Cardiovascular disease is frequently diagnosed in birds that are presented to veterinary hospitals, and atherosclerosis is a common cardiovascular condition identified in postmortem evaluations of pet psittacine birds. Atherosclerotic lesions are accumulations of lipids, smooth muscle cells, macrophages, and foam cells in the intimal layer of a blood vessel, narrowing the lumen. A reduced lumen diameter in a blood vessel typically results in physiological complications, such as ischemia, vascular remodeling, and obstructed blood flow. The treatment for atherosclerosis is often aimed at providing medications that help limit the negative effects of ischemia, a consequence of reduced blood flow. However, other therapeutic measures that have been recommended involve nutritional support, exercise, and control of secondary disorders. Nutritional therapies for the prevention and treatment of atherosclerosis have minimal evidence-based data to support their use in psittacine birds. Nonetheless, there are anecdotal reports and published studies using other animal species to investigate the benefits of diet and nutritional supplements to prevent and treat cardiovascular disease. Fish oil, ginger, ginkgo, cinnamon, cranberries, dates, dill, alfalfa, fenugreek, ginseng, red pepper, saffron, gardenia, and turmeric have all been promoted as nutritional supplements for their beneficial effects on preventing and treating atherosclerosis. The nutritional supplement with the most scientific data supporting its use in psittacine birds is fish oil, a source of omega-3 fatty acids. Although omega-3 fatty acids may hold the most promise, all nutritional supplements require further investigation to support or refute their use in psittacine birds for the prevention, management, or treatment of atherosclerosis and cardiovascular disease in general.
The primary objective of this study was to determine the pharmacokinetics of cannabidiol (CBD), cannabidiolic acid (CBDA), and Δ9-tetrahydrocannabinol (THC) with and without the addition of a food slurry in the Hispaniolan Amazon parrot (Amazona ventralis). Twelve healthy adult parrots of both sexes weighing 0.260-0.323 kg (mean 0.289 kg) were enrolled. Six birds were administered a target dose of 28 mg/kg of CBD, 113 mg/kg of CBDA, and 2.7 mg/kg of THC via commercially available hemp oil solution that was administered orally into the crop via a syringe, followed by a slurry-formulated diet dosed at 15 mL/kg. The remaining 6 birds were administered 28 mg/kg of CBD in hemp oil solution PO without the addition of a food slurry. Serial blood samples were obtained at time points 0, 1, 2, 3, 6, 8, and 12 hours posttreatment in a balanced incomplete block design. Pharmacokinetic parameters were determined by noncompartmental analysis. Statistical analysis of pharmacokinetic parameters between groups was not possible due to the naïve pooled-data approach used. The areas under the concentration-time curve (AUC) were 444 and 514 h*ng/mL, maximum plasma concentrations (Cmax) were 63.3 and 64 ng/ mL, time to achieve Cmax (Tmax) were 4 and 2 hours, and the plasma half-life (t½) results were 7.17 and 3.34 hours for the fed and fasted groups, respectively, for CBD. No adverse effects were appreciated in any bird. The results indicated a slower rate of absorption of CBD compared with elimination for the fed group, suggesting that the addition of a food slurry may serve as an extended-release formulation for CBD. The apparent lack of differences between the AUC and Cmax between fed and fasted groups suggests that food does not increase the relative bioavailability of this hemp product in Hispaniolan Amazon parrots, but slows down the absorption time and extends the half-life.
