Dermatologic diseases in psittacine birds: An investigational approach

Avian Dermatology

Dermatologic conditions are common in avian practice and can be caused by a huge array of potential disorders, ranging from infectious diseases, ectoparasites, metabolic disorders, nutritional deficiencies, and management deficits. The skin is the largest organ in the body and has the potential to lead to significant discomfort and welfare compromise when pathology is present. Some conditions may be relatively pathognomonic based on gross findings, whereas others may require a full diagnostic workup to investigate. Getting to the bottom of skin lesions and disorders often involves identification and correction of the underlying cause, rather than just treating the lesions present in the integument.

Fibrolipoma subcutáneo en Loro Amazónico (Amazona aestiva): Evaluación clínica, histopatológica y técnica quirúrgica

Los lipomas son neoplasias benignas conformadas por adipocitos bien diferenciados, delimitados por un delicado estroma fibroso reticular. Éstos constituyen el tumor cutáneo más frecuente en aves, siendo masas blandas que generalmente aparecen en el tejido subcutáneo. Se describe el caso de un loro amazónico (Amazona aestiva) en cautiverio, que fue llevado a consulta debido a una masa ulcerada en la región de la cadera. El diagnóstico citológico refirió que se trataba de un lipoma, y ante la ineficacia del tratamiento local, se procedió con la extirpación quirúrgica de la masa. El tratamiento posquirúrgico consistió en limpiezas con clorhexidina al 0,5 % por 15 días (d), e ibuprofeno por vía oral, por 3 d. La masa fue remitida para su estudio histopatológico, refiriendo como diagnóstico morfológico un fibrolipoma. Los puntos de sutura fueron retirados a los 18 d, observándose una cicatrización completa.

Managing the Health of Captive Flocks of Birds

There are many intersecting aspects to the avicultural management of a captive flock. Extensive knowledge of the natural history of the species kept is key to fulfilling the environmental, social, nutritional, and behavioral requirements of the birds, whether in a mixed- or sole-species aviary. Species compatibility with the environment, climate, and other co-occupants plays a role as well, as does hygiene, good avicultural management, and veterinary involvement and consultation. In understanding and meeting these requirements, optimal health can be maintained through the reduction or elimination of stressors and the maintenance of normal physiologic function.

Prevalence and risk factors for feather-damaging behavior in psittacine birds: Analysis of a Japanese nationwide survey

A case control study was conducted to estimate the prevalence of feather-damaging behavior and evaluate the correlation with risk factors among pet psittacine birds in Japan. Although feather-damaging behavior among pet parrots is frequently observed in Japan, its prevalence and potential risk factors have not been investigated. Therefore, we conducted an online questionnaire survey on parrot owners throughout Japan to examine regional differences in feather-damaging behavior and associated risk factors. In total, 2,331 valid responses were obtained. The prevalence of feather-damaging behavior was 11.7%, in general agreement with prior studies. The highest prevalence was among Cockatoos (Cacatua spp., etc.; 30.6%), followed by Lovebirds (Agapornis spp.; 24.5%) and African grey parrots (Psittacus erithacus; 23.7%). Multivariate logistic regression was carried out to calculate the adjusted odds ratio (ORadj) for potential risk factors and adjust the confounding of the variables. The odds of feather-damaging behavior were significantly higher for Conures (Aratinga spp., Pyrrhura spp., Thectocercus acuticaudatus, Cyanoliseus patagonus) (ORadj = 2.55, P = 0.005), Pacific parrotlets (Forpus coelestis) (ORadj = 3.96, P < 0.001), African grey parrots (ORadj = 6.74, P < 0.001), Lovebirds (ORadj = 6.79, P < 0.001) and Cockatoos (ORadj = 9.46, P < 0.001) than Budgerigars (Melopsittacus undulatus), and for young adults (ORadj = 1.81, P = 0.038) and adults (ORadj = 3.17, P < 0.001) than young birds, and for signs of separation anxiety (ORadj = 1.81, P < 0.001). Species, bird age and signs of separation anxiety were significantly higher risk factors for feather-damaging behavior than any other potential risk factors. Our findings, which include broad species diversity, are a good source of data for predicting risk factors for feather-damaging behavior and could be useful in preventing declines in welfare.

