Julie A. Smith

Evaluation of Medetomidine, Clove Oil and Propofol for Anesthesia of Leopard Frogs, Rana pipiens

ABSTRACT The clinical effects of medetomidine, clove oil and propofol were evaluated in 36 clinically healthy leopard frogs, Rana pipiens. Under controlled laboratory conditions, heart and respiratory rates were measured at defined intervals during each trial. Corneal, superficial and deep pain withdrawal and righting reflexes were evaluated over time following a single drug administration. Medetomidine (150 μ/kg) failed to produce clinically apparent sedation in any of the frogs (n=12) despite a reduction in respiratory rate. Immersion in a clove oil (eugenol) bath (310 - 318 mg/L for 15 min) induced surgical anesthesia in all frogs (n=12). However, the duration of anesthesia was variable, ranging from less than 5 min to 65 min. Gastric prolapse was a common side effect of clove oil anesthesia (50%, 6/12) but the significance of this effect is unclear. Propofol (10 mg/kg) injected perivascularly in the sublingual plexus area induced sedation in all frogs (n=12) and light anesthesia in 58% (7/12). Propofo...

Agreement between direct and indirect blood pressure measurements obtained from anesthetized Hispaniolan Amazon parrots

OBJECTIVE To determine the level of agreement between direct and indirect blood pressure measurements obtained from healthy Hispaniolan Amazon parrots (Amazona ventralis) anesthetized with isoflurane. DESIGN Validation study. ANIMALS 16 healthy adult Hispaniolan Amazon parrots. PROCEDURES Parrots were anesthetized, and a 26-gauge, 19-mm catheter was placed percutaneously in the superficial ulnar artery for direct measurement of systolic, mean, and diastolic arterial pressures. Indirect blood pressure measurements were obtained with a Doppler ultrasonic flow detector and an oscillometric unit. The Bland-Altman method was used to compare direct and indirect blood pressure values. RESULTS There was substantial disagreement between direct systolic arterial blood pressure and indirect blood pressure measurements obtained with the Doppler detector from the wing (bias, 24 mm Hg; limits of agreement, -37 to 85 mm Hg) and from the leg (bias, 14 mm Hg; limits of agreement, -14 to 42 mm Hg). Attempts to obtain indirect blood pressure measurements with the oscillometric unit were unsuccessful. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that there was substantial disagreement between indirect blood pressure measurements obtained with a Doppler ultrasonic flow detector in anesthetized Hispaniolan Amazon parrots and directly measured systolic arterial blood pressure.

CLINICAL AND CARDIORESPIRATORY EFFECTS OF PROPOFOL IN THE SPOTTED BAMBOO SHARK (CHYLLOSCYLLIUM PLAGIOSUM)

Abstract Sharks are important exhibit animals in aquariums and zoologic institutions worldwide. Although veterinarians are encountering these species more frequently in these institutions, our knowledge regarding safe restraint and anesthesia is limited. To date there have been only a few anecdotal reports or studies evaluating the effects of tricaine methane sulfonate (MS-222), ketamine hydrochloride, and tiletamine and zolazepam (Telazol) in sharks. The purpose of this study was to evaluate the clinical and cardiorespiratory effects of propofol in spotted bamboo sharks (Chylloscyllium plagiosum). Nine wild-caught adult female spotted bamboo sharks (mean weight 2.4 kg ± SD 1.45 kg) were used in this study. Propofol (2.5 mg/kg) was administered over 30 sec via the caudal tail vein. Heart rate, respiratory rate, time to relaxation, escape response, loss of righting reflex, and response to noxious stimuli (fin pinch) were evaluated and recorded at baseline and 5, 10, 15, 30, 45, 60, and 75 min after propofol administration. A surgical plane of anesthesia was achieved when the shark lost its righting reflex, did not respond to noxious painful stimuli, and no longer resisted handling. The righting reflex was lost within 5 min of propofol administration, and a surgical plane of anesthesia was observed in all nine sharks. Heart rate (P = 0.5) and respiratory rate (P = 0.5) did not change significantly over time. The righting response returned within 60 min in 44% (4/9) of the sharks, 75 min in 22% (2/ 9) of the sharks, and over 200 min in 33% (3/9) of the sharks. All nine animals recovered uneventfully. Propofol provided a safe anesthetic event for spotted bamboo sharks.