Respiratory acariasis caused by the mite Sternostoma tracheacolum can result in significant disease in the Gouldian finch (Chloebia gouldiae), an endangered Australian passerine. A previous study published at the authors' institution reviewed morbidity and mortality of S. tracheacolum in Gouldian finches from May 2013 to March 2021 as well as a prophylactic ivermectin treatment protocol. The mite-associated mortality rate was 39%, with no reduction in mortality observed after ivermectin treatment. In response to this finding, the institution trialed an alternative prophylactic treatment protocol using doramectin in November 2021. Doramectin, an antiparasitic drug in the avermectin family, was administered to 68 Gouldian finches at a dosage of 1 mg/kg SC for 2 doses. The average time between doses was 15.8 days. Concurrently, meloxicam was also administered at 1 mg/kg SC. Treatment was well tolerated, with 2.8% (2/72) of the finches showing tachypnea immediately after the first treatment; this resolved within 10 days. A review of Gouldian finch mortality from January 2022 to December 2024 was performed. Mild mite infection was identified postmortem in 3.4% (2/58) of the mortalities but was not considered a significant contributor to death. Five (8.6%, 5/58) other birds had significant respiratory inflammation of undetermined origin, where mites were a possible etiology but could not be confirmed. This study describes a prophylactic doramectin protocol for Gouldian finches that effectively reduced mortality associated with S. tracheacolum.
An approximately 5-year-old male mallard duck (Anas platyrhynchos) was presented for assessment and treatment of bilateral mandibular ramal fractures. Physical examination revealed the presence of complete, open mandibular fractures at the rostral third of both mandibles, with ventral displacement of the rostral segments. An initial repair attempt consisted of a suture passed between the proximal and rostral fragments to form a simple interrupted suture on each side, which failed soon after the procedure. The second repair used a 1.1-mm nonthreaded Steinman pin inserted through the fracture site into the right rostral mandibular fragment, then pulled retrograde into the right proximal fragment. The exposed rostral end of the pin was bent ventrally at a 90° angle. This was repeated on the left side. Next, 1.1-mm threaded pins were inserted ventrally into the mandibular rami and directed dorsally, engaging both ventral and dorsal mandibular cortices. The exposed ends of the nonthreaded and threaded pins were cut short and joined with intravenous tubing filled with methyl methacrylate, forming a type I extra-skeletal fixator on each side. An additional crossbar was applied to the rostral pins using intravenous tubing filled with methyl methacrylate, providing interfixator stability. The patient was housed in a protected environment and demonstrated immediate return to normal feeding behavior. Thirty-eight days after the second repair, the bird was found to have removed the entire fixator apparatus; however, on recheck, the fracture site showed excellent stability and functional healing. The bird remained fully functional 4.5 years after the mandibular fracture repair surgery.
Parrots (Psittaciformes) comprise a large group of approximately 400 species of birds. There are currently no comprehensive reviews of parrot ophthalmology in the peer-reviewed literature. This review describes the unique ocular variations of parrots, including visual ability and anatomic adaptations. A comprehensive summary of ophthalmic diagnostic tests, including aqueous tear measurements, tonometry, conjunctival cytology, conjunctival microbiology, and ocular ultrasonography, in clinically normal psittacine birds is presented. Common ocular disorders of parrots and their treatments are discussed. Aqueous tear production can be measured using Schirmer tear tests, phenol red thread tests, and endodontic absorbent paper point tear tests. Intraocular pressure is best measured with a rebound tonometer; however, applanation tonometry has also been described. Conjunctival cytology, conjunctival microbiology, and ocular ultrasonography are useful in determining disease etiopathology. Topical neuromuscular blocking agents may be effectively used with caution to induce pharmacologic mydriasis in psittacine birds. Ongoing research should be performed on all available psittacine bird species to increase sample size and available data from which normal reference intervals can be determined.
