Pharmacokinetics of tulathromycin in fetal sheep and pregnant ewes

Macrolides are important antimicrobials frequently used in human and veterinary medicine in the treatment of pregnant women and pregnant livestock. They may be useful for the control of infectious ovine abortion, which has economic, animal health, and human health impacts. In this study, catheters were surgically placed in the fetal vasculature and amnion of pregnant ewes at 115 (±2) days of gestation. Ewes were given a single dose of 2.5 mg/kg tulathromycin subcutaneously, and drug concentrations were determined in fetal plasma, maternal plasma, and amniotic fluid at 4, 8, 12, 24, 36, 48, 72, 144, and 288 hr after drug administration. Pharmacokinetic parameters in maternal plasma were estimated using noncompartmental analysis and were similar to those previously reported in nonpregnant ewes. Tulathromycin was present in fetal plasma and amniotic fluid, indicating therapeutic potential for use against organisms in these compartments, though concentrations were lower than those in maternal plasma. Time‐course of drug concentrations in the fetus was quite different than that in the ewe, with plasma concentrations reaching a plateau at 4 hr and remaining at this concentration for the remainder of the sampling period (288 hr), raising questions about how tulathromycin may be transported into or metabolized and eliminated by the fetus.     

IMAGING DIAGNOSIS—VERTEBRAL POLYOSTOTIC LYMPHOMA IN A GERIATRIC DOG

A 9‐year‐old spayed female Scottish terrier presented with an 8‐day history of progressive paraparesis. Neurological examination suggested a painful T3‐L3 myelopathy. Multifocal uniform contrast‐enhancing masses involving the vertebral bodies, pedicles, laminae, and spinous processes of two vertebrae and compressing the spinal cord were present on MRI. Fluoroscopic‐guided fine needle aspiration of one of the vertebral lesions revealed a predominantly lymphoblastic population of cells compatible with a diagnosis of lymphoma. To the authors’ knowledge, this represents the first published case of canine lymphoma with vertebral involvement, characterized with MRI.     

Male Burmese pythons follow female scent trails and show sex‐specific behaviors

Animals communicate with potential mates using species‐specific signals, and pheromones are powerful sexual signals that modify conspecific behavior to facilitate mate location. Among the vertebrates, snakes are especially adept in mate searching via chemical trailing, which is particularly relevant given that many snake species are invasive outside their native ranges. Chemical signals used in mate choice are, thus, potentially valuable tools for management of invasive snake species. The Burmese python (Python bivittatus) is an invasive snake in the Florida Everglades where it is negatively impacting native fauna. In this study, we sought to: (i) determine if males can follow conspecific chemical trails in a Y‐maze; and (ii) describe the mate searching behaviors exhibited by males while trailing. All males consistently followed a single female scent trail in the maze, but when only a male scent trail was present they did not discriminate between the male and blank arms. Rate of tongue‐flicking, a proxy for chemosensory sampling, was also marginally higher when males were following female versus male scent trails. However, when both female and male scent trails were simultaneously present in the Y‐maze, males did not show a preference for the female arm, although the tongue‐flick rate was higher in the female‐only trial compared to female versus male. Analyses of multiple male behaviors individually and using an ethogram revealed that behaviors were more frequent and complex in the female‐only trials compared to male‐only trials. Additional behavioral trials are needed to determine if an effective pheromonal approach to Burmese python management is possible.     

Use of pimobendan in feline congenital heart failure

A 6-month-old domestic shorthair cat was referred for evaluation of sudden lethargy and tachypnea following ovariohysterectomy. Upon failure of improvement with supportive care, a cardiologist identified congenital tricuspid dysplasia with signs of heart failure. Furosemide, enalapril, and pimobendan were used to reduce clinical signs and improve length and quality of life.     

Quantifying fishing effort: a synthesis of current methods and their applications

The need to accurately quantify fishing effort has increased in recent years as fisheries have expanded around the world and many fish stocks and non‐target species are threatened with collapse. Quantification methods vary greatly among fisheries, and to date there has not been a comprehensive review of these methods. Here we review existing approaches to quantify fishing effort in small‐scale, recreational, industrial, and illegal, unreported and unregulated (IUU) fisheries. We present the strengths and limitations of existing methods, identifying the most robust methods and the critical knowledge gaps that must be addressed to improve our ability to quantify and map fishing effort. Although identifying the ‘best’ method ultimately depends on the intended application of the data, in general, quantification methods that are based on information on gear use and spatial distribution offer the best approaches to representing fishing effort on a broad scale. Integrating fisher’s knowledge and involving fishers in data collection and management decisions may be the most effective way to improve data quality and accessibility.