David Sanchez-Migallon Guzman

University of California, Davis | UCD · Department of Veterinary Medicine and Epidemiology

Objective: To evaluate behaviors associated with inflammatory pain induced by carrageenan injection in the cockatiel and determine interobserver agreement. Animals: 16 adult cockatiels. Methods: Cockatiels were randomly assigned as either treatment (carrageenan injection) or control (sham injection) group. The treatment group received a subcut...

A 2-year-old male African penguin (Spheniscus demersus) was presented to a veterinary teaching hospital for evaluation of a previously diagnosed subclinical, marked regenerative anemia. Physical examination at the zoological institution demonstrated biliverdinuria and pale oral mucous membranes. Diagnostic tests performed on the penguin since the d...

OBJECTIVE To determine the pharmacokinetic parameters of hydromorphone hydrochloride and its metabolite, hydromorphone-3-glucuronide (H3G), after a single IV and IM dose in great horned owls ( Bubo virginianus ). ANIMALS 6 healthy adult great horned owls (3 females and 3 males). PROCEDURES A single dose of hydromorphone (0.6 mg/kg) was administer...

Objective: To determine the pharmacokinetics of 8 cannabinoids and 5 metabolites after oral administration of single and multiple doses of a cannabidiol (CBD)-cannabidiolic acid (CBDA)-rich hemp extract to orange-winged Amazon parrots (Amazona amazonica) as well as to evaluate the extract's adverse effects. Animals: 12 birds. Procedures: Based...

Rabbits occupy facets of veterinary medicine spanning from companion mammals, wildlife medicine, zoologic species, and research models. Therefore, analgesia is required for a variety of conditions in rabbits and is a critical component of patient care. Considerations when selecting an analgesic protocol in rabbits include timing of administration,...

This article provides an overview of the current understanding of evidence-based clinical analgesic use in birds. The field of avian analgesia has dramatically expanded during the last 20 years, affording more options for alleviating both acute and chronic pain. These options include opioids, nonsteroidal anti-inflammatory drugs, local anesthetics,...

The recognition and assessment of pain in avian species are crucial tools in providing adequate supportive care in clinical, laboratory, zoologic, rehabilitation, and companion animal settings. With birds being a highly diverse class of species, there is still much to be determined regarding how to create specific criteria to recognize and assess p...

Although cockatiels are among the most common avian species maintained as companion animals in the United States, information on standard hematologic reference values for this species is limited. The objectives of this study were to establish hematologic reference intervals (RI) for cockatiels, compare methods using both the Natt-Herrick technique...

A 1-year-old intact female inland bearded dragon (Pogona vitticeps) was presented approximately 24 hours following observed ingestion of a marble. Orthogonal whole-body radiographs with and without contrast revealed a spherical radiopaque foreign body within the gastric lumen and no passage of contrast material beyond the foreign body, suggestive o...

Fluoroscopic angiography evaluates the heart and vascular tree in real time and can be recorded for further diagnostic analysis and measurements. Although reports have been published of the use of fluoroscopic angiography in birds, this technique has not been evaluated in any avian species. The purpose of this study was to evaluate a fluoroscopic a...

The appropriate recognition and assessment of pain in animals is an essential tool that can be used by veterinary professionals, rehabilitators, household caregivers, and others to provide supportive care and analgesia to patients. Although the use of behavioral, postural, and facial changes to recognize pain have been studied in popular domestic s...

OBJECTIVE To document clinicopathologic findings in domestic rabbits with liver lobe torsion and identify prognostic factors. ANIMALS 82 rabbits. PROCEDURE Medical records of 4 institutions were reviewed to identify rabbits with an antemortem diagnosis of liver lobe torsion that were examined between 2010 and 2020. RESULTS The prevalence of live...

Objectives: To determine the pharmacokinetics of butorphanol tartrate incorporated into poloxamer 407 (P407) after subcutaneous administration to orange-winged Amazon parrots (Amazona amazonica). Animals: Six orange-winged Amazon parrots, ages 28 to 45 years. Procedures: A sterile formulation of butorphanol in P407 (But-P407) as a 25% gel was...