Free-ranging, nocturnal raptors are frequently presented to wildlife centers due to trauma, and ocular trauma is a common finding in these cases. Measurement of intraocular pressure (IOP) is a critical part of an ophthalmic examination; however, reference values for comparison are lacking in nocturnal species. Rebound tonometry was used to measure IOPs of normal eyes from free-ranging, nocturnal raptors (eastern screech owls [Megascops asio], great horned owls [Bubo virginianus], and barred owls [Strix varia]) presented to a wildlife rehabilitation center. In total, 248 eastern screech, 105 great horned, and 70 barred owl eyes were evaluated in this study. All IOP measurements were collected using a rebound tonometer on the "d" setting while owls were restrained in an upright position. The mean IOP for eastern screech owls was 9.22 ± 3.98 mmHg and 9.35 ± 3.47 mmHg for the right and left eyes, respectively, with a combined mean of 9.28 ± 3.76 mmHg. The mean IOP for great horned owls was 12.71 ± 6.16 mmHg and 12.86 ± 6.62 mmHg for the right and left eyes, respectively, with a combined mean of 12.78 ± 6.35 mmHg. The mean IOP for barred owls was 10.41 ± 4.37 mmHg and 10.97 ± 4.72 mmHg for the right and left eyes, respectively, with a combined mean of 10.66 ± 4.51 mmHg. Intraocular pressure results did not differ significantly between the right and left eyes for any species. These normal values will provide clinicians reference ranges for comparison and allow more accurate screening for ocular pathology.
Grey parrots (Psittacus erithacus) are commonly kept as pet birds around the world, but little is known about their plasma vitamin and mineral concentrations. The aim of this study was to establish reference intervals for vitamins A, D, and E and various minerals (calcium, cobalt, copper, iron, iodine, potassium, magnesium, manganese, molybdenum, sodium, inorganic phosphorus, selenium, and zinc) in the plasma of 88 adult pet grey parrots in Germany. The samples were collected during routine health checks and analyzed using a point-of-care device, an autoanalyzer, inductively coupled plasma mass spectrometry, and high-performance liquid chromatography. No significant (all P > 0.05) influence of sex on the analytes was found. However, feed supplementation did significantly increase plasma vitamin D (P < 0.001) and iodine (P = 0.003) concentrations. Vitamin D concentrations were also significantly greater (P = 0.024) in birds with access to outdoor aviaries and natural sunlight. The results show that these factors play important roles and should be considered in the husbandry and management of these parrots, as well as in the interpretation of blood results. The established reference intervals should help to improve the medical care of grey parrots and better monitor and optimize feeding and husbandry.
The purpose of this study was to establish the pharmacokinetic profile of intravenous bupivacaine during isoflurane anesthesia in hens (Gallus gallus domesticus). Bupivacaine is an amide local anesthetic that works by blocking sodium channels and is 4 times as potent as lidocaine. Though bupivacaine is not recommended for intravenous injection, the purpose of this study was to mimic an accidental intravenous injection. A single dose of preservative-free bupivacaine at 2 mg/kg was administered intravenously over 20 seconds in 6 healthy layer chickens weighing 1340 6 193.4 grams. Each hen was placed under isoflurane anesthesia and intubated prior to drug administration. Blood was collected at baseline once under anesthesia and then at 1, 2, 5, 10, 15, 30, 60, 90, 120, 180, and 240 minutes postdrug administration. Vitals were monitored routinely and recorded. Each patient recovered without any complications. Plasma was separated and immediately frozen at -808C (-1128F) until it was assayed for bupivacaine by high-performance liquid chromatography. A 2-compartment model was used to estimate pharmacokinetic parameters, including clearance (median 59.2, range 43.2-77.1 mL/min/kg), terminal half-life (median 18.2, range 12.4-36.4 min), apparent volume of distribution at steady state (median 1571.7, range 961.6-2113.4 mL/kg), area under the curve (median 33.9, range 26.0-46.3 min*mg/mL), and mean residence time (median 24.3, range 15.1-48.9 min). These results describe the pharmacokinetics of bupivacaine in healthy laying hens anesthetized with isoflurane and can be used in the creation of future experimental designs of the use of bupivacaine in this species.
