Rupture of the cranial cruciate ligament associated with deformity of the proximal tibia in five dogs

Excessive mechanical stress due to caudal sloping of the tibial plateau may result in early breakdown of the cranial cruciate ligament (CrCL). Five dogs with CrCL rupture associated with caudal sloping of the proximal tibial plateau are described. All were small dogs, of between three and six years of age, with a mean bodyweight of 9.3 kg, which had acute hindlimb lameness. Radiographic examination revealed cranial displacement of the tibia, with a tibial angle varying from 58 to 60 degrees. All cases were treated with a lateral fabellotibial suture and cranial cuneiform osteotomy of the proximal tibia. All dogs were using the operated limb three days after surgery, with normal gait re-established after a mean period of 10 days. Excessive tibial plateau sloping is not a frequent cause of hindlimb lameness in small animals, although it is important to consider it as a predisposing factor for rupture of the CrCL.     

Chemical restraint of peccaries with tiletamine/zolazepam and xylazine or tiletamine/zolazepam and butorphanol

Objective To evaluate the use of a combination of tiletamine/zolazepam and xylazine (TZX) in collared and white‐lipped peccaries and to compare its efficacy as an anesthetic technique with that of tiletamine/zolazepam and butorphanol (TZB). Study design Prospective experimental trial. Animals Seven white‐lipped peccaries (Tayassu pecari) (four females and three males) and four collared peccaries (Tayasu tajacu) (two males and two females). Methods Animal immobilization was attempted with TZX and TZB (IM) on two different occasions. Heart and respiratory rates (HR, RR), rectal temperature (RT), sedation, muscle relaxation, posture, auditory response and analgesia were evaluated every 15 minutes during immobilization. Induction, anesthesia, standing and walking time were determined after drug administration. Results Doses for white‐lipped peccaries were 1.23 ± 0.26 mg kg^?1 (mean ± SD) of TZ and 1.23 ± 0.26 mg kg^?1 of X, and 1.46 ± 0.09 mg kg^?1 of TZ and 0.14 ± 0.008 mg kg^?1 of B; doses for collared peccaries were 1.51 ± 0.29 mg kg^?1 of TZ and 1.51 ± 0.29 mg kg^?1 of X and 1.68 ± 0.02 mg kg^?1 of TZ and 0.17 ± 0.002 mg kg^?1 of B. In white‐lipped peccaries, both drug combinations provided a smooth induction and good immobilization for more than an hour. Anesthesia and standing times were significantly longer in animals given TZB, whereas walking time was significantly longer in animals given TZX. A significant decrease in HR was observed with both treatments. Respiratory rate decreased significantly with TZX, but the rate remained higher than with TZB. Induction and recovery quality in white‐lipped peccaries was better with TZB than with TZX. Neither protocol provided adequate immobilization in collared peccaries. Conclusion and clinical relevance At the doses described, TZB is effective in providing a long period of immobilization, whereas TZX is adequate for short to medium immobilization in white‐lipped peccaries. Neither drug combination was effective in collared peccaries at the doses given.     

Assessment of dexmedetomidine/ketamine anesthesia in golden-headed lion tamarins (Leontopithecus chrysomelas)

OBJECTIVE: To compare the anesthetic and cardiovascular effects of dexmedetomidine/ketamine combinations in golden-headed lion tamarins. STUDY DESIGN: Prospective blinded randomized study. ANIMALS: Six healthy golden-headed lion tamarins, three males and three females were studied (mean body weight +/- SD = 0.498 +/- 0.054 kg). METHODS: The animals were given one of the dexmedetomidine/ketamine combinations (0.005/10, 0.01/10, and 0.01/5 mg kg(-1) IM; treatments 5D/10K, 10D/10K, and 10D/5K, respectively) on three successive occasions. Time to sedation and recumbency, as well as anesthesia, standing, and walking times were recorded. Heart and respiratory rate, arterial blood pressure, hemoglobin saturation, and rectal temperature were recorded during anesthesia. Sedation, muscle relaxation, and auditory response were evaluated after drug administration. RESULTS: Heart rate decreased after two combinations (10D/5K and 10D/10K). Respiratory rate and rectal temperature progressively decreased in all the treatments. Arterial blood pressures were maintained in 5D/10K and 10D/5K treatments and decreased after 10D/10K administration. There were no differences in sedation and recumbency time between the treatments, but anesthesia time was significantly longer in treatment 10D/10K (67.80 +/- 13.30 minutes) compared to treatments 10D/5K (44.54 +/- 8.25 minutes) and 5D/10K (30.60 +/- 6.80 minutes). Standing time was shorter in treatment 10D/10K (11.13 +/- 10.01 minutes) than in treatments 5D/10K (18.20 +/- 10.03 minutes) and 10D/5K (19.12 +/- 14.55 minutes), and walking time was longer in treatment 5D/10K (20.00 +/- 12.46 minutes) compared with treatments 10D/10K (16.00 +/- 3.43 minutes) and 10D/5K (12.40 +/- 5.02 minutes). Anesthetic quality was significantly better 5 and 15 minutes after treatments 10D/10K and 10D/5K than after treatment 5D/10K. Analgesia scores were higher after administration of 10D/10K than after the 5D/10K treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Dexmedetomidine/ketamine is useful for chemical immobilization of golden-headed lion tamarins, but bradycardia and hypotension warrant close monitoring.     