Objectives: To evaluate a carrageenan-induced inflammatory model in the cockatiel (Nymphicus hollandicus) using weight-bearing load, rotational perch locomotion, thermal threshold withdrawal, and footpad dimensions. Animals: 16 adult cockatiels (8 males and 8 females). Procedures: Cockatiels were randomly assigned into 2 groups as either treat...

Maropitant citrate is a synthetic neurokinin‐1 receptor antagonist and substance P inhibitor used for control of emesis in dogs in cats. Maropitant citrate is used empirically in birds, despite a lack of pharmacokinetic data in avian species. The objective of this study was to determine the pharmacokinetic profile of a single dose of maropitant cit...

A 9-year-old female spayed Holland Lop rabbit (Oryctolagus cuniculus) presented with abnormal eyelid positioning on the right eye of 2 week duration. A full neurological examination revealed ptosis, enopthalmia, decreased palpebral reflex of the right eye. A pre and post contrast CT-study confirmed a large heterogeneously contrast-enhancing and par...

OBJECTIVE To document the clinical signs, diagnosis, and treatment of urolithiasis in green iguanas ( Iguana iguana ) and to report on the composition of uroliths from green iguanas submitted to the Minnesota Urolith Center for analysis. ANIMALS 21 green iguanas with urolithiasis. PROCEDURES Medical record databases of multiple veterinary teachin...

Envenomation in avian species can result in death, with few cases of successful treatment described. A juvenile, wild-caught, intact female red-tailed hawk (Buteo jamaicensis) used in falconry was presented for emergency evaluation after being bitten by a Northern Pacific rattlesnake (Crotalus oreganus) approximately 2 hours before presentation. On...

OBJECTIVE To evaluate neurological tests and expected results in inland bearded dragons ( Pogona vitticeps ) and generate recommendations for bearded dragon–specific neurological examination. ANIMALS 26 healthy adult inland bearded dragons. PROCEDURES A complete neurological examination utilizing tests described in both mammals and reptiles was p...

OBJECTIVE To determine the clinical and pathological findings of rabbits diagnosed with lymphoma. ANIMALS 16 rabbits. PROCEDURES The medical and pathology records database of the Veterinary Medical Teaching Hospital at the University of California, Davis was searched for rabbits diagnosed with lymphoma from 1996 to 2019. RESULTS Mean age of the...

OBJECTIVE To determine the pharmacokinetics and potential adverse effects of pimobendan after oral administration in New Zealand White rabbits ( Ocytolagus cuniculi ). ANIMALS 10 adult sexually intact (5 males and 5 females) rabbits. PROCEDURES 2 pilot studies were performed with a pimobendan suspension or oral tablets. Eight rabbits received 7.5...

CASE DESCRIPTION An 8-year-old sexually intact female eclectus parrot ( Eclectus roratus ) with a 4-day history of hyporexia and lethargy and a 1-day history of tenesmus was examined. CLINICAL FINDINGS Severe leukocytosis characterized by severe heterophilia and moderate monocytosis was present. Marked dilation of the proventriculus and ventriculu...

Objective: To determine epidemiological features of cardiovascular disease in rabbits examined at a veterinary teaching hospital and characterize clinical and pathological findings. Animals: 59 rabbits. Procedures: Medical records from 2001 to 2018 were reviewed, and data were collected. Echocardiographic images and histologic diagnoses were r...

Pain recognition is more challenging in birds than in domestic animals and typically relies on the assessment of species-specific behaviors. Avian analgesia is an active area of research, and drug recommendations may be different by species, especially for opioids and even within related parrot species. In general, butorphanol is used in psittacine...

A 27-y-old female black-handed spider monkey (Ateles geoffroyi) was evaluated 13 d after an ovariohysterectomy because of abdominal distension, anorexia, and absent urination. The animal was diagnosed with a uroabdomen and urethral obstruction from computed tomographic findings and fluid creatinine levels. During exploratory laparotomy, a defect in...

This prospective study evaluated oral transmucosal pentobarbital sodium at three doses in 110 wild-caught wild birds requiring euthanasia. Birds received transmucosal pentobarbital at five (430 mg/kg), six (516 mg/kg), and seven times (602 mg/kg) the intravenous dose for mammals. Time to first effects and loss of consciousness, presence of pupillar...

