International recommendations for training future toxicologic pathologists participating in regulatory-type, nonclinical toxicity studies

The International Federation of Societies of Toxicologic Pathologists (IFSTP) proposes a common global framework for training future toxicologic pathologists who will support regulatory-type nonclinical toxicology studies. Trainees optimally should undertake a scientific curriculum of at least 5 years at an accredited institution leading to a clinical degree (veterinary medicine or medicine). Trainees should then obtain 4 or more years of intensive pathology practice during a residency and/or on-the-job "apprenticeship," at least 2 years of which must be focused on regulatory-type toxicologic pathology topics. Possession of a recognized pathology qualification (i.e., certification) is highly recommended. A non-clinical pathway (e.g., a graduate degree in medical biology or pathology) may be possible if medically trained pathologists are scarce, but this option is not optimal. Regular, lifelong continuing education (peer review of nonclinical studies, professional meetings, reading, short courses) will be necessary to maintain and enhance one's understanding of current toxicologic pathology knowledge, skills, and tools. This framework should provide a rigorous yet flexible way to reliably train future toxicologic pathologists to generate, interpret, integrate, and communicate data in regulatory-type, nonclinical toxicology studies.     

Chondrosarcoma arising in a multilobular chondroma in a cat

A large mass firmly attached to bone was found on the skull in an adult, male cat. A diagnosis of chondrosarcoma arising in a multilobular chondroma was made from a biopsy specimen and confirmed at necropsy.     

Improved Prediction of Ovulation Time may Increase Pregnancy Rates to Artificial Insemination in Lactating Dairy Cattle

A prospective observational study was conducted in two Australian dairy herds to assess the potential for improving pregnancy rates (proportions of inseminations that result in pregnancy) to artificial insemination (AI) if the time of ovulation could be predicted with more certainty. Herd 1 calved year‐round and inseminations were performed during two periods each day. Herd 2 calved during autumn–winter and inseminations were performed only after the morning milking each day. In both herds, the AI to ovulation interval of enrolled cows was determined by trans‐rectal ovarian ultrasonography approximately 0, 12, 24 and 36 h after AI, and pregnancy was assessed by palpation per rectum 35–56 days after AI. Also, in Herd 1 vaginal electrical resistance (VER) measurements were taken at approximately 0, 12, 24 and 36 h after AI, and in Herd 2 cows were fitted with neck mounted activity meters that monitored cow activity count in 2‐h periods. There was substantial variation in the intervals from AI to ovulation within and between herds (mean ± SD 21.2 ± 10.7, n = 102; 14.7 ± 10.4, n = 100 in herds 1 and 2, respectively). Pregnancy rates were higher for inseminations close to, but preceding, ovulation. Using combined herd data (n = 202), the highest pregnancy rate (50.8%) was observed for inseminations between 0 and 16 h before ovulation, a period in which only a modest proportion of inseminations (31.2%) occurred. In contrast, pregnancy rate was significantly lower (28.7%; risk ratio 0.6; 95% CI 0.4–1.0; p = 0.039) for inseminations between 16 and 32 h before ovulation, a period where the highest proportion of inseminations (53.2%) occurred. Thus pregnancy rates could potentially be improved if a greater proportion of inseminations were conducted shortly before ovulation. In Herd 1, mean VER during the peri‐ovulatory period varied with time from ovulation. Lowest values (mean ± SEM, VER = 64.8 ± 1.2, n = 55) occurred approximately 18 h before ovulation and were significantly lower than measurements approximately 6 h before ovulation (67.4 ± 1.0; n = 73; p = 0.003). Further work is required to determine if VER can be used to identify ovulation time and hence the optimal time to inseminate in individual animals. In Herd 2 a modest proportion of inseminations (26.9%) occurred between 24 and 40 h after the onset of increased cow activity where the highest pregnancy rate (67.9%) was observed, whereas a significantly lower pregnancy rate (42.4%; risk ratio 0.6; 95% CI 0.4–0.9; p = 0.036) was observed for inseminations between 8 and 24 h after the onset of increased cow activity where the highest proportion of inseminations (56.7%) occurred. Thus cow activity monitoring may be useful to identify the optimal time to inseminate cows. Results from this study indicate that improved methods of ovulation prediction may allow better insemination timing relative to ovulation and consequently increased pregnancy rates.     

