Effects of ketamine, diazepam, and their combination on intraocular pressures in clinically normal dogs

OBJECTIVE: To evaluate the effects of ketamine, diazepam, and the combination of ketamine and diazepam on intraocular pressures (IOPs) in clinically normal dogs in which premedication was not administered. ANIMALS: 50 dogs. PROCEDURES: Dogs were randomly allocated to 1 of 5 groups. Dogs received ketamine alone (5 mg/kg [KET5] or 10 mg/kg [KET10], IV), ketamine (10 mg/kg) with diazepam (0.5 mg/kg, IV; KETVAL), diazepam alone (0.5 mg/kg, IV; VAL), or saline (0.9% NaCl) solution (0.1 mL/kg, IV; SAL). Intraocular pressures were measured immediately before and after injection and at 5, 10, 15, and 20 minutes after injection. RESULTS: IOP was increased over baseline values immediately after injection and at 5 and 10 minutes in the KET5 group and immediately after injection in the KETVAL group. Compared with the SAL group, the mean change in IOP was greater immediately after injection and at 5 and 10 minutes in the KET5 group. The mean IOP increased to 5.7, 3.2, 3.1, 0.8, and 0.8 mm Hg over mean baseline values in the KET5, KET10, KETVAL, SAL, and VAL groups, respectively. All dogs in the KET5 and most dogs in the KETVAL and KET10 groups had an overall increase in IOP over baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with baseline values and values obtained from dogs in the SAL group, ketamine administered at a dose of 5 mg/kg, IV, caused a significant and clinically important increase in IOP in dogs in which premedication was not administered. Ketamine should not be used in dogs with corneal trauma or glaucoma or in those undergoing intraocular surgery.     

Short- and long-term outcome and factors predicting survival after surgical tube cystostomy for treatment of obstructive urolithiasis in small ruminants

OBJECTIVE: To evaluate outcome of small ruminants after tube cystostomy without urethral flushing. STUDY DESIGN: Retrospective clinical study. ANIMALS: Small ruminants (n=63; 50 goats, 13 sheep). METHODS: Medical records (January 1996-October 2003) for all small ruminants undergoing tube cystostomy were analyzed. Signalment, laboratory data, intraoperative findings, urolith type, and postoperative outcome were compared. Long-term follow-up was obtained at 6 and > or= 12 months postoperatively. RESULTS: Most animals were castrated males. Pygmy goats were overrepresented. Mean time to normal urination after tube cystostomy was 11 days, and mean hospitalization was 14 days. Seventy-six percent of animals were successfully treated with tube cystostomy (90% of those discharged from hospital). Short- and long-term survival was good for those animals with follow-up data. Reobstruction occurred in <20% of animals at 6 and 12 months. Goats, castrated males, and animals with normal serum potassium, no fluid in the abdomen, or no urethral process amputation were more likely to survive. Stone type, bladder appearance, and age at castration were not associated with outcome. CONCLUSION: Surgical tube cystostomy without urethral flushing is an effective technique for resolution of obstructive urolithiasis in small ruminants. CLINICAL RELEVANCE: Goats, small ruminants with an intact urethral process, absence of abdominal fluid, and serum potassium concentration <5.2 mEq/L at admission were all associated with survival after tube cystostomy. Castrated males may also be more likely to survive. These factors should be considered in management of small ruminants with urolithiasis.     