The development of smaller orthopedic plates and screws has facilitated their use in avian fracture repair. Avian bone differs from mammalian bone in its biomechanical properties due to adaptations for flight, necessitating avian-specific orthopedic biomechanical studies. Screw pullout strength has not been studied in avian bone. The aims of this study were to 1) compare the axial pullout strength of cortical and locking screw designs in the tibiotarsus and femur of the Pekin duck (Anas platyrhynchos domesticus) and 2) investigate the effects of sex and screw location in bone on screw pullout strength. Locking and cortical screws were inserted in 5 locations: the distal metaphysis, distal diaphysis, middiaphysis, proximal diaphysis, and proximal metaphysis of femora (n = 28) and tibiotarsi (n = 40) from 20 Pekin ducks. Screws were tested to failure in axial pullout and maximum force recorded. Data were analyzed by a linear mixed-effects model. There were no significant differences in screw pullout strength between locking and cortical screws or between sexes. On average, maximum force was highest at the middiaphysis in the femur and at the distal diaphysis of the tibiotarsus. These results suggest that when using 2.0-mm and 1.5-mm screws in avian femoral and tibiotarsal bones, respectively, screw positioning in denser diaphyseal regions may be more critical to screw pullout strength than the choice between cortical and locking screw designs.
Two budgerigars (Melopsittacus undulatus) were presented for coelomic distension. Contrast barium gastrointestinal radiographic examination showed that both birds had abdominal wall hernias containing intestinal loops. Tenesmus was observed in both patients, and hernia repair surgery was performed. In case 1, an X-shaped incision was made in the skin covering the patient's hernia. This was followed by a transverse incision of the hernial sac and removal of the oviduct, as the hernial contents exceeded the capacity of the intestinal peritoneal cavity. The intestine was reduced into the peritoneal cavity, and the hernial ring was closed. In case 2, a ring-shaped skin incision was made over the patient's hernia and hernial sac. The removal of the oviduct followed this because the hernial contents could not be reduced to the intestinal peritoneal cavity. Because of the intestinal enlargement, it could not be completely reinserted into the cavity and the hernial ring could not be closed. In both patients, the hernial ring was formed by a transverse rent in the aponeurosis between the distal pubic bones. The hernial sac consisted of double-layered septae composed of fibrous connective and adipose tissue, with no muscular tissue. The hernial sac was likely formed in the parietal peritoneum of the ventral body wall, based on its anatomical location and histopathological characteristics. These findings confirm that both patients had true hernias. This report describes the site of formation of the hernial ring and the structure of the hernial sac in budgerigars.
Commercial point-of-care (POC) devices are commonly used to rapidly and cost-effectively measure the concentrations of vertebrate blood components such as metabolites and electrolytes. However, these devices can provide inaccurate results, and their utility must be rigorously tested by comparing results with those obtained from a reference assay. This study evaluated the accuracy of the veterinary AlphaTrak 3 glucometer (Zoetis, Kalamazoo, MI, USA) for use in 2 phylogenetically distant avian taxa, the house finch (Haemorhous mexicanus, order Passeriformes) and the rosy-faced lovebird (Agapornis roseicollis, order Psittaciformes), compared with an enzyme end-point colorimetric assay (Cayman Chemical, Ann Arbor, MI, USA) as the reference. This POC device was used to measure blood glucose in 30 house finch and 32 rosy-faced lovebird samples. The level of agreement between assays and the POC device reliability were determined with the Bland-Altman method and the Pearson product moment correlation. All the samples contained detectable glucose concentrations, but 9 finch samples had glucose concentrations exceeding the glucometer's upper detection limit and were eliminated. The POC device produced consistent results for both species. Relative to the reference assay, the glucometer overestimated glucose concentrations by 3.8% in house finch samples and by 8.7% in rosy-faced lovebird samples. There was good agreement between glucose concentrations measured with the 2 assay methods in the rosy-faced lovebird, but not in the house finch (allowable error <15%). These findings confirm the need to test the validity and accuracy of measurements with commercial glucometers, and they highlight that the reliability of these devices should be tested for each species under consideration.
