Effect of common sedation agents on feline splenic size determined via ultrasonography.

AIMS: To evaluate the effect of IM administration of three sedative drugs, acepromazine, alfaxalone and dexmedetomidine, in combination with morphine, on the size of the feline spleen using ultrasonography. METHODS: Twenty-four client-owned cats undergoing elective de-sexing or minor procedures were recruited for a focused ultrasonographic examination of the spleen prior to and at 10, 20 and 30 minutes following administration of one of three randomly assigned IM sedation protocols: 0.05 mg/kg acepromazine (ACE group), 3 mg/kg alfaxalone (ALF group), or 10 µg/kg dexmedetomidine (DEX group), in combination with 0.5 mg/kg morphine. B-mode images of the spleen were collected and measured following a standardised protocol. Cardiorespiratory parameters and sedation score were also recorded. Mean thickness of the head, body and tail of the spleen for each group at 10, 20 and 30 minutes after drug administration was compared to baseline. RESULTS: Mean splenic thickness increased over time in the ACE group (thickness of body at T0 = 8.9 (SE 2.1) mm and at T30 = 10.5 (SE 2.0) mm; p = 0.001) and the ALF group (thickness of body at T0 = 8.8 (SE 1.0) mm and at T30 = 10.3 (SE 1.7) mm; p = 0.022) but not in the DEX group (thickness of body at T0 = 8.6 mm (1.2) and at T30 = 8.9 mm (0.6); p = 0.67). Mean arterial blood pressure in the DEX group was significantly higher than in the other groups (p = 0.002). Sedation scores in the DEX group were consistently high for the entire period. However, the sedation score in the ACE group increased over 30 minutes (p = 0.007). Sedation score in the ALF group was highest at 10 minutes but gradually decreased over the following 20 minutes (p = 0.003). CONCLUSIONS: Sedation with IM dexmedetomidine and morphine did not change splenic size, whereas acepromazine or alfaxalone and morphine increased it regardless of the degree of sedation. CLINICAL RELEVANCE: Where splenomegaly is identified in a cat sedated with acepromazine or alfaxalone, the effects of the sedation protocol could be considered as a possible cause.

Factors influencing oral cancer screening preferences in patients attending Tertiary Care University Oral Health Clinic.

BACKGROUND: Understanding factors that influence patients' preferences towards oral cancer (OC) screening is imperative to provide high-quality evidence-based OC screening interventions that can be targeted for population-level uptake. This study determined adult patients' knowledge and awareness of OC, and how health behaviours influenced their preferences towards OC screening. METHODS: This cross-sectional study used a 42-point questionnaire, between February and May 2020 using a combination of in-person and telephone interviews. Chi-square test and multiple logistic regression analysis were applied to confounding factors that returned statistical significance against OC knowledge and awareness. Significance of P < 0.05 was accepted. RESULTS: Sixty-eight (38.6%) participants out of a total 176 had good knowledge of OC and 89 (50.6%) had good awareness. A total of 31.8% reported preference for OC screening by a general dental practitioner (GDP) over a general medical practitioner (GMP). Majority (72.7%) reported acceptance of OC screening at their next GDP visit. Ages 56-70 (OR = 0.357, 95% CI) and previous smokers (OR = 0.336, 95% CI) significantly influenced screening preferences. Knowledge of risk factors did not significantly influence OC screening preferences (χ2 = 3.178, P = 0.075). CONCLUSIONS: Significant gaps in OC knowledge, screening and role of GDPs exist with smoking history and age influencing OC screening preferences.

Calcaneotibial screws for immobilisation of the tarsocrural joint of dogs in extension: effect of the angle of screw placement on the force to failure in a canine cadaveric model.

