Laurel Degernes - Academia.edu (original) (raw)

Papers by Laurel Degernes

Javma-journal of The American Veterinary Medical Association, Oct 1, 2009

Objective—To determine outcome of bougienage for treatment of benign esophageal stricture (BES) i... more Objective—To determine outcome of bougienage for treatment of benign esophageal stricture (BES) in dogs and cats and identify risk factors for the condition. Design—Retrospective case series. Animals—20 dogs and 8 cats with BES. Procedures—Medical records were reviewed for information on signalment, clinical features, and outcome. Long-term outcome information was obtained with a questionnaire. Results—Esophageal bougienage was performed with dilators ranging from 5 to 15 mm in diameter; median numbers of bougienage procedures were 3 (dogs) and 4.5 (cats). A good outcome, defined as tolerance of solid food with regurgitation less than once a week, was achieved in 14 dogs and 6 cats. Complications were minimal, with nonfatal esophageal perforation occurring in 1 cat. Four dogs and 1 cat were euthanized or died because of esophageal disease. Dogs with BES were more likely to be female, have a recent history of general anesthesia, have received an antimicrobial orally, or have a history of vomiting than were dogs in a reference population. Cats with BES were more likely to have a recent history of general anesthesia, vomiting, or gastrointestinal tract trichobezoars than were cats in a reference population. Doxycycline-induced esophagitis was the suspected cause of BES in 3 cats. Although general anesthesia was associated with development of BES in 18 dogs and 5 cats, concurrent potential causes of esophageal injury were common. Conclusions and Clinical Relevance—Results suggested that esophageal bougienage was a safe and effective treatment for most dogs and cats with BES, with outcomes similar to those reported for balloon dilation.

Comparative Biochemistry and Physiology Part C: Comparative Pharmacology, 1987

The thin caudoventral muscle (TCM) of the muscular stomach of domestic turkeys was surgically exp... more The thin caudoventral muscle (TCM) of the muscular stomach of domestic turkeys was surgically exposed and painted with solutions of saline or 0.1, 0.25,0.5, and 1 .O% benzalkonium chloride (BC), a cationic surfactant shown to irreversibly damage neurons but not muscle tissue in mammals. 2. Following fluoroscopic observations of gastric motility for 2 weeks, turkeys were euthanized, the entire muscular stomach was excised and weighed, and serial frozen sections of the TCM were taken for evaluation of the number and size of neurons in the myenteric plexus. 3. Treatment with 0.5 and 1.0% BC resulted in loss of motility in the TCM, significant hypertrophy (P < 0.001) of the CTM, a 70% decrease in number and 60% decrease in size of myenteric neurons, and a 4-fold increase in thickness of the serosa, compared with saline-treated controls.

PubMed, May 1, 1994

Venous access devices connected to jugular vein catheters were implanted SC in 2 groups of 6 Whit... more Venous access devices connected to jugular vein catheters were implanted SC in 2 groups of 6 White Carneau pigeons (Columba livia). Total parenteral nutrition (TPN), or a control solution (lactated Ringer's solution) was infused as a bolus 4 times daily. Physiologic, hematologic, and biochemical variables were monitored over 5 days. Complications in the TPN-treated pigeons included 8.7% weight loss during the 5-day trial, hyperglycemia for up to 90 minutes after infusion, and glucosuria after infusion. Control pigeons lost 1.3% of their body weight and did not become hyperglycemic or glucosuric after infusion. Hematocrit in both groups of pigeons decreased to a value slightly below published reference values for pigeons. Five pigeons developed venous thrombosis in the proximal part of the cranial vena cava. Results indicated that intermittent administration of TPN is possible in birds; however, further research is required to develop better techniques for administration of TPN solutions. Additionally, it is important to determine, more specifically, the caloric and nutrient requirements of pigeons under stress and receiving TPN.

Veterinary Surgery, Jul 1, 1998

Objective-To measure pullout strength of four pin types in avian humeri and tibiotarsi bones and ... more Objective-To measure pullout strength of four pin types in avian humeri and tibiotarsi bones and to compare slow-speed power and hand insertion methods. Study Design-Axial pin extraction was measured in vitro in avian bones. Animal Population-Four cadaver red-tailed hawks and 12 live red-tailed hawks. Methods-The pullout strength of four fixator pin designs was measured: smooth, negative profile threaded pins engaging one or two cortices and positive profile threaded pins. Part 1: Pins were placed in humeri and tibiotarsi after soft tissue removal. Part 2: Pins were placed in tibiotarsi in anesthetized hawks using slow-speed power or hand insertion. Results-All threaded pins, regardless of pin design, had greater pullout strength than smooth pins in all parts of the study (P < .OOOl). The cortices of tibiotarsi were thicker than the cortices of humeri (P < .OOOl). There were few differences in pin pullout strengths between threaded pin types within or between bone groups. There were no differences between the pullout strength of pins placed by slow-speed power or by hand. Conclusions-There is little advantage of one threaded pin type over another in avian humeri and tibiotarsi using currently available pin designs. There were few differences in pin pullout strengths between humeri and tibiotarsi bones. It is possible that the ease of hand insertion in thin cortices minimizes the potential for wobbling and therefore minimizes the difference between slow-speed drill and hand insertion methods. Clinical Relevance-Threaded pins have superior bone holding strength in avian cortices and may be beneficial for use with external fixation devices in birds.

