Sonia M Hernandez-Divers

Publications of Sonia M Hernandez-Divers

• Investigation of shell disease in map turtles (graptemys spp.).

  Authors: Stephen J Hernandez-Divers, Patrick Hensel, Juliet Gladden, Sonia M Hernandez-Divers, Kurt A Buhlmann, Chris Hagen, Susan Sanchez, Kenneth S Latimer, Mary Ard, Alvin C Camus

  Journal of wildlife diseases. 08/2009; 45(3):637-52.

  Nineteen map turtles (Graptemys spp.) maintained under natural conditions were investigated because of chronic shell abnormalities. Animals were evaluated using a novel shell scoring system thatNineteen map turtles (Graptemys spp.) maintained under natural conditions were investigated because of chronic shell abnormalities. Animals were evaluated using a novel shell scoring system that divided the 54 scutes into six regions, with each region scored for lesion extent and severity, and summated to produce a total shell disease score (TSDS). Complete blood counts and various biochemistry analytes (total protein, albumin, globulin, urea, uric acid, 25-hydroxycholecalciferol, phosphorus, and ionized and total calcium) were measured. Under ketamine-medetomidine-morphine anesthesia, cytology tape strips and full thickness shell biopsies were collected aseptically for microbiologic, histologic (including scoring of biopsy quality), and ultrastructural evaluations. The TSDSs were low and ranged from 4 to 22 (median = 9) out of a possible score of 54. There were no correlations between TSDS and any hematologic or biochemistry parameter. The histologic quality of shell biopsies was good, and normal shell structure, by both light and electron microscopy, is described. Small clefts and pitting lesions were noted in 8/19 sections. There was no evidence of erosion, ulceration, inflammation, or infectious agents, but algae and diatoms were observed. Six biopsies yielded aerobic isolates (Chryseobacterium indologenes, Aeromonas hydrophila, Ralstonia pickettii, and Morganella morganii), whereas 11 shell samples grew various clostridial anerobes. No fungal organisms were cultured. Although the etiology of the lesions described remains unknown, the use of a scoring system in conjunction with full thickness biopsies is suggested to help standardize investigations into chelonian shell disease in the future.

• Backyard chicken flocks pose a disease risk for neotropic birds in Costa Rica.

  Authors: Sonia M Hernandez-Divers, Pedro Villegas, Carlos Jimenez, Stephen J Hernandez-Divers, Maricarmen Garcia, Sylva M Riblet, C Ron Carroll, Barry M O'Connor, Julie L Webb, Michael J Yabsley, Susan M Williams, Susan Sanchez

  Avian diseases. 01/2009; 52(4):558-66.

  Pathogens of free-ranging chickens create a risk of disease for wild birds, some of which migrate to the United States, as well as potential economic losses for resource-poor farmers. Free-roamingPathogens of free-ranging chickens create a risk of disease for wild birds, some of which migrate to the United States, as well as potential economic losses for resource-poor farmers. Free-roaming backyard chickens are commonly kept in shade-grown coffee plantations, habitats that attract large numbers of wild birds. The husbandry and pathogen prevalence of backyard chicken flocks in San Luis, Costa Rica, were investigated. Based on serologic evidence, Newcastle disease virus, infectious laryngotracheitis virus, infectious bronchitis virus, chicken anemia virus, and infectious bursal disease virus, as well as both Mycoplasma gallisepticum and Mycoplasma synoviae, appear to be significant diseases of this population, and thus, we consider these backyard chickens potential reservoirs for these diseases. There was no evidence of avian influenza. Interviews, clinical examinations, and microscopic examination of tissues led us to believe that poxvirus is also a significant cause of morbidity and mortality in these chickens. We found that Escherichia coli isolates were resistant against tilmicosin, tetracycline, ampicillin, amoxicillin with clavulanic acid, ticarcillin, and cephalothin, and contained genes considered responsible for conferring tetracycline resistance. Additionally, although production was not measured, we suspect that husbandry and lack of preventative medicine are directly related to the diseases reported, all of which negatively affect production.