AIMS: To compare the force to failure under axial loading of a calcaneotibial screw placed approximately perpendicular to the tibia with that of a screw placed perpendicular to the calcaneus, when used to immobilise the tarsus in an ex vivo canine model. METHODS: Twelve pairs of cadaveric hindlimbs from large breed dogs, without orthopaedic or soft tissue disease, were prepared by transecting the limb at the level of the stifle and stripping the limbs of all musculature from the stifle to mid-metatarsus, including removal of the common calcaneal tendon from all limbs. The limbs in each pair were randomly assigned to receive a calcaneotibial screw placed perpendicular to the long axis of either the calcaneus (C group) or the tibia (T group) with the tarsus in full extension. The distal limb was potted in resin and the proximal tibia was pinned to allow biomechanical testing in compressive loading. Testing was performed to apply an axial load using a material testing machine in a proximodistal direction through the tibia, advancing at a rate of 10 mm/second. The force to failure was recorded in kN and compared between groups. RESULTS: The median force to failure of the C group was 0.86 (min 0.50; max 1.64) kN which was higher than the T group which had a median force to failure of 0.74 (min 0.26, max1.05) kN (p = 0.004). All modes of failure were by screw pull-out. CONCLUSIONS: A calcaneotibial screw placed at an angle approximately perpendicular to the long axis of the calcaneus, has a higher force to failure under axial loading than a calcaneotibial screw that is placed at an angle approximately perpendicular to the tibia, in a canine cadaveric model. CLINICAL RELEVANCE: A temporary calcaneotibial screw is a common method of immobilising the tarsus in extension to protect primary repair of a common calcaneal tendon injury. Placing a calcaneotibial screw perpendicular to the calcaneus may be a more reliable option for immobilisation of the tarsus to protect a common calcaneal tendon repair compared to screws placed perpendicular to the tibia. However extrapolation of these results into a clinical setting requires caution.

Changes in circulating concentrations of testosterone and estrone sulfate after human chorionic gonadotropin administration and subsequent to castration of 2-year-old stallions.

Reproductive steroids testosterone (T) and estrone sulfate (E1S) are used as diagnostic markers for cryptorchidism in horses. The human chorionic gonadotropin (hCG) stimulation test is used as a diagnostic aid because administration of this hormone results in greater incremental differences in circulating steroid concentrations. Thoughts regarding optimal sampling times following hCG administration, however, are inconsistent. Additionally, determination of half-life of these steroids is important in postsurgical samples to confirm complete removal of testicular tissue. Objectives of this study, therefore, were to determine optimal sampling periods for peak T and E1S after hCG administration and half-life of these steroids after castration. Eight pony stallions were randomly assigned to control or treatment groups (5000 IU hCG). Blood samples were collected following hCG administration. Subsequently, stallions were castrated and blood samples were collected post-castration. The T concentrations were greatest at 72 h after hCG and were greater (P < 0.02) in samples from hCG-treated than control animals: 9,903.4 ± 384 and 784.0 ± 192 pg/mL, respectively (Mean ± SEM). The T concentrations were also greater at 1, 12, 24, 48 and 96 h. The E1S concentrations did not change after administration of hCG. The T response to hCG administration was biphasic with a maximal response between 48-96 h after administration. Half-lives of T and E1S were 1.1 and 0.7 h, respectively, and concentration of T and E1S was similar to that of geldings at 24 h post-castration, which, therefore, should be considered an optimal time to ensure complete castration has occurred.

Building confidence in skin sensitisation potency assessment using new approach methodologies: report of the 3rd EPAA Partners Forum, Brussels, 28th October 2019.

Skin sensitising substances that induce contact allergy and consequently risk elicitation of allergic contact dermatitis (ACD) remain an important focus regarding the replacement of animal experimentation. Current in vivo methods, notably the local lymph node assay (LLNA) refined and reduced animal usage and led to a marked improvement in hazard identification, characterisation and risk assessment. Since validation, regulatory confidence in the LLNA approach has evolved until it became the first choice assay in most regulated sectors. Currently, hazard identification using the LLNA is being actively replaced by a toolbox of non-animal approaches. However, there remains a need to increase confidence in the use of new approach methodologies (NAMs) as replacements for LLNA sensitiser potency estimation. The EPAA Partners Forum exchanged the current state of knowledge on use of NAMs in various industry sectors and regulatory environments. They then debated current challenges in this area and noted several ongoing needs. These included a requirement for reference standards for potency, better characterisation of applicability domains/technical limitations of NAMs, development of a framework for weight of evidence assessments, and an increased confidence in the characterisation of non-sensitisers. Finally, exploration of an industry/regulator cross-sector user-forum on skin sensitisation was recommended.

