Effects of enhancing vitamin D status by 25-hydroxycholecalciferol supplementation,alone or in combination with calcium and phosphorus,on sternum mineralisation and breast meat quality in broilers

1. The aim of the present study was to examine the effects of improving vitamin D status in broiler diets by supplementary 25-hydroxycholecalciferol (25OHD₃), alone or in combination with calcium (Ca) and available phosphorus (aP), on live performance, sternum mineralisation and breast meat quality in broilers.

2. A total of 936 1-d-old Ross 308 broilers were used in the study. After gender determination at the hatchery, chicks from each sex were randomly distributed into three dietary treatments. The following dietary treatments were used in the experiment from hatch to 38 d: (1) A control diet formulated to meet all of the nutrient requirements of broiler chicks according to the management guide; (2) The control diet supplemented with 18.7–15.0 µg/kg of 25OHD₃; and (3) The control diet supplemented with 18.7–15.0 µg/kg of 25OHD₃ plus Ca + aP.

3. Improvement in vitamin D status by 25OHD₃ supplementation, alone or in combination with Ca and aP, had no effect on body weight and feed conversion ratio of broilers.

4. The serum 25OHD₃ concentration significantly increased with 25OHD₃ and 25OHD₃ plus Ca + aP supplementation (P < 0.05), whereas the ionised Ca and Mg concentrations remained unchanged.

5. Sternum absolute weight, ash content and the concentrations of Ca and P significantly increased (P < 0.01) with supplementation of 25OHD₃, alone or in combination with Ca + aP.

6. Supplemental 25OHD₃, alone or in combination with Ca + aP, slightly increased pH₂₄ (P = 0.05) and decreased (P < 0.01) squeezable water loss in breast meat, whereas it had no significant effect on lightness, yellowness and sarcoplasmic protein solubility.

7. In conclusion, the results suggested that enhancing vitamin D status by 25OHD₃ supplementation alone or in combination with Ca + aP may improve sternum structure and mineral accretion. Furthermore, supplemental 25OHD₃, even in a nutritionally complete diet, may offer an effective way to improve protein solubility in female broilers.     

钙与维生素D_3对肉品质的影响

本文首次系统阐述了钙与维生素D3对肉的嫩度及其他食用品质与感官品质的影响 ,并对二者改善肉品质的机理作了深入分析 ,最后指出了今后的研究方向     

The effect of intramuscularly administered vitamin D3 on serum vitamin D metabolites and electrolytes in vitamin D3 deficient dairy cows

The effect of intramuscular administration of vitamin D₃ (1×10⁶ IU D₃/100 kg bodyweight) to 3 different dairy breeds on the serum levels of vitamin D₃, 25-OH-D₂, 25-OH-D₃, Ca, inorganic P and Mg was studied.The vitamin metabolites and the electrolytes were analysed on 9 occasions during a 36-day period. Vitamin D₃ was analysed on 6 occasions during the same period. No significant breed differences were observed except for 25-OH-D₃ (P ≤ 0.05). The D₃ level rose in 1 day from < 2 ng/ml to 906 ng/ml and decreased to below 50 % of the peak level after 6 days. At the end of the experiment (day 36) vitamin D₃ was < 2 ng/ml. 25-OH-D₃ rose from < 2 ng/ml to 106 ng/ml in 6 days and stayed at this level during the whole experiment. 25-OH-D₂ decreased from 16 ng/ml to 5 ng/ml during the observation period.     

Effects of packaging atmospheres on beef instrumental tenderness, fresh color stability, and internal cooked color