Ocular trauma is a significant contributor to mortality in wild birds, particularly in owls. Despite the critical role of vision in survival, ocular biometric data for brown hawk-owls (Ninox scutulata) remain limited. This study establishes ultrasonographic reference values for ocular structures in the brown hawk-owl. Using B-mode ultrasonography, biometric parameters including corneal thickness, anterior chamber depth, lens thickness, vitreous chamber depth, axial length of the globe, and pecten oculi height were measured in 64 eyes from 32 individuals (26 adults and 6 juveniles). Correlations among these ocular biometric parameters were also analyzed. No significant differences were observed between the left and right eyes or between the horizontal and sagittal imaging planes. However, significant biometric differences were found between adult and juvenile owls, except for pecten oculi height. No significant correlations were identified between body weight and most ocular biometric parameters, except for a slight positive correlation with anterior chamber depth. Axial globe length showed positive correlations with anterior chamber depth, lens thickness, and vitreous chamber depth. Establishing normal ocular biometric values may enhance diagnostic accuracy and will serve as a valuable reference for veterinary ophthalmology, wildlife rehabilitation, and species conservation in brown hawk-owls.
Avian orthopedic disorders are common but can be challenging to diagnose. Radiographic examination and, to a lesser extent, computed tomography are the main diagnostic techniques used to assess avian orthopedic problems, whereas sonography is rarely applied. The objective of this study was to determine whether B-mode ultrasonography could be used to noninvasively evaluate the pectoral region and peripheral skeleton of 17 live feral pigeons (Columba livia f. dom.) (body weight: 270 ± 34.5 g) presented for clinical examination. The ultrasound examination (General Electric ≥ LOGIQ S7 Expert, GE Healthcare, Buckinghamshire, UK) was performed using a GE L8-18I-D "hockey stick" transducer with an 8-18 MHz frequency range (AME Ultrasound, Suffern, NY, USA). The results of the pigeon ultrasound examinations provided clinical data regarding the bone cortex and surrounding soft tissues of the pectoral region, shoulder girdle, wing, and leg. The overall long bone thickness, total cortical bone thickness, and clavicle thickness of each bird were measured using radiography and B-mode sonography to determine the statistical concordance between these diagnostic methods using the Lin concordance correlation coefficient and Bland-Altman plots. Fisher z-transformation was used to calculate 95% confidence intervals and standardize P values for each connection. The agreement analysis revealed a significant positive concordance between radiographic and ultrasound measurements for overall long bone thickness (Lin concordance correlation coefficient = 0.655, 95% CI: 0.520-0.758, P < 0.001); no other comparisons were significant. This study provides evidence that B-mode ultrasonography can qualitatively assess pigeons' musculoskeletal systems, notably in the pectoral area and proximal limbs. This technique can also be used to acquire measurements of the structures thicker than 0.2 cm, which may be used for osteosynthesis planning or monitoring neoplastic conditions posttreatment.
Sedation is a common procedure in avian practice and benzodiazepines are often used as sole agents or in combination with other drugs to sedate avian patients. Midazolam and diazepam have been evaluated in zebra finches (Taeniopygia guttata); however, lorazepam has not. Our aim was to determine the sedation effective dose 50 (ED50) of intranasal (NAS) lorazepam in zebra finches. Using the Dixon up-and-down method, the first randomly selected finch received 0.25 mg/kg NAS lorazepam. Sedation was scored after 20 minutes: 1) recumbent = 0 versus not recumbent = 1; 2) captured at first attempt = 0 versus not captured at first attempt = 1; 3) absence of righting reflex within 2 seconds = 0 versus righting reflex within 2 seconds = 1. Total sedation score was calculated by adding the 3 parameters; birds were classified as sedated if scored ≤1 and as not sedated if scored ≥2. Based on the first bird's classification, the next random bird received an increase (if preceding bird was not sedated) or deduction (if preceding bird was sedated) by a factor of 2. Crossover events (contradictive responses between 2 sequential animals) were noted. A total of 15 animals (5 males, 10 females), weighing 12.16-18.80 g, were used. A total of 6 crossover events were identified. The highest and the lowest dose administered were 1 and 0.0625 mg/kg, respectively. Lorazepam NAS ED50 was 0.3 mg/kg by the Dixon up-and-down method. No morbidity or mortality was noted, and all birds recovered uneventfully. Future studies evaluating this sedation protocol are needed to further determine the practical clinical value of lorazepam as a sedative drug in passerine species.