Veterinary Clinics of North America: Exotic Animal Practice, May 1, 2008

Waterfowl populations may serve as sentinel species for natural and anthropogenic toxicologic pro... more Waterfowl populations may serve as sentinel species for natural and anthropogenic toxicologic problems in the environment. Unfortunately, many toxins cause nonspecific clinical signs, acute mortality, and subtle or no pathologic changes, making toxicologic investigations extremely difficult. The purpose of this article is to review important waterfowl toxins, including heavy metals, pesticides, botulism, mycotoxins, algal toxins, and petroleum oil. When applicable, clinical signs, diagnosis, pathologic findings, and treatment are discussed. Although most of the information in the literature is based on wild waterfowl populations or experimental toxicologic investigations, the information is also applicable to captive waterfowl populations.

Veterinary Pathology, 1997

Seminars in Avian and Exotic Pet Medicine, 1995

Waterfowl populations may serve as sentinel species for natural and man-made toxicological proble... more Waterfowl populations may serve as sentinel species for natural and man-made toxicological problems in the environment. Many toxins cause nonspecific clinical signs, acute mortality, and subtle or no pathological changes, which make toxicological investigations extremely difficult. The purpose of this report is to review the most common toxins causing problems in waterfowl populations, including heavy metals, pesticides, botulism, mycotoxins, algal toxins, and petroleum oil. Where applicable, clinical signs, diagnosis, pathology, and treatment will be discussed. Although most of the information in the literature is based on wild waterfowl populations or experimental toxicological investigations, the information is also applicable to captively managed waterfowl population.

Journal of Avian Medicine and Surgery, Dec 1, 2002

This paper reports on the anesthesia and liver biopsy techniques used in adult and nestling pigeo... more This paper reports on the anesthesia and liver biopsy techniques used in adult and nestling pigeon guillemots (Cepphus columba) to test for continued exposure to residual crude oil in the marine environment. Populations of pigeon guillemots have declined significantly in Prince William Sound, Alaska, USA, possibly because of residual effects of crude oil in the environment after the Exxon Valdez oil spill in March 1989. Measurement of hepatic cytochrome P450 1A (CYP1A) is currently the best way to assess crude oil exposure from food sources; however, lethal sampling to obtain adequate liver tissue was not desirable in this declining population of birds. As part of a larger study to identify factors limiting the recovery of pigeon guillemots and other seabird populations, we surgically collected liver samples from adult and nestling guillemots to provide samples for measurement of hepatic CYP1A concentrations. Results from the larger study were reported elsewhere. Liver samples were taken from 26 nestling (1998) and 24 adult (1999) guillemots from a previously oiled site (Naked Island; 12 chicks, 13 adults) and from a nonoiled site (Jackpot Island/Icy Bay; 14 chicks, 11 adults). The birds were anesthetized with isoflurane. No surgical complications occurred with any of the birds and all adult and nestling birds survived after surgery to the point of release or return to the nest. Thirteen out of 14 chicks from the Jackpot Island/Icy Bay and 8 out of 12 chicks from Naked Island fledged. Four chicks at Naked Island were depredated before fledging. All adults abandoned their nests after surgery, so the study sites were revisited the following summer (2000) in an attempt to assess overwinter survival of the adults. All but 1 adult biopsied bird at the nonoiled site (Icy Bay) was found renesting, whereas only 2 birds at the previously oiled site (Naked Island) were similarly observed. The percent of 1999 breeders at Naked Island that returned to their nest sites to breed again in 2000 was low at nests of biopsied birds and nonbiopsied birds alike, suggesting that factors other than the surgical procedure were responsible for the low return rate among this group. These survival results provide strong support for using experienced veterinarians for nonlethal invasive sample collection from birds to document exposure to crude oil in the marine environment.