Effect of insulation with bubble wrap and an absorbent pad on heat loss in anaesthetised cats.

Aims: To evaluate the efficacy of insulating the limbs and thorax of cats with a combination of bubble wrap and an absorbent, plastic-lined pad in reducing heat loss during ovariohysterectomy. Methods: A preliminary study was performed to compare heat loss of 1 L bags of Hartmann's solution heated to 38°C which were either wrapped in two layers of bubble wrap and an absorbent pad (n = 6) or were unwrapped (n = 6). Bags were allowed to cool in a temperature-controlled room and the temperature of the bags was measured every 10 minutes for 60 minutes. The clinical study, included 16 intact female cats undergoing ovariohysterectomy. The cats were premedicated with I/M morphine and either medetomidine or dexmedetomidine, and anaesthesia was induced with I/V propofol and maintained with isoflurane in 100% oxygen. Cats were randomly assigned to either the treatment group (n = 8) whose limbs and thorax wrapped with two layers of bubble wrap and an absorbent pad immediately after induction, or the control group (n = 8) which were unwrapped. Body temperature (measured with an oesophageal temperature probe), heart rate, respiratory rate, mean arterial pressure and partial pressure of end-tidal CO2 were recorded immediately after induction (T start), before surgery started (T surgery), and at the end of isoflurane administration (T end). The times from T end to extubation, from T end to when the cat could maintain sternal recumbency and from T end to when the cat was able to stand, were also recorded. Results: In the preliminary study of heat loss by fluid bags, the mean temperature at 60 minutes was higher in wrapped bags (35.4 (SD 0.2)°C) compared to unwrapped bags (33.0 (SD 0.3)°C; p < 0.01). For cats undergoing ovariohysterectomy, mean body temperature of wrapped cats was higher than that of unwrapped cats both at T surgery (36.0 (SE 0.3) vs. 34.5 (SE 0.3)°C; p = 0.001) and at T end (37.2 (SE 0.5) vs. 36.0 (SE 0.5)°C; p = 0.01). Wrapped cats regained the ability to stand more rapidly that unwrapped cats (26.4 (SE 5.8) vs. 47.0 (SE 5.8) minutes p = 0.01). Conclusions: Wrapping the limbs and thorax of cats undergoing ovariohysterectomy in a combination of bubble wrap and absorbent pads reduced heat loss, which in turn improved recovery time from general anaesthesia. Clinical relevance: This inexpensive and practical method may reduce perioperative hypothermia, in cats undergoing abdominal surgery.

Priorities among HIV-positive individuals for tuberculosis preventive therapies.

BACKGROUND: There has been slow uptake of isoniazid preventive therapy (IPT) among people living with HIV (PLWH).METHODS: We surveyed adults recently diagnosed with HIV in 14 South African primary health clinics. Based on the literature and qualitative interviews, sixteen potential barriers and facilitators related to preventive therapy among PLWH were selected. Best-worst scaling (BWS) was used to quantify the relative importance of the attributes. BWS scores were calculated based on the frequency of participants' selecting each attribute as the best or worst among six options (across multiple choice sets) and rescaled from 0 (always selected as worst) to 100 (always selected as best) and compared by currently receiving IPT or not.RESULTS: Among 342 patients surveyed, 33% (n = 114) were currently taking IPT. Having the same standard of life as someone without HIV was most highly prioritized (BWS score = 67.3, SE = 0.6), followed by trust in healthcare providers (score, 66.3 ± 0.6). Poor standard of care in public clinics (score, 30.6 ± 0.6) and side effects of medications (score, 33.7 ± 0.6) were least prioritized. BWS scores differed by IPT status for few attributes, but overall ranking was similar (spearman's rho = 0.9).CONCLUSION: Perceived benefits of preventive therapy were high among PLWH. IPT prescription by healthcare providers should be encouraged to enhance IPT uptake among PLWH.