• Hematology of the Pascagoula map turtle (Graptemys gibbonsi) and the southeast Asian box turtle (Cuora amboinensis).

  Authors: David Perpiñán, Sonia M Hernandez-Divers, Kenneth S Latimer, Thomas Akre, Chris Hagen, Kurt A Buhlmann, Stephen J Hernandez-Divers

  Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 10/2008; 39(3):460-3.

  Turtle populations are decreasing dramatically due to habitat loss and collection for the food and pet market. This study sought to determine hematologic values in two species of turtles to helpTurtle populations are decreasing dramatically due to habitat loss and collection for the food and pet market. This study sought to determine hematologic values in two species of turtles to help assess health status of captive and wild populations. Blood samples were collected from 12 individuals of the Pascagoula map turtle (Graptemys gibbonsi) and seven individuals of the southeast Asian box turtle (Cuora amboinensis) from the Savannah River Ecology Laboratory (South Carolina, USA). The hematologic data included hematocrit, total solids, erythrocyte count, leukocyte count, and differential and percentage leukocyte counts. Low hematocrit values and high basophil counts were found in both species. The basophil was the most abundant leukocyte in the Pascagoula map turtle (median = 0.80 x 10(9)/L), whereas in the Southeast Asian box turtle the most abundant leukocyte was the heterophil (median = 2.06 x 10(9)/L).

• Of birds, people (and coffee): research and conservation in Costa Rica.

  Authors: Sonia M Hernandez-Divers

  Journal of avian medicine and surgery. 04/2008; 22(1):59-65.

• Endoscopic orchidectomy and salpingohysterectomy of pigeons (Columba livia): an avian model for minimally invasive endosurgery.

  Authors: Stephen J Hernandez-Divers, Scott J Stahl, G Heather Wilson, Michael McBride, Sonia M Hernandez-Divers, Tanya Cooper, Nancy Stedman

  Journal of avian medicine and surgery. 04/2007; 21(1):22-37.

  To evaluate a minimally invasive endosurgical system in birds, endoscopic orchidectomy and salpingohysterectomy were evaluated in 11 male and 14 female pigeons (Columba livia). Anesthesia wasTo evaluate a minimally invasive endosurgical system in birds, endoscopic orchidectomy and salpingohysterectomy were evaluated in 11 male and 14 female pigeons (Columba livia). Anesthesia was maintained by using isoflurane delivered by a pressure-cycle ventilator and produced good to excellent anesthesia during 96% of procedures. Endosurgery was performed with a 2.7-mm telescope system, 3-mm human pediatric laparoscopy instruments, and a 4.0-MHz radiofrequency device. Mean +/- SD surgery times for bilateral orchidectomy and salpingohysterectomy procedures were 39 +/- 18 minutes and 34 +/- 15 minutes, respectively. Procedures were generally straightforward, with any minor complications easily overcome. Surgical complications were generally minor, with mild hemorrhage and focal coagulative damage to the kidney being most common. All pigeons recovered quickly (20 +/- 11 minutes), with 95% displaying good to excellent recoveries. No birds exhibited any clinically apparent morbidity or mortality associated with endosurgery. At least 1 male and 1 female bird were subjected to elective euthanasia and necropsy on postoperative days 1, 3, 5, 10, 20, and 90 to determine the success and side effects of surgery. Gross and histologic abnormalities, when observed, were generally mild, with hemorrhage and partial necrosis of the cranial kidney present in 27% of males. Mild damage or hematoma associated with the left kidney was also reported in 28% of females. The surgical objectives were achieved in 23 of 25 pigeons. The 2 surgical failures (regenerated testes in a male and large oviductal remnant in a female) were attributed to endosurgical inexperience and occurred during the first procedures. Salpingohysterectomy does not appear to prevent ovarian development and ovulation in the pigeon, at least not during the first 3 postoperative months. Orchidectomy and salpingohysterectomy appear to be safe procedures when performed using appropriate equipment and techniques. Endosurgery offers a valuable, minimally invasive alternative to the standard coeliotomy techniques commonly used in birds.

