Joerg Mayer

The Efficacy of Intranasal Administration of Dexmedetomidine and Ketamine to Yellow-Bellied Sliders (Trachemys scripta scripta)

Abstract The purpose of this study was to evaluate the efficacy of dexmedetomidine and ketamine and reversal with atipamezole administered intranasally to Trachemys scripta scripta. Eight healthy adult turtles received 0.2 and 10 mg/kg of dexmedetomidine and ketamine, respectively. Heart rate, respiratory rate, temperature, and sedation (on a scale of 0–4) were measured. Blood was collected 45 min post induction for drug plasma levels from both the subcarapacial and tail veins, followed by intranasal atipamezole administration (0.5 mg/kg). The most frequent sedation scores (2 and 3) provided a level of sedation deep enough to perform a thorough physical exam and minor clinical procedures. All of the turtles became active in 18.9 ± 7 min after atipamezole administration. No adverse effects were observed and all measured cardiopulmonary parameters were within normal limits. Plasma levels of both dexmedetomidine and ketamine indicated adequate absorption and distribution with no difference in the levels obtained from either the subcarapacial or the tail venipuncture sites. A combination of dexmedetomidine–ketamine can be used intranasally to induce moderate to heavy sedation for physical examination, venipuncture, and other minor procedures in the yellow-bellied slider without adverse effects. In addition, the intranasal administration of atipamezole appears efficacious for reversal of dexmedetomidine. Intranasal administration of anesthetic agents holds promise for sedating and anesthetizing chelonians, which are often difficult to thoroughly examine and restrain for biological sample collection, both in the clinic and in the field.

Diagnostic Imaging of Peripheral Vestibular Disease in a Chinese Goose (Anser cygnoides)

Abstract A 20-year-old Chinese goose (Anser cygnoides) presented for severe left-sided head tilt and circling to the left. Peripheral vestibular disease associated with otitis media extending into the left quadrate bone was diagnosed by magnetic resonance imaging and computed tomography. Otoscopy confirmed a ruptured tympanic membrane, and a brainstem auditory evoked response test confirmed loss of hearing in the affected ear. Surgery to remove the caseous material and long-term medical therapy improved the birds head tilt and quality of life. Otitis, hearing loss, and vestibular disease are rare in birds but can be managed after appropriate investigation. This is the first reported use of multiple advanced diagnostic tests and successful treatment of vestibular disease in a goose.

Pharmacokinetics of Levetiracetam in Healthy Hispaniolan Amazon Parrots (Amazona ventralis) After Oral Administration of a Single Dose

Abstract Long-term anticonvulsive treatments have been poorly described in birds, and few pharmacokinetic studies have been performed, with mixed results. Levetiracetam, a new anticonvulsive drug, has shown good efficacy for monotherapy or adjunctive treatment of seizures in both human and veterinary medicine. To determine pharmacokinetics of levetiracetam in Hispaniolan Amazon parrots (Amazona ventralis), 20 healthy birds were randomly divided into 2 groups and administered either a 50 mg/kg (n = 10) or a 100 mg/kg (n = 10) oral dose of levetiracetam with no observable adverse effects. Blood samples were collected at baseline and at 12 time intervals (6 per group) for 16 hours. The concentration–time profiles resembled characteristic absorption, with maximum plasma concentrations of 61.0 μg/mL and 95.1 μg/mL at 60 minutes; terminal half-lives at 2.38 and 2.37 hours; volumes of distribution of 0.807 and 0.773 L/kg, with an area under the curve at 14 100 and 28 820 mg × min/L; and clearance rates of 3.65 and 3.60 mL/min per kg, respectively. Plasma concentrations were greater than 5.5 mg/L for up to 9.4 and 12 hours, suggesting an 8- and 12-hour oral dosing at 50 and 100 mg/kg, respectively, would be sufficient to maintain targeted values. Clinically, doses and frequencies may need escalation based on differences in species and individuals, and drug levels should be monitored.