Evidence for a Diagenetic Origin of Vera Rubin Ridge, Gale Crater, Mars: Summary and Synthesis of Curiosity's Exploration Campaign.

This paper provides an overview of the Curiosity rover's exploration at Vera Rubin ridge (VRR) and summarizes the science results. VRR is a distinct geomorphic feature on lower Aeolis Mons (informally known as Mount Sharp) that was identified in orbital data based on its distinct texture, topographic expression, and association with a hematite spectral signature. Curiosity conducted extensive remote sensing observations, acquired data on dozens of contact science targets, and drilled three outcrop samples from the ridge, as well as one outcrop sample immediately below the ridge. Our observations indicate that strata composing VRR were deposited in a predominantly lacustrine setting and are part of the Murray formation. The rocks within the ridge are chemically in family with underlying Murray formation strata. Red hematite is dispersed throughout much of the VRR bedrock, and this is the source of the orbital spectral detection. Gray hematite is also present in isolated, gray-colored patches concentrated toward the upper elevations of VRR, and these gray patches also contain small, dark Fe-rich nodules. We propose that VRR formed when diagenetic event(s) preferentially hardened rocks, which were subsequently eroded into a ridge by wind. Diagenesis also led to enhanced crystallization and/or cementation that deepened the ferric-related spectral absorptions on the ridge, which helped make them readily distinguishable from orbit. Results add to existing evidence of protracted aqueous environments at Gale crater and give new insight into how diagenesis shaped Mars' rock record.

Plasma NT-proBNP and Cell-Free DNA Concentrations after Prolonged Strenuous Exercise in Working Farm Dogs.

BACKGROUND: Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration is increased in dogs with myocardial dysfunction, and cell-free DNA (cfDNA) increases in numerous disease states. In humans, both of these biomarkers can be altered after endurance exercise. OBJECTIVE: To investigate the effect of prolonged strenuous exercise on circulating NT-proBNP and cfDNA concentrations in working farm dogs. ANIMALS: Six healthy, privately owned working farm dogs (4 Huntaways and 2 heading dogs) from the same hill country farm in New Zealand. METHODS: Prospective, nonrandomised cohort study. Venous blood samples were collected before and after the dogs worked over 4 days. Plasma NT-proBNP concentrations were measured by a commercially available ELISA assay and cfDNA concentrations were determined by fluorometry without prior DNA extraction. RESULTS: The baseline (before work, Day 1) median plasma NT-proBNP concentration was 664 pmol/L. A linear mixed-effects model showed that work increased plasma NT-proBNP concentrations by 101 ± 9% (P < 0.001), but with each consecutive day of work, NT-proBNP concentrations declined by 16 ± 4% (P < 0.001). The baseline median plasma cfDNA concentration was 653 ng/mL, and plasma cfDNA concentrations increased by 138 ± 45 ng/mL after work (P = 0.004). CONCLUSIONS AND CLINICAL IMPORTANCE: The plasma concentration of NT-proBNP in healthy Huntaways and heading dogs after work can exceed the upper limit of the reference range. Results in dogs sampled on the day of prolonged strenuous exercise should be interpreted with caution. Plasma concentrations of cfDNA also increase with exercise, but further studies are needed to establish reference ranges in healthy dogs.

Identification of the Beagle 2 lander on Mars.

