Heterotopic Ossification Bone Formation in the Frontal Bones of an African Grey Parrot (Psittacus erithacus).

A 5-year-old, male African grey parrot (Psittacus erithacus) was presented with multiple, slow-growing, firm, bilateral masses around the dorsal orbital rims. Computer tomographic imaging revealed mild, incomplete bridging bone formation on the rostrodorsal aspects of the head. A moderate amount of smooth bone formation was identified at the rostrodorsal aspect to the left orbit, with minimal associated soft tissue swelling. Surgical biopsies were collected from the masses and histopathological analysis of the most rostral right mass showed well-differentiated bone, surrounded by dense fibrous connective tissue. Scattered, well-differentiated osteocytes were present within the bone. No evidence of neoplastic changes or infectious agents were identified. The histopathological changes were consistent with metaplastic bone formation. History obtained from the owner revealed recent head trauma, which likely induced the cranial heterotopic ossification in the African grey parrot.

Cerebellar Hypoplasia in Two Juvenile African Grey Parrots (Psittacus erithacus).

Two sibling 12-week-old DNA-sexed female African grey parrots (Psittacus erithacus) were presented for progressive whole-body tremors, proprioceptive deficits, and an inability to stand unassisted. A third bird in the clutch (DNA-sexed as a male) exhibited no clinical signs. Physical examination of the affected birds revealed ataxia, inability to stand without assistance, and a reliance on their beaks to assist with their mobility. Hematologic and biochemical analyses were normal, as were radiographic images of both birds. Cerebellar disease of unknown origin was diagnosed, and the birds were euthanized. Postmortem examinations of the brains of both parrots revealed marked reduction in cerebellar size and poor folia formation. Microscopic review of the cerebellums demonstrated decreased density of the granular layer and thinning of the molecular layer with poorly organized and differentiated Purkinje fibers, consistent with a diagnosis of cerebellar hypoplasia. There are limited clinical reports and experimental studies examining cerebellar disease in birds. Conditions described have included cerebellar hypoplasia, cerebellar abiotrophy, and cerebellar dysplasia. Although these terms are used interchangeably due to similar clinical signs, histopathology is needed to differentiate between the different disease conditions. This case describes cerebellar hypoplasia that suggested a developmental etiology in 2 African grey parrots.

Treatment of Recurrent Multifocal Cutaneous Squamous Cell Carcinoma in an African Grey Parrot (Psittacus erithacus) with Intralesional Carboplatin in Poloxamer 407.

A 16-year-old male Congo African grey parrot (Psittacus erithacus) was presented with an ulcerated wing mass that was excised and diagnosed on histopathology as squamous cell carcinoma (SCC). A second surgery was performed to completely excise the tumor margins, resulting in over 5 years of remission for the neoplasm. However, over the next 6 years the patient developed SCC in 3 new locations on the body, as well as 2 squamous papillomas. The 2 papillomas were surgically excised and did not recur. Due to their size and location, none of the 3 new SCCs were amenable to complete excision. Instead, the 3 SCCs were managed with a series of treatments with intralesional carboplatin in poloxamer 407 and carbon dioxide surgical laser debridements. This treatment regimen has resulted in long-term (52 months, 30 months, and 17 months) resolution for all 3 of the SCCs. The overall survival time for the patient, from the initial diagnosis to the time of this report, is over 2900 days. While being treated for the 3 SCCs, the African grey parrot had no overt signs of complications or adverse side effects.

Brain Ependymoma in an African Grey Parrot (Psittacus erithacus erithacus).

A 14-year-old unsexed African grey parrot (Psittacus erithacus erithacus) was presented with a 12-hour history of neurological signs and vomiting. The external physical examination of the patient revealed lethargy, moderate hypothermia, a head tilt, and horizontal nystagmus. Whole-body radiographic imaging and blood biochemistry parameters were unremarkable, and a serological test to detect bornavirus was negative. A computed tomography scan of the bird revealed a large cystic lesion located on the fourth ventricle of the brain. In spite of treatment (nonsteroidal anti-inflammatory drugs and antibiotic and antiparasitic therapy), the parrot's health continued to decline, and it was euthanatized 12 days after presentation. A complete postmortem examination was performed on the patient's brain. Histopathological interpretation of tissues submitted described a large neoformation composed of cells arranged in perivascular pseudorosettes. Hyperchromatic nuclei and marked anisokaryosis were suggestive of a malignant tumor. The tissue mass was associated with significant dilation of the fourth ventricle and a severe peripheral gliosis. The histopathological diagnosis of the neoformation was an ependymoma. Ependymomas are glial tumors of the ependymal cells that line the central canal and the ventricles of the brain and are rarely described in mammals. In birds, ependymomas were only described in budgerigars (Melopsittacus undulatus). In human medicine, the recommended treatment is surgical removal of the tumor when possible, followed by radiotherapy.