• Health evaluation of a radiocollared population of free-ranging Baird's tapirs (Tapirus bairdii) in Costa Rica.

  Authors: Sonia M Hernandez-Divers, Roberto Aguilar, Danilo Leandro-Loria, Charles R Foerster

  Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 07/2005; 36(2):176-87.

  The health of a population of free-ranging tapirs (Tapirus bairdii) inhabiting Corcovado National Park, Costa Rica, was assessed as part of an ongoing ecologic study. Nineteen tapirs were immobilizedThe health of a population of free-ranging tapirs (Tapirus bairdii) inhabiting Corcovado National Park, Costa Rica, was assessed as part of an ongoing ecologic study. Nineteen tapirs were immobilized between March 1997 and February 2000, and samples of blood, skin biopsies, and ectoparasites were collected. Ticks were identified as Amblyomma oblongoguttatum or A. coelebs. Hematology and serum biochemistry results suggest statistically significant differences between free-ranging and captive populations that should be interpreted with caution in view of inherent environmental differences between the two populations. Five of 17 animals tested positive for Leptospira bratislava, and 12 individuals tested positive for Venezuelan equine encephalitis. One of nine skin biopsies examined was abnormal and diagnosed as leukoderma. This report represents the first health assessment of a free-ranging population of tapirs.

• Renal evaluation in the healthy green iguana (Iguana iguana): assessment of plasma biochemistry, glomerular filtration rate, and endoscopic biopsy.

  Authors: Stephen J Hernandez-Divers, Scott J Stahl, Nancy L Stedman, Sonia M Hernandez-Divers, Juergen Schumacher, Christopher S Hanley, Heather Wilson, Anand N Vidyashankar, Ying Zhao, Wilson K Rumbeiha

  Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 06/2005; 36(2):155-68.

  Plasma biochemistry, iohexol clearance, endoscopic renal evaluation, and biopsy were performed in 23 clinically healthy 2-yr-old green iguanas (Iguana iguana). Mean (+/- SD) values for packed cellPlasma biochemistry, iohexol clearance, endoscopic renal evaluation, and biopsy were performed in 23 clinically healthy 2-yr-old green iguanas (Iguana iguana). Mean (+/- SD) values for packed cell volume (30 +/- 3%), total protein (62 +/- 7 g/L, 6.2 +/- 0.7 g/dl), albumin (25 +/- 2 g/L, 2.5 +/- 0.2 g/dl), globulin (37 +/- 6 g/L, 3.7 +/- 0.6 g/ dl), total calcium (3.0 +/- 0.2 mmol/L, 12.0 +/- 0.7 mg/dl), ionized calcium (1.38 +/- 0.1 mmol/L), phosphorus (1.32 +/- 0.28 mmol/L, 4.1 +/- 0.9 mg/dl), uric acid (222 +/- 100 micromol/L, 3.8 +/- 1.7 mg/dl), sodium (148 +/- 3 mmol/L or mEq/ L), and potassium (2.6 +/- 0.4 mmol/L or mEq/L) were considered within normal limits. Values for urea were low (< 1.4 mmol/L, < 4 mg/dl) with 70% of samples below the detectable analyzer range. After the i.v. injection of 75 mg/ kg iohexol into the caudal (ventral coccygeal or tail) vein, serial blood collections were performed over 32 hr. Iohexol assays by high-performance liquid chromatography produced plasma iohexol clearance graphs for each lizard. A three-compartment model was used to fit area under the curve values and to obtain the glomerular filtration rate (GFR) using regression analysis. The mean GFR (SD) was 16.56 +/- 3.90 ml/kg/hr, with a 95% confidence interval of 14.78-18.34 ml/kg/hr. Bilateral endoscopic renal evaluation and biopsy provided tissue samples of excellent diagnostic quality, which correlated with tissue harvested at necropsy and evaluated histologically. None of the 23 animals demonstrated any adverse effects of iohexol clearance or endoscopy. Recommended diagnostics for the evaluation of renal function and disease in the green iguana include plasma biochemical profiles, iohexol clearance, endoscopic examination, and renal biopsy.