The Comparative Cardiopulmonary Effects of Spontaneous and Controlled Ventilation by Using the Hallowell EMC Anesthesia WorkStation in Hispaniolan Amazon Parrots (Amazona ventralis)

Abstract This investigation assessed the cardiopulmonary performance, core body temperatures, and arterial blood gases of Hispaniolan Amazon parrots (Amazona ventralis) during 60 minutes of isoflurane anesthesia, using the Hallowell EMC Anesthesia WorkStation (AWS) in combination with controlled intermittent positive pressure ventilation (C-IPPV) or a nonrebreathing system (Bain circuit) with spontaneous ventilation (SV) (n = 6 birds/group). Direct arterial blood pressures, arterial blood gases, end-tidal carbon dioxide (ETco2), end-tidal isoflurane concentration, heart rates, respiratory rates, and esophageal temperatures were monitored during a 60-minute period of isoflurane anesthesia. Compared with baseline measurements and SV, C-IPPV significantly decreased Paco2 and increased pHa but did not significantly reduce mean arterial blood pressure. No significant difference in esophageal temperature was observed between the birds receiving C-IPPV and those breathing spontaneously on the Bain circuit. The PaCO2-ETco2 gradient was significantly greater in birds receiving SV compared with birds receiving C-IPPV. According to the measured parameters, there were neither deleterious effects nor any apparent advantages associated with positive pressure ventilation. The Hallowell EMC AWS appears to be safe and effective when anesthetizing small birds and will be particularly useful during anesthetic periods when positive pressure ventilation is indicated.

Fungal Periodontal Osteomyelitis in a Chameleon, Furcifer pardalis

ABSTRACT An adult 175 g imported panther chameleon, Furcifer pardalis, was presented with a three month history of an open wound on the ventral, rostral mandible. Previous treatments were oral enrofloxacin, and topical application of hydrogen peroxide and an OTC antibiotic preparation. Husbandry and diet appeared adequate and the chameleon was alert with good body condition. Physical examination revealed missing teeth, firm swellings of the rostral and left hemimandibles, an open wound on the rostroventral mandible and symphyseal luxation. Empirical initial treatment included chlorhexidine rinse to the open wound, and cephelexin and metronidazole orally. Metabolic, thermal, and humidity needs were also addressed. On CBC, a large microfilaria and a monocytosis were identified. Radiographically, proliferative lesions were noted in both hemimandibles. Histologic evaluation of bone biopsy yielded numerous branching septate hyphae suggestive of Aspergillus spp.. Acinetobacter spp. sensitive to amikacin and gen...

Intermittent Bradyarrhythmia in a Hispaniolan Amazon Parrot (Amazona ventralis)

ABSTRACT A clinically normal 2-year-old Hispaniolan Amazon parrot (Amazona ventralis) was found to have periodic second-degree atrioventricular (AV) block with variable nodal conductions while anesthetized with isoflurane during a thermal-support research project. Arrhythmias were observed on 5 successive weekly electrocardiograms. A complete cardiac evaluation, including a diagnostic electrocardiogram, revealed intermittent bradyarrhythmias ranging from a 2:1 to a 7:1 second-degree AV block, with concurrent hypotensive episodes during the nodal blocks. Results of a complete blood cell count, plasma biochemical profile, blood gas analysis, and atropine-response test, as well as radiography and auscultation, revealed no obvious cause for the arrhythmias. Echocardiography demonstrated cardiac wall thickness, chamber size, and systolic function similar to other psittacine birds. On return to the colony, the parrot continued to be outwardly asymptomatic despite the dramatic conduction disturbances. Although cardiac arrhythmias, including second-degree AV block, have been widely reported in birds, the wide variation of nodal conductions, the intermittent nature, and an arrhythmia with a 7:1 second-degree AV block that spontaneously reverts to normal as seen in this case have not been well documented in parrots.

Effects of propofol on intraocular pressure in premedicated and nonpremedicated dogs with and without glaucoma

OBJECTIVE To establish a study cutoff for evidence of glaucoma on the basis of IOP measurements from a large population of healthy dogs and to assess the effects of IV propofol administration on IOPs in premedicated and nonpremedicated dogs with and without glaucoma defined by this method. DESIGN Prospective, descriptive study. ANIMALS 234 client-owned dogs. PROCEDURES IOPs measured in 113 healthy dogs (226 eyes) were used to calculate an IOP value indicative of glaucoma. The IOPs were measured in an additional 121 dogs (237 eyes) undergoing ophthalmic surgery. Midazolam-butorphanol was administered IV as preanesthetic medication to 15 and 87 dogs with and without glaucoma, respectively. A placebo (lactated Ringer solution) was administered IV to 8 and 11 dogs with and without glaucoma, respectively. Anesthesia of surgical patients was induced with propofol IV to effect. The IOPs and physiologic variables of interest were recorded before (baseline) and after preanesthetic medication or placebo administration and after propofol administration. RESULTS An IOP > 25 mm Hg was deemed indicative of glaucoma. Compared with baseline measurements, mean IOP was increased after propofol administration in nonpremedicated dogs without glaucoma and unchanged in nonpremedicated dogs with glaucoma. Propofol-associated increases in IOP were blunted in premedicated dogs without glaucoma; IOP in affected eyes of premedicated dogs with glaucoma was decreased after preanesthetic medication and after propofol administration. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that preexisting IOP influences the response to anesthetic drugs, and administration of preanesthetic medication with muscle-relaxing properties may blunt or reduce propofol-induced increases in IOP. Further research with a larger number of dogs is needed to confirm our results in dogs with glaucoma.