Fresh meat color is a major factor influencing the purchase of meat products by consumers, whereas tenderness is the primary trait determining overall eating satisfaction of consumers. The objectives of this research were to determine the effects of packaging atmosphere on fresh beef color stability, cooked color, and tenderness. Longissimus lumborum muscles (n = 14 pairs) from USDA Select, A-maturity carcasses were assigned to either 14-d tenderness measurement or to display and then to 18-d [80% O(2), 20% CO(2) (HiO(2)) modified atmosphere packaging (MAP)] or 28-d [vacuum package (VP) and ultra low (ULO(2)) plus CO MAP blends] tenderness measurement. Loins were then fabricated on d 7 postmortem into 2.54-cm-thick steaks. Steaks 8 to 10 caudal to the first 7 steaks were bisected, assigned to a packaging treatment, and used for internal cooked color. One full steak was used for initial tenderness. Packaging treatments were as follows: vacuum-packaging (VP); 80% O(2), 20% CO(2) (HiO(2)); 0.4% CO, 35% CO(2), 64.6%N(2) (ULO(2)CO); 0.4% CO, 99.6% CO(2) (ULO(2)COCO(2)); 0.4% CO, 99.6% N(2) (ULO(2)CON(2)); or 0.4% CO, 99.6% Ar (ULO(2)COAr). Steaks packaged in HiO(2) MAP were in dark storage (2 degrees C) for 4 d, and all other steaks were in dark storage for 14 d. Steaks were displayed under fluorescent lighting (2,153 lx; 3,000 K) for 7 d, with instrumental color measured on d 0 and 7 of display. Trained color panelists (n = 10) assigned color scores. Steaks for Warner-Bratzler shear force and cooked color were cooked to 70 degrees C. Steaks packaged in the 4 ULO(2) MAP blends with CO had no change (P > 0.05) or increased (P < 0.05) a* values for fresh color. Steaks packaged in VP or the 4 ULO(2) MAP blends with CO had little or no surface discoloration. Steaks packaged in HiO(2) MAP discolored faster (P < 0.05) and 56% more (P < 0.05) than those in any other packaging treatment. There were no differences (P > 0.05) in Warner-Bratzler shear force on d 14 postmortem. Steaks packaged in HiO(2) MAP were less tender (P < 0.05) than the other treatments at the end of display but had 10 d less aging due to a shorter dark storage period. Steaks packaged in HiO(2) had the lowest (P < 0.05) a* values for internal cooked color of all packaging treatments. Steaks packaged in ULO(2)COCO(2) and VP had intermediate a* values, whereas those packaged in ULO(2)COAr, ULO(2)CO, and ULO(2)CON(2) had the greatest (P < 0.05) a* values for internal cooked color. Ultra-low oxygen packaging treatments had longer fresh color stability than steaks packaged in HiO(2) MAP and equal or better tenderness. Packaging atmospheres altered the internal cooked color, with steaks packaged in HiO(2) MAP exhibiting premature browning.     

Effects of anabolic implants of oestradiol alone or in combination with trenbolone acetate on the ultrastructure of mammary glands in female lambs regarding their interference in prolactin secretion

The side-effects of anabolic steroid implants on mammary gland ultrastructure were evaluated in female lambs treated with oestradiol (n = 10) and with oestradiol plus trenbolone acetate (n = 10). Ten non-implanted lambs were used as controls. Apart from the ultrastructural study of the mammary gland, an assessment of the prolactin pituitary cell population was carried out by immunological methods. Our results showed that oestrogenic implants exert stimulating effects on mammary gland development, both by activating the synthesis process at mammary gland cell levels and by increasing prolactin pituitary production. Nevertheless, there was no evidence of secretory products in the lumen of the gland. Implants containing trenbolone acetate counteracted the mammary stimulus of oestrogens showing ultrastructural images of cell autolysis and necrosis.     

Pharmacodynamics of oxytetracycline administered alone and in combination with carprofen in calves

The pharmacodynamics (PD) of oxytetracycline was investigated against a strain of Mannheimia haemolytica. In vitro measurements, comprising minimum inhibitory concentration (MIC), minimum bactericidal concentration and time-kill curves, were conducted in five matrices; Mueller Hinton Broth (MHB), cation-adjusted MHB (CAMHB) and calf serum, exudate and transudate. MICs were much higher in the biological fluids than in MHB and CAMHB. Ratios of MIC were, serum: CAMHB 19 : 1; exudate:CAMHB 16.1; transudate:CAMHB 14 : 1. Ex vivo data, generated in the tissue cage model of inflammation, demonstrated that oxytetracycline, administered to calves intramuscularly at a dose rate of 20 mg/kg, did not inhibit the growth of M haemolytica in serum, exudate and transudate, even at peak concentration. However, using in vitro susceptibility in CAMHB and in vivo-determined pharmacokinetic (PK) variables, average and minimum oxytetracycline concentrations relative to MIC (C(av)/MIC and C(min)/MIC) predicted achievement of efficacy for approximately 48 hours after dosing. Similar C(av)/MIC and C(min)/MIC data were obtained when oxytetracycline was administered in the presence of carprofen. PK-PD integration of data for oxytetracycline, based on MICs determined in the three biological fluids, suggests that it possesses, at most, limited direct killing activity against M haemolytica. These data raise questions concerning the mechanism(s) of action of oxytetracycline, when administered at clinically recommended dose rates.     