The 2003 Beagle 2 Mars lander has been identified in Isidis Planitia at 90.43° E, 11.53° N, close to the predicted target of 90.50° E, 11.53° N. Beagle 2 was an exobiology lander designed to look for isotopic and compositional signs of life on Mars, as part of the European Space Agency Mars Express (MEX) mission. The 2004 recalculation of the original landing ellipse from a 3-sigma major axis from 174 km to 57 km, and the acquisition of Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE) imagery at 30 cm per pixel across the target region, led to the initial identification of the lander in 2014. Following this, more HiRISE images, giving a total of 15, including red and blue-green colours, were obtained over the area of interest and searched, which allowed sub-pixel imaging using super high-resolution techniques. The size (approx. 1.5 m), distinctive multilobed shape, high reflectivity relative to the local terrain, specular reflections, and location close to the centre of the planned landing ellipse led to the identification of the Beagle 2 lander. The shape of the imaged lander, although to some extent masked by the specular reflections in the various images, is consistent with deployment of the lander lid and then some or all solar panels. Failure to fully deploy the panels-which may have been caused by damage during landing-would have prohibited communication between the lander and MEX and commencement of science operations. This implies that the main part of the entry, descent and landing sequence, the ejection from MEX, atmospheric entry and parachute deployment, and landing worked as planned with perhaps only the final full panel deployment failing.

Antimicrobial resistance patterns of bacteria isolated from canine urinary samples submitted to a New Zealand veterinary diagnostic laboratory between 2005-2012.

AIMS: To identify and describe culture and antimicrobial resistance (AMR) patterns in bacteria isolated from canine urinary samples submitted to a New Zealand veterinary diagnostic laboratory. METHODS: Records from a veterinary diagnostic laboratory were examined for bacterial isolates cultured from canine urine samples between January 2005 and December 2012. Culture and susceptibility results were compiled with information on the age, sex and breed of dog. Repeat submissions were removed. Susceptibility was assessed using results of the Kirby-Bauer disk diffusion method, for a standard panel including amoxicillin-clavulanic acid (AMC), cefovecin (from 2010-2012), cephalothin, clindamycin, enrofloxacin and trimethoprim-sulphonamide (TMS). RESULTS: A total of 5,786 urine samples were submitted for analysis, and 3,135 bacterial isolates were cultured from 2,184 samples. Of these 3,135 isolates, 1,104 (35.2%) were Escherichia coli, 442 (14.1%) were Staphylococcus spp., 357 (11.4%) Proteus mirabilis and 276 (8.8%) were Enterococcus spp. The frequency of culture-positive samples increased with increasing age in both female and male dogs (p<0.001). The percentage of E. coli isolates resistant to AMC and cephalothin increased between 2005 and 2012 (p<0.001), as did resistance to enrofloxacin (p=0.022), but there was no change in resistance to TMS (p=0.696). Enrofloxacin was the antimicrobial with the least resistance shown by the four most common bacteria isolated during the course of the study. CONCLUSIONS AND CLINICAL RELEVANCE: The results of this study provide important regional information regarding the prevalence of bacterial uropathogens and their susceptibility patterns. There was an increase in resistance to some commonly used antimicrobials in the treatment of urinary tract infections. Having access to regional antimicrobial susceptibility results is crucial when forming guidelines for the use of antimicrobials for the treatment of urinary tract infections. Given changes in practising habits and antimicrobial usage over time, ongoing monitoring and surveillance of resistance in pathogens is needed.

Policies for the vaccination of cats and dogs in New Zealand veterinary practices.