Medical Causes of Feather Damaging Behavior

Feather damaging behavior (FDB), also referred to as feather picking, feather plucking, or pterotillomania, is one of the most common and frustrating clinical presentations in captive psittacines. The clinical approach to identify underlying medical conditions associated with FDB is reviewed. Primary feather or skin diseases as well as systemic diseases may lead to this syndrome. This article focuses on the medical causes of FDB documented in the current avian literature. Medical causes are presented using the VITAMIN D algorithm. Key components of the multifaceted therapeutic approach in managing FDB of medical origin are discussed.

Vegetative Endocarditis due to Staphylococcus aureus in an Umbrella Cockatoo (Cacatua alba)

A 15-year-old, female cockatoo (Cacatua alba) was presented with a history of intermittent cloacal prolapse of 1-year duration. After each prolapse, the owner would digitally reduce the distended cloacal tissue within approximately 12-24 hours, for short-term resolution. The cockatoo was examined 3 times over a 7-month period and received supportive care with leuprolide acetate, behavioral modification, and diet change. After the third examination, the owner decided to proceed with a surgical cloacopexy. Five days after the last examination and before the procedure was scheduled, the cockatoo was reexamined for acute onset of weakness, anorexia, lethargy, and right-leg paresis. Despite supportive treatment, the cockatoo's clinical condition declined, and it went into respiratory arrest. Resuscitative efforts, including manual ventilation and cardiovascular support, were unsuccessful, and the bird died. Results of postmortem examination revealed vegetative endocarditis with intralesional bacteria cultured as Staphylococcus aureus, right-hindlimb myonecrosis, hepatitis, and nephritis. We suspect that the source of the hematogenous S aureus infection in this cockatoo was translocation from the owner's skin from the repeated manual manipulation and replacement of the prolapsed cloacal tissue.

Multiple Infiltrative Intraosseous Lipomas in the Appendicular Skeleton of a Rose-breasted Cockatoo (Eolophus roseicapilla) with a Humeral Fracture

A 9-year-old female rose-breasted cockatoo (Eolophus roseicapilla) was presented for a humeral fracture. At presentation, the bird was severely lethargic and obese. On physical examination, an open right humeral fracture, healed left ulnar fracture, and intertarsal joint swelling were present. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with heterophilia and increased creatine kinase and aspartate aminotransferase activities consistent with musculoskeletal lesions. Radiographs confirmed a right humeral fracture and showed severe polyostotic lytic and expansile lesions of the appendicular skeleton, as well as an enlarged hepatic silhouette. Surgical repair of the fracture was attempted, but the bird died during the procedure. Postmortem examination revealed severe bone deformities involving the fractured humerus, both ulnas, and the left tibiotarsus. Histologic findings were consistent with multiple intraosseous lipomas of the long bones and severe hepatic lipidosis. To our knowledge, this is the first report of multiple intraosseous lipomas in a bird.

Functional analysis and treatment of self-injurious feather plucking in a black vulture (Coragyps atratus)

The etiology and maintenance of self-injurious feather plucking (FP) have been attributed to biological and environmental processes, yet a definitive solution has not been found. The current study investigated the application of a functional analysis and function-based treatment to reduce the FP of a black vulture (Coragyps atratus). FP was found to be maintained by positive reinforcement in the form of contingent attention. A treatment consisting of noncontingent reinforcement decreased FP, and levels of FP remained low during schedule thinning. The current study further demonstrates the validity of function-based assessment and treatment with captive animals.