Effects of intramuscular alfaxalone alone or in combination with diazepam in swine

ObjectiveTo describe the use of intramuscular (IM) premedication with alfaxalone alone or in combination with diazepam in pigs.Study designRandomised‐controlled trial.AnimalsTwelve healthy 2 month‐old Landrace x Large White pigs weighing 21.3 ± 2.4 kg.MethodsAnimals were distributed randomly into two groups: group A (n = 6) 5 mg kg^?1 of IM alfaxalone; and group AD (n = 6) 5 mg kg^?1 of IM alfaxalone + 0.5 mg kg^?1 of IM diazepam mixed in the same syringe. The total volume of injectate was standardized at 14 mL by dilution in 0.9% sodium chloride. Pain on injection, the degree of sedation and the quality of and time to induction of recumbency were evaluated. Once pigs were recumbent, reflexes were evaluated. Pulse and respiratory rates and arterial oxygen saturation were recorded at 5 and 10 minutes after drug administration. Pigs were then moved to another room for subsequent anaesthesia.ResultsTwo animals of group A and one of group AD showed slight pain on drug injection. Time to lateral recumbency (in seconds) was shorter in group AD (mean 203 ± SD 45 range 140–260) than group A (302 ± 75, range 220–420; p < 0.05). In group AD sedation was deeper, and on recumbency there was better muscle relaxation. When moved for anaesthesia, two pigs in Group A showed slight resistance but did not vocalize. There were no differences in physiologic measurements between groups, although in both groups, respiratory rate was significantly lower at ten compared with five minutes post drug injection. There was no apneoa.Conclusions and clinical relevanceIM administration of alfaxalone combined with diazepam resulted in a rapid onset of recumbency and deep sedation, with minimal side effects. The combination might be useful for premedication, but volume of injectate will limit its use to small pigs.     

Pharmacokinetics and pharmacodynamics of intravenous romifidine and propranolol administered alone or in combination for equine sedation

Objective

Propranolol has been suggested for anxiolysis in horses, but its sedation efficacy and side effects, both when administered alone and in combination with α₂-adrenoceptor agonists, remain undetermined. This study aimed to document the pharmacokinetics and pharmacodynamics of propranolol, romifidine and their combination.

Effects of zeranol and trenbolone acetate on testis function, live weight gain and carcass traits of bulls

The ability of zeranol and trenbolone acetate (trenbolone) to alter testis function, weight gain and carcass traits of young bulls was studied. In Exp. 1, the effects of age at initial zeranol implantation was determined. After a 235-d experimental period, sequential implantation (56-d intervals) beginning at 100 or 150 d of age had reduced testis growth (P less than .01), sperm production (P less than .01) and serum testosterone concentration in response to gonadotropin releasing hormone (GnRH; P less than .01). The 200-d age group was partially suppressed, while the 250-d age group was not affected. Body weights were similar to controls in all groups. In Exp. 2, bulls previously implanted with zeranol at 175 and 231 d of age received single implants of zeranol, trenbolone or trenbolone plus zeranol at approximately 300 d of age. At slaughter (135 d later), body weight and carcass characteristics in all treatments were similar to controls. However, trenbolone reduced sperm production (P less than .05), zeranol reduced sperm production and testes weight (P less than .05), but trenbolone plus zeranol was similar to controls. Mean testosterone response to GnRH was suppressed in all implant groups on d 65 (P less than .01), but only in trenbolone or trenbolone plus zeranol groups on d 112 (P less than .05). Results indicate that zeranol suppresses spermatogenesis and testosterone production if implanted before approximately 200 d of age. Reduction of endogenous testosterone without alteration of weight gain or carcass characteristics may be of benefit if behavioral or masculinity traits of bulls are altered. Also, it appears that no benefit is derived from implanting bulls with both trenbolone and zeranol.     