AIMS: To determine current practices and attitudes towards vaccination of dogs and cats of veterinarians in New Zealand; the methods used for informing clients on which vaccines to use, and the preferred site for vaccination of cats. METHODS: A postal questionnaire was sent to all 483 listed veterinary practices in New Zealand during February 2012. Some questions were specific to pet dogs, cats, or working farm dogs. Responses were categorised according to practice type and geographical region of the respondent. Factors associated with respondent recommendation of annual vaccination with modified live viral (MLV) vaccines were examined using logistic regression analysis. Vaccines that were considered to be essential for every animal were defined as core; those that may be recommended for animals whose location or lifestyle placed them at risk, were defined as non-core. RESULTS: There were 204 useable returns, equivalent to a response rate of 42.2%, distributed across the country. Annual vaccination with MLV vaccines of dogs was recommended by 54/198 (27.3%) respondents, and of cats by 107/181 (59.1%) respondents. Factors associated with the recommendation of annual administration of MLV vaccines to dogs included being a companion animal practice, a desire for policies on vaccination to be left to individual clinics, and having one veterinarian in the practice. Administration of the final vaccination for puppies was recommended at ≥14 weeks old by 55/185 (29.7%) respondents, and for kittens at ≥13 weeks old by 42/183 (23%) respondents. Of respondents that administered MLV vaccines annually, 62/103 (60.2%) believed reducing the frequency of vaccination would reduce income, and 52/103 (50.5%) considered it would have a negative effect on animal health. Advice to enable clients to decide which non-core vaccines were administered was given by 181/199 (91%) respondents. Factors considered when recommending a vaccine included consideration of risk to individual patients (190/203; 93.6%), requirements of boarding kennels/catteries (165/203; 81.3%) and clinic vaccination policy (142/203; 70%). The preferred site for administering MLV vaccines to cats was the dorsal neck or inter-scapular region (137/198; 69.2%). Amongst respondents, 18 wanted disease surveillance information to allow for truly informed decisions to be made about vaccination. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians can now compare their own vaccination practices and attitudes with those of veterinarians nationally, and internationally. There is a need for national surveillance information and for continued education of the public and commercial kennel and cattery owners for optimal vaccination strategies to be developed.

Attitudes and perceptions of veterinary paraprofessionals in New Zealand to postoperative pain in dogs and cats.

AIM: To survey the attitudes and perceptions of veterinary paraprofessionals in New Zealand to postoperative pain in dogs and cats. METHODS: In December 2011, veterinary paraprofessionals (VP) from throughout New Zealand were invited to participate in an online survey. Eleven questions, which were divided into five sections, were used to determine demographic information, the respondents' assessment of pain after commonly performed surgeries in dogs and cats, their opinions on provision of analgesia, who had responsibility for pain monitoring and the use of any formal pain scoring system in the practice. RESULTS: Data from 165 respondents were able to be used, and 162 (98%) respondents to the survey were female. According to the respondents' estimates, fracture repair in dogs and repair of diaphragmatic hernias in cats had the highest pain score following surgery. Neutering procedures involving dogs were scored higher than for cats (p<0.01). All respondents agreed that animals benefit from perioperative analgesia. The veterinary nurse was reported to be predominantly responsible for monitoring pain in animals postoperatively by 116/165 (70.3%) respondents. Of 165 respondents, 154 (93%) considered that their knowledge of pain and assessment of pain could be enhanced. CONCLUSIONS: This survey reflects the attitudes and perceptions of a sample of VP in New Zealand to postoperative pain in dogs and cats. The results indicate that all respondents believe that surgery results in sufficient pain to warrant analgesic therapy. Routine neutering surgeries were considered to be more painful in dogs than in cats. The current survey also provides information to educators on potential areas of focus, given that 93% of respondents felt that their knowledge of pain and assessment of pain could be enhanced.

Prioritizing Parental Worry Associated with Duchenne Muscular Dystrophy Using Best-Worst Scaling.

Duchenne muscular dystrophy (DMD) is a progressive, fatal pediatric disorder with significant burden on parents. Assessing disease impact can inform clinical interventions. Best-worst scaling (BWS) was used to elicit parental priorities among 16 short-term, DMD-related worries identified through community engagement. Respondents viewed 16 subsets of worries, identified using a balanced, incomplete block design, and identified the most and least worrying items. Priorities were assessed using best-worst scores (spanning +1 to -1) representing the relative number of times items were endorsed as most and least worrying. Independent-sample t-tests compared prioritization of parents with ambulatory and non-ambulatory children. Participants (n = 119) most prioritized worries about weakness progression (BW score = 0.64) and getting the right care over time (BW = 0.25). Compared to parents of non-ambulatory children, parents of ambulatory children more highly prioritized missing treatments (BW = 0.31 vs. 0.13, p < 0.001) and being a good enough parent (BW = 0.06 vs. -0.08, p = 0.010), and less prioritized child feeling like a burden (BW = -0.24 vs. -0.07, p < 0.001). Regardless of child's disease stage, caregiver interventions should address the emotional impact of caring for a child with a progressive, fatal disease. We demonstrate an accessible, clinically-relevant approach to prioritize disease impact using BWS, which offers an alternative to the use of traditional rating/ranking scales.