In vitro follicle culture shows that progestagens are the maturation-inducing hormones (MIH) and possible regulators of the ovulation-mediating hormone PGE2 in female Eurasian perch Perca fluviatilis

In European aquaculture, Eurasian perch, Perca fluviatilis L., is perceived as one of the most highly valuable freshwater fish species and a strong candidate for the development of freshwater aquaculture. In the pursuit of improving the quality of reproduction in this domesticated species, investigating the hormones mediating the final oocyte maturation (FOM) is therefore indispensable. But, the exact nature of the maturation-inducing hormone (MIH) in Eurasian perch is unknown. To further validate the existence of a maturation-inducing activity behind potential hormonal candidates in this species, we in vitro tested a group of nine hormones: cortisol (Co), 11-deoxycortisol (11-D), corticosterone (coS), 11-deoxycorticosterone (DOC), 17α,20βdihydroxy-4-pregnen-3-one (DHP) and 17α,20β,21 trihydroxy-4-pregnen-3-one (THP), prostaglandin E₂ (PGE2), estradiol-17β (E2) and testosterone (T), in their ability to trigger FOM advancement and the production of sex steroids potentially involved in FOM. Using mature female perch, two in vitro experiments were conducted with oocytes at the start of the FOM. The follicles were incubated for 62 h in Cortland media with and without human chorionic gonadotropin (hCG). By the end of the incubation, only DHP and THP triggered the full advancement in FOM even at low doses with the effect of DHP being in vivo validated. However, the de novo productions of E2 and DHP were not shown to be regulated by either of the MIH candidates. Progestagens are hence more credible candidates as MIH than corticosteroids in Eurasian perch. Our in vitro study also revealed that both PGE2 and DHP are strongly associated with ovulation and that PGE2 might have slightly contributed to such DHP activity.

     

Cardiovascular effects of desflurane following acute hemorrhage in dogs

Objective: To determine the cardiovascular effects of desflurane in dogs following acute hemorrhage. Design: Experimental study. Animals: Eight mix breed dogs. Interventions: Hemorrhage was induced by withdrawal of blood until mean arterial pressure (MAP) dropped to 60 mmHg in conscious dogs. Blood pressure was maintained at 60 mmHg for 1 hour by further removal or replacement of blood. Desflurane was delivered by facemask until endotracheal intubation could be performed and a desflurane expiratory end‐tidal concentration of 10.5 V% was maintained. Measurements and main results: Systolic, diastolic, and mean arterial blood pressure (SAP, DAP and MAP), central venous pressure (CVP), cardiac output (CO), stroke volume (SV), cardiac index (CI), systemic vascular resistance (SVR), heart rate (HR), respiratory rate (RR), partial pressure of carbon dioxide in arterial blood (PaCO₂), and arterial pH were recorded before and 60 minutes after hemorrhage, and 5, 15, 30, 45 and 60 minutes after intubation. Sixty minutes after hemorrhage, SAP, DAP, MAP, CVP, CO, CI, SV, PaCO₂, and arterial pH decreased, and HR and RR increased when compared with baselines values. Immediately after intubation, MAP and arterial pH decreased, and PaCO₂ increased. Fifteen minutes after intubation SAP, DAP, MAP, arterial pH, and SVR decreased. At 30 and 45 minutes, MAP and DAP remained decreased and PaCO₂ increased, compared with values measured after hemorrhage. Arterial pH increased after 30 minutes of desflurane administration compared with values measured 5 minutes after intubation. Conclusions: Desflurane induced significant changes in blood pressure and arterial pH when administered to dogs following acute hemorrhage.     

