The application of geometric morphometrics to explore potential impacts of anthropocentric selection on animals' ability to communicate via the face: the domestic cat as a case study

During their domestication via artificial selection, humans have substantially modified the morphology and thus visual appearance of non-human animals. While research highlights the negative impact of these modifications on physical functioning, little is known about their impact on behavior and signaling, either toward humans or conspecifics. Changes in the appearance of the face, such as those associated with, but not limited to, facial expressions, form an important part of non-verbal communication. In companion animals, the face is one of their most visually diverse features (due to human-driven selection), which may impact the visual clarity of expressions and other forms of signaling. Using the domestic cat as our model, we applied a new analytical technique in order to understand the impact of breed variation on relative positioning of facial landmarks, chosen specifically for their association with the production of various facial movements, and the expression of affect. We then assessed the extent to which facial appearances known to be associated with a specific underlying state (i.e., pain, assessed via a validated, facial pain score), could be reliably detected in a morphologically diverse population. Substantial baseline variation in landmarks was identified at both the cephalic (e.g., brachycephalic, dolichocephalic, mesocephalic) as well as breed levels. While differences in facial pain scores could successfully differentiate between “pain” and “no pain” in the facial appearance of domestic shorthaired cats (DSH), these differences were no longer detectable when assessed within a larger more morphologically diverse population, after corrections for multiple testing were applied. There was also considerable overlap between pain scores in the DSH “pain” population and the neutral faces of other breeds. Additionally, for several paedomorphic breeds, their neutral face shapes produced scores indicative of greater pain, compared to most other breeds, including the DSH cats actually in pain. Our findings highlight the degree to which anthropocentric selection might disrupt the communicative content of animals' faces, in this case the domestic cat. These results also suggest a potential human preference for features extending beyond the infantile, to include negatively-valenced facial forms such as pain

Applicability of crystalline cellulose membrane in the treatment of skin wounds induced in Wistar rats

PURPOSE:To evaluate the healing of skin wounds induced experimentally in rats using a crystalline cellulose membrane (Veloderm(r)).METHODS:Thirty-two rats were divided into two groups: control group (CG) wounds treated with a solution of 0.9% sodium chloride and Veloderm(r) group (VG) wounds treated with a crystalline cellulose membrane. The rats were evaluated at different times over twenty-six days.RESULTS:Weight loss was observed in the animals from both groups in the early stages, with greater weight in the VG animals at the end. Times of predominant hypothermia, pink color of the wound in both groups over all time points, increased granulation tissue in the CG animals, the presence of slight oozing from the wound and feature in the VG animals, more serous exudation of the bloody feature, greater wound contraction and pain in the CG animals and an absence of pain and earlier complete wound healing in the VG rats were also observed.CONCLUSION:The crystalline cellulose membrane is effective in the treatment of wounds in rats, easy to use, protects and maintains the humidity of the wound, decreases pain, eases the visualization and control of the evolution of the lesion

Cardiorespiratory and endocrine effects of endogenous opioid antagonism by naloxone in ponies anaesthetised with halothane

Halothane depresses cardiorespiratory function and activates the pituitary-adrenal axis, increasing beta endorphin. In horses, beta endorphin may enhance the anaesthetic-associated cardiorespiratory depression and mortality risk. The authors studied endogenous opioid effects on cardiorespiratory function and pituitary-adrenal activity in halothane-anaesthetised ponies by investigating opioid antagonism by naloxone. Six ponies were anaesthetised three times (crossover design). Anaesthesia was induced with thiopentone and maintained with 1.2 per cent halothane for 2 hours. Immediately after induction, naloxone was administered either intra venously (0.5 mg kg(-1) bolus then 0.25 mg kg(-1) hour(-1) for 2 hours) or intrathecally (0.5 mg) or was replaced by saline as control. Pulse and respiratory rates, arterial blood gases, cardiac output and plasma cortisol and adrenocorticotrophic hormone (ACTH) concentrations were measured. All groups developed cardiorespiratory depression (40 per cent decrease in cardiac output) and plasma cortisol increased. Plasma ACTH concentration was higher in ponies treated with intrathecal naloxone. Endogenous opioids may inhibit ACTH Secretion, attenuating the stress response to halothane anaesthesia in equidae. (C) 2001 Harcourt Publishers Ltd

Midazolam and ketamine induction before halothane anaesthesia in ponies: cardiorespiratory, endocrine and metabolic changes

Six Welsh gelding ponies were premedicated with 0.03 mg/kg of acepromazine intravenously (i.v.) prior to induction of anaesthesia with midazolam at 0.2 mg/kg and ketamine at 2 mg/kg i.v.. Anaesthesia was maintained for 2 h using 1.2% halothane concentration in oxygen. Heart rate, electrocardiograph (EGG), arterial blood pressure, respiratory rate, blood gases, temperature, haematocrit, plasma arginine vasopressin (AVP), dynorphin, beta-endorphin, adrenocorticotropic hormone (ACTH), cortisol, dopamine, noradrenaline, adrenaline, glucose and lactate concentrations were measured before and after premedication, immediately after induction, every 20 min during anaesthesia, and at 20 and 120 min after disconnection. Induction was rapid, excitement-free and good muscle relaxation was observed. There were no changes in heart and respiratory rates, Decrease in temperature, hyperoxia and respiratory acidosis developed during anaesthesia and slight hypotension was observed (minimum value 76 +/- 10 mm Hg at 40 mins), No changes were observed in dynorphin, beta-endorphin, ACTH, catecholamines and glucose, Plasma cortisol concentration increased from 220 +/- 17 basal to 354 +/- 22 nmol/L at 120 min during anaesthesia; plasma AVP concentration increased from 3 +/- 1 basal to 346 +/- 64 pmol/L at 100 min during anaesthesia and plasma lactate concentration increased from 1.22 +/- 0.08 basal to 1.76 +/- 0.13 mmol/L at 80 min during anaesthesia, Recovery was rapid and uneventful with ponies taking 46 +/- 6 min to stand. When midazolam/ketamine was compared with thiopentone or detomidine/ketamine for induction before halothane anaesthesia using an otherwise similar protocol in the same ponies, it caused slightly more respiratory depression, but less hypotension. Additionally, midazolam reduced the hormonal stress response commonly observed during halothane anaesthesia and appears to have a good potential for use in horses

Radiographic study of distal radial physeal closure in thoroughbred horses

Monthly radiography was performed to study distal radial physeal closure in ten male and ten female Throughbred horses. The height, thoracic circumference and metacarpus circumference were also measured, Distal radial physeal closure time was sooner in females than males, and took 701 +/- 37 and 748 +/- 55 days respectively