Comparison of morphine and carprofen administered alone or in combination for analgesia in dogs undergoing ovariohysterectomy

In this study the analgesic efficacy of the pure agonistic opioid morphine and the cyclo-oxygenase type-2-selective carprofen were compared since there is no previous specific comparative study for these two common analgesics. Forty-five bitches undergoing elective ovariohysterectomy were randomly assigned to one of three groups; receiving morphine 0.4 mg/kg bodyweight pre-operatively and 0.2 mg/kg every 4-6 hours thereafter (Morphine group), receiving a once-off carprofen 4 mg/kg injection (Carprofen group) or receiving both morphine and carprofen (MorphCarp group). The dogs were premedicated with acepromazine 0.01 mg/kg and induced with either thiopentone 5-10 mg/kg or propofol 4-6 mg/kg. General anaesthesia was maintained with halothane in oxygen. The degree of pain was assessed over a 24-hour period under blinded conditions using a pain scale modified from the University of Melbourne pain scale and the Glasgow composite pain tool. Physiological parameters such as respiratory rate, pulse rate and body temperature were also assessed over the same time period. There was no significant difference in pain-scores and thus analgesia offered by the three analgesia protocols at any assessment point across the three groups, but there were differences within groups across time points. Baseline total pain-scores were lower than scores at all post-operative points within all three groups. Both morphine and carprofen provided good analgesia without any obvious adverse effects. This study indicates that at the dosages indicated above, carprofen administered on its own produces analgesia equal to that produced by morphine and that the two drugs administered together do not produce better analgesia than either drug administered on its own.     

The effect of estradiol, trenbolone acetate, or zeranol on growth rate, mammary development, carcass traits, and plasma estradiol concentrations of beef heifers.

The effect of a single implantation (on d 1) with one or two long-acting, biodegradable estradiol implants (1E or 2E) on plasma estradiol concentrations in beef heifers was determined. The growth rates of these (2E) heifers, and of heifers repeatedly implanted with trenbolone acetate (TBA) or zeranol (Z) on d 1, 84, 168, and 252 of the trial, were compared to growth rates of controls. Trenbolone acetate alone was compared to TBA + 2E, and 2E was compared to 1E. At a mean age of 84 d (d 1 of experiment), 81 Hereford x Friesian heifers were allocated at random to the following treatments: Control (n = 15); TBA (n = 15); 1E (n = 12); 2E (n = 15); Z (n = 13); or TBA + 2E (n = 11). Mean live weight (kg) prior to slaughter on d 368 and hot carcass weight (kg) for heifers assigned to treatment Groups 1 to 6, respectively, were 366 and 200, 391 and 212, 374 and 201, 386 and 207, 387 and 210, and 391 and 208 (residual SD = 30.3 and 20.2). Heifers assigned to both the 2E and Z treatments were heavier on d 368 (P less than .05) and had longer teats on d 279 (P less than .05), less pelvic fat (P less than .05), and heavier kidneys (P less than .005) than control heifers. Heifers assigned to the TBA treatment had shorter teats on d 279 (P less than .001) but greater final live weight (P less than .05) and carcass weight than control heifers. Heifers given TBA alone had more pelvic fat (P less than .05) and lighter kidneys (P less than .05) than those given TBA + 2E. Mean estradiol concentrations in both the ipsilateral and contralateral jugular veins of heifers assigned to the 2E and TBA + 2E treatments, and in the ipsilateral jugular veins of heifers given 1E, were greater (P less than .05) than those in control heifers; concentrations did not decline during the experiment.     

