Pharmacokinetics of articaine hydrochloride and its metabolite articainic acid after subcutaneous administration in red deer (Cervus elaphus)

AIM: To develop and validate a simple and sensitive method using liquid chromatography-mass spectrometry (LC-MS) for quantification of articaine, and its major metabolite articainic acid, in plasma of red deer (Cervus elaphus), and to investigate the pharmacokinetics of articaine hydrochloride and articainic acid in red deer following S/C administration of articaine hydrochloride as a complete ring block around the antler pedicle.

METHODS: The LC-MS method was validated by determining linearity, sensitivity, recovery, carry-over and repeatability. Articaine hydrochloride (40?mg/mL) was administered S/C to six healthy male red deer, at a dose of 1?mL/cm of pedicle circumference, as a complete ring block around the base of each antler. Blood samples were collected at various times over the following 12 hours. Concentrations in plasma of articaine and articainic acid were quantified using the validated LC-MS method. Pharmacokinetic parameters of articaine and articainic acid were estimated using non-compartmental analysis.

RESULTS: Calibration curves were linear for both articaine and articainic acid. The limits of quantifications for articaine and articainic acid were 5 and 10?ng/mL, respectively. Extraction recoveries were >72% for articaine and >68% for articainic acid. After S/C administration as a ring block around the base of each antler, mean maximum concentrations in plasma (C_max) of articaine were 1,013.9 (SD 510.1) ng/mL, detected at 0.17 (SD 0.00) hours, and the C_max for articainic acid was 762.6 (SD 95.4) ng/mL at 0.50 (SD 0.00) hours. The elimination half-lives of articaine hydrochloride and articainic acid were 1.12 (SD 0.17) and 0.90 (SD 0.07) hours, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE: The LC-MS method used for the quantification of articaine and its metabolite articainic acid in the plasma of red deer was simple, accurate and sensitive. Articaine hydrochloride was rapidly absorbed, hydrolysed to its inactive metabolite articainic acid, and eliminated following S/C administration as a ring block in red deer. These favourable pharmacokinetic properties suggest that articaine hydrochloride should be tested for efficacy as a local anaesthetic in red deer for removal of velvet antlers. Further studies to evaluate the safety and residues of articaine hydrochloride and articainic acid are required before articaine can be recommended for use as a local anaesthetic for this purpose.     

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.     

Factors underlying the investment decision in energy-saving systems in Dutch horticulture

In the Netherlands the greenhouse sector is a major user of energy. It accounts for 7% of the total national energy use and for 79% of the total energy use in agriculture. In order to sustain this sector on the long term, it is important that its use of energy is lowered. One way of reducing energy use by horticultural producers is investing in energy-saving systems. The purpose of this paper is to provide a better understanding of the investment behavior of firm operators in the adoption of energy-saving systems. Research objectives of the paper are (1) to analyze factors underlying the decision to invest, (2) to explore factors underlying the optimal size of investments. Three investment theories were used to construct an empirical model of investment. Consequently, this model was estimated in a two-stage procedure to analyze the factors influencing the decision of farmers to invest and the level of investments. The paper ends with policy implications.     

Effects of dietary fermentable carbohydrates on energy metabolism in group-housed sows

The effect of dietary nonstarch polysaccharide (NSP) content on the metabolic rate in group-housed sows was studied. Twelve groups of six nonpregnant sows were each fed one of four experimental diets similar in composition except for the starch and NSP content. Exchanging sugar beet pulp silage (SBPS) for tapioca created the difference in starch and NSP ratio in the diet. On a DM basis, diets contained 0, 10, 20, or 30% SBPS. Sows were group-housed and fed at 1.30 times the assumed maintenance energy requirements. Nitrogen and energy balances were measured per group during a 7-d experimental period, which was preceded by a 33-d adaptation period. Both digestibility and metabolizability of energy decreased with increasing dietary SBPS content (P < 0.05). Heat production and energy retention were unaffected by the exchange of starch for NSP (P > 0.1). Based on energy retention data and apparent fecal digestibilities of crude protein, crude fat, starch, and NSP, the estimated net energy value of fermented NSP was 13.4 kJ/g. The present study shows that group-housed sows are capable of using energy from fermented NSP (i.e., NSP from SBPS) as efficiently as energy from digested starch (i.e., starch from tapioca).     

