Oxygen-18 variations in sulfate ions in sea water and saline lakes

A new method measures the oxygen-isotopic composition of dissolved sulfate ions and barium sulfate. Sulfate ions in the oceans are enriched in oxygen-18 by 9.5 per mille relative to mean ocean water and show only minor variations, probably because the exchange rate with water is slow enough to prevent local equilibrium with surface waters. Sulfate ions in saline lakes and brines have oxygen-18 enrichment of from 7 to 23 per mille relative to mean ocean water;the value of the highest enrichment observed is about the same as that of atmospheric oxygen.     

Electroencephalographic Responses to a Noxious Surgical Stimulus in Mules,Horses, and Ponies

The aim of this study was to investigate the electroencephalographic (EEG) response of equidae to a castration stimulus. Study 1 included 11 mules (2½–8 years; 230–315 kg) and 11 horses (1½–3½ years; 315–480 kg); study 2 included four ponies (15–17 months; 176–229 kg). They were castrated under halothane anesthesia after acepromazine premedication (IV [study 1] and intramuscular [study 2]) and thiopental anesthetic induction. Animals were castrated using a semiclosed technique (study 1) and a closed technique (study 2). Raw EEG data were analyzed and the EEG variables, median frequency (F50), total power (Ptot), and spectral edge frequency (F95), were derived using standard techniques at skin incision (skin) and emasculation (emasc) time points. Baseline values of F50, Ptot, and F95 for each animal were used to calculate percentage change from baseline at skin incision and emasculation. Differences were observed in Ptot and F50 data between hemispheres in horses but not mules (study 1) and in one pony (study 2). A response to castration (>10% change relative to baseline) was observed in eight horses (73% of animals) and four mules (36% of animals) for F50 and nine horses (82%) and four mules (36%) for Ptot. No changes in F95 data were observed in any animal in study 1. Responses to castration were observed in three ponies (75% of animals) for F50, one pony (25%) for F95, and all ponies for Ptot. Alteration of acepromazine administration and castration technique produced a protocol that identified changes in EEG frequency and power in response to castration.     

ULTRASONOGRAPHIC EVALUATION OF BILIARY CYSTADENOMAS IN CATS

The purpose of this study was to describe the ultrasonographic appearance of biliary cystadenomas in cats and compare the findings to a similar rare form of liver tumor in humans. Biliary cystadenomas are uncommon, benign liver tumors of older cats that may occur as focal or multifocal cystic lesions within the liver. The records of 10 cats which had abdominal ultrasonography and histologic diagnosis of biliary cystadenoma were reviewed. The average age of affected cats was 13.3 years (range 10-16 years). Eight cats were neutered males and two were neutered females. In three cats, the tumors were not seen ultrasonographically due to their small size or from being obscured by near-field reverberation echoes. The remaining seven cats had solitary (4 cats) or multifocal (3 cats) masses corresponding to variable ultrasonographic patterns: multilocular masses containing thin-walled cysts, hyperechoic masses with cystic components, or masses of mixed echogenicity with cystic components. The masses had variable ultrasonographic patterns when multifocal disease was present. Recognizable cysts were evident somewhere within the tumors seen ultrasonographically, although sometimes the cysts appeared very small. The biliary cystadenomas were thought to be clinically silent. Although liver enlargement or a cranial abdominal mass was palpable in 4 cats, no consistent trend of clinical signs, CBC or serum biochemical abnormalities could be directly attributed to biliary cystadenoma. The treatment of choice is surgical resection of the tumor, as continued growth may compress adjacent vital structures within the liver. The differential diagnosis of biliary cystadenomas from other cystic liver lesions such as hepatic cysts, hematomas, abscesses, parasitic cysts, or other liver tumors is discussed.     

IMAGING DIAGNOSIS—A CASE OF SPONTANEOUS HEPATIC PORTAL VEIN GAS IN AN 11‐MONTH‐OLD WEST HIGHLAND WHITE TERRIER

An 11‐month‐old female entire West Highland White Terrier presented for chronic diarrhea with acute deterioration in demeanor and progression to systemic inflammatory response syndrome. Transcutaneous abdominal ultrasonography identified colonic ulceration and secondary mucosal gas. Suspected hepatic portal vein gas and hepatic parenchyma gas were also visualized. The patient was stabilized and managed for ulcerative colitis. Based on endoscopic biopsies, the dog was diagnosed with severe, chronic, pyogranulomatous colitis. On repeat ultrasonographic evaluation the portal vein and hepatic gas had resolved but the patient deteriorated and was ultimately euthanized due to sepsis.     

