfur content of forage samples and sulfate concentration of water samples were measured. Total sulfur intake was estimated for pairs of forage and water samples. RESULTS: Total sulfur intake was estimated for 454 pairs of forage and water samples. In general, highest forage sulfur contents did not coincide with highest water sulfate concentrations. Overall, 52 of the 454 (11.5%) sample pairs were estimated to yield total sulfur intake (as a percentage of dry matter) > or = 0.4%, assuming water intake during conditions of high ambient temperature. Most of these premises were in north-central (n = 19) or western (19) states. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that on numerous beef cow-calf operations throughout the United States, consumption of forage and water could result in excessively high sulfur intake. All water sources and dietary components should be evaluated when assessing total sulfur intake. Knowledge of total sulfur intake may be useful in reducing the risk of sulfur-associated health and performance problems in beef cattle.     

Effect of background serum lithium concentrations on the accuracy of lithium dilution cardiac output determination in dogs

OBJECTIVES: To assess the effect of increasing serum lithium concentrations on lithium dilution cardiac output (LiDCO) determination and to determine the ability to predict the serum lithium concentration from the cumulative lithium chloride dosage. ANIMALS: 10 dogs (7 males, 3 females). PROCEDURE: Cardiac output (CO) was determined in anesthetized dogs by measuring LiDCO and thermodilution cardiac output (TDCO). The effect of the serum lithium concentration on LiDCO was assessed by observing the agreement between TDCO and LiDCO at various serum lithium concentrations. Also, cumulative lithium chloride dosage was compared with the corresponding serum lithium concentrations. RESULTS: 44 paired observations were used. The linear regression analysis for the effect of the serum lithium concentration on the agreement between TDCO and LiDCO revealed a slope of -1.530 (95% confidence interval [CI], -2.388 to -0.671) and a y-intercept of 0.011 (r2 = 0.235). The linear regression analysis for the effect of the cumulative lithium chloride dosage on the serum lithium concentration revealed a slope of 2.291 (95% CI, 2.153 to 2.429) and a y-intercept of 0.008 (r2 = 0.969). CONCLUSIONS AND CLINICAL RELEVANCE: The LiDCO measurement increased slightly as the serum lithium concentration increased. This error was not clinically relevant and was minimal at a serum lithium concentration of 0.1 mmol/L and modest at a concentration of 0.4 mmol/L. The serum lithium concentration can be reliably predicted from the cumulative lithium dosage if lithium chloride is administered often within a short period.