Copyright (c) 2013 All rights reserved. http://works.bepress.com/marcy_souza Recent documents in Marcy J Souza en-us Wed, 01 May 2013 01:40:43 PDT 3600 http://works.bepress.com/marcy_souza/34 http://works.bepress.com/marcy_souza/34 Mon, 29 Apr 2013 11:53:07 PDT Approximately 5.4 million cubic yards of coal fly ash and water spilled into the Emory River embayment of Watts Bar Reservoir in east Tennessee on Dec 22, 2008. Raccoons were collected in 2009 and 2010 from the spill site (10/y) and unexposed areas (5/y) to determine whether metals and metalloids were accumulating in raccoons and if any negative health effects resulted from exposure to the spilled coal fly ash. Tissues were analyzed from each animal to determine the concentrations of 26 metals/metalloids. Complete blood cell counts (CBC), plasma biochemistry panels, and histopathology of select tissues also were performed. Results were analyzed by year and exposure status. Although significant differences were present in some tissues for some metals/metalloids, only arsenic in hair, iron in muscle, nickel in hair, selenium in hair and muscle, strontium in hair, and vanadium in hair and liver were increased in spill site animals (one or both years) compared with unexposed animals. No clinically important differences were observed between groups regarding CBC or plasma biochemistry analyses. Lesions were observed on histopathology in some tissues, but there was no difference in the prevalence of lesions between spill site and unexposed animals. There does not seem to be any important accumulation of metals/metalloids or negative health effects in raccoons associated with exposure to coal fly ash compared with unexposed animals.

]]> Marcy J. Souza et al. http://works.bepress.com/marcy_souza/33 http://works.bepress.com/marcy_souza/33 Wed, 01 Aug 2012 07:36:45 PDT OBJECTIVE: To determine the antinociceptive and sedative effects of tramadol in Hispaniolan Amazon parrots (Amazona ventralis) following IV administration. ANIMALS: 11 healthy Hispaniolan Amazon parrots of unknown sex. PROCEDURES: Tramadol hydrochloride (5 mg/kg, IV) and an equivalent volume (≤ 0.34 mL) of saline (0.9% NaCl) solution were administered to parrots in a complete crossover study design. Foot withdrawal response to a thermal stimulus was determined 30 to 60 minutes before (baseline) and 15, 30, 60, 120, and 240 minutes after treatment administration; agitation-sedation scores were determined for parrots at each of those times. RESULTS: The estimated mean changes in temperature from the baseline value that elicited a foot withdrawal response were 1.65° and -1.08°C after administration of tramadol and saline solution, respectively. Temperatures at which a foot withdrawal response was elicited were significantly higher than baseline values at all 5 evaluation times after administration of tramadol and were significantly lower than baseline values at 30, 120, and 240 minutes after administration of saline solution. No sedation, agitation, or other adverse effects were observed in any of the parrots after administration of tramadol. CONCLUSIONS AND CLINICAL RELEVANCE: Tramadol hydrochloride (5 mg/kg, IV) significantly increased the thermal nociception threshold for Hispaniolan Amazon parrots in the present study. Sedation and adverse effects were not observed. These results are consistent with results of other studies in which the antinociceptive effects of tramadol after oral administration to parrots were determined.

]]> Marcy J. Souza et al. http://works.bepress.com/marcy_souza/32 http://works.bepress.com/marcy_souza/32 Wed, 01 Aug 2012 07:34:39 PDT Marcy J. Souza et al. http://works.bepress.com/marcy_souza/31 http://works.bepress.com/marcy_souza/31 Wed, 01 Aug 2012 07:31:14 PDT Marcy J. Souza et al. http://works.bepress.com/marcy_souza/30 http://works.bepress.com/marcy_souza/30 Wed, 01 Aug 2012 07:29:08 PDT Marcy J. Souza et al. http://works.bepress.com/marcy_souza/29 http://works.bepress.com/marcy_souza/29 Wed, 01 Aug 2012 07:26:04 PDT Marcy J. Souza et al. http://works.bepress.com/marcy_souza/28 http://works.bepress.com/marcy_souza/28 Wed, 31 Aug 2011 08:34:31 PDT William Allen Hill et al. http://works.bepress.com/marcy_souza/27 http://works.bepress.com/marcy_souza/27 Thu, 25 Aug 2011 07:28:32 PDT Eleven cases of pyometra were diagnosed in a captive exotic felid collection over 3 yr in seven African lions (Panthera leo), two tigers (P. tigris), one liger (lion-tiger crossbreed), and one leopard (P. pardus). Clinical signs included anorexia, lethargy, vulvar discharge, and vomiting. Diagnosis was based on clinical signs, complete blood cell counts, plasma biochemistry and electrolyte values, radiographs, and abdominal ultrasonography. The most common findings on complete blood count and biochemistry profiles were leukocytosis (15,000/L) and hyperproteinemia (8.2 g/dL) due to increased globulins. Abdominal radiographic findings were largely nonspecific, but ultrasonography routinely showed a distended, fluid-filled uterus. Each case was treated with ovariohysterectomy and systemic antibiotic therapy. Lions were shown to be at an increased risk for developing pyometra compared with other species. Pyometra should be considered as a differential diagnosis in anorexic or lethargic intact female large felids, and ovariohysterectomy may be warranted in nonbreeding female lions.