Cardiovascular effects of romifidine in dogs

OBJECTIVE: To characterize the cardiovascular effects of romifidine at doses ranging from 5 to 100 microg/kg of body weight, IV. ANIMALS: 25 clinically normal male Beagles. PROCEDURE: Romifidine was administered IV at a dose of 5, 10, 25, 50, or 100 microg/kg (n = 5/group). Heart rate, arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, body temperature, cardiac output, and PCV were measured immediately prior to and at selected times after romifidine administration. Cardiac index, stroke index, rate-pressure product, systemic and pulmonary vascular resistance indices, and left and right ventricular stroke work indices were calculated. Degree of sedation was assessed by an observer who was blinded to the dose administered. RESULTS: Romifidine induced a decrease in heart rate, pulmonary arterial pressure, rate-pressure product, cardiac index, and right ventricular stroke work index and an increase in central venous pressure, pulmonary capillary wedge pressure, and systemic vascular resistance index. In dogs given romifidine at a dose of 25, 50, or 100 microg/kg, an initial increase followed by a prolonged decrease in arterial pressure was observed. Arterial pressure immediately decreased in dogs given romifidine at a dose of 5 or 10 microg/kg. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that IV administration of romifidine induces dose-dependent cardiovascular changes in dogs. However, the 2 lowest doses (5 and 10 microg/kg) induced less cardiovascular depression, and doses > or = 25 microg/kg induced similar cardiovascular changes, suggesting that there may be a ceiling on the cardiovascular effects of romifidine.     

Apparent ileal and total-tract nutrient digestion by pigs as affected by dietary nondigestible oligosaccharides

The effects of two types of nondigestible oligosaccharides (NDO), fructooligosaccharides (FOS), and transgalactooligosaccharides (TOS) were studied on growing and weanling pigs' nutrient digestion. Dietary NDO were included at the expense of purified cellulose. Twenty-five 57-d-old growing pigs, averaging 15.9+/-.6 kg on d 0 of the experiment, were fed a corn-based control diet or the control with 6.8 or 13.5 g of FOS/kg or 4.0 or 8.0 g of TOS/kg (five pigs per diet). Feces were collected on d 28 to 32, and small-intestinal digesta were collected (slaughter technique) on d 42 to 47 of the experiment. Feeds, feces, and digesta were analyzed for DM, inorganic matter, CP, ether extract, and crude fiber. Dietary NDO did not significantly affect apparent fecal and small intestinal digestion of nutrients in growing pigs. After being fed a NDO-free diet through d 10 after weaning, 38-d-old weanling pigs (n = 20), averaging 10.4+/-.8 kg on d 0 of the experiment, were fed a control diet (based on cornstarch, casein, and oat husk meal) or the control with 10 or 40 g of FOS or TOS/kg (four pigs per diet). Feces and urine were collected on d 13 to 17, and ileal digesta were collected via a postvalve T-cecum cannula on d 33 to 37 of the experiment. Feeds, feces, and digesta were analyzed for DM, inorganic matter, CP, ether extract, starch, NDF, ADF, ADL, Ca, P, Mg, Fe, Cu, and Zn. Nonstarch neutral-detergent soluble carbohydrates (NNSC) completed the mass balance for the carbohydrates. Urine was analyzed for N and minerals. The apparent fecal digestion of NNSC increased in the NDO-supplemented diets. The TOS-fed pigs tended (P<.10) to have a higher apparent fecal digestion of CP than the FOS-fed and control pigs but excreted more N via the urine (P<.01). Nitrogen and mineral balances were not affected. The FOS was nearly completely degraded prececally. Mean fiber digestion was lower at the fecal compared with the ileal level, as was the extent of NDO effects. This indicates that fiber digestion requires more than 2 wk to adapt to dietary NDO. Apparent ileal digestion of hemicellulose increased for the NDO-supplemented diets (P<.05), but that of NNSC decreased (P<.001). Thus, under the well-controlled conditions of this experiment, dietary NDO hardly affected nutrient digestion in well-kept growing and weanling pigs. However, digestion of dietary nonstarch carbohydrates may be affected.     

