Prevalence and significance of extracellular myelin‐like material in canine cerebrospinal fluid

Background: Myelin‐like material in canine cerebrospinal fluid (CSF) specimens has been attributed to demyelinating or myelomalacic conditions. In our experience, myelin‐like material is observed frequently, especially in lumbar samples, and in a variety of disease conditions. Objectives: The objective of this study was to determine if there are associations between the presence of myelin‐like material and CSF collection site, body weight, underlying disease, and patient outcome. Methods: Wright–Giemsa‐stained cytocentrifuged specimens of CSF from the cerebellomedullary cistern (n=51) and lumbar cistern (n=47) of 98 dogs with neurologic disease were evaluated retrospectively for the presence and amount of extracellular myelin‐like material. Results were compared based on collection site, body weight, type of neurologic disease, and outcome. Results: Myelin‐like material was observed in 20/98 (20%) samples and was more frequently observed in lumbar (17/47, 36%) than cerebellomedullary samples (3/51, 6%) (P=.0028). Samples from dogs <10 kg were more likely to contain myelin (14/36, 39%) compared with dogs ≥10 kg (5/60, 8%) (P=.0052). Larger amounts of myelin‐like material were observed in CSF from dogs with intervertebral disk disease compared with other diseases (P=.045). No association was found between myelin‐like material and outcome. Conclusion: The association of extracellular myelin‐like material in canine CSF samples with sampling site and body weight suggests it is more often an artifact of collection technique and anatomy rather than the result of neurologic disease. Myelin‐like material in CSF is not associated with a poorer prognosis.     

Longterm investigation in an Austrian dairy herd with low prevalence of paratuberculosis detection of antibodies in blood and milk

Paratuberculosis (Johne's disease), which is widely distributed throughout the world, is caused by Mycobacterium avium subspecies paratuberculosis (MAP). Diagnosis of subclinically infected cattle is challenging and is especially problematic in herds with low prevalence of MAP. The aim of this long-term study was the comparison of different diagnostic tests for MAP and specific antibodies in a herd with low prevalence of MAP. Three different commercially available serum-ELISA (Svanovir-ELISA, Svanova, Uppsala, Sweden; IDEXX-ELISA, IDEXX Laboratories, Maine, USA; Pourquier-ELISA, Institut Pourquier, Montpellier, France) and two milk ELISA (Svanovirm-ELISA Svanova, Uppsala, Sweden; Pourquier-ELISA, Institut Pourquier, Montpellier, France) were compared. Apart from these indirect diagnostic tests, two methods for the detection of the etiologic agent (bacteriologic culture and real-time PCR of faecal samples) were performed. In January 2005 the first and in April 2005 the second herd investigation of all animals older than 2 years (n=335) were carried out. Blood, milk and faecal samples were taken. From November 2005 until April 2006 follow up investigations were performed. For this purpose, blood-, milk- and faecal samples were monthly taken from 63 selected animals. The highest number of blood- and milk samples with a detectable antibody-level was found by the Svanovir-ELISA. There was a significant correlation between serum- and milk- Svanovir-ELISA results, whereas the agreement between ELISA and faecal culture/PCR was low. Significant correlations between Svanovir-serum-ELISA results and milk somatic cell counts could be registered. Moreover, there was significant agreement between IDEXX-serum-ELISA results with the age and number of lactations of the cows, as well as the mother's MAP-status.     

Repellent effects of the essential oil of Lavendula angustifolia against adults of Hyalomma marginatum rufipes

The repellent effects of the essential oil of Lavendula angustifolia on adults of Hyalomma marginatum rufipes was studied at concentrations of 5, 10 and 20% v/v. A suitable tick climbing bioassay based on the questing behaviour of ticks was used to test for repellency. High percentage repellency (range 70-100) was shown at all concentrations of the essential oil of L. angustifolia, although at 5% v/v it only persisted for the first 40 minutes compared with 120 minutes at other concentrations (10 and 20% v/v). The repellent strength of L. angustifolia compared well (P > 0.05) with that of DEET (N,N-diethyl-m-toluamide), a commercial reference repellent, for the 2-hour period of the study.     

A direct method for fatty acid methyl ester synthesis: application to wet meat tissues, oils, and feedstuffs

A simplified protocol to obtain fatty acid methyl esters (FAME) directly from fresh tissue, oils, or feedstuffs, without prior organic solvent extraction, is presented. With this protocol, FAME synthesis is conducted in the presence of up to 33% water. Wet tissues, or other samples, are permeabilized and hydrolyzed for 1.5 h at 55 degrees C in 1 N KOH in MeOH containing C13:0 as the internal standard. The KOH is neutralized, and the FFA are methylated by H(2)SO(4) catalysis for 1.5 h at 55 degrees C. Hexane is then added to the reaction tube, which is vortex-mixed and centrifuged. The hexane is pipetted into a gas chromatography vial for subsequent gas chromatography. All reactions are conducted in a single screw-cap Pyrex tube for convenience. The method meets many criteria for fatty acid analysis, including not isomerizing CLA or introducing fatty acid artifacts. It is applicable to fresh, frozen, or lyophilized tissue samples, in addition to oils, waxes, and feedstuffs. The method saves time and effort and is economical when compared with other methods. Its unique performance, including easy sample preparation, is achieved because water is included rather than eliminated in the FAME reaction mixtures.     