Supranutritional oral supplementation with vitamin D3 and calcium and the effects on beef tenderness

Ultimate meat tenderness can be influenced by numerous preslaughter and postmortem management techniques. Increased levels of intracellular Ca2+, through postmortem injection, infusion, or marination, have been shown to improve the tenderness of cooked meat products. Oral supplementation with vitamin D3 effectively increases serum Ca2+ and has been hypothesized to increase muscle Ca2+ content, the activity of muscle proteases, and thus the tenderness of cooked beef. Individual Charolais x Hereford heifers (n = 191) were assigned to an unsupplemented control group or groups that were supplemented via oral bolus (for dose regulation purposes) with one of seven levels of vitamin D3 (1, 2, 3, 4, or 5 x 10(6) IU D3/d, 2 x 10(6) IU DS/d plus 75 g CaCO3 or 4 x 106 IU D3/d plus 75 g CaCO3) for 2, 4, 6, or 8 d antemortem. Individual feedlot performance, serum Ca2+ levels, and carcass data were collected, and eight longissimus steaks/carcass were used to obtain Warner-Bratzler shear force values measured at 2, 7, 14, and 21 d postmortem for longissimus steaks cooked to 70 degrees or 85 degrees C. Cattle supplemented with 4 x 10(6) IU D3/d plus 75 g of CaCO3 had lower daily feed intake (as-fed) and reduced (P < 0.05) average daily gains compared with controls during the 8-d supplementation period. Additionally, supplemented cattle had numerically higher dressing percentages, possibly due to less fill at the time of slaughter, because carcass weights and USDA yield grades did not differ (P > 0.05) across treatment groups. Supplementation with 1, 2, 3, 4, or 5 x 10(6) IU D3/d, for 2 or more days, increased (P < 0.05) serum Ca2+ concentrations compared with controls. Whereas cattle that received additional dietary Ca2+ in the form of CaCO3 had the lowest blood serum Ca2+ concentration. Although blood serum Ca2+ was increased, supplementation with any level of vitamin D3 for any length of time up to 8 d did not improve (P > 0.05) Warner-Bratzler shear force at 2, 7, 14, or 21 d of postmortem aging compared with controls when steaks were cooked to final internal temperatures of either 70 (control means 6.27, 4.91, 4.64, and 3.80 kg, respectively) or 85 degrees C (control means 7.31, 5.32, 4.69, and 4.46 kg, respectively). Results indicated that oral supplementation with vitamin D3 (at high or low doses) for 2 to 8 d before slaughter increased serum Ca2+ concentration but does not improve cooked longissimus tenderness.     

Plasma and milk concentrations of vitamin D3 and 25-hydroxy vitamin D3 following intravenous injection of vitamin D3 or 25-hydroxy vitamin D3.

Plasma levels of vitamin D3 or 25-hydroxyvitamin D3 in ewes after administration of a single massive intravenous dose of vitamin D3 (2 X 10(6) IU) or 25-hydroxy vitamin D3 (5 mg) were determined at zero, one, two, three, five, ten and 20 days postinjection. In six ewes injected with vitamin D3 conversion of vitamin D3 to 25-hydroxy vitamin D3 resulted in a six-fold increase in the plasma 25-hydroxy vitamin D3 level within one day. Elevated levels were maintained until day 10 but by day 20 a substantial decline in the plasma 25-hydroxy vitamin D3 level had occurred. Peak levels of vitamin D3 were reached one day after injection and then continuously declined until day 20. Administration of 25-hydroxy vitamin D3 increased plasma concentrations of 25-hydroxy vitamin D3 to fivefold higher levels than those observed when vitamin D3 was injected, with approximately threefold higher levels of 25-hydroxy vitamin D3 maintained for five days. On day 10 and day 20 ewes which were injected with 25-hydroxy vitamin D3 still maintained plasma levels of 25-hydroxy vitamin D3 which were twice as high as those of ewes injected with vitamin D3. In six ewes injected with vitamin D3, a sharp increase in vitamin D3 level in milk occurred within one day and more than a tenfold elevation of milk vitamin D3 concentrations were maintained for ten days. By 20 days the milk vitamin D3 level had returned to preinjection levels. These observations suggest that indirect supplementation of the suckling ruminant with vitamin D3 may be achieved through maternal injection and subsequent mammary transfer.     