The fundamentals of fracture management and methods of fixation (external coaptation, intramedullary pinning, external skeletal fixation, bone plating) are reviewed with emphasis in small exotic mammals. The specific fractures of the bones of the thoracic lib, pelvic limb, vertebra, and skull are discussed, detailing anatomic considerations and par...

Objective: To evaluate the pharmacokinetics of hydromorphone hydrochloride after IM and IV administration to orange-winged Amazon parrots (Amazona amazonica). Animals: 8 orange-winged Amazon parrots (4 males and 4 females). Procedures: Hydromorphone (1 mg/kg) was administered once IM. Blood samples were collected 5 minutes and 0.5, 1.5, 2, 3,...

Objective: To evaluate the thermal antinociceptive effects of hydromorphone hydrochloride after IM administration to orange-winged Amazon parrots (Amazona amazonica). Animals: 8 healthy adult parrots (4 males and 4 females). Procedures: In a randomized crossover study, each bird received hydromorphone (0.1, 1, and 2 mg/kg) and saline (0.9% NaC...

Avian species have varying analgesic responses to opioid drugs. Some of this variability could be due to extrinsic factors such as administration route or dose. However, intrinsic factors such as gene expression or polymorphic differences in opioid receptors may be important components. Objectives: The objectives of this study were to determine t...

Objective: To characterize the CT findings and epidemiological features of acquired dental disease in rabbits. Animals: 100 client-owned rabbits (Oryctolagus cuniculus). Procedures: Medical records were searched to identify rabbits that underwent skull CT for any reason from 2009 to 2017. History, signalment, and physical examination findings...

Objective: To determine the pharmacokinetics of amantadine after oral administration of single and multiple doses to orange-winged Amazon parrots (Amazona amazonica). Animals: 12 adult orange-winged Amazon parrots (6 males and 6 females). Procedures: A single dose of amantadine was orally administered to 6 birds at 5 mg/kg (n = 2), 10 mg/kg (2...

Objective: To compare the torsional mechanical properties of 2 external skeletal fixators (ESFs) placed with 2 intramedullary pin (IP) and transfixation pin (TP) size combinations in a model of raptor tibiotarsal bone fracture. Sample: 24 ESF-synthetic tibiotarsal bone model (polyoxymethylene) constructs. Procedures: Synthetic bone models were...

Objective: To determine the thermal antinociceptive effects of butorphanol tartrate and butorphanol tartrate in a sustained-release 25% poloxamer 407 (P407) gel formulation (But-P407) in parrots. Animals: 13 orange-winged Amazon parrots (Amazona amazonica). Procedures: First, butorphanol tartrate (5 mg/kg) or saline (0.9% NaCl) solution was ad...

Atorvastatin is a synthetic statin administered in its active form and used for the treatment of dyslipidemias. In the current study, the effects of atorvastatin were evaluated on plasma lipid profiles and the potential for adverse effects after once daily PO dosing of atorvastatin for 30 days in Hispaniolan Amazon parrots (Amazona ventralis). Sixt...

A 33-year-old male blue and gold macaw (Ara ararauna) presented with a 5-month history of an ulcerated lesion and feather loss at the tail base. Two 4-mm biopsies obtained by the primary care veterinarian were consistent with uropygial gland adenocarcinoma. The bird was examined at the Veterinary Medical Teaching Hospital, University of California,...

Objective: To compare a ventral and a left lateral endoscopic approach to coelioscopy in bearded dragons (Pogona vitticeps). Animals: 18 adult bearded dragons. Procedures: In a randomized crossover design involving 2 surgical approaches, anesthetized bearded dragons first underwent coelioscopy with a ventral approach (left lateral of midline n...

The general principles of soft tissue surgery in rabbits, including presurgical considerations, surgical principles and postoperative considerations, are discussed. The indications, approach and complications associated with soft tissue surgeries in rabbits of the integumentary system (removal of the perineal skin folds and inguinal pouches), the e...