• Comparison of isoflurane and sevoflurane anesthesia after premedication with butorphanol in the green iguana (Iguana iguana).

  Authors: Sonia M Hernandez-Divers, Juergen Schumacher, Scott Stahl, Stephen J Hernandez-Divers

  Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 06/2005; 36(2):169-75.

  The anesthetic and cardiopulmonary effects of butorphanol followed by sevoflurane or isoflurane were compared in 23 male green iguanas (Iguana iguana). Heart and respiratory rates were recordedThe anesthetic and cardiopulmonary effects of butorphanol followed by sevoflurane or isoflurane were compared in 23 male green iguanas (Iguana iguana). Heart and respiratory rates were recorded before administration of butorphanol (2 mg/kg i.m.) and at 30 min after premedication. Anesthesia was induced in 12 iguanas (group 1) with isoflurane (5%) and in 11 iguanas (group 2) with sevoflurane (7%). Heart rate, relative arterial oxygen hemoglobin saturation (SpO2), and end-tidal CO2 concentrations (EtCO2) were measured every minute for the first 5 min and every 5 min thereafter. Arterial blood gas parameters were determined at 10 and 40 min after induction. Thirty minutes after butorphanol administration, no significant changes in heart and respiratory rate were seen as compared with baseline values. Quality and time to induction were superior with butorphanol-sevoflurane (6 +/- 3 min) than with butorphanol-isoflurane (9 +/- 4 min). Vaporizer settings during maintenance ranged between 1-3% and 2-4%, respectively. No significant differences in heart rate were noted between groups. In the sevoflurane group, SpO2 values were > 90% throughout. Although SpO2, values were < 90% at 20, 25, and 30 min in the isoflurane group, no significant differences in SpO2 values were seen over time and between groups. A significant decrease in EtCO2 with time was present in both groups, with no significant differences between the groups. At 10 and 40 min, arterial blood oxygen saturation values were > 90% in both groups and no significant differences were noted with time and between groups. Recovery time was significantly longer in the butorphanol-isoflurane group (35 +/- 27 min) than in the butorphanol-sevoflurane group (7 +/- 4 min). The cardiopulmonary effects of butorphanol-isoflurane and butorphanol-sevoflurane assessed in this study are similar, and both inhalants appear to be safe and effective for induction and maintenance in the green iguana.

• Endoscopic sex determination and gonadal manipulation in Gulf of Mexico sturgeon (Acipenser oxyrinchus desotoi).

  Authors: Stephen J Hernandez-Divers, Robert S Bakal, Brian H Hickson, Clarence A Rawlings, Heather G Wilson, MaryAnn Radlinsky, Sonia M Hernandez-Divers, Samuel R Dover

  Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 01/2005; 35(4):459-70.

  Seventeen Gulf of Mexico sturgeons (Acipenser oxyrinchus desotoi) underwent endoscopic sex determination, gonadal biopsy, and various reproductive surgeries as part of a conservation developmentSeventeen Gulf of Mexico sturgeons (Acipenser oxyrinchus desotoi) underwent endoscopic sex determination, gonadal biopsy, and various reproductive surgeries as part of a conservation development plan. The fish were anesthetized with tricaine methanesulfonate (MS-222) buffered with sodium bicarbonate and maintained on a recirculating water anesthesia circuit. A 6-mm Ternamian EndoTip Cannula, placed through the ventral midline, midway between pectoral and pelvic fins, permitted the introduction of a 5-mm telescope. Swim bladder aspiration and CO2 insufflation of the coelomic cavity provided excellent observation. Second and third cannulae were placed under direct visual control, lateral and cranial or caudal to the telescope cannula. Sex determination was successfully performed in all fish; however, five of 17 sturgeons (29%) required endoscopic gonadal biopsy to confirm sex. Bilateral ovariectomy or orchidectomy was successfully performed in three males and four females. Unilateral ovariectomy and bilateral ligation of the müllerian ducts using an extracorporeal suturing technique was accomplished in an additional three females. No apparent morbidity was associated with the anesthesia or endoscopic surgery in any fish. The ability to safely perform minimally invasive reproductive surgery in fish may have important management and conservation benefits.