Journal of Veterinary Medical Education, Sep 1, 2006

Injured or sick wild avian species, especially raptors (birds of prey, including hawks, owls, fal... more Injured or sick wild avian species, especially raptors (birds of prey, including hawks, owls, falcons, and eagles), can present different challenges to veterinary students and veterinarians who are trained in companion avian medicine (e.g., parrot medicine). Proper capture and restraint, feeding, housing, and certain diagnostic and treatment techniques involving raptors require different skills, knowledge, and resources than working with parrots. We developed an innovative raptor medicine program that enables students to acquire proficiency in safe capture, restraint, and examination techniques and in common diagnostic and treatment procedures. A self-assessment survey was developed to determine students' confidence and proficiency in 10 procedures taught in the lab. Groups were compared by class status (Year 1 vs. Year 2 and 3) and level of prior raptor experience (non-experienced or experienced). In surveys conducted before and after teaching two sets of raptor training labs, students rated themselves significantly more proficient in all 10 diagnostic and treatment procedures after completing the two raptor laboratories. The greatest improvements were observed in technical skill procedures such as fluid administration, intramuscular injections, cloacal swabs, venipuncture, and bandaging. Our approach to incorporating elective wildlife learning experiences into the veterinary curriculum may be replicable in other veterinary schools, with or without a wildlife rehabilitation program.

PubMed, Oct 1, 2008

Avian anesthesia has advanced over the past 2 decades. A variety of inhalation and injectable ane... more Avian anesthesia has advanced over the past 2 decades. A variety of inhalation and injectable anesthetics have been documented to be safe in widely diverse taxonomic groups. In addition, the ability to maintain and monitor cardiovascular and respiratory parameters within normal physiologic ranges has improved. This article emphasizes concepts and equipment that are applicable for companion avian patients typically seen in veterinary clinics; however, much of this information may also be used for wild bird anesthesia and in field conditions.

Journal of the Association of Avian Veterinarians, 1990

RAPTOR: from the Latin word" rapere," meaning to grip or grasp. Since most birds of pre... more RAPTOR: from the Latin word" rapere," meaning to grip or grasp. Since most birds of prey use their feet to grasp their prey," raptor" is a general term defining any predatory bird. reventing or treating foot problems (bumblefoot) in captive or rehabilitating raptors can be ...

Journal of Zoo and Wildlife Medicine, Dec 14, 2012

A captive parakeet auklet at the North Carolina Zoo evaluated for weight loss, lethargy, and dysp... more A captive parakeet auklet at the North Carolina Zoo evaluated for weight loss, lethargy, and dyspnea had radiographic evidence of a distended, stone-filled ventriculus (bird 1). Multiple stones (n = 76) were removed surgically, but the bird died and a large ventricular diverticulum was diagnosed at necropsy. This bird and seven other parakeet auklets had been transferred 3 yr earlier from a zoo in Ohio. Radiographic investigation revealed that 6 of 7 Ohio birds had stones in their ventriculus (n= 2-26), but only 1 of 7 radiographed North Carolina Zoo auklets had one small stone. Further diagnostic imaging (survey and contrast radiographs, fluoroscopy, CT scans [n = 2]) of six Ohio and two North Carolina birds was conducted to determine if other birds had ventricular abnormalities (birds 2-9). No ventricular diverticula were diagnosed using imaging techniques, although two Ohio birds (birds 6 and 7) required surgical intervention to remove 12-26 stones. A small ventricular diverticulum was identified in bird 6 during surgery. That bird died of unrelated causes 11 mo after surgery, but bird 7 remains clinically normal more than 4 yr later, along with four other auklets with stones (n = 2-15; birds 2-5). It is possible that without surgical intervention, these birds may develop ventricular disease, presumably due to chronic mechanical trauma to the thin-walled ventriculus. It was hypothesized that the Ohio birds ingested stones in their previous exhibit, with a loose stone substrate, and retained them for at least 3 yr. Possible causes for stone ingestion include trituration (for grinding, mixing coarse ingesta), gastric parasite reduction, hunger suppression, accidental ingestion while feeding, or behavioral causes, but the underlying cause in these birds was not determined. Based on these results, parakeet auklets and other alcids should not be housed, or at least fed, on a loose stone substrate.