A retrospective case series that included 253 free-ranging birds of prey admitted to a rehabilitation center was conducted to describe the treatment and outcome of antebrachial fractures. Medical records from birds of prey belonging to 21 species admitted with antebrachial fracture between 1989 and 2015 at the University of California, Davis, were...

The efficacy and safety of anesthetic techniques in wildlife have increased greatly, but complications still exist. Some of these complications are predictable but others, such as hyperthermia, acidosis, and capture myopathy may result from the capture event. With anesthesia of domestic animals, it is often possible to titrate induction drugs to mi...

Background: Bone marrow aspirate assessments provide valuable information about hematopoietic status and hematologic disease. Hematopoietic cell differentials and morphologies have been anecdotally described in psittacines, but quantitative studies are lacking. Objectives: We aimed to determine differential cell counts and calculate granulocyte:...

A 4-year-old castrated male lop-eared rabbit (Oryctolagus cuniculus) presented for right thoracic limb weakness of one week's duration. Radiographs of the limb and adjacent spine were unremarkable. Despite treatment with meloxicam, limb weakness slowly progressed. Four months after initial presentation, neurologic examination revealed monoplegia wi...

Background Mammary fibroadenomas are one of the most common tumors of female companion rats (Rattus norvegicus forma domestica). The objectives of this study were to determine if subcutaneous administration of a deslorelin implant following excision of fibroadenomas can prevent or delay development of additional mammary tumors and increase survival...

We report a case of ventricular septal defect causing congestive heart failure in a two-year-old, male common degu (Octodon degus). The patient presented for anorexia and dental disease, and a grade 4/6 holosystolic cardiac murmur was detected on physical exam. Thoracic radiographs showed cardiomegaly and a diffuse interstitial pulmonary pattern, c...

Case description: A 4-year-old spayed female mixed-breed rabbit was evaluated because of a 3-year history of sneezing and nasal discharge that were refractory to medical management. Clinical findings: Signs of chronic left-sided rhinitis and sinusitis were observed on physical examination and confirmed by CT evaluation. Lysis of the rostral aspe...

A female Swainson's toucan (Ramphastos ambiguus swainsonii) was presented for examination with a 2-year history of mucoid nasal discharge and abnormal growth of the rhamphotheca. Nasal cytologic examination and culture results were consistent with mixed aerobic and anaerobic bacterial rhinitis. Radiographic and computed tomographic imaging demonstr...

Objective: To characterize clinical and pathological findings of rabbits evaluated at a veterinary teaching hospital because of dystocia. Design: Retrospective case series. Animals: 9 client-owned rabbits and 1 wild rabbit with signs of dystocia evaluated at a veterinary teaching hospital from 1996 through 2016. Procedures: Medical records o...

en Background Rats are popular companion animals that are often presented to veterinarians for treatment of skin diseases. However, descriptions of dermatoses in rats have primarily been limited to case reports and text books. Hypothesis/Objectives To document skin diseases and their prevalence in companion rats examined in northern California, U...

OBJECTIVE To describe a technique for endoscopic evaluation of the coelomic viscera of koi ( Cyprinus carpio ) and to evaluate the ability to visually examine coelomic structures by use of an approach cranial or caudal to the pelvic girdle. ANIMALS 16 subadult koi. PROCEDURES Koi were anesthetized with buffered tricaine methanesulfonate. Coelioscop...

OBJECTIVE To determine pharmacokinetics after oral administration of single and multiple doses and to assess the safety of zonisamide in Hispaniolan Amazon parrots ( Amazona ventralis ). ANIMALS 12 adult Hispaniolan Amazon parrots. PROCEDURES Zonisamide (30 mg/kg, PO) was administered once to 6 parrots in a single-dose trial. Six months later, a mu...

Background: Hamsters are popular companion animals which may present to veterinarians for treatment of skin diseases. Most descriptions of dermatoses in hamsters have primarily been in case reports and in text books. Hypothesis/objectives: To document skin diseases and their prevalence in companion hamsters examined in northern California, USA,...

Islands have been used as model systems for studies of speciation and extinction since Darwin published his observations about finches found on the Galapagos. Amazon parrots inhabiting the Greater Antillean Islands represent a fascinating model of species diversification. Unfortunately, many of these birds are threatened as a result of human activi...

