The Effects of Onychectomy (Declawing) on Antebrachial Myology across the Full Body Size Range of Exotic Species of Felidae.

While people are familiar with the practice of declawing domestic cats, "onychectomy", as it is also known, is also performed on non-domesticated species, including pantherines, to prolong their use for entertainment purposes. Although the surgery (the partial or complete removal of the distal phalanx) has clear osteological implications, its myological effects have never been studied. As the mass of an animal increases cubically as a product of its volume, while the areas of its paws only increase as a square, larger felids have higher foot pressures and, therefore, the surgery may have particularly substantial functional effects on larger cats. In this study, we evaluate the forearms of clawed and declawed non-domestic felid specimens that spanned the body size range of the whole family to evaluate the effects of onychectomy on muscle fiber architecture. We found that the deep digital flexors (the muscles most directly affected by onychectomy) of declawed felids are significantly lighter (~73%) and less powerful (46-66%) than those of non-declawed felids, while other muscles do not make up for these reductions. Thus, onychectomy has a substantial effect on the myological capabilities of cats, and because these deficiencies are not compensated for in biomechanically disadvantaged larger felids, it probably has even more functionally devastating consequences for these species.

Cancer screening in Australia: future directions in melanoma, Lynch syndrome, and liver, lung and prostate cancers.

While Australia now has well-established national screening programs for breast, bowel and cervical cancers, research continues into the feasibility of developing systematic screening programs for a number of other cancers. In this paper, experts in their fields provide perspectives on the current state of play and future directions for screening and surveillance for melanoma, Lynch syndrome, and liver, lung and prostate cancers in Australia. Although the evidence does not support population screening, there may be opportunities to prevent thousands of deaths through systematic approaches to the early detection of lung cancer and melanoma, testing for Lynch syndrome, and organised surveillance for hepatocellular carcinoma among individuals at high risk - guided by targeted research. The paper also looks at what impact new prostate specific antigen testing guidelines are having on screening for prostate cancer.