Asymmetrical Cloacoplasty for the Treatment of Chronic Cloacal Prolapse in Psittaciformes: A Case Series.

Chronic cloacal prolapse is a common condition in psittacine birds, particularly in cockatoos and African grey parrots (Psittacus erithacus). Techniques to permanently reduce the prolapse have been developed and include cloacal sutures, percutaneous cloacopexy, and open circumcostal or rib cloacopexy. Several complications, some of which are life-threatening, have been reported with these tissue reduction techniques. Cloacoplasty surgeries have also been advocated, but most often as an adjunct therapy. Recurrence of cloacal prolapse may occur in traditional symmetrical cloacoplasty techniques since straining pressure remains. In this case series, 5 psittacine birds (2 male and 2 female umbrella cockatoos [Cacatua alba] and 1 male African grey parrot) with chronic recurrent cloacal prolapses were treated with a novel asymmetrical cloacoplasty technique. A semicircular excision at the mucocutaneous junction from the right side with a 2-layer closure reduced the cloacal opening by 50%-75%. A tension-relieving suture was applied to aid in healing of the incision. All 5 cases had successful outcomes with no recurrent prolapses (6 months to 3 years of follow-up), except for 1 case, due to incisional dehiscence. This animal underwent a second surgical procedure that incorporated the tension-relieving suture and has not had a recurrent prolapse in over a year. This asymmetrical cloacoplasty technique provides a simple but effective method of cloacal prolapse treatment and prevention in cases of recurrent and chronic cloacal prolapses, and creates a midline physical barrier not present in symmetrical cloacoplasties. Long-term complications may include cloacolith formation or dystocia in females, and therefore reproductive management of female birds is required.

Comparison of Dorsoventral Erect and Ventrodorsal Supine Radiographic Views for the Evaluation of Intracoelomic Organs in Clinically Normal African Grey Parrots (Psittacus erithacus).

Standard positioning for radiographic evaluation may require sedation and can be deleterious in critically ill birds. A prospective crossover study was performed in 15 clinically normal African grey parrots (Psittacus erithacus) to describe an alternative, unrestrained radiographic view. Whole-body radiographs were obtained in unrestrained dorsoventral erect (DVE) views and in anesthetized ventrodorsal supine (VDS) views. Visualization of various anatomic items in each view was scored by 3 observers. The surface area of the air sacs and the width of the heart, liver, thorax, and cardiohepatic waist were measured in DVE and VDS views. Measurements were obtained by 3 observers, and 1 observer repeated the measurements twice. Intraobserver and interobserver agreement were assessed. Major rotation of the coelom and superimposition of the limbs over the coelom were, respectively, observed in 4 of 15 (27%) and 15 of 15 (100%) of the DVE views and not observed in VDS views. The evaluation of the respiratory tract structures was considered limited in DVE views compared with VDS views, and the surface areas of the air sacs were significantly smaller. The proventriculus and ventriculus were more visible in the DVE view. The visualization of the heart was not significantly different between the 2 views. The absolute measures of heart, liver, and cardiohepatic waist width were significantly larger in the DVE view compared with the VDS view. Moderate intraobserver and interobserver agreement was observed in the evaluation of the 2 views. In conclusion, the DVE view could be adequate to assess the heart and the upper digestive tract. This positioning is likely to provide clinically relevant information for cases in which general anesthesia or dorsal recumbency is contraindicated.

Ocular Iridociliary Adenoma in a Congo African Grey Parrot (Psittacus erithacus).