Objective The aim of this study was to evaluate and compare the effect of three clinically applicable screw hole diameters on rabbit femoral torsional structural properties. Sample Eighteen pairs of skeletally mature New Zealand White rabbit femora (36 bones). Materials and Methods Femora with a bicortical hole at mid-diaphysis from one of the 3-dr...

OBJECTIVE To evaluate thermal antinociceptive effects and pharmacokinetics of buprenorphine hydrochloride after IM administration to cockatiels ( Nymphicus hollandicus ). ANIMALS 16 adult (≥ 2 years old) cockatiels (8 males and 8 females). PROCEDURES Buprenorphine hydrochloride (0.3 mg/mL) at each of 3 doses (0.6, 1.2, and 1.8 mg/kg) and saline (0....

OBJECTIVE To evaluate the thermal antinociceptive effects and pharmacokinetics of hydromorphone hydrochloride after IM administration to cockatiels ( Nymphicus hollandicus ). ANIMALS 16 healthy adult cockatiels. PROCEDURES During the first of 2 study phases, each cockatiel received each of 4 treatments (hydromorphone at doses of 0.1, 0.3, and 0.6 m...

This report describes post-traumatic ocular lymphoma in 3 companion rabbits; 2 rabbits with unilateral disease and 1 with bilateral disease. Historical findings suggestive of a traumatic event included either external unilateral ocular trauma or bilateral phacoemulsification. Severe corneal changes, presence of an anterior chamber mass(es), low int...

A 3-year-old, 4.0 kg, female, spayed Silver Marten cross rabbit (Oryctolagus cuniculus) was presented for evaluation of a suspected recurring spindle cell sarcoma following primary excision by the referring veterinarian. Physical examination revealed a large subcutaneous mass on the left metatarsus and a fine needle aspirate revealed suspected neop...

A 4-year-old intact female Holland lop rabbit (Oryctolagus cuniculus) was referred for evaluation of a luxated right coxofemoral joint. Cranioventral luxation of the right femoral head was confirmed with pelvic radiographs at the referring veterinarian 3 days prior. On presentation, a nonweight bearing right pelvic limb lameness was appreciated. A...

OBJECTIVE To compare the disposition of fentanyl citrate after a single IV injection in isoflurane-anesthetized red-tailed hawks ( Buteo jamaicensis ) and Hispaniolan Amazon parrots ( Amazona ventralis ). ANIMALS 6 adult red-tailed hawks and 6 adult Hispaniolan Amazon parrots. PROCEDURES Anesthesia was induced and maintained with isoflurane; interm...

OBJECTIVE To determine effects of 3 plasma concentrations of fentanyl on the minimum alveolar concentration of isoflurane (MAC iso ) and cardiovascular variables in Hispaniolan Amazon parrots ( Amazona ventralis ). ANIMALS 6 adult parrots. PROCEDURES In phase 1, anesthesia was induced and maintained with isoflurane; intermittent positive-pressure v...

OBJECTIVE To describe the torsional and axial compressive properties of tibiotarsal bones of red-tailed hawks (Buteo jamaicensis). SAMPLE 16 cadaveric tibiotarsal bones from 8 red-tailed hawks. PROCEDURES 1 tibiotarsal bone from each bird was randomly assigned to be tested in torsion, and the contralateral bone was tested in axial compression. Inta...

Previous studies have validated the clinical use of opioids with μ-receptor affinities for pain management in raptors. Buprenorphine has a longer duration of action and minimal adverse effects when compared with other opioids in American kestrels ( Falco sparverius). To evaluate the thermal antinociceptive effects, sedative effects, and duration of...

OBJECTIVE To describe diagnosis, treatment, and outcome of and risk factors for ophthalmic disease in leopard geckos ( Eublepharis macularius ) evaluated at a veterinary teaching hospital. DESIGN Retrospective case series. ANIMALS 112 of 144 (78%) leopard geckos that were evaluated at a veterinary teaching hospital in January 1985 through October 2...