Sedative, analgesic and cardiorespiratory effects of romifidine in cats

OBJECTIVE: To evaluate the sedative, analgesic, and cardiorespiratory effects of intramascular (IM) romifidine in cats. STUDY DESIGN: Prospective, randomized experimental trial. ANIMALS: Ten healthy adult cats. METHODS: Romifidine (100, 200, and 400 microg kg(-1)) or xylazine (1 mg kg(-1)) was given IM in a cross-over study design. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), hemoglobin saturation, oscillometric arterial pressure, and scores for sedation, muscle relaxation, position, auditory response, and analgesia were determined before and after drug administration. Time to recumbency, duration of recumbency, and time to recover from sedation were determined. Subjective evaluation and cardiorespiratory variables were recorded before and at regular intervals for 60 minutes after drug administration. RESULTS: Bradycardia developed in all cats that were given romifidine or xylazine. No other significant differences in physiologic parameters were observed from baseline values or between treatments. Increasing the dose of romifidine did not result in increased sedation or muscle relaxation. Cats given xylazine showed higher sedation and muscle relaxation scores over time. Analgesia scores were significantly higher after administration of romifidine (400 microg kg(-1)) and xylazine (1 mg kg(-1)) than after romifidine at 100 or 200 microg kg(-1). Duration of lateral recumbency was not significantly different between treatments; however, cats took longer to recover after administration of 400 micro g kg(-1) romifidine. CONCLUSIONS AND CLINICAL RELEVANCE: Bradycardia is the most important adverse effect after IM administration of romifidine at doses ranging from 100 to 400 microg kg(-1) or 1 mg kg(-1) of xylazine in cats. The sedative effects of romifidine at 200 microg kg(-1) are comparable to those of 1 mg kg(-1) of xylazine, although muscle relaxation and analgesia were significantly less with romifidine than with xylazine.     

Intraocular pressure determination in clinically normal red-footed tortoise (Geochelone carbonaria).

Intraocular pressure (IOP) reflects a balance between aqueous humor production and outflow and is often an essential ophthalmic diagnostic procedure in animals. The objective of this study was to estimate IOP in clinically normal red-footed tortoises (Geochelone carbonaria) of various sizes by using applanation tonometry. Intraocular pressures were estimated for 25 captive red-footed tortoises (10 males, 10 females, and 5 animals of unknown sex) by using an applanation tonometer after topical anesthesia. Body length ranged from 5.1 to 54.9 cm, measured from nuchal to anal scutes. Five measurements from each eye were obtained by a single observer in an ambient temperature of approximately 30 degrees C. Observer's reliability was good (intraclass r = 0.75), and IOP did not change over the ordered sequence of five replicate measurements. For individual tortoises the correlation for IOP between the left and right eyes was low (r = 0.20). The paired t-test did not show any statistical effect (P = 0.426) for the difference in IOP between the left and right eyes. Mean IOP determined for 10 confirmed males and 10 confirmed females did not differ between sexes (P = 0.244). The mean IOP of five small tortoises (< 10 cm long) was not significantly different (P = 0.244) from that of 20 large tortoises (> 10 cm long). In red-footed tortoises there does not appear to be any relation between carapace length and IOP.     

Cardiopulmonary and isoflurane‐sparing effects of epidural or intravenous infusion of dexmedetomidine in cats undergoing surgery with epidural lidocaine