A 19-year-old female Congo African grey parrot (Psittacus erithacus) presented for an oval, solid, pigmented, suspected intraocular mass with extrascleral extension through the inferior cornea of the left eye. The eye was nonvisual, and intraocular portions of the mass significantly altered the posterior chamber. Neoplasia was confirmed by biopsy, and enucleation was performed because of the severity of ocular disease, loss of vision, enhancement of patient comfort, and potential metastasis. Histopathologic examination of the entire globe revealed a pigmented iridociliary adenoma. Iridociliary adenomas have been rarely reported in birds, and this case report details diagnosis and treatment. Iridociliary adenomas in other species are often benign, indicating this neoplasia can be successfully treated with no reoccurrence by complete excision.

IRON STORAGE DISEASE IN AFRICAN GREY PARROTS ( PSITTACUS ERITHACUS) EXPOSED TO A CARNIVOROUS DIET.

Within a 2-wk period, three African grey parrots ( Psittacus erithacus) presented for emergency treatment. All three parrots had depressed behavior, an inability to fly, and significant weight loss. Plasma chemistry abnormalities included severe hypoproteinemia and elevated liver enzymes in all parrots. Two of the parrots died, and histologic examination with hematoxylin and eosin and Prussian blue stains revealed severe hepatic iron storage. Quantitative analysis confirmed high hepatic iron concentrations. Iron accumulation was attributed to ingestion of a carnivorous bird diet or selectively eating too much fruit and vegetables high in ascorbic acid. Management entailed husbandry changes including switching the remaining parrots to a low-iron diet. Psittacine species exposed to carnivorous bird diets are at risk of developing iron storage disease.

Use of a Compounded Poloxamer 407 Antibiotic Topical Therapy as Part of the Successful Management of Chronic Ulcerative Dermatitis in a Congo African Grey Parrot ( Psittacus erithacus).

A 23-year-old, 425-g male African grey parrot ( Psittacus erithacus) was evaluated for chronic ulcerative dermatitis of the axillary regions under both wings. Initial swab cultures of the sites had revealed a coagulase-positive methicillin-resistant Staphylococcus aureas (MRSA) with marked antibiotic resistance. A second swab culture obtained 8 weeks after the initial culture showed heavy growth of a coagulase-positive Staphylococcus species, which could not be speciated, but showed the same sensitivity as the previous culture. Previous treatment included systemic antibiotics and a topical antimicrobial cream, with variable response and only temporary resolution. On examination, full-thickness, ulcerative, necrotic dermatitis was present under both wings with intermittent bleeding and subdermal tissue exposure. Initial treatment included wound debridement, oral antibiotics, topical therapy, analgesics, and bandages. After a relapse, a poloxamer gel containing 2% doxycycline, 1% chloramphenicol, and 0.5% mupirocin was used in combination with oral antibiotics and analgesics. On follow-up examination, the skin lesions had completely resolved and the patient was doing well and remains normal 4 years later. This report emphasizes the importance of prompt, aggressive multi-modal therapy for MRSA and other dermal bacterial infections in pet birds that may represent zoonoses or have carrier-state zoonotic potential. Preparation by a compounding pharmacy of a transdermal poloxamer gel containing antibiotics shows promise for severe, infected, ulcerative skin lesions in birds when other therapies fail to achieve a cure.

Plasma protein, haematologic and blood chemistry changes in African grey parrots (Psittacus erithacus) experimentally infected with bornavirus.

Bornaviruses are considered to be the causative agent of proventricular dilatation disease (PDD) in psittacine birds. In order to detect haematological and blood chemistry changes during the development of PDD and a possible correlation with clinical signs and the virological status, six African grey parrots (Psittacus erithacus) were experimentally infected with parrot bornavirus 4 (PaBV-4) by subcutaneous route. All six parrots developed clinical signs of varying extent and successful infection was confirmed in all the birds by seroconversion or detection of RNA of the PaBV-4 infection strain. Based on population-based and intra-individual reference ranges established during 12 months prior to experimental infection, only minor haematological changes were detected in individual birds after infection. Changes in blood chemistry were restricted to aspartate aminotransferase, creatine kinase, total protein, glucose and uric acid. Plasma protein electrophoresis revealed marked changes starting 10 weeks post infection characterized by an increase in the γ-globulin fraction and a gradual decrease to normal values during weeks 22-34. Indications of an acute-phase reaction at the initial stages of infection were not detected. While three birds suffered from clinical signs of PDD, which included weight loss and neurological disorders and died before development of haematological and plasma protein changes, recovery of clinical disease was paralleled in the remaining birds by an increase in γ-globulins and bornavirus-specific antibody titres.