SUCCESSFUL REDUCTION OF FEATHER-DAMAGING BEHAVIOR BY SOCIAL RESTRUCTURING IN A GROUP OF GOLDEN CONURES (GUARUBA GUAROUBA)

A variety of infectious and noninfectious causes may contribute to feather-damaging behavior (FDB) in birds. This paper describes an episode of FDB behavior related to an isosexual group composition in a group of 20 golden conures (Guaruba guarouba) kept in a collective aviary. After ruling out infectious causative agents and analyzing the social bird group composition over a period of 10 yr, the male to female ratio of the group was reduced from 1.7 to 1.0. This intervention resulted in a significant improvement of the feather condition and improved reproduction. Further analysis revealed that FDB was not correlated to age, gender, or origin. In addition, FDB was associated with stress, as reflected by an elevated heterophil : lymphocyte ratio that decreased significantly following social restructuring. This study stresses the importance of an appropriate male to female ratio when golden conures are kept in aviaries.

Knemidokoptiasis in a Wild Bird, the Little Spiderhunter ( Arachnothera longirostra cinereicollis), in Sumatra, Indonesia

We report knemidokoptiasis in a wild male Little Spiderhunter ( Arachnothera longirostra cinereicollis; family Nectariniidae; order Passeriformes) from Jambi, Sumatra, Indonesia, in September 2017. Microscopic examination of a scraping from its leg lesion revealed the presence of Knemidocoptes jamaicensis as the cause of the condition.

Antifungal Therapy in Birds: Old Drugs in a New Jacket

The use of antifungals in birds is characterized by interspecies and interindividual variability in the pharmacokinetics, affecting drug safety and efficacy. Oral antifungal drug absorption is a complex process affected by drug formulation characteristics, gastrointestinal anatomy, and physiology. New antifungal drug delivery systems can enhance drug stability, reduce off-target side effects, prolong residence time in the blood, and improve efficacy. Topical administration of antifungals through nebulization shows promising results. However, therapeutic output is highly influenced by drug formulation and type of nebulizer, indicating these factors should be taken into account when selecting this medication route.

Prevalence of Neoplastic Diseases in Pet Birds Referred for Surgical Procedures

Neoplastic disease is common in pet birds, particularly in psittacines, and treatment should be primarily aimed at tumor eradication. Nineteen cases of pet birds submitted to diagnostic and/or therapeutic surgical procedures due to neoplastic disease characterized by the presence of visible masses were retrospectively analyzed; affected species, types of neoplasms and respective locations, and outcomes of surgical procedures were determined. All birds undergoing surgery belonged to the order Psittaciformes; the Blue-fronted parrot (Amazona aestiva) was the prevalent species. Lipoma was the most frequent neoplasm in the sample studied. Most neoplasms affected the integumentary system, particularly the pericloacal area. Tumor resection was the most common surgical procedure performed, with high resolution and low recurrence rates.

Developmental morphology of Knemidokoptes pilae on an infested red-crowned parakeet (Cyanoramphus novaezelandiae)

A captive 4-year-old female red-crowned parakeet (Cyanoramphus novaezelandiae) presented with anorexia, diminished activity and thick, beige, crusted lesions over the cere, legs, wings and cloaca. Deep skin scrapings from various lesions identified Knemidokoptes pilae as the causative agent. For treatment, the crusts were debrided, and the lesions were topically treated with ivermectin, chlorhexidine and silver sulfadiazine. The parakeet died the day after treatment. Previous studies examining K. pilae have focused primarily on the morphologic characteristics of adult female mites. This study presents a more comprehensive morphologic analysis, with examination of K. pilae at different stages of development (eggs, larvae and adult males and females).