Gross and histologic evaluation of effects of photobiomodulation, silver sulfadiazine, and a topical antimicrobial product on experimentally induced full-thickness skin wounds in green iguanas (Iguana iguana)

OBJECTIVE To assess effects of photobiomodulation, silver sulfadiazine, and a topical antimicrobial product for the treatment of experimentally induced full-thickness skin wounds in green iguanas (Iguana iguana). ANIMALS 16 healthy subadult green iguanas. PROCEDURES Iguanas were anesthetized, and three 5-mm cutaneous biopsy specimens were obtained from each iguana (day 0). Iguanas were randomly assigned to 2 treatment groups, each of which had a control treatment. Wounds in the topical treatment group received silver sulfadiazine, a topical antimicrobial product, or no treatment. Wounds in the laser treatment group received treatment with a class 4 laser at 5 or 10 J/cm2 or no treatment. Wound measurements were obtained daily for 14 days. Iguanas were euthanized, and treatment sites were evaluated microscopically to detect ulceration, bacterial contamination, reepithelialization, necrosis, inflammation, fibrosis, and collagen maturity. RESULTS On day 14, wounds treated with a laser at 10 J/cm2 were significantly smaller than those treated with silver sulfadiazine, but there were no other significant differences among treatments. Histologically, there were no significant differences in ulceration, bacterial infection, reepithelialization, necrosis, inflammation, fibrosis, and collagen maturity among treatments. CONCLUSIONS AND CLINICAL RELEVANCE Photobiomodulation at 10 J/cm2 appeared to be a safe treatment that was tolerated well by green iguanas, but it did not result in substantial improvement in histologic evidence of wound healing, compared with results for other treatments or no treatment.

THE USE OF THE LIGASURE™ DEVICE FOR SCROTAL ABLATION IN MARSUPIALS

Abstract Five sugar gliders (Petaurus breviceps), ranging in age from 3 mo to 3.5 yr of age, and one opossum (Didelphis virginianus), age 4.5 mo, presented for elective orchiectomy and scrotal ablation. The LigaSure™ device was safely used for orchiectomy and scrotal ablation in both species. Surgical time with the LigaSure was approximately 4 sec. No grooming of the incision site or self-mutilation was seen in the first 72 hr postoperatively. One sugar glider required postoperative wound care approximately 10 days postoperatively following incision-site grooming by a conspecific. The LigaSure provides a rapid, technologically simple and safe surgical technique for scrotal ablation and orchiectomy in the marsupial patient that minimizes surgical, anesthetic, and recovery times.

Spontaneous spinal plexiform perineurioma in a juvenile chicken (Gallus domesticus)

A 2-mo-old pet chicken (Gallus domesticus) was presented because of lameness and a hind limb mass of 1 mo duration. Radiographs revealed a soft tissue mass extending from the mid-femur into the body wall. Cytology of a sample obtained from a fine-needle aspirate was unremarkable. The bird was prepared for surgical investigation of the mass but died acutely at the time of pre-medication. Autopsy revealed an extradural mesenchymal neoplasm that focally compressed the lumbar spinal cord, extended into and along the adjacent nerve structures, and displaced the kidneys, skeletal muscle, and body wall. Histopathology was consistent with a perineurioma, which was positive for alcian blue and negative for S100, GLUT1, and neurofilament proteins on immunohistochemistry. PCR testing of tumor tissue was negative for gallid herpesvirus 2 (Marek’s disease virus) and avian leukosis virus. Although the etiology of the mass was not determined, our case highlights a severe manifestation of an uncommonly diagnosed tumor in the chicken. Though uncommon, perineurioma should be considered a differential diagnosis for lameness in the chicken.

BILATERAL HYDRONEPHROSIS IN A SUGAR GLIDER (PETAURUS BREVICEPS)

Abstract An adult, intact male sugar glider (Petaurus breviceps) presented for acute caudal abdominal swelling. Treatment by the referring veterinarian included aspiration of urine from the swelling. On physical examination, mild depression, pale mucus membranes, and caudal abdominal swelling were noted. Focused ultrasonographic assessment revealed a fluid-filled caudal abdominal structure and subjective bladder wall thickening. The following day, the sugar glider was severely depressed. Hematology results included hypoglycemia, hyperkalemia, hyponatremia, and azotemia. Ultrasonography revealed bilateral hydronephrosis and hydroureter. Despite supportive care, the animal died. Postmortem examination confirmed bilateral ureteral dilation, renal petechial hemorrhage, and dilation of the right renal pelvis. Submucosal edema, hemorrhage, and lymphoplasmacytic infiltration of the urinary bladder, ureters, and renal pelvises were noted. Hyperplasia of the urinary bladder and ureteral epithelium, coupled with inflammation, may have caused functional obstruction leading to bilateral hydronephrosis and hydroureter. This is the first reported case of hydronephrosis in a marsupial.