Insulinoma in a ferret

Insulinoma was diagnosed in a 7-year-old female ferret examined because of generalized seizures, intermittent paraplegia, and abnormal behavior. Low serum glucose, high serum insulin, and infinite amended insulin/glucose ratio values in this ferret supported the clinical diagnosis of insulinoma. Histologic examination of the pancreas confirmed the diagnosis of insulinoma. The clinical signs and laboratory evaluations in this case and in a previously reported case of insulinoma in a ferret were consistent with variations reported in dogs with insulinoma.     

Effects of challenge dose on the clinical and immune responses of cattle vaccinated with reduced doses of Brucella abortus strain 19

Fifty-seven pregnant beef heifers that were unvaccinated or previously vaccinated with Brucella abortus S19, at a dose of either 10⁹ or 10¹⁰ colony-forming units (CFU), were challenge-exposed intraconjunctivally with virulent B. abortus S2308 at a dose of 9.4 × 10⁶ CFU (Experiment 1) or 5.2 × 10⁷ CFU (Experiment 2). In Experiment 1, S19 afforded significant protection (P < 0.01) against challenge exposure in that 8 of 9 unvaccinated heifers, 1 of 11 vaccinated with 10⁹ CFU, and 3 of 10 vaccinated with 10¹⁰ CFU aborted or delivered weak, non-viable calves. In Experiment 2, vaccination did not afford significant protection (P> 0.05) in that 9 of 9 unvaccinated heifers, 8 of 10 vaccinated with 10⁹ CFU, and 8 of 8 vaccinated with 10¹⁰ CFU aborted. Serologic responses to B. abortus were determined by three standard tests, as well as a quantitative fluorometric immunoassay (FIAX) and an enzyme-linked immunosorbent assay. In Experiment 1, the early serologic response, 0–8 weeks after challenge, appeared greater for controls than for vaccinates, but in Experiment 2, the early response, 0–6 weeks after challenge exposure, appeared greater for vaccinates than for controls. The lymphocyte blast transformation assay, using heat-killed B. abortus as an antigen, was performed sequentially after challenge exposure. In general, mean responses were significantly higher (P < 0.05) for vaccinated than for non-vaccinated heifers. For individual heifers, an association could not be established between the lymphocyte blast transformation assay and the clinical response to challenge exposure.     

Occurrence and distribution of Raspberry bushy dwarf virus in commercial Rubus plantations in England and Wales

Serological surveys for Raspberry bushy dwarf virus (RBDV) made between 1995 and 1997 and covering ≈ 10% of the commercial farms growing Rubus (red raspberry and hybrid berries) in England and Wales showed that this virus was present on approximately one-quarter of all farms and in approximately one-sixth of all plots tested. RBDV was found in all of the four main raspberry cultivars being grown at that time (Autumn Bliss, Glen Moy, Glen Prosen and Leo), in Loganberry and in Tayberry. Fifteen RBDV genotypes (including two that appeared to be mixed) were identified using RT-PCR/RFLPs, but the majority of genotypes were found only rarely. Of the RBDV isolates tested, two genotypes each comprised 12·5% and another 46·4%. None of the three most common genotypes was associated solely with single Rubus cultivars and vice versa . It is suggested that two separate outbreaks of RBDV are occurring in England and Wales. One outbreak comprises the most frequent genotype combined with one of the moderately frequent genotypes; this outbreak is largely confined to the main growing areas and is either spreading between farms or coming from multiple local sources. Circumstantial evidence suggests that these isolates (and hence this first outbreak) are of the RB pathotype. The second outbreak consists of the other moderately frequent genotype and those genotypes which are less common. These genotypes appear to be more scattered across England and Wales and seem more likely to be coming from local sources and not to be spreading naturally between commercial farms.