REPAIR OF A FEMORAL FRACTURE IN A CONGO AFRICAN GREY PARROT ( PSITTACUS ERITHACUS ERITHACUS) WITH A PARACORTICAL-CLAMP-CERCLAGE TECHNIQUE.

A 1-yr-old female Congo African grey parrot ( Psittacus erithacus erithacus) was admitted with a lameness of the right pelvic limb. On the radiographs a closed, caudolaterally displaced, comminuted, diaphyseal fracture of the femur was diagnosed. Surgery under general anesthesia was performed in order to repair the fracture with a paracortical-clamp-cerclage technique. This straightforward and effective technique has been developed as a low-cost treatment for simple and comminuted diaphyseal fractures in dogs and cats. Fixation is obtained with clamps, shaped during surgery, and attached to the bone shaft with cerclage wire. This technique led to immediate weight-bearing, appropriate bone healing, and permanent fixation of the implants in the patient. To the best of the authors' knowledge, this case represents the first report of a surgical repair of a femoral fracture with a paracortical-clamp-cerclage technique in a bird.

Multicentric Cryptococcosis in a Congo African Grey Parrot ( Psittacus erithacus erithacus).

An approximately 10-year-old, female Congo African grey parrot ( Psittacus erithacus erithacus) developed progressive, unilateral exophthalmos and buphthalmos. Survey radiographs revealed a large, coelomic, soft tissue mass, which was confirmed on computed tomography scan. Aspirates of both the contents of the buphthalmic globe and coelomic mass were consistent with Cryptococcus species. Initial results were later confirmed with serum antigen latex agglutination and polymerase chain reaction testing, and the organism was then identified as Cryptococcus neoformans with DNA sequencing. During the course of 1 year, the bird was treated with combinations of oral terbinafine, fluconazole, and flucytosine, as well as intraocular amphotericin B. The coelomic mass dramatically decreased in size during the course of treatment, but the globe continued to enlarge. The bird died after exhibiting ataxia and seizures approximately 13 months after initial diagnosis, and necropsy confirmed colonization of the cerebrum and meninges with Cryptococcus. Cryptococcus remains a rare fungal disease of birds that is often refractory to treatment.

Endoscopic Removal of Gastrointestinal Foreign Bodies in Two African Grey Parrots ( Psittacus erithacus) and a Hyacinth Macaw ( Anodorhynchus hyacinthinus).

Two African grey parrots ( Psittacus erithacus) and one hyacinth macaw ( Anodorhynchus hyacinthinus) were examined because of varying clinical signs ranging from general lethargy to seizure-like episodes and regurgitation. Radiography and fluoroscopy in the 3 birds demonstrated variable degrees of gastric abnormalities, suggesting the presence of foreign material or stricture-like defects. Upper gastrointestinal rigid endoscopy by ingluviotomy revealed foreign bodies that were removed endoscopically. Minor postoperative complications were pulmonary congestion or mild aspiration and cardiac arrhythmia, both of which resolved, and no serious deleterious effects were associated with endoscopy in the short or long term. Endoscopy is recommended for examination and removal of foreign bodies from the upper gastrointestinal tract because it is less invasive and traumatic than traditional surgical approaches.

Variations in an African Grey parrot's speech patterns following ignored and denied requests.

Communicative competence is one measure of an individual's ability to navigate conversations with social partners. The current study explored the possibility of basic communicative competence in a non-mammal speaker, a speech-using African Grey parrot. Spontaneous conversations between one Grey named Cosmo and her caregiver were recorded, from which three corpora (i.e., bodies of text) of Cosmo's vocalizations were developed: (1) Baseline: Vocalizations containing no requests, (2) Ignored Requests: Vocalizations immediately following Cosmo's caregiver ignoring Cosmo's requests, and (3) Denied Requests: Vocalizations immediately following Cosmo's caregiver denying Cosmo's requests. The distributions of social (e.g., "I love you," kiss sounds) and nonsocial (e.g., answering machine beeps, "That's squirrel") vocalizations, as well as speech and nonword vocalizations, were statistically different across the three corpora. Additionally, qualitative analysis of the datasets indicated Cosmo was persistent in repeating vocalizations when denied and ignored, and interrupted her caregiver more often when requests were denied compared to ignored. Neither repetition nor interruption occurred during the Baseline conversations. The data indicate that despite the outcome being the same (i.e., request was unmet), Cosmo treated an ignored request differently than a denied request, modifying her vocalizations in accord with the specific context. Such modification is evidence of basic communicative competence.