OBJECTIVE To determine the pharmacokinetics and sedative effects of 2 doses of a concentrated buprenorphine formulation after SC administration to red-tailed hawks ( Buteo jamaicensis ). ANIMALS 6 adult red-tailed hawks. PROCEDURES Concentrated buprenorphine (0.3 mg/kg, SC) was administered to all birds. Blood samples were collected at 10 time poin...

This article reviews the current understanding of the anatomy and physiology of pain in birds, with consideration of some of its differences from mammalian pain. From transduction to transmission, modulation, projection, and perception, birds possess the neurologic components necessary to respond to painful stimuli and they likely perceive pain in...

The medical record database of a veterinary teaching hospital was searched from 2000 through 2014 for records of client-owned rabbits with positive cultures from odontogenic abscesses. Data reviewed included sex, age, abscess location, sampling technique, previous antimicrobial treatments, microorganisms identified and antibiotic susceptibility of...

Mammary fibroadenomas are the most common subcutaneous tumors of female companion rats (Rattus nor-vegicus). 1 In premenopausal women with hormone-receptor-positive breast cancers, GnRH agonist treatment is recommended. 2 Female intact client-owned rats with mammary fibroadenomas were recruited in this random-ized blinded trial followed by cohort s...

This article presents relevant advances in avian medicine and surgery over the past 5 years. New information has been published to improve clinical diagnosis in avian diseases. This article also describes new pharmacokinetic studies. Advances in the understanding and treatment of common avian disorders are presented in this article, as well. Althou...

Meloxicam has been shown to have a safe and favorable pharmacodynamic profile with individual variability in Hispaniolan Amazon parrots (Amazona ventralis). In the current study, we determined the pharmacokinetics of a sustained-release formulation of meloxicam after subcutaneous administration to Hispaniolan Amazon parrots. Twelve healthy adult pa...

OBJECTIVE To determine the pharmacokinetics and adverse effects following SC administration of ceftiofur crystalline free acid (CCFA) in New Zealand White rabbits. ANIMALS 6 adult sexually intact female New Zealand White rabbits. PROCEDURES Each rabbit was administered 40 mg of CCFA/kg SC. A blood sample was obtained immediately before (0 minutes),...

OBJECTIVE To assess rheological properties and in vitro diffusion of poloxamer 407 (P407) and butorphanol-P407 (But-P407) hydrogels and to develop a sustained-release opioid formulation for use in birds. SAMPLE P407 powder and a commercially available injectable butorphanol tartrate formulation (10 mg/mL). PROCEDURES P407 and But-P407 gels were com...

OBJECTIVE To evaluate effects of administration of a 4.7-mg deslorelin acetate implant on egg laying in healthy cockatiels (Nymphicus hollandicus). ANIMALS 52 cockatiels. PROCEDURES 26 breeding pairs (a female and its respective male in each pair) were selected on the basis of their history of egg laying. Female birds were sedated and received a 4....

OBJECTIVE To determine pharmacokinetics of butorphanol tartrate incorporated into poloxamer 407 (P407) after SC administration to Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS 11 adult Hispaniolan Amazon parrots (6 males and 5 females; 11 to 27 years old). PROCEDURES A sterile formulation of butorphanol in P407 (But-P407) 25% (percentage...

Previous studies have validated the clinical use of opioids with μ-receptor affinities for pain management in raptors. Buprenorphine appears to have a longer duration of action and minimal adverse effects when compared to other opioids in American kestrels (Falco sparverius). To determine the pharmacokinetics of a sustained release formulation of b...

To evaluate the toxicity of short-term high doses of meloxicam in American kestrels (Falco sparverius), 32 male captive-born, 1- to 4-year-old American kestrels were randomly assigned to 4 groups: 3 groups treated with meloxicam (n = 9 per group) and a control group (n = 5). Meloxicam was administered orally via feeding tube in the proventriculus a...

To determine the pharmacokinetics of piperacillin/tazobactam in Hispaniolan Amazon parrots (Amazona ventralis), 8 healthy adult parrots of both sexes were used in a 2-part study. In a pilot study, piperacillin (87 mg/kg) in combination with tazobactam (11 mg/kg) was administered intramuscularly (IM) to 2 birds, and blood samples were obtained at 0,...