ULTRASOUND ELASTOGRAPHY OF THE LIVER,SPLEEN, AND KIDNEYS IN CLINICALLY NORMAL CATS

A large amount of overlap exists in the B‐mode ultrasound appearance of normal and abnormal liver, spleen, and kidney tissues in cats. Therefore, invasive tissue sampling procedures remain the standard method for diagnosing diseases in these organs. The purpose of our study was to assess the feasibility of ultrasound elastography as a technique for improving noninvasive characterization of the feline liver, spleen, and kidneys. Elastography was performed on 10 unsedated, clinically healthy cats. Numeric (strain) values (0 = softest to 255 = firmest) assigned to color pixels within regions of interest resulted in median scores (interquartile ranges) of body wall, 207.50 (189.75–224.00); liver, 119.00 (105.00–138.25); spleen, 127.50 (121–00–142.00); right renal cortex, 83.50 (64.00–130.00); right renal near field, 125.50 (110.75–139.75); left renal cortex, 77.50 (52.00–116.25); and left renal near field, 126.00 (114.00–145.25). Strain values were not different between organs. Body wall median was the only significantly different value (P < 0.05). Strain ratio values of body wall:organ were as follows: liver, 1.76 (1.38–2.00); spleen, 1.68 (1.47–1.83); right renal cortex, 2.31 (1.61–3.15); right renal near field, 1.62 (1.41–2.01); left renal cortex, 2.66 (1.45–4.13); and left renal near field, 1.51 (1.29–1.89). Subjectively, hepatic and splenic parenchymal tissues were homogeneous in compressibility and similar in elasticity to one another. Renal cortical tissue was softer compared to medullary tissue. Findings indicated that ultrasound elastography is a feasible technique for objectively and subjectively characterizing the feline liver, spleen, and kidneys. Further research is needed in cats with confirmed diseases of these organs, to compare the diagnostic sensitivity of ultrasound elastography vs. B‐mode ultrasonography.     

Potassium Permanganate is Not an Effective Pond Disinfectant to Control Dero digitata

Proliferative gill disease (PGD) is a major problem in cultured channel catfish, Ictalurus punctatus. This parasite requires Dero digitata to complete its life cycle. It is believed potassium permanganate disinfects ponds and reduces D. digitata populations, but this practice has not been verified experimentally. We evaluated potassium permanganate as a pond disinfectant to reduce D. digitata populations before stocking fish. In the first study, 2 L catfish pond mud and 18 L pond water were placed in each of 16 20‐L microcosms. Four microcosms were dosed at each of four potassium permanganate treatment levels (0, 10, 20, and 30 mg/L). After treatment, D. digitata present in the sample were counted. In a second study, benthic populations were compared in 10 0.04 ha ponds before and after treatment with 20 mg/L potassium permanganate. In the microcosm study, all treatment levels significantly (P < 0.05) reduced D. digitata populations relative to controls. However, in the field trial, there were no significant (P < 0.05) differences pre‐ and post‐treatment with potassium permanganate at 20 mg/L in Dero populations or total benthic organism populations. Although we believed such high levels of potassium permanganate would sterilize the pond, the results of the pond treatments in this study indicate otherwise.     

Xenobiotic organic compounds in runoff from fields irrigated with treated wastewater

Investigations of agricultural nonpoint source pollution typically focus on a relatively narrow range of targeted toxic and biostimulatory compounds (e.g., specific pesticides, nutrients). Regular application of numerous other organic compounds to agricultural fields in pesticide formulations, irrigation water, soil amendments, and fertilizers may result in their transport into surface waters via runoff. We examined whether potentially toxic dissolved and particle-associated "nontarget" organic compounds were present in surface runoff from agricultural fields irrigated with disinfected tertiary recycled water or wastewater effluent-dominated streamwater. Gas chromatographic-mass spectrometric analyses of filtered runoff samples revealed the presence of numerous nontarget compounds of potential toxicological significance including pesticide transformation products, pesticide adjuvant chemicals, plasticizers, flame retardants, pharmaceuticals, and personal care product ingredients. Although the toxicity of many of these compounds is poorly characterized, some may elicit subtle but profound toxicological effects. Agricultural runoff also represented a source of allochthonous natural organic matter to the stream system.     

Golden bowerbird (Prionodura newtonia) habitat in past, present and future climates: predicted extinction of a vertebrate in tropical highlands due to global warming

A generalised linear model was used to predict climatically suitable habitat for the golden bowerbird (Prionodura newtonia De Vis), an endemic species of the Wet Tropics of North Queensland. Mean temperature of the coldest quarter and mean precipitation of the wettest quarter were found to be the best habitat predictors. For independent validation data, accuracy was 67% (Kappa statistic, n=30). Past, and future habitats suitable to the golden bowerbird were mapped by altering the temperature and precipitation input to the model. In the current climate, total potential habitat is estimated to be 1564 km², occurring as a number of separate patches with distinct bowerbird subpopulations. Past habitat was most limiting, 406 km², during the Holocene climatic optimum (c. 5000-3600 YBP, +2 °C and +50% rainfall relative to today). With future warming, assuming a 10% decrease in rainfall, potential habitat is reduced to 582 km² (1 °C warming), 163 km² (2 °C warming) and 37 km² (3 °C warming). Thus, global warming in the coming decades is likely to be a significant threat to the survival of this and similar upland and highland species in the tropics.     