Effect of repeated administration of combination trenbolone acetate and estradiol implants on growth, carcass traits, and beef quality of long-fed Holstein steers

Our objective was to determine the effect of repeated use of implants on feedlot performance and carcass characteristics of Holstein cattle. Holstein steers (n = 128) weighing an average of 211 kg were blocked by weight and randomly assigned to 16 pens. At the start of the trial (d 0), pens were assigned to one of four treatments: 1) nonimplanted control (C); 2) implant on d 0, 112, and 224 (T3); 3) implant on d 112 and 224 (T2); and 4) implant on d 224 (T1). Component TE-S implants (120 mg of trenbolone acetate and 24 mg of estradiol per implant) were used for all treatments during the 291-d feeding period. Over the course of the study, T2 and T3 cattle had greater ADG and final weights than C and T1 cattle (P < 0.05). Steers were harvested at a commercial abattoir on d 291. Hot carcass weights of T3 steers were greater than those of C and T1 steers (P < 0.05). Dressing percentage, adjusted 12th-rib fat, percentage of kidney, pelvic, and heart fat, yield grade, and longissimus color were not different among treatments (P > or = 0.26). Longissimus muscle areas (LMA) of T2 and T3 carcasses were larger than LMA of C (P < 0.01). No USDA Select carcasses were produced from C cattle, whereas the percentage of Select carcasses from implanted cattle ranged from 10 to 18%. Skeletal maturity advanced (P < 0.05) progressively with each additional implant. Steaks from T3 carcasses had a higher percentage of protein than controls (P < 0.05) and were less tender than all other treatments (P < 0.05). Repeated administration of combination trenbolone acetate and estradiol implants increased ADG and resulted in heavier carcasses with larger LMA. Administration of three successive implants decreased tenderness of Holstein beef, and resulted in more advanced skeletal maturity scores.     

Effects of dexmedetomidine alone or in combination with opioids on intraocular pressure in healthy Beagle dogs

ObjectiveTo evaluate the effects of dexmedetomidine alone or in combination with different opioids on intraocular pressure (IOP) in dogs.Study designExperimental, prospective, crossover, randomized, blinded study.AnimalsA total of six Beagle dogs (two males and four females) aged 2 years and weighing 15.9 ± 2.9 kg (mean ± standard deviation).MethodsDogs were distributed randomly into seven treatments (n = 6 per treatment) and were administered dexmedetomidine alone (10 μg kg^–1; Dex) or in combination with butorphanol (0.15 mg kg^–1; DexBut), meperidine (5 mg kg^–1; DexMep), methadone (0.5 mg kg^–1; DexMet), morphine (0.5 mg kg^–1; DexMor), nalbuphine (0.5 mg kg^–1; DexNal) or tramadol (5 mg kg^–1; DexTra). All drugs were administered intramuscularly. IOP was measured before drug injection (time 0, baseline) and every 15 minutes thereafter for 120 minutes (T15–T120).ResultsThere were significant reductions in IOP compared with baseline in treatments Dex and DexMep at times T30–T120, and in treatment DexMet at T15–T90. IOP decreased compared with baseline in treatments DexBut, DexNal and DexTra at all evaluation times. No changes in IOP were seen in treatment DexMor. The mean IOP values in treatment DexMet at T105–T120 were higher than those for other treatments.Conclusions and clinical relevanceDexmedetomidine alone or in combination with butorphanol, meperidine, methadone, nalbuphine or tramadol resulted in decreased IOP for 120 minutes in dogs. The magnitude of the reduction was small and lacked clinical significance.     

Effects of methadone, alone or in combination with acepromazine or xylazine, on sedation and physiologic values in dogs