Desert rose (Adenium obesum) is a plant from the family Apocynaceace that can cause cardiac glycoside toxicosis if ingested. A 33-year-old male blue and gold macaw (Ara ararauna) ate a desert rose flower from an indoor houseplant. After ingestion, the patient fell onto the floor, regained its balance, and then ran to its owners who witnessed the patient "foaming at the mouth" with its "cheeks turning blue." The macaw proceeded to collapse, continued to foam at the mouth, and had what appeared to be a seizure. Upon presentation 2 hours postexposure, the macaw was moribund, in shock, and recumbent with rigid limbs and had dark blue cheeks and severe bradycardia (40 beats per minute). The bird was placed in flow-by oxygen in a warm incubator and, shortly thereafter, began regurgitating frank blood and passing melena. The patient's treatment protocol included atropine, parenteral fluids, dextrose, calcium-gluconate, vitamins, anti-inflammatory therapy, antibiotics, and activated charcoal gavage. The initial plasma biochemistry panel revealed a severe hyperkalemia (>10 mmol/L) that was treated with furosemide. Diagnostic testing and supportive treatment continued for 12 days, including hyperbaric oxygen therapy. Continuous incubator flow-by oxygen coupled with multiple hyperbaric oxygen treatments significantly improved perfusion, facilitating recovery. Three years following exposure to the desert rose flower, the owners consider the bird to have normal behavior and no clinical signs associated with the toxicosis.
Deslorelin acetate is a gonadotropin-releasing hormone agonist commonly used for reproductive suppression in birds. Female psittacine birds routinely undergo vitellogenesis, with resulting high blood lipids, which may predispose them to several lipid disorders, including atherosclerosis. This study evaluated the effects of deslorelin implants on blood lipids and steroid hormones in cockatiels (Nymphicus hollandicus). Sixteen female cockatiels were randomly assigned to receive a 4.7-mg deslorelin implant subcutaneously or a sham procedure. Plasma samples were collected at baseline and at 1, 2, 4, and 6 months postimplantation. Lipid and lipoprotein profiling were performed by high-resolution polyacrylamide gel electrophoresis, and steroid hormones were analyzed via liquid chromatography tandem spectrometry. Deslorelin significantly reduced plasma triglycerides, total cholesterol, intermediate-density lipoproteins, and high-density lipoproteins at 1 month postimplantation compared with controls, with some effects persisting up to 2 months for intermediate-density lipoproteins. Four of 8 cockatiels were found to be hyperlipidemic in the deslorelin group over the 6-month treatment period compared with 8 of 8 cockatiels in the control group. Progesterone concentrations were lower in the deslorelin group. Estradiol concentrations decreased transiently at 1 month but did not reach statistical significance. These findings highlight deslorelin's potential to modulate lipid metabolism in female cockatiels and suggest a temporal effect lasting 1-2 months. This study provides novel insights into the metabolic effects of deslorelin beyond its reproductive role and may have implications for managing hyperlipidemia in avian species.