Influence of body condition and bovine somatotropin on estrous behavior, reproductive performance, and concentrations of serum somatotropin and plasma fatty acids in postpartum Brahman-influenced cows

Ninety-nine multiparous Brahman-influenced (1/4 to 3/8 Brahman) cows were managed to achieve low (BCS = 4.3 +/- 0.1; n = 50) or moderate (BCS = 6.1 +/- 0.1; n = 49) body condition (BC) to determine the influence of bovine somatotropin (bST) on estrous characteristics, reproductive performance, and concentrations of serum GH and plasma NEFA. Beginning 32 d postpartum, cows within each BC were assigned randomly to treatment with or without bST. Non-bST-treated cows received no treatment, and treated cows were administered bST (Posilac, 500 mg s.c.) on d -35, -21, and -7 before initiation of the breeding season. On d -7, all cows received an intravaginal, controlled internal drug-releasing (CIDR) device. On d 0 (initiation of the 70-d breeding season), the CIDR were removed and cows received prostaglandin F2alpha (PGF2alpha). Blood samples were collected from the median caudal vein of the cows at each bST treatment and at d -28 and 0. Estrous behavior was monitored by radiotelemetry during the first 30 d of the breeding season. Growth hormone was increased (P < 0.05) in low and moderate BC cows treated with bST. The percentage of cows detected in estrus during the first 30 d of the breeding season was decreased (P = 0.05) for low BC (64%) compared with moderate BC (82%) cows. The interval to first estrus tended (P = 0.07) to be shorter in low BC-bST-treated cows (3.7 +/- 1.9 d) than in moderate BC-bST-treated cows (9.6 +/- 1.8 d). During the first 30 d of the breeding season, cows in low BC had a decreased (P = 0.02) number of mounts received and increased (P = 0.001) quiescence between mounts compared with cows in moderate BC. The number of mounts received was reduced (P = 0.04) in bST-treated cows. More (P = 0.02) cows treated with bST became pregnant during the first 3 d of the breeding season compared with non-bST-treated cows. The cumulative first-service conception rate tended (P = 0.07) to be greater for bST-low BC cows than non-bST-treated cows in low or moderate BC. On d 0, NEFA were greater (P < 0.05) in bST-treated vs. non-bST-treated cows. Low BC and bST reduced the intensity of behavioral estrus in postpartum Brahman-influenced cows. However, bST increased the first-service conception rate during the first 30 d of breeding and pregnancy rates during the first 3 d of breeding in postpartum Brahman-influenced cows.     

Phase I study to determine the maximal tolerated dose and dose-limiting toxicities of orally administered idarubicin in dogs with lymphoma

Background

Idarubicin, a PO bioavailable anthracycline antibiotic‐class chemotherapeutic, could have substantial convenience advantages over currently available similar class agents in use that require IV delivery.

Objectives

The primary objective of this study was to determine the maximally tolerated dose (MTD), dose‐limiting toxicities (DLTs), and basic pharmacokinetic parameters of oral idarubicin exposure in dogs with lymphoma after a single oral dose. A secondary objective was to document preliminary antitumor efficacy in an expanded treatment cohort using the established MTD.

Animals

Client‐owned dogs with measurable lymphoma.

Methods

Dogs (n = 31) were enrolled in a prospective open label phase I study of oral idarubicin. By means of a 3 + 3 cohort design, dose escalations were made with 3 dogs per dose level, and the MTD was established based on the number of patients experiencing a DLT. Plasma concentrations of idarubicin and idarubicinol were determined by postdose sampling. Assessment of antitumor efficacy focused on evaluation of accessible, measurable lymph nodes and skin lesions by modified RECIST guidelines.

Results

The MTD in dogs > 15 kg body weight was 22 mg/m². Adverse hematologic events (neutropenia and thrombocytopenia) were the predominant DLT and generally correlated with higher plasma concentrations of idarubicin and idarubicinol.

Conclusions and Clinical Importance

PO administered idarubicin was generally well‐tolerated and had preliminary antitumor activity in dogs with lymphoma. Furthermore, the potential clinical advantage of a safe and efficacious oral anthracycline alternative supports further investigations of this agent in repeated‐dose, randomized clinical trials.