Performance of sows fed high levels of nonstarch polysaccharides during gestation and lactation over three parities

The effect of feeding sows a starch diet or a diet with a high level of nonstarch polysaccharides (NSP) during gestation, lactation, or both gestation and lactation during the first three parities on reproductive performance, body weight, and backfat was studied. Four-hundred and forty-four postpuberal gilts were allotted to a 2 x 2 x 2 factorial experiment. Treatments were diet composition during gestation (including the weaning-to-estrus interval; G-Starch: 274 g/kg of starch and 123 g/kg of fermentable NSP or G-NSP: 86 g/kg of starch and 300 g/kg of fermentable NSP), diet composition during lactation (L-Starch: 293 g/kg of starch and 113 g/kg of fermentable NSP or L-NSP: 189 g/kg of starch and 216 g/kg of fermentable NSP) and group-housing system during gestation (free access stalls or electronic feeding). Both gestation diets were formulated to be isoenergetic. During lactation, sows were given free access to the lactation diets from d 6 after parturition onwards. Body weight and backfat gains during gestation were lower in sows fed the G-NSP diet than in those fed the G-starch diet (P < 0.001). The effects were more pronounced in the electronic feeding system than in the free access stalls. These results indicate an overestimation of the energy value of fermentable NSP. Body weight and backfat losses during lactation were less in sows fed the G-NSP diet during gestation than in those fed the G-starch diet (P < 0.05),which can be explained by a 0.4 kg/d higher (P < 0.001) feed intake during lactation of the sows fed the G-NSP diet. Sows fed the L-NSP diet lost more backfat during lactation than sows fed the L-starch diet (P < 0.05). The number of total piglets born and live-born piglets was 0.5 piglet higher in sows fed the G-NSP diet than in those fed the G-starch diet (P < 0.05). Lactation diet did not affect the number of total piglets born or live-born piglets. This study shows that, although high NSP diets negatively influence body weight and backfat thickness of the sows, it is possible to feed sows a diet with a high level of fermentable NSP diet during both gestation and lactation without negative effects on reproductive performance. Under the conditions of this study, feeding sows a diet with a high level of fermentable NSP during gestation and a high level of starch during lactation seems the most favorable feeding strategy.     

Effects of dietary fermentable carbohydrates on behavior and heat production in group-housed sows

The effects of dietary nonstarch polysaccharides (NSP) on behavior and heat production in group-housed sows were studied. Twelve groups of six nonpregnant sows were fed one of four experimental diets that were similar in composition except for starch and NSP contents. Exchanging sugar beet pulp silage (SBPS) for tapioca created the difference in dietary starch and NSP ratio. On a dry matter (DM) basis, diets contained 0, 10, 20, or 30% SBPS. Sows were group-housed. Intake of fermentable NSP (fNSP) for diets containing 0, 10, 20, or 30% SBPS averaged 7.06, 9.18, 11.61, and 13.73 g x kg(-0.75) d(-1), respectively. Sows were fed, once a day at 0800. Dry matter intake for diets containing 0, 10, 20, or 30% SBPS, averaged 38.05, 38.38, 38.53, and 38.35 g x kg(-075) x d(-1), respectively, and ME intake averaged 523, 518, 514, and 493 kJ x kg(-0.75) x d(-1), respectively. On average, sows spent 177 min/d on physical activity, of which 8.8% was spent on eating. Time spent in physical activity was affected by diet (P = 0.005). Sows fed 0 or 10% SBPS spent more time on physical activity than sows fed 20 or 30% SBPS (P = 0.002). Energy cost of physical activity averaged 464 kJ x kg(-0.75) x d(-1) (standard estimated mean of 31) and was similar for diets (P = 0.679). Total heat production (HP) and activity-related heat production (AHP) were affected by diet (P < 0.05). Sows tended to be quieter when fNSP intake increased (P = 0.063). The effect of fNSP intake on HP and AHP was not constant during the day. During the night period, fNSP intake did not affect HP and AHP (P > 0.10). During the day period, increased fNSP intake decreased HP (P = 0.006) and tended to decrease AHP (P = 0.062). During eating, increased fNSP intake increased HP (P = 0.012) and tended to increase AHP (P = 0.074). Despite similar DMI, sows fed 0 or 10% SBPS spent less time eating than sows fed 20 or 30% SBPS (P = 0.009). Feed consumption rate was higher (P = 0.003) in groups fed 0 or 10% SBPS than in groups fed 20 or 30% SBPS. Feed consumption rate decreased by 0.19 g DM x kg(-0.75). min(-1) (P = 0.003) for each gram of fNSP intake. The energy saving effect of physical activity on the NE value of fNSP from SBPS ranged between 2.3 and 3.7 kJ/g of fNSP intake. In conclusion, intake of fNSP from SBPS affected energy expenditure for physical activity (P = 0.063); however, this effect was not constant during the day.