Diagenesis and clay mineral formation at Gale Crater, Mars.

The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its secondary mineral assemblage. Building on conclusions from sedimentary observations by the Mars Science Laboratory team, we assume diagenetic, in situ alteration. The modeling shows that the mineral assemblage formed by the reaction of a CO2-poor and oxidizing, dilute aqueous solution (Gale Portage Water) in an open system with the Fe-rich basaltic-composition sedimentary rocks at 10-50°C and water/rock ratio (mass of rock reacted with the starting fluid) of 100-1000, pH of ∽7.5-12. Model alteration assemblages predominantly contain phyllosilicates (Fe-smectite, chlorite), the bulk composition of a mixture of which is close to that of saponite inferred from Chemistry and Mineralogy data and to that of saponite observed in the nakhlite Martian meteorites and terrestrial analogues. To match the observed clay mineral chemistry, inhomogeneous dissolution dominated by the amorphous phase and olivine is required. We therefore deduce a dissolving composition of approximately 70% amorphous material, with 20% olivine, and 10% whole rock component.

Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars.

Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine-rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.

The pharmacokinetics of methimazole in a novel lipophilic formulation administered transdermally to healthy cats.

AIM: To determine the pharmacokinetics of a novel lipophilic formulation of transdermal methimazole compared to oral carbimazole. METHODS: Healthy cats received 5 mg carbimazole orally every 12 hours for 13 treatments (n=6), then received transdermal methimazole (n=5) at a dose of 5 mg, then 10 mg, once daily on the pinna for 7 days, with 21 days between treatments. Concentrations of methimazole in serum over 24 hours and at 148 hours were determined by high performance liquid chromatography. RESULTS: Concentrations of methimazole in serum for the first 24 hours were not reliably detected in all cats treated with 5 mg methimazole transdermally, while for those receiving 5 mg carbimazole orally and 10 mg methimazole transdermally all cats had detectable concentrations of methimazole in serum. The maximum concentration and area under the curve were lower in cats receiving 10 mg methimazole transdermally (108 (SD 25) ng/mL and 2544 (SD 216) mg-hour/mL, respectively) than those receiving 5 mg oral carbimazole (355 (SD 113) ng/mL and 31,866 (SD 439) ng-hour/mL, respectively) (p<0.05). The time at maximal concentration and elimination half-life were longer for 10 mg transdermal methimazole (5.2 (SD 1.1) hours and 13 (SD 3) hours, respectively) compared to 5 mg oral carbimazole (2.1 (SD 1.6) hours and 5.1 (SD 1.2) hours, respectively). At 148 hours, mean concentrations of methimazole in serum were higher in cats receiving 10 mg methimazole transdermally (506 (SD 165) ng/mL) than for 5 mg oral carbimazole (255 (SD 28) ng/mL) or 5 mg transdermally (204 (SD 76) ng/mL). The mean relative bioavailability of 10 mg transdermal methimazole compared to oral carbimazole was 48 (min 43, max 55)%. CONCLUSION: Transdermal methimazole at a dose of 10 mg administered to the pinnae of healthy cats once daily in a novel lipophilic formulation has half the relative bioavailablity compared to 5 mg oral carbimazole. CLINICAL RELEVANCE: Transdermal methimazole can be absorbed from the skin of healthy cats.

A comparison of anaesthetic recoveries in cats following induction with either alfaxalone or ketamine and diazepam.