Javma-journal of The American Veterinary Medical Association, Dec 15, 2001

Journal of Avian Medicine and Surgery, Dec 1, 2018

The motion of wing joints is a critical factor for successful flight in avian patients, but littl... more The motion of wing joints is a critical factor for successful flight in avian patients, but little information is available about goniometry in birds. Elbow and carpus joints in flexed and extended positions from 10 orthopedically normal wings of 6 adult wild barred owls (Strix varia) were evaluated with the animals under general anesthesia using a modified universal plastic goniometer and an electrogoniometer. These measurements were compared to those obtained using radiographic assessment. Intra-and interobserver reliability was calculated. Measurements in live animals were compared to those obtained from frozen-thawed carcasses. Results showed that the modified universal plastic goniometer can be used to obtain accurate results for elbow flexion and extension and for carpal flexion with good to excellent reliability compared to measurements collected from radiographic assessment. Measurements obtained using an electrogoniometer were less accurate and less reliable than those obtained with a plastic goniometer, possibly because of the size and configuration of the model used. Comparison of measurements from live animals and carcasses revealed no significant differences between mean measurements and suggested that further evaluation of carcasses as a model for study of goniometry measurements in avian wing joints should be considered.

Journal of the Association of Avian Veterinarians, 1989

Journal of Avian Medicine and Surgery, Mar 1, 2007

This report describes the author's experiences in participating in avian research during 3 field ... more This report describes the author's experiences in participating in avian research during 3 field seasons in remote areas in Prince William Sound (PWS), located in south-central Alaska. Veterinary support was needed to biopsy the livers of nestling and adult pigeon guillemots (Cepphus columba) and adult black oystercatchers (Haematopus bachmani). These surgeries were part of larger research studies investigating guillemot and oystercatcher populations and possible continued exposure to residual crude oil in the marine environment after the Exxon Valdez oil spill in PWS in 1989.

Journal of Avian Medicine and Surgery, Jun 1, 2005

During the winters of 2000-01 and 2001-02, 400 trumpeter (Cygnus buccinator; n ϭ 365) and tundra ... more During the winters of 2000-01 and 2001-02, 400 trumpeter (Cygnus buccinator; n ϭ 365) and tundra (Cygnus columbianus columbianus; n ϭ 35) swans died in northwest Washington State. The carcasses were collected and frozen for necropsy, completed in May 2001 (n ϭ 172) and May 2002 (n ϭ 228). Although most swans died of lead poisoning, 64 (16%) swans had gross pathologic lesions consistent with aspergillosis (trumpeter swan, n ϭ 62; tundra swan, n ϭ 2). Mild fungal infections consisted of small, nonobstructive lesions in the air sacs, trachea, or lungs, with lesions isolated to 1 area. Severe fungal infections consisted of large, extensive infiltrating lesions in the respiratory tract, with 68% of lesions in more than 1 area (lungs, air sacs, or trachea) and many with complete fibrinous casts within air sacs or trachea. Male swans were twice as likely as females to have fungal lesions, although there was no difference in the ratio of males and females with mild or severe infections. Juvenile swans (Ͻ1 year of age) were twice as likely as adults and subadults to have fungal lesions and were also more likely to develop severe versus mild aspergillosis infections (n ϭ 19, n ϭ 1, respectively). Although the number of swans with concurrent lead poisoning and aspergillosis was nearly 30% higher than that of swans with aspergillosis only, when compared with the total number of swans submitted for necropsy, swans with lead poisoning were 75% less likely to have fungal lesions than non-lead-poisoned swans, possibly because of rapid death from lead poisoning.

Journal of Avian Medicine and Surgery, 2005

Journal of Wildlife Diseases, 2013

Waterfowl are natural reservoirs for zoonotic pathogens, and abundant resident (nonmigratory) Can... more Waterfowl are natural reservoirs for zoonotic pathogens, and abundant resident (nonmigratory) Canada Geese (Branta canadensis) in urban and suburban environments pose the potential for transmission of Campylobacter through human contact with fecal deposits and contaminated water. In June 2008 and July 2009, we collected 318 fecal samples from resident Canada Geese at 21 locations in and around Greensboro, North Carolina, to test for Campylobacter. All campylobacter species detected were C. jejuni isolates, and prevalences in 2008 and 2009 were 5.0% and 16.0%, respectively. Prevalence of C. jejuni-positive sampling sites was 21% (3/14) and 40% (6/15) in 2008 and 2009, respectively. All C. jejuni isolates were susceptible to a panel of six antimicrobial agents (tetracycline, streptomycin, erythromycin, kanamycin, nalidixic acid, and ciprofloxacin). We used pulsed-field gel electrophoresis and flatyping to identify several strain types among these isolates. Multilocus sequence typing of representative isolates revealed six sequence types, of which two (ST-3708 and ST-4368) were new, two (ST-702 and ST-4080) had been detected previously among C. jejuni from geese, and two (ST-991 and ST-4071) were first reported in C. jejuni from an environmental water source and a human illness, respectively. These results indicate a diverse population of antibiotic-susceptible C. jejuni in resident Canada Geese in and around Greensboro, North Carolina, and suggest a need for additional assessment of the public health risk associated with resident Canada Geese in urban and suburban areas.