]]> S McCain et al. Publications http://works.bepress.com/marcy_souza/26 http://works.bepress.com/marcy_souza/26 Sat, 20 Aug 2011 08:18:36 PDT Positron emission tomography (PET) is often used to stage and monitor human cancer and has recently been used in a similar fashion in veterinary medicine. The most commonly used radiopharmaceutical is 2-Deoxy-2-[(18) F]-Fluoro-d-glucose ((18) F-FDG), which is concentrated and trapped within cells that use glucose as their energy substrate. We characterized the normal distribution of (18) F-FDG in 10 healthy Hispaniolan Amazon parrots (Amazona ventralis) by performing whole body PET scans at steady state, 60min after injection. Significant variability was found in the intestinal activity. Avian species are known to reflux fluid and electrolytes from their cloaca into their colon. To evaluate reflux as the cause of variability in intestinal distribution of (18) F-FDG, dynamic PET scans were performed on the coelomic cavity of six Hispaniolan Amazon parrots from time 0 to 60min postinjection of radiotracer. Reflux of radioactive material from the cloaca into the colon occurred in all birds to varying degrees and occurred before 60min. To evaluate the intestinal tract of clinical avian patients, dynamic scans must be performed starting immediately after injection so that increased radioactivity due to metabolism or hypermetabolic lesions such as cancer can be differentiated from increased radioactivity due to reflux of fluid from the cloaca.

]]> Marcy J. Souza et al. http://works.bepress.com/marcy_souza/25 http://works.bepress.com/marcy_souza/25 Fri, 04 Mar 2011 12:02:52 PST Marcy J. Souza et al. http://works.bepress.com/marcy_souza/24 http://works.bepress.com/marcy_souza/24 Fri, 04 Mar 2011 12:01:12 PST A 4-month-old intact female domestic rabbit (Oryctolagus cuniculus) was evaluated for a recent onset of lethargy, anorexia, foul-smelling red urine, diarrhea, and a soft subcutaneous swelling in the inguinal region. Physical examination confirmed the presence of a flocculent subcutaneous swelling in the ventral pelvic region. Whole body radiographs showed an approximately 5
3.5
3.5 cm structure of mineral opacity within the subcutaneous tissues ventral to the pelvic girdle. Cytology of fluid aspirated from the mass and an excretory urogram supported the diagnosis of a herniation of the urinary bladder through the right caudoventral abdominal body wall. The hernia was successfully repaired with an inguinal herniorrhaphy and replacement of the bladder within the abdominal cavity. The etiology of this herniation could not be definitively determined but was likely congenital or non-traumatically acquired in origin. This is the first published report describing the surgical repair of an inguinal herniation and incarceration of the urinary bladder in an intact female rabbit.

]]> Vanessa Grunkemeyer et al. http://works.bepress.com/marcy_souza/23 http://works.bepress.com/marcy_souza/23 Fri, 04 Mar 2011 11:55:57 PST Erika E. Evans et al. http://works.bepress.com/marcy_souza/22 http://works.bepress.com/marcy_souza/22 Mon, 28 Feb 2011 09:17:15 PST Little research has been performed examining pain control in avian species, and analgesia is becoming increasingly important in veterinary medicine. Tramadol is a relatively new drug that provides analgesia by opioid (mu), serotonin and norepinephrine pathways, with minimal adverse effects. In this study, three red-tailed hawks were dosed orally (11 mg/kg) with tramadol. Blood was collected at various time points between 0 and 360 min and analyzed with HPLC to determine concentrations of tramadol and M1 (O-desmethyltramadol), the predominate active metabolite. Although plasma concentrations of tramadol and M1 associated with analgesia in any avian species is unknown, based on the obtained data and known therapeutic concentrations in humans, future studies should evaluate the analgesia associated with an oral dosage regimens of 15 mg/kg for red-tailed hawks. Pharmacodynamic studies are needed to better determine plasma concentrations of tramadol and M1 that are associated with analgesia in birds.