AIM: To determine if cats anaesthetised with alfaxalone have different recoveries to cats anaesthetised with a combination of ketamine and diazepam. METHODS: Anaesthesia for ovariohysterectomy was induced in cats with either alfaxalone (n=23) or a combination of ketamine and diazepam (n=22). All cats were premedicated with combinations of acepromazine and morphine. Recoveries were scored using a categorical grading scheme applied to 18 parameters over 60 minutes following extubation. The parameters scored covered movement, sensitivity to touch, sound and light, body position, sneezing and vocalisation. One person scored all recoveries and they were blinded to the induction drug used. Scores were compared between drugs at different times using the Kruskal-Wallis rank sum test. RESULTS: Recovery scores were not normally distributed. Analysis of the data using the Kruskal-Wallis rank sum test revealed that cats induced with alfaxalone showed an increase in recovery scores at 5 minutes for pawing at the head (p=0.001). No parameters differed significantly at 10 and 20 minutes. For cats anaesthetised with ketamine and diazepam there was an increase at 30 minutes in pacing, jerky sudden movements, unsettledness and increased sensitivity to touch at the surgical site and on the head (p≤0.01). At 60 minutes cats anaesthetised with ketamine and diazepam still showed an increase in unsettledness compared to those cats anaesthetised with alfaxalone (p=0.005). CONCLUSIONS: The results suggest that recoveries of cats following alfaxalone induction are significantly different to recoveries after induction with ketamine and diazepam. Overall, cats induced with ketamine and diazepam had more active and unsettled recoveries than alfaxalone over the 60-minute period observed. CLINICAL RELEVANCE: Cats recovering from alfaxalone anaesthesia have more settled recoveries than cats recovering from ketamine and diazepam anaesthesia. If a quiet settled recovery is desired following a surgical procedure, alfaxalone is likely to be a better choice than ketamine and diazepam.

The prevalence of ocular lesions associated with hypertension in a population of geriatric cats in Auckland, New Zealand.

AIMS: To provide an estimate of the prevalence of ocular lesions associated with hypertension in geriatric cats in Auckland, New Zealand and to evaluate the importance of examination of the ocular fundi of cats over eight years of age. METHODS: A total of 105 cats ≥8 years of age were examined and clinical signs recorded. Blood was collected for the laboratory measurement of the concentrations of blood urea nitrogen (BUN), glucose and creatinine in serum, urine was collected for determination of urine specific gravity (USG), and blood pressure (BP) was measured using high definition oscillometry equipment. A cat was determined to have systemic hypertension with a systolic BP ≥160 mm Hg and a diastolic BP ≥100 mm Hg. Each animal had an ocular fundic examination using a retinal camera to diagnose ocular lesions associated with hypertension, including retinopathies, choroidopathies and optic neuropathies. RESULTS: Blood pressure was successfully recorded in 73 cats. Of these, 37 (51%) had no hypertensive ocular lesions and no underlying disease diagnosed, 24 (33%) had no hypertensive ocular lesions detected, but underlying disease such as chronic kidney disease, hyperthyroidism or diabetes mellitus was diagnosed, and 12 (16%) cats had evidence of hypertensive ocular lesions. Ten of the cats with hypertensive ocular lesions were hypertensive at the time of the first visit and two were normotensive. One additional cat had hypertensive ocular lesions, but it was not possible to obtain consistent BP readings in this animal. Chronic kidney disease was the most commonly diagnosed concurrent disease in cats with hypertensive ocular lesions (n=6). Mean systolic BP for cats with hypertensive ocular lesions (168.0 (SE 6.29) mm Hg) was higher than for those with no ocular lesions (144.7 (SE 3.11) mm Hg) or those with no lesions but with underlying disease (146.0 (SE 4.97) mm Hg) (p=0.001). CONCLUSIONS: Ocular fundic examination of cats over eight years of age allows identification of cats with hypertensive ocular lesions, often before the owner or veterinarian is aware the cat has a problem with its vision. This may result in diagnosis of systemic hypertension allowing early treatment and resolution of lesions. CLINICAL RELEVANCE: The current study demonstrates that ocular lesions resulting from hypertension occur frequently enough in cats in Auckland to support the recommendation for fundic examination in cats over eight years of age as part of the routine physical examination.

Martian fluvial conglomerates at Gale crater.

Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.