ObjectiveTo compare the cardiorespiratory, anesthetic-sparing effects and quality of anesthetic recovery after epidural and constant rate intravenous (IV) infusion of dexmedetomidine (DEX) in cats given a low dose of epidural lidocaine under propofol-isoflurane anesthesia and submitted to elective ovariohysterectomy.Study designRandomized, blinded clinical trial.AnimalsTwenty-one adult female cats (mean body weight: 3.1 ± 0.4 kg).MethodsCats received DEX (4 μg kg^?1, IM). Fifteen minutes later, anesthesia was induced with propofol and maintained with isoflurane. Cats were divided into three groups. In GI cats received epidural lidocaine (1 mg kg^?1, n = 7), in GII cats were given epidural lidocaine (1 mg kg^?1) + DEX (4 μg kg^?1, n = 7), and in GIII cats were given epidural lidocaine (1 mg kg^?1) + IV constant rate infusion (CRI) of DEX (0.25 μg kg^?1 minute^?1, n = 7). Variables evaluated included heart rate (HR), respiratory rate (f_R), systemic arterial pressures, rectal temperature (RT), end-tidal CO₂, end-tidal isoflurane concentration (e′ISO), arterial blood gases, and muscle tone. Anesthetic recovery was compared among groups by evaluation of times to recovery, HR, f_R, RT, and degree of analgesia. A paired t-test was used to evaluate pre-medication variables and blood gases within groups. anova was used to compare parametric data, whereas Friedman test was used to compare muscle relaxation.ResultsEpidural and CRI of DEX reduced HR during anesthesia maintenance. Mean ± SD e′ISO ranged from 0.86 ± 0.28% to 1.91 ± 0.63% in GI, from 0.70 ± 0.12% to 0.97 ± 0.20% in GII, and from 0.69 ± 0.12% to 1.17 ± 0.25% in GIII. Cats in GII and GIII had longer recovery periods than in GI.Conclusions and clinical relevanceEpidural and CRI of DEX significantly decreased isoflurane consumption and resulted in recovery of better quality and longer duration, despite bradycardia, without changes in systemic blood pressure.     

Effects of tiletamine/zolazepam-romifidine-atropine in ocelots (Leopardus pardalis)

OBJECTIVES: To evaluate the effects of a combination of tiletamine-zolazepam-romifidine-atropine in ocelots. DESIGN: Prospective experimental trial. ANIMALS: Eight captive adult ocelots (three females and five males). METHODS: Calculated doses of tiletamine-zolazepam (3.75 mg kg(-1)), romifidine (50 microg kg(-1)) and atropine (0.04 mg kg(-1)) were administered intramuscularly. After immobilization, animals were weighed and the real doses determined. Heart rate, respiratory frequency, noninvasive systolic, diastolic, and mean arterial pressure, arterial oxygen hemoglobin saturation, and rectal temperature were measured. Data were analyzed by means of anova for repeated measures, followed by the Tukey test to compare values over time. RESULTS: Doses administered were 3.4 +/- 0.6 mg kg(-1) of tiletamine-zolazepam, 0.04 +/- 7.0 mg kg(-1) of romifidine, and 0.03 +/- 0.007 mg kg(-1) of atropine. The mean time to recumbency and duration of immobilization were 7.0 +/- 4.5 and 109.2 +/- 27.9 minutes, respectively. The median times to standing and walking were 52.3 [0-90] and 2.3 [0-69.3] minutes, respectively. A decrease in heart rate was observed 45 minutes following drug administration. Arterial blood pressure was maintained during the study. CONCLUSIONS AND CLINICAL RELEVANCE: This protocol produced good immobilization in ocelots with minimal changes over time in cardiovascular parameters.     

Comparison of medetomidine-ketamine and dexmedetomidine-ketamine anesthesia in golden-headed lion tamarins

The cardiovascular, respiratory, and anesthetic effects of medetomidine-ketamine (20 microg/kg bodyweight [BW] and 10 mg/kg BW) (MK group) or dexmedetomidine-ketamine (10 microg/kg BW and 10 mg/kg BW) (DK group) were studied in golden-headed lion tamarins. Heart rate decreased after administration of both combinations; this reduction was statistically greater in the DK group than in the MK group after 15 and 45 minutes. Systolic arterial pressure decreased in a similar way in both groups, except at 15 minutes, when systolic arterial pressure was significantly lower in the DK group. Diastolic arterial pressure, mean arterial pressure, respiratory rate, and rectal temperature were progressively reduced in all groups. Sedation time was significantly shorter and anesthesia time was significantly longer in the DK group compared with MK group. Anesthetic quality and analgesia scores were significantly greater at 5 and 15 minutes in the DK group compared with the MK group. The administration of dexmedetomidine-ketamine is as safe and effective as the administration of medetomidine-ketamine in tamarins.