Coelomic swelling in a spayed female corn snake (Elaphe guttata guttata).

body weight administered intramuscularly and anesthesia was induced using 5% sevoflurane (Ultane, Abbott Laboratories, North Chicago, IL) in 100% oxygen at 0.5 l/min. The snake was maintained on a ventilator (Vetronics, Bioanalytical Systems, Inc., West Lafayette, IN) at 10 breaths per min for the entire procedure, and cardiac function was monitored with an ECG analyzer (Vetronics, Bioanalytical Systems, Inc., West Lafayette, IN) and Doppler monitor (Parks Medical Electronics Inc., Aloha, OR). We placed the snake in a right lateral recumbency. Starting at a point approximately halfway between the snout and the vent (just cranial to the coelomic mass), we made a 10-cm caudally directed ventrolateral skin incision between the first and second row of scales lateral to the ventral scutes. Once the skin incision was made, we incised the body wall and a large quantity of transparent yellow fluid (20 ml) flowed out. as well as a low total protein of 4.5 mg/dl (normal range is 6.6 ± 1.0 mg/dl). On the radiographs, we observed approximately 20 oval nodules ranging in size from 1 cm to 2 cm within the central coelomic area where the swelling occurred (Fig. 1). We recommended surgical removal of the mass, and the owner gave permission. Before commencing surgery, we obtained a computed tomography scan to characterize the extent of the coelomic mass and any possible involvement of other organs. The computed tomography scan showed that the coelomic mass did not involve the liver and lung and that all the nodules had a similar density (Fig. 2). The scan also suggested that fluid was present in the coelomic cavity (Fig. 3). Surgery to remove the mass was carried out the next day. The snake was premedicated with 1 mg butorphanol (Torbugesic, Fort Dodge Animal Health, Fort Dodge, IA) per kg The owner of an 8-year-old, spayed female, captive-born corn snake (Elaphe guttata guttata) presented it to the Exotic Animal Medicine Department at Tufts Cummings School of Veterinary Medicine because of a swelling in the midsection of the snake’s body. The owner reported that the snake had last eaten one freshly killed adult mouse 2 weeks before presentation but had regurgitated the food 2 days later. Usually the snake ate a dead (recently killed or previously frozen) 20-g mouse every 4–5 days. Defecation was normal, and the owner had not observed other indicators of gastrointestinal problems aside from the regurgitation. Six months previously, the snake had an ovariosalpingectomy to remove nine eggs that had been retained for over 3 months and were the cause of severe coelomitis. The snake recovered uneventfully and no further health problems had been observed until now. On physical examination, the snake was alert and responsive and weighed 940 g. We qualitatively assessed her body condition as ideal (index of 5 of 9). We could palpate an oblong, soft, multilobulated swelling of the coelom, approximately 18 cm long and 6 cm wide, that started at a point roughly midway between her snout and vent. We collected a blood sample from the ventral tail vein for a complete blood count and serum biochemistry analysis and also took whole-body radiographs. The hemogram was within normal range. However, biochemical analysis showed a mild hypophosphatemia of 3.7 mg/dl (normal range is 3.8 ± 1.2 mg/dl) and hyponatremia of 148 mEq/l (normal range is 164 ± 9 mEq/l) Coelomic swelling in a spayed female corn snake (Elaphe guttata guttata)

Ectopia cordis in a crested gecko (Rhacodactylus ciliatus).

ABSTRACT A newborn male crested gecko (Rhacodactylus ciliatus) was presented for evaluation immediately after birth because of a bright red movable and pulsating mass emerging from the ventral midline of the rib cage. On physical exam the animal was extremely depressed, and the bright red thoracic mass reported by the owner was identified as a beating heart. The gecko died a short time after presentation and was submitted for a postmortem examination. Gross examination revealed that the entire heart and some adipose tissue were protruding through a 0.4 cm × 0.2 cm elliptical congenital cutaneous cleft located on the ventral aspect of the caudal rib cage. No other gross abnormalities were detected. To the best of our knowledge, this is the first case report of ectopia cordis in a gecko.