KNEMIDOKOPTINID (EPIDERMOPTIDAE: KNEMIDOKOPTINAE) MITE INFESTATION IN WILD RED-CROWNED PARAKEETS (CYANORAMPHUS NOVAEZELANDIAE): CORRELATIONS BETWEEN MACROSCOPIC AND MICROSCOPIC FINDINGS

During a study on health and disease in Red-crowned Parakeets (Cyanoramphus novaezelandiae) on Tiritiri Matangi Island and Little Barrier Island (Hauturu-o-Toi) in New Zealand between 2011 and 2013, an outbreak of feather loss prompted the collection of skin biopsies (n = 135) under anesthesia from the head of captured birds. A subset of samples (n = 7) was frozen to obtain whole specimens for identification of ectoparasites. Mites (range 1-11) were observed in 79/135 (58.5%) skin biopsies, whereas feather loss was only found in 47/142 (33.1%) birds captured during the sampling period. Compact orthokeratotic hyperkeratosis and acanthosis were found in association with mites. Procnemidocoptes janssensi (Acari: Epidermoptidae, Knemidokoptinae) was identified from whole mites obtained from skin biopsies. We describe the presence, pathology, and stages of infestation for knemidokoptinid mange in a wild parrot population in New Zealand. Given the clinical and pathologic changes observed and poor knowledge of the parasite's New Zealand host and geographic distribution, further work is recommended for this and sympatric parrots, to understand relationships between the host, parasite, environment, and expression of disease. Results from this study reinforce the value of including biopsy samples for the investigation of skin disease in wild birds, particularly to link etiologic agents with pathologic changes.

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.

Feather loss and feather destructive behavior in pet birds

Feather loss in psittacine birds is a common and frustrating clinical presentation. Causes include medical and nonmedical causes of feather loss with and without overt feather destructive behavior. Underlying causes include inappropriate husbandry and housing; parasitic, viral and bacterial infections; metabolic and allergic diseases; and behavioral disorders. Prior to a diagnosis of a behavioral disorder, medical causes of feather loss must be excluded through a complete medical work-up including history, physical examination, and diagnostic testing. This article focuses on common medical and nonmedical causes of feather loss and feather destructive behavior and approaches to diagnosis and treatment.

Dermatological conditions affecting the beak, claws, and feet of captive avian species

Captive avian species are presented for veterinary care for a variety of conditions and clinical signs. Although many of these presented birds seek veterinary care for other causes, some of these presentations involve dermatologic conditions that involve the beak, claws, and feet. A variety of presentations commonly seen include trauma to the beak, claws, and/or feet; leg-band injuries, pododermatitis, infectious causes, and beak growth abnormalities. Other less common presentations include thermal burns to the feet, self-mutilation of the feet, tumors of the feet and claws, and avian gout.

Application of a single vascularised skin flap in eastern imperial eagle with skin defects

Skin defects are a frequent problem in avian clinical practice. They require rapid and effective therapy due to the absence of available skin around the skin defects and desiccation of the surrounding tissue. Within the period of one year, between March 2010 and April 2011, several specimens of eastern imperial eagle (Aquila heliaca) were treated at the Clinic of Exotic and Free-Living Animals of the University of Veterinary Medicine and Pharmacy in Košice. Three of them (cases 1, 2 and 3) had damaged skin on their limbs. The skin defects presented in these patients required surgical treatment by a vascularised skin flap. Acceptance of the skin flap on the entire recipient site was seen in all three patients. Complete healing, as well as functioning of the damaged sites were observed within two months from the surgery. Using surgical treatment in case of extensive skin damages, as well as skin damages in hardly accessible locations, helps to prevent a number of complications associated with the management of the treatment of open wounds. The given method appears suitable also due to a better cosmetic effect and lower degree of stress to the patients.

Wound healing and management in psittacine birds

Psittacines and other companion avian species often develop wounds requiring some form of medical or surgical therapy. Advancing technology in the field of wound care and management continues to evolve for use by the veterinary clinician. Although not all wounds can be successfully treated, many can be reduced and minimized with therapy. Consideration of the overall health, management, and nutrition of the avian patient will also aid in wound management. The avian patient with normal immune function and optimal nutrition will have improved wound healing compared with an immunocompromized or malnourished patient. The duration of treatment and potential stress of the wound-management program should also be taken into consideration when selecting a treatment program for the avian patient.