The terms asymptomatic and subclinical are the same in the veterinary lexicon: a critical analysis.

OBJECTIVE: The term asymptomatic and its antonyms symptomatic and symptom apply exclusively to humans. However, veterinarians commonly use these terms instead of subclinical and clinical. We examined the use of these terms to determine how, by whom, and in what context they are used. SAMPLE: Veterinary articles on PubMed. PROCEDURES: We searched PubMed for the terms asymptomatic, subclinical, and symptomatic within the title and abstract or as MeSH terms, restricting the search to veterinary (nonhuman) species, and downloaded and categorized each article based on species, topic, field of study, and presumed primary language of the authors. We noted whether the term appeared in the title or abstract or as a MeSH term and described the frequencies of use of these terms within each category. RESULTS: The term asymptomatic appeared in 2,248 entries, mostly in the title or abstract. The term symptomatic appeared in 956 entries, also mostly in the title or abstract. Non-English-speaking authors used asymptomatic but not symptomatic relatively more frequently in the past decade. Certain fields of study, or disease specialties, used the terms more frequently; conversely, other fields of study, or specific journals, avoided the terms. CLINICAL RELEVANCE: Authors of articles about animals use the term asymptomatic interchangeably with subclinical and symptomatic interchangeably with clinical. Distinct language cultures appear to exist within different veterinary fields. However, no ambiguity appears to exist with the use of these terms. Therefore, asymptomatic is the same as subclinical and symptomatic is the same as clinical in the veterinary lexicon. Both terms should be equally acceptable.

Association of oxidative stress with motor neuron disease in horses.

OBJECTIVE: To investigate the influence of oxidative stress in terms of antioxidant capacity and lipid peroxidation on the probability of motor neuron disease (MND) in horses. ANIMALS: 88 horses with MND (cases) and 49 controls. PROCEDURES: Blood samples were collected from all horses enrolled, and RBCs and plasma were harvested. Activity of the enzyme erythrocytic superoxide dismutase 1 (SOD1) was determined in the RBCs. Plasma concentrations of α-tocopherols and ß-carotenes and activity of glutathione peroxidase were also evaluated. Degree of lipid peroxidation was measured by determining plasma concentrations of lipid hydroperoxides. Differences were evaluated between horse groups. RESULTS: Cases had lower erythrocyte SOD1 activity than did controls, but the difference was not significant. On the other hand, plasma vitamin E concentrations differed significantly between groups, with the cases having lower concentrations. Neither plasma vitamin A concentration nor glutathione peroxidase activity differed between groups; however, cases had significantly higher concentrations of lipid hydroperoxides (18.53µM) than did controls (12.35µM). CONCLUSIONS AND CLINICAL RELEVANCE: Horses with MND differed from those without MND by having a lower plasma concentration of vitamin E and higher concentrations of lipid hydroperoxides. Results parallel the findings in humans with sporadic amyotrophic sclerosis and provide evidence supporting the involvement of oxidative stress in the 2 conditions.

Comparison of pregnancy diagnosis in dairy cattle by use of a commercial ELISA and palpation per rectum.

OBJECTIVE: To compare agreement between 2 pregnancy tests in dairy cattle. DESIGN: Evaluation study. ANIMALS: 976 and 507 cattle for phases 1 and 2, respectively. PROCEDURES: Blood samples were collected, and palpation per rectum (PPR) was performed on cattle. Blood samples for the pregnancy-specific protein B (PSPB) ELISA were sent by courier to a commercial laboratory with results returned later. Results of PPR were extracted from herd records. Statistical comparison of results was performed by use of a mixed linear model and N analysis. RESULTS: Of 571 cattle classified as pregnant by the PSPB ELISA in phase 1, 30 (5%) were nonpregnant by PPR. Mean +/- SE adjusted optical density (OD) of cattle classified pregnant by both tests was significantly higher (0.31 +/- 0.01), compared with the adjusted OD of cattle classified pregnant by the PSPB ELISA and nonpregnant by PPR (0.22 +/- 0.02). Of 255 cows classified pregnant by the PSPB ELISA in phase 2, 31 (12%) were nonpregnant by PPR. Mean +/- SE adjusted OD of cattle classified pregnant by both tests was significantly higher (0.26 +/- 0.01), compared with the adjusted OD of cattle classified pregnant by the PSPB ELISA and nonpregnant by PPR (0.21 +/- 0.01). The N value was 0.82 and 0.81 for phases 1 and 2, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Good agreement existed between the 2 tests, especially at longer intervals after insemination. Discrepant results appeared to be attributable to a nonviable fetus, embryonic loss, or fetal loss.

Cryptosporidium and dairy cattle in the Catskill/Delaware watershed: a quantitative risk assessment.

We carried out a study to estimate the public health risk posed by dairy cattle located in New York City's Catskill/Delaware watershed, as measured by daily C. parvum-like oocyst loading. A Monte Carlo simulation model that takes into account the nature of the dairy cattle population within the target area, age-specific incidence/prevalence rates, as well as differential fecal production and oocyst-shedding intensity rates was used to address the objectives. Additionally, the model was designed to distinguish between zoonotic and nonzoonotic species/genotypes of Cryptosporidium. Total estimated daily C. parvum-like oocyst shedding across all age/production categories was estimated at 4.15 x 10(10). The zoonotic C. parvum comprised 93.5% of this load. It was estimated that preweaned calves produce 99.5% of the total daily C. parvum ocyst burden. The recently described nonzoonotic C. bovis was estimated to have a daily load of 2.2 x 10(9) oocysts across all age/production strata. C. parvum deer-like genotype was estimated to have a total daily load of 1.3 x 10(9) oocysts. The results of this study support earlier assertions that strategies aimed at reducing the cryptosporidial risk posed by dairy cattle to public health will be most efficacious if aimed at preweaned calves.