]]> Marcy J. Souza et al. http://works.bepress.com/marcy_souza/21 http://works.bepress.com/marcy_souza/21 Fri, 16 Apr 2010 13:47:26 PDT D Mann et al. http://works.bepress.com/marcy_souza/20 http://works.bepress.com/marcy_souza/20 Fri, 16 Apr 2010 13:41:22 PDT Fishes, unlike most other vertebrate groups, continue to add sensory hair cells to their ears for much of their lives. However, it is not clear whether the addition ever stops or how the addition of sensory cells impacts hearing ability. In this article, we tested both questions using the zebrafish, Danio rerio. Our results not only have important implications for understanding the consequences of adding sensory receptors, but these results for normal zebrafish also serve as valuable baseline information for future studies of select mutations on the ear and hearing of this species. Our results show that hair cell production continues in uncrowded zebrafish up to 10 months of age (about one-third of a normal life span), but despite this addition there is no change in hearing sensitivity or bandwidth. Therefore, hearing is not related to the number of sensory cells in the ear in juvenile and adult animals. We also show that despite no net addition of hair cells after about 10 months, hair cells are still being produced, but at a lower rate, presumably to replace cells that are dying. Moreover, crowding of zebrafish has a marked impact on the growth of the fish and on the addition of sensory cells to the ear. We also demonstrate that fish size, not age, is a better indicator of developmental state of zebrafish.

]]> D M. Higgs et al. http://works.bepress.com/marcy_souza/19 http://works.bepress.com/marcy_souza/19 Fri, 16 Apr 2010 13:36:57 PDT Animals that thrive both on land and underwater are faced with the task of interpreting stimuli in different media. This becomes a challenge to the sensory receptors in that stimuli (e.g., sound, motion) may convey the same type of information but are transmitted with different physical characteristics. We used auditory brainstem responses to examine hearing abilities of a species that makes full use of these two environments, the American alligator (Alligator mississipiensis). In water, alligators responded to tones from 100 Hz to 2,000 Hz, with peak sensitivity at 800 Hz. In air, they responded to tones from 100 Hz to 8,000 Hz, with peak sensitivity around 1,000 Hz. We also examined the contribution to hearing of an air bubble that becomes trapped in the middle ear as the animal submerges. This bubble has been previously implicated in underwater hearing. Our studies show that the trapped air bubble has no affect on auditory thresholds, suggesting the bubble is not an important adaptation for underwater hearing in this species.

]]> D M. Higgs et al. http://works.bepress.com/marcy_souza/18 http://works.bepress.com/marcy_souza/18 Fri, 16 Apr 2010 13:30:17 PDT Investigations of the development of auditory form and function have, with a few exceptions, thus far been largely restricted to birds and mammals, making it difficult to postulate evolutionary hypotheses. Teleost fishes represent useful models for developmental investigations of the auditory system due to their often extensive period of posthatching development and the diversity of auditory specializations in this group. Using the auditory brainstem response and morphological techniques we investigated the development of auditory form and function in zebrafish (Danio rerio) ranging in size from 10 to 45 mm total length. We found no difference in auditory sensitivity, response latency, or response amplitude with development, but we did find an expansion of maximum detectable frequency from 200 Hz at 10 mm to 4000 Hz at 45 mm TL. The expansion of frequency range coincided with the development of Weberian ossicles in zebrafish, suggesting that changes in hearing ability in this species are driven more by development of auxiliary specializations than by the ear itself. We propose a model for the development of zebrafish hearing wherein the Weberian ossicles gradually increase the range of frequencies available to the inner ear, much as middle ear development increases frequency range in mammals.

]]> D M. Higgs et al. http://works.bepress.com/marcy_souza/17 http://works.bepress.com/marcy_souza/17 Fri, 16 Apr 2010 13:24:07 PDT Marcy J. Souza et al. http://works.bepress.com/marcy_souza/16 http://works.bepress.com/marcy_souza/16 Fri, 16 Apr 2010 13:20:36 PDT Marcy J. Souza et al. http://works.bepress.com/marcy_souza/15 http://works.bepress.com/marcy_souza/15 Fri, 16 Apr 2010 13:16:36 PDT Marcy J. Souza et al.