• Reptile neoplasia: a retrospective study of case submissions to a specialty diagnostic service.

  Authors: Michael M Garner, Sonia M Hernandez-Divers, James T Raymond

  The veterinary clinics of North America. Exotic animal practice. 10/2004; 7(3):653-71, vi.

  This retrospective study appears to be the largest publication to date regarding the prevalence of neoplasia in reptiles. As in previous publications, neoplasia is most common in snakes, followed byThis retrospective study appears to be the largest publication to date regarding the prevalence of neoplasia in reptiles. As in previous publications, neoplasia is most common in snakes, followed by lizards, chelonians, and crocodilians. Several interesting trends were documented in this study, some of which appear to be previously unidentified, and some that support the findings of previous publications.

• Diagnosis of skeletal injuries in Chelonians using computed tomography.

  Authors: Noha Abou-Madi, Peter V Scrivani, George V Kollias, Sonia M Hernandez-Divers

  Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 07/2004; 35(2):226-31.

  Computed tomography (CT) was used to diagnose the cause of lameness in a radiated tortoise (Geochelone radiata) and to determine the extent of shell and skeletal trauma in two snapping turtlesComputed tomography (CT) was used to diagnose the cause of lameness in a radiated tortoise (Geochelone radiata) and to determine the extent of shell and skeletal trauma in two snapping turtles (Chelydra serpentina). The radiated tortoise's lameness was ultimately attributed to luxation of the right-shoulder joint that was not detected during plain film radiography. Axial and appendicular fractures were identified in one of the snapping turtles that were not detected during plain film radiography. In each patient, the information obtained during CT provided important diagnostic, therapeutic, or prognostic information.

• Principles of wound management of small mammals: hedgehogs, prairie dogs, and sugar gliders.

  Authors: Sonia M Hernandez-Divers

  The veterinary clinics of North America. Exotic animal practice. 02/2004; 7(1):1-18, v.

  The management of wounds is a common scenario for the exotic animal practitioner. When presented with such cases, the practitioner must first adhere to the firmly established principles of woundThe management of wounds is a common scenario for the exotic animal practitioner. When presented with such cases, the practitioner must first adhere to the firmly established principles of wound healing, and then modify available treatment modalities to fit the needs of the species at hand. Practicing wound management on exotic patients can be challenging due to their small size, unusual anatomy, difficult behaviors, and tendency for developing secondary stress-related health problems. A review of the stages of wound healing as well as traditional wound management techniques is provided here. This review is followed by a summary of typical wounds encountered in hedgehogs, prairie dogs, and sugar gliders, as well anatomic, physiologic, and behavioral characteristics that should be taken into consideration when managing wounds on such species.

• Neoplasia of reptiles with an emphasis on lizards.

  Authors: Sonia M Hernandez-Divers, Michael M Garner

  The veterinary clinics of North America. Exotic animal practice. 02/2003; 6(1):251-73.

  Neoplasia is an important form of disease in saurians. According to previous reviews, the organs most commonly affected by neoplastic disease are the hematopoeitic system, the hepatic system, and theNeoplasia is an important form of disease in saurians. According to previous reviews, the organs most commonly affected by neoplastic disease are the hematopoeitic system, the hepatic system, and the skin. However, our own review suggests that tumors of the musculoskeletal system are also prevalent. Neoplasia should be considered as a significant differential diagnosis when presented with a lizard that has nonspecific clinical signs. The previously described diagnostic techniques should be applied to obtain a rapid and accurate definitive diagnosis. As more cases of neoplastic disease in saurians are reported, a comprehensive study of the data, including detailed examination of environmental factors, may bring forth causative agents. According to Withrow, cancer is one of the leading killers of pet animals, and thus has become a real concern for dog and cat owners [67]. Given that most people will either know someone with cancer or experience cancer first hand, the general public is more educated than ever on neoplastic disorders. As veterinarians, it is important to become familiar with the neoplastic diseases in all species, and to be educated in tumor pathophysiology and treatment. The public expects veterinarians to be dependable sources of knowledge and compassion.