Evaluation of jitter by stimulated single-fiber electromyography in normal dogs

Single-fiber electromyography (SFEMG), a technique used to investigate neuromuscular transmission, has been described previously in the pelvic limb of dogs. Because preferential involvement of isolated muscle groups can occur in disorders of neuromuscular transmission, SFEMG was done in the peroneus longus (PL), extensor carpi radialis (ECR), and orbicularis oculi (OO) muscles of 10 adult, clinically normal dogs. Jitter was calculated as the mean absolute value of the consecutive differences in latency of 50 single muscle fiber action potentials after stimulation of intramuscular nerve bundles at the level of the motor point in at least 20 muscle fibers per muscle. Bilateral recordings were performed in 3 dogs. Mean jitter values were determined for each muscle, and differences among muscle groups and among dogs were compared. The upper limits of mean consecutive difference (mean plus 3 standard deviations) for the PL, ECR, and OO muscles were 21.94, 22.53, and 23.39 micros, respectively, and the upper limit of mean consecutive difference for individual muscle fibers in the respective fiber pools was 28.62, 36.39, and 35.68 micros. Jitter values for the ECR and OO were significantly higher than the jitter value for the PL muscle (P < .05). Significant differences among muscles or dogs or between sides were not observed for the ECR. Significant differences among dogs were observed for OO jitter values and were attributed to extremely low jitter values in 1 dog. Significant differences were demonstrated between sides for the PL and were attributed to small sample size. Results of this study provide normative data that can be used in the application of the stimulated SFEMG technique to dogs with suspected disorders of neuromuscular transmission.     

A scabby mouth-like condition in Saanen goat kids

Extract

Madam;—In December of last year we encountered a condition in Saanen goat kids which closely resembled scabby mouth.     

Single vaccination provides limited protection to ducks and geese against H5N1 high pathogenicity avian influenza virus

Since 2002, high pathogenicity avian influenza (HPAI) has spread from Asia to Europe and into Africa, causing the largest epizootic of HPAI of the last 50 yr, including infecting domestic and wild waterfowl. Our study was conducted to investigate whether a single vaccination of 7-day-old domestic ducks and geese with inactivated oil emulsion vaccines resulted in protection against HPAI virus challenge at 30 days of age. In ducks, some but not all vaccines decreased oropharyngeal and cloacal viral shedding for different periods postchallenge when compared with the sham group. In geese, decreased morbidity signs and mortality were noted but limited to some vaccines. Best protection was seen with a vaccine homologous to HPAI challenge virus. Limited decreases in oropharyngeal and cloacal viral shedding and mixed results were attained when looking at seroconversion. Our results indicate a single dose of oil-emulsified vaccine optimized for chickens did not provide adequate protection for ducks and geese against HPAI virus, and, at a minimum, additional research is needed to formulate waterfowl-specific vaccines.     

Successful drug development despite adverse preclinical findings part 1: processes to address issues and most important findings

Unexpected adverse preclinical findings (APFs) are not infrequently encountered during drug development. Such APFs can be functional disturbances such as QT prolongation, morphological toxicity or carcinogenicity. The latter is of particular concern in conjunction with equivocal genotoxicity results. The toxicologic pathologist plays an important role in recognizing these effects, in helping to characterize them, to evaluate their risk for man, and in proposing measures to mitigate the risk particularly in early clinical trials. A careful scientific evaluation is crucial while termination of the development of a potentially useful drug must be avoided. This first part of the review discusses processes to address unexpected APFs and provides an overview over typical APFs in particular classes of drugs. If the mode of action (MoA) by which a drug candidate produces an APF is known, this supports evaluation of its relevance for humans. Tailor-made mechanistic studies, when needed, must be planned carefully to test one or several hypotheses regarding the potential MoA and to provide further data for risk evaluation. Safety considerations are based on exposure at no-observed-adverse-effect levels (NOAEL) of the most sensitive and relevant animal species and guide dose escalation in clinical trials. The availability of early markers of toxicity for monitoring of humans adds further safety to clinical studies. Risk evaluation is concluded by a weight of evidence analysis (WoE) with an array of parameters including drug use, medical need and alternatives on the market. In the second part of this review relevant examples of APFs will be discussed in more detail.     

Bilateral hydronephrosis secondary to endometriosis managed by endoscopic ureteral stent placement in a captive Guinea baboon (Papio papio)

Spontaneous endometriosis is an estrogen-dependent, progressive and painful disease that affects a variety of nonhuman primates, including several species of baboons (Papio sp.). This case documents multimodal management of severe endometriosis in a captive female baboon within a zoological institution. An 18-yr-old, intact female Guinea baboon (Papio papio) was found to have an enlarged uterus. Fifteen months post ovariohysterctomy, scarring associated with endometrial tissue resulted in ureteral strictures, bilateral hydronephrosis, and azotemia. Cystoscopic placement of bilateral ureteral stents with fluoroscopy was performed and resulted in short-term clinical improvement. The animal's condition declined and euthanasia was elected 4 mo after ureteral stent placement. Severe endometriosis with secondary inflammation resulting in bilateral hydroureter and hydronephrosis, as well as concurrent cystitis, ureteritis, and pyelonephritis were confirmed at necropsy. Despite possible complications, ureteral stents can be considered a useful therapeutic option in patients with ureteral disease.     

Seroprevalence of bovine viral diarrhea virus neutralizing antibodies in finisher hogs in Ontario swine herds and targeted diagnostic testing of 2 suspect herds

A pilot study was initiated to determine the seroprevalence of bovine viral diarrhea virus (BVDV) neutralizing antibodies in finisher hogs in Ontario swine herds, including 2 swine herds with clinical syndromes suspicious of BVDV. No herds were positive for BVDV antibodies by virus neutralization. The 2 swine herds with clinical disease suggestive of pestivirus infection were also negative for antibodies to BVDV in indirect fluorescent antibody assays. Prevalence of BVDV in Ontario swine farms is negligible.