Functional diversity vs. monotony: the effect of a multiforage diet as opposed to a single forage diet on animal intake,performance, welfare,and urinary nitrogen excretion

The objective of this study was to determine the effect of offering animals a multiforage choice (MF) of fresh herbages on dry matter intake (DMI), live weight gain, and animal welfare, in comparison with a monotonous diet of ryegrass (Lolium perenne L.). Twenty ram lambs (30.5 ± 0.9 kg initial live weight; mean ± SEM), were randomly allocated to either a diet consisting of diverse MF choice or a single forage ryegrass (SF) diet (n = 10 per treatment) for 35 d. Both diets were fed ad libitum; however, the MF diet was composed of set dry matter ratios of 24% chicory (Cichorium intybus L.), 30% lucerne (Medicago sativa L.), 25% plantain (Plantago lanceolata L.), and 21% ryegrass. The DMI of the MF lambs was 48% greater (P < 0.01) and the within animal day-to-day coefficient of variation (CV) of intake was 26% lower (P < 0.01) than the SF lambs. The average daily gain (ADG) of lambs offered the MF diet was 92% greater (P < 0.01) than the lambs offered the SF diet. The within-animal day-to-day CV of intake was negatively related to ADG (r = −0.59; P < 0.01). The MF lamb’s urinary N concentration was 30% lower (P < 0.01) than that of the SF lambs. The SF lambs spent more time (P < 0.05) exhibiting stereotypic behaviors in the afternoon and spent more time observing other animals than the MF. Overall, allocating an MF choice of fresh herbages as opposed to a single forage diet of ryegrass increases DMI and thereby animal performance, while potentially reducing urinary N excretion.     

Modelling trade offs between public and private conservation policies

To reduce global biodiversity loss, there is an urgent need to determine the most efficient allocation of conservation resources. Recently, there has been a growing trend for many governments to supplement public ownership and management of reserves with incentive programs for conservation on private land. At the same time, policies to promote conservation on private land are rarely evaluated in terms of their ecological consequences. This raises important questions, such as the extent to which private land conservation can improve conservation outcomes, and how it should be mixed with more traditional public land conservation. We address these questions, using a general framework for modelling environmental policies and a case study examining the conservation of endangered native grasslands to the west of Melbourne, Australia. Specifically, we examine three policies that involve: (i) spending all resources on creating public conservation areas; (ii) spending all resources on an ongoing incentive program where private landholders are paid to manage vegetation on their property with 5-year contracts; and (iii) splitting resources between these two approaches. The performance of each strategy is quantified with a vegetation condition change model that predicts future changes in grassland quality. Of the policies tested, no one policy was always best and policy performance depended on the objectives of those enacting the policy. This work demonstrates a general method for evaluating environmental policies and highlights the utility of a model which combines ecological and socioeconomic processes.     

The challenge of monitoring biodiversity in payment for environmental service interventions

Payments for environmental services (PES) aim to improve the supply of environmental services by making payments to service providers, which are conditional on the provision of those services. Payments cannot be conditional unless the service can be effectively monitored, making monitoring of service provision a central feature of PES. We introduce a framework for designing monitoring programmes in PES schemes for biodiversity conservation. We suggest that decisions must be made concerning the indicators to be used (e.g. species, threats or positive actions), how they will be monitored (e.g. using ground-based or remote-sensed data) and how the monitoring information will be used to differentiate payments (e.g. trends over time, performance relative to neighbouring sites, performance against a target). We then use this framework to examine the feasibility of monitoring species and threat indicators in a community-based biodiversity payment scheme in Menabe, Madagascar. We find that detecting population changes, differences between sites, or whether a target has been met is only feasible for the most common indicators, suggesting that it may not be possible to base payments on the species conservationists are most interested in. If payments need to be based on relatively common indicators, threat indicators may be more appropriate than common species indicators due to a stronger relationship to the service of interest (presence of a rare species). It is, however, possible to incorporate information from rare indicators using accumulation curves to compare between sites. This study highlights the impact of indicator choice on the monitoring effort required in a biodiversity PES. We urge caution in the design of payment schemes and suggest it can be detrimental to structure a scheme around an indicator that cannot be effectively monitored.