Modern veterinary vaccines and the Shaman's apprentice

This paper is an overview and assessment of new, commercially available veterinary vaccines placed in a historical context. The authors critically evaluate the current state of the field of veterinary vaccines in both food and companion animals and the promises for future vaccine development. The authors maintain that there is considerable variability in safety and sustained efficacy among veterinary vaccines, especially those developed for companion animals. It is proposed that establishment of an international vaccine advisory committee be supported which would function to apprise the veterinary profession of the current status of vaccines and their use.     

Cattle-level risk factors associated with fecal shedding of Shiga toxin-encoding bacteria on dairy farms, Minnesota, USA

The objective of this study was to identify individual cattle-level risk factors associated with fecal shedding of Shiga toxin-encoding bacteria (STB), a surrogate for Shiga toxin-producing E. coli (STEC), on 28 organic and conventional dairy farms. It was found that small organic herds (fewer than 100 cows) were associated with higher odds of Shiga toxin-encoding bacteria (STB) shedding from 2 (all cattle and all cows) of 3 cattle models, followed by small conventional herds, compared with large conventional herds. Preweaned calves [odds ratio (OR) = 2.6, 95% confidence interval (CI): 1.2, 5.7] had higher odds of shedding STB compared with adult cows. Calves more than 28 days of age (OR = 2.0, 95%CI: 1.0, 4.4) were more likely to shed STB than calves less than 28 days of age. This information may be helpful for identifying potential control strategies such as targeted vaccination or management practices.     

Pathogenesis of a Texas feline immunodeficiency virus isolate: an emerging subtype of clade B

We have recently provided evidence that Texas feline immunodeficiency virus (FIV-TX) isolates are an emerging subtype sharing a common ancestry with clade B isolates. Specific, pathogen-free cats were infected, intravenously, with 500, 2000 or 8000TCID(50) of the FIV-TX53 virus to study the acute stage of infection. Infection of cats resulted in lymphadenopathy at 10 days post-infection (p.i.). By 7 weeks p.i., gag specific antibody could be detected from sera of all infected cats. Virus could be detected by culturing PBMC and by nested capsid PCR. A reduction in the absolute numbers of lymphocytes and neutrophils was observed in infected cats although there was no trend identified between this reduction and the viral dose administered. By 11 weeks p.i., the CD4(+)/CD8(+) T cell ratios from all infected cats had dropped from approximately 2 to below 1. While decrease in the ratio was dependent on the viral dose, the T cell ratios of cats receiving the highest dose had significantly dropped below 1 by 4-7 weeks p.i. This decrease in the ratio was accompanied by a sharp and temporal decline in the absolute CD4(+) T cells and a slight increase in the absolute CD8(+) T cell numbers with a dramatic expansion of cells with CD8beta(low) chain expression.     

Effects of time, initial composition, and stabilizing agents on the results of canine cerebrospinal fluid analysis

BACKGROUND: Cerebrospinal fluid (CSF) is considered highly labile, but not all samples are analyzed immediately. Changes in the composition of CSF could potentially affect diagnostic test results and thus influence decisions about patient management. There has been little scientific inquiry into how variables such as time, initial composition, and storage conditions affect results of standard laboratory analysis of CSF. OBJECTIVES: The objectives of this study were to determine the effects of time, protein concentration, and presence or absence of exogenous stabilizing agents on standard CSF analysis results. METHODS: Thirty abnormal CSF samples from 26 dogs were evaluated. Samples were divided into aliquots comprising different treatment groups and stored at 4 degrees C. Total nucleated cell count (TNCC), differential cell count (DCC), and cell morphology were evaluated for all groups; protein concentration was measured for selected groups. Unaltered aliquots were analyzed immediately (T0Hr) and at 2, 4, 8, 12, 24, and 48 hours (T2Hr-T48Hr); aliquots with added fetal calf serum (FCS) or hydroxyethyl starch (hetastarch) were analyzed at T48Hr. RESULTS: Significant time-dependent changes were observed in DCC in unaltered samples. Mononuclear cells deteriorated more rapidly than did neutrophils. Based on microscopic examination and subjective scoring of cell morphology, cells were consistently more degenerate by T24Hr compared with T0Hr. Samples with protein concentrations > or =50 mg/dL were less susceptible to cell deterioration than those with lower protein concentrations. Adding either FCS or hetastarch improved sample stability. CONCLUSIONS: Delayed analysis of canine CSF by 4-8 hours is unlikely to alter diagnostic interpretation, especially for samples with protein concentrations > or =50 mg/dL. The likelihood of misinterpretation is higher for samples with low cellularity or low protein concentration. We provide specific recommendations for adding FCS or hetastarch to samples that will not be analyzed within 1 hour.     

Acaricidal efficacy against cattle ticks and acute oral toxicity of Lippia javanica (Burm F.) Spreng

Tropical Animal Health and Production - In search for low-cost, safe and environmentally benign plant-based alternatives to commercial pesticides, the efficacy of Lippia javanica aqueous leaf...