Erythrocyte sedimentation rate (ESR) is a simple, inexpensive test that is an indirect measure of the acute-phase protein response to inflammation. Acute-phase assays can increase detection of illnesses when used in conjunction with other hematological tests, and may be more sensitive to some diseases than white blood cell counts. This study assessed the usefulness of testing ESR with a microhematocrit tube for detecting inflammatory and infectious conditions in rehabilitated birds. Values were measured in 119 clinically healthy birds from 5 orders, and differences between ages, orders, and healthy and unhealthy birds were compared. Cutoff values to differentiate clinically normal birds from those with trauma or infections were done by receiver operating characteristic curves, nonparametric methods, and a linear regression-based method to account for differences in packed cell volume (PCV). The ESRs of unhealthy birds (n = 188) were used to assess performance of the different cutoff methods. The receiver operating characteristic curve cutoffs for infected birds in Accipitriformes, in Strigiformes, and for combined orders had good sensitivity (78-97%), specificity (94-100%), and area under the curve values (0.913-0.990), but performance was likely overestimated due to sample size limitations. There was a significant negative correlation between PCV and ESR, but regression-based cutoffs had the worst overall performance, and all methods had low sensitivity for unhealthy passerines. Erythrocyte sedimentation rate appears to be a useful test in some orders, can be easily implemented, and can be performed with the same sample used to determine PCV and total protein, increasing diagnostic information without the need for additional blood or testing costs. However, species-, age-, and sex-specific differences must be further investigated to fully assess the usefulness of this test.
The metacarpophalangeal joint is a compound joint composed of the major and minor metacarpals and the minor and major digits. Although the motion of this joint is restricted, it plays an important role in minor adjustments in flight. The ability of birds to gain lift and fly with limited or inhibited function of this joint has not been well studied in raptors. This report represents the first published case of successful rehabilitation and release of a bald eagle (Haliaeetus leucocephalus) after complete arthrodesis of a metacarpophalangeal joint luxation. The patient was presented to the Louisiana State University Wildlife Hospital of Louisiana with a chronic, complete luxation of the left metacarpophalangeal joint and articular fracture of an unknown origin. Owing to the chronicity of the injury, a closed reduction and stabilization with conservative management were not achievable. Articular debridement and external fixation with a type 1A fixator were used to immobilize the joint. Complete anatomic reduction was not achieved; however, this did not inhibit the bird's ability to gain lift, land, and navigate in the air. Postrelease monitoring was not pursued for this patient. Arthrodesis should be considered a viable treatment option for metacarpophalangeal joint luxations in bald eagles or other large raptors.
The family Ramphastidae includes toucans (Ramphastos sp), mountain toucans (Andigena sp), toucanets (Aulacorhynchus sp, Selenidera sp), and aracaris (Pteroglossus sp). These birds are endemic to Central and South America and are popular birds for zoological parks and as companion animals. This retrospective study summarizes the histologic findings of 273 toucans, 24 mountain toucans, 240 aracaris, and 64 toucanets (601 total specimens) submitted to 4 diagnostic laboratories from 1994 through January 2013. Infectious diseases were most common (53.1%, 319/601), followed by nutrition-based deposition disorders (36.4%, 219/601) and cardiovascular disease (10.3%, 62/601). Among infectious diseases, bacterial diseases were most common (57%, 182/319, including 45 cases of mycobacteriosis). Mycotic diseases (14.1%, 45/319) included ventricular candidiasis (73.3%, 33/45), aspergillosis (13.3%, 6/45), and undetermined fungus (13.3%, 6/45). Viral infection was limited to 3 cases with 2 cutaneous poxvirus cases and 1 West Nile virus case. Parasitic infections were found in 93 cases, including nematodiasis (64.5%, 60/93, predominantly Capillaria sp). Intestinal trematodiasis, muscle cysts of Sarcocystis sp, hepatic hemoprotozoan macroschizonts, biliary and intestinal trematodiasis, amoebiasis, and cestodiasis represented <5% of cases. Parasitic infections were undetermined in 6.4% (6/93) of cases. Deposition cases included iron storage disease (77.7%, 230/296), gout (14.9%, 44/296), and amyloidosis (7.4%, 22/296). Cardiovascular disease (62 cases) included atherosclerosis (48.4%, 30/62) and degenerative cardiac disease (4.8%, 3/62); 3 cases of dilated cardiomyopathy were found in young aracaris. The results of this study indicate that mortalities could be diminished in < 1 year old birds by improved prevention and treatment of enteric infections and that, in > 1 year old birds, prevention and treatment of Capillaria sp and hemochromatosis may also substantially reduce mortality.