ObjectiveTo evaluate the effects of methadone, administered alone or in combination with acepromazine or xylazine, on sedation and on physiologic values in dogs.Study designRandomized cross-over design.AnimalsSix adult healthy mixed-breed dogs weighing 13.5 ± 4.9 kg.MethodsDogs were injected intramuscularly with physiologic saline (Control), or methadone (0.5mg kg⁻¹) or acepromazine (0.1 mg kg⁻¹) or xylazine (1.0 mg kg⁻¹), or acepromazine (0.05 mg kg⁻¹) plus methadone (0.5 mg kg⁻¹) or xylazine (0.5 mg kg⁻¹) plus methadone (0.5 mg kg⁻¹) in a randomized cross-over design, with at least 1-week intervals. Sedation, pulse rate, indirect systolic arterial pressure, respiratory rate (RR), body temperature and pedal withdrawal reflex were evaluated before and at 15-minute intervals for 90 minutes after treatment.ResultsSedation was greater in dogs receiving xylazine alone, xylazine plus methadone and acepromazine plus methadone. Peak sedative effect occurred within 30 minutes of treatment administration. Pulse rate was lower in dogs that received xylazine either alone or with methadone during most of the study. Systolic arterial pressure decreased only in dogs receiving acepromazine alone. When methadone was administered alone, RR was higher than in other treatments during most of the study and a high prevalence of panting was observed. In all treatments body temperature decreased, this effect being more pronounced in dogs receiving methadone alone or in combination with acepromazine. Pedal withdrawal reflex was absent in four dogs receiving methadone plus xylazine but not in any dog in the remaining treatments.Conclusions and clinical relevanceMethadone alone produces mild sedation and a high prevalence of panting. Greater sedation was achieved when methadone was used in combination with acepromazine or xylazine. The combination xylazine–methadone appears to result in better analgesia than xylazine administered alone. Both combinations of methadone/sedative were considered effective for premedication in dogs.     

Analgesic effects of epidurally administered levogyral ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy

OBJECTIVE: To evaluate the analgesic and adverse effects of epidurally administered levogyral (S[+]) ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy. ANIMALS: 30 dogs scheduled for ovariohysterectomy. PROCEDURE: Dogs were randomly allocated to 1 of 3 groups. Dogs in group 1 received S(+) ketamine (1 mg/kg), dogs in group 2 received S(+) ketamine (0.5 mg/kg) and morphine (0.05 mg/kg), and dogs in group 3 received S(+) ketamine (1 mg/kg) and morphine (0.025 mg/kg). The skin was incised 15 minutes after epidural administration of analgesics. Heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), oxygen saturation as measured by pulse oximetry, and arterial blood gases were obtained before anesthesia, 15 minutes after epidural administration of analgesics, 15 and 30 minutes after initiation of surgery, and at the end of surgery. During the intraoperative period, an increase of > or =20% in baseline values for HR, RR, and SBP was considered a sign of intraoperative pain. Signs of pain and adverse effects were assessed at 2, 4, and 8 hours postoperatively. RESULTS: There were no significant differences in intraoperative or postoperative measurements among the 3 groups. No dogs had intraoperative signs of pain. Mean postoperative pain assessment scores were <3.5 in all 3 groups. Salivation was the most frequent adverse effect in dogs in groups 1 and 3, and sedation occurred more frequently in dogs in groups 2 and 3. CONCLUSIONS AND CLINICAL RELEVANCE: All 3 analgesic regimens provided good respiratory and cardiovascular stability intraoperatively and adequate postoperative analgesia with minimal adverse effects.     

Effects of phenylbutazone alone or in combination with flunixin meglumine on blood protein concentrations in horses

OBJECTIVE: To assess effects of treatment with phenylbutazone (PBZ) or a combination of PBZ and flunixin meglumine in horses. ANIMALS: 24 adult horses. PROCEDURE: 13 horses received nonsteroidal antiinflammatory drugs (NSAIDs) in a crossover design. Eleven control horses were exposed to similar environmental conditions. Treated horses received PBZ (2.2 mg/kg, PO, q 12 h, for 5 days) and a combination of PBZ and flunixin meglumine (PBZ, 2.2 mg/kg, PO, q 12 h, for 5 days; flunixin meglumine, 1.1 mg/kg, IV, q 12 h, for 5 days). Serum samples were obtained on day 0 (first day of treatment) and day 5, and total protein, albumin, and globulin were measured. RESULTS: 1 horse was euthanatized with severe hypoproteinemia, hypoalbuminemia, and colitis during the combination treatment. Comparisons revealed no significant difference between control horses and horses treated with PBZ alone. There was a significant difference between control and treated horses when administered a combination of PBZ and flunixin meglumine. Correction for horses with values >2 SDs from the mean revealed a significant difference between control horses and horses administered the combination treatment, between control horses and horses administered PBZ alone, and between horses receiving the combination treatment and PBZ alone. Gastroscopy of 4 horses revealed substantial gastric ulcers when receiving the combination NSAID treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of the study indicates the need for caution when administering a combination NSAID treatment to horses because the detrimental effects may outweigh any potential benefits.