Malignant Melanoma of the Syrinx and Liver in an African Grey Parrot ( Psittacus erithacus erithacus).

A 20-year-old, female African grey parrot ( Psittacus erithacus erithacus) was examined because of ataxia and weakness. Radiographs were unremarkable, and results of a complete blood cell count revealed leukocytosis and heterophilia. Because of poor response to therapy with meloxicam, doxycycline, and enrofloxacin; deteriorating condition; and poor prognosis, the parrot was euthanatized. Postmortem examination revealed 2 dark red nodules in the liver. No grossly visible mass was observed in the syrinx. Histologic examination of the liver and syrinx revealed similar foci of round, oval, and polygonal cells exhibiting severe pleomorphism, with poorly demarcated cytoplasmic borders and moderate amounts of eosinophilic cytoplasm containing brown to black granules (melanin). The mitotic index was 15. The presence of melanin pigment is consistent with a diagnosis of melanoma at both sites. The multifocal distribution and intravascular invasion indicate metastasis; however, the site of origin was unknown. To our knowledge, this is the first recorded case of melanoma in an avian syrinx.

Bilateral Aural Adenocarcinoma in a Congo African Grey Parrot ( Psittacus erithacus erithacus).

A 28-year-old female Congo African grey parrot ( Psittacus erithacus erithacus) was evaluated because of a mass in the left external auditory meatus. Results of a computed tomography scan revealed an osteolytic left hemimandibular mass with irregular bone production and a soft tissue mass in the left external auditory meatus. Results of cytologic examination of fine needle aspirates of the hemimandible were interpreted as adenocarcinoma with reactive osteoblasts. The owner chose palliative treatment, and a debulking procedure was performed on the left external auditory meatus mass 52 days after initial presentation to control self-trauma. Euthanasia was elected 67 days after initial presentation because of poor prognosis associated with the development of bilateral masses of the external auditory meatus and lateral deviation of the mandible, findings that were confirmed by postmortem examination. Histopathologic results confirmed the diagnosis of bilateral aural adenocarcinoma with invasion of both temporal bones and hemimandibles.

Effects of Meloxicam on Hematologic and Plasma Biochemical Analyte Values and Results of Histologic Examination of Kidney Biopsy Specimens of African Grey Parrots (Psittacus erithacus).

In this study we evaluated the effects of meloxicam administered at 0.5 mg/kg IM q12h for 14 days on hematologic and plasma biochemical values and on kidney tissue in 11 healthy African grey parrots (Psittacus erithacus). Before treatment with meloxicam, blood samples were collected and renal biopsy samples were obtained from the cranial portion of the left kidney from each of the birds. On day 14 of treatment, a second blood sample and biopsy from the middle portion of the left kidney were obtained from each bird. All birds remained clinically normal throughout the study period. No significant differences were found between hematologic and plasma biochemical values before and after 14 days of treatment with meloxicam, except for a slight increase in median beta globulin and corresponding total globulin concentrations, and a slight decrease in median phosphorus concentration. Renal lesions were absent in 9 of 10 representative posttreatment biopsy samples. On the basis of these results, meloxicam administered at the dosage used in this study protocol does not appear to cause renal disease in African grey parrots.

Pharmacokinetics of Amitriptyline HCl and Its Metabolites in Healthy African Grey Parrots ( Psittacus erithacus ) and Cockatoos (Cacatua Species).

Amitriptyline, a tricyclic antidepressant, is used clinically to treat feather-destructive behavior in psittacine birds at a recommended dosage of 1-5 mg/kg PO q12-24h, which has been extrapolated from human medicine and based on anecdotal reports. The purpose of this pilot study was to describe the individual and population pharmacokinetic parameters of amitriptyline after a single oral dose at 1.5 mg/kg, 4.5 mg/kg, and 9 mg/kg in healthy African grey parrots ( Psittacus erithacus , n = 3) and cockatoos (Cacatua species, n = 3). Three birds received an initial 1.5 mg/kg oral dose, and blood samples were collected for 24 hours at fixed time intervals. Serum concentrations of amitriptyline and its metabolites were determined by polarized immunofluorescence. After determining the initial parameters and a 14-day washout period, 2 African grey parrots and 1 cockatoo received a single oral dose at 4.5 mg/kg, and 3 cockatoos and 1 African grey parrot received a single oral dose at 9 mg/kg. Concentrations reached the minimum therapeutic range reported in people (60 ng/mL) in 4 of 10 birds (4.5 and 9.0 mg/kg). Concentrations were within the toxic range in 1 African grey parrot (9 mg/kg), with regurgitation, ataxia, and dullness noted. Serum concentrations were nondetectable in 3 birds (1.5 and 4.5 mg/kg) and detectable but below the human therapeutic range in 3 birds (1.5 mg/kg and 9 mg/kg). Drug concentrations were continuing to increase at the end of the study (24 hours) in 1 bird. Elimination half-life varied from 1.6 to 91.2 hours. Population pharmacokinetics indicated significantly varied absorption, and elimination constants varied between species. Although amitriptyline appeared to be tolerated in most birds, disposition varies markedly among and within species, between the 2 genera, and within individual birds. The current recommended dosage of 1-5 mg/kg q12h in psittacine birds appears insufficient to achieve serum concentrations within the human therapeutic range and does not yield predictable concentrations. Results of this study suggest doses of up to 9 mg/kg may be necessary, although that dose may produce adverse events in some birds, and elimination half-life is sufficiently variable that dosing intervals are not predictable. Therapeutic drug monitoring combined with response to therapy is indicated to determine individual therapeutic ranges.

Immunohistochemical Study of Aquaporins in an African Grey Parrot (Psittacus erithacus) With Hydrocephalus.

A 5-month-old African grey parrot (Psittacus erithacus) was examined after 3 weeks of weakness, ataxia, mental depression, and seizures. Results of a complete blood cell count and plasma biochemical analysis were unremarkable. Magnetic resonance imaging revealed a severe bilateral hydrocephalus. The bird failed to improve with supportive care, and the owner requested euthanasia. Necropsy findings were severe bilateral hydrocephalus with no evidence of cerebrospinal fluid obstruction. Histologic examination of the brain revealed microspongiosis, edema, gliosis, and neuronal chromatolysis of surrounding periventricular tissue. Aquaporins (AQP) and astrocytes were examined to elucidate the participation of these water channel proteins and glial cells in the pathophysiology and resolution of hydrocephalus. Results showed AQP4 and glial fibrillary acidic protein were overexpressed, especially near the ventricles, but expression of AQP1 was decreased. This is the first report, to our knowledge, of AQP immunolabeling in hydrocephalus in avain species.

Bacteria Isolated From the Skin of Congo African Grey Parrots ( Psittacus erithacus ), Budgerigars ( Melopsittacus undulatus ), and Cockatiels ( Nymphicus hollandicus ).

Little is known about the normal bacterial flora of the skin of birds. To identify the bacterial organisms that reside on the integument of companion psittacine birds in a normal physiologic state, skin cultures were taken from 75 psittacine birds comprising 25 Congo African grey parrots ( Psittacus erithacus ), 25 budgerigars ( Melopsittacus undulatus ), and 25 cockatiels ( Nymphicus hollandicus ). All birds were adults and in good health with no underlying identifiable diseases, had not been on antibiotics in the preceding 2 months or longer, and had no skin or feather abnormalities. Cultures were taken from the axillary region and incubated on bovine blood agar plates. Positive cultures were identified for 52 out of 75 birds, and a total of 89 bacterial colonies grew. The most frequently identified bacterial organisms belonged to the genus Staphylococcus followed by Corynebacterium. Several other genera of bacteria were also isolated. Of the 89 bacterial colonies, 25 were identified to the species level and 50 to the genus level, and 14 were identified as either a nonfermenter or coliform.