IN VIVO CONFOCAL MICROSCOPY FOR CHARACTERIZATION OF MYCOTIC KERATITIS IN OWLS (BUBO SCANDIACUS, STRIX VARIA) AND A WOODCOCK (SCOLOPAX MINOR): THREE CASES

This case series describes the use of in vivo confocal microscopy in the diagnosis and treatment of mycotic keratitis in two owls (one Bubo scandiacus, one Strix varia) and one woodcock (Scolopax minor). Each bird was at increased risk of fungal infection due to recent injury or stress. Ophthalmic findings in all birds included blepharospasm, ocular discharge, ulcerative keratitis, white or yellow corneal plaques, and anterior uveitis. Fungal hyphae were identified in corneal samples from all three eyes examined cytologically and in all three eyes by using in vivo confocal microscopy. Aspergillus fumigatus was isolated from a corneal culture in one bird. Despite medical treatment, progressive ocular disease prompted enucleation in two birds. Fungal hyphae were detected by histopathology in one of the two enucleated eyes. In vivo confocal microscopy aided the diagnosis of fungal keratitis in all birds and was the only diagnostic method that allowed immediate, real-time quantification of the extent (area and depth) and severity of mycotic keratitis.

The ocular pyogranulomatous lesion in a Gentoo penguin (Pygoscelis papua) from the Antarctic Peninsula: evaluation of microbiological and histopathological analysis outcomes

In this study, it was aimed to present the results of microbiological, cytological, histopathological, and immunohistochemical analyses of ocular samples from an Antarctic (Ardley Island, King George Island) Gentoo penguin chick (Pygoscelis papua) with a pyogranulomatous lesion in the right eye. Samples were taken from both the healthy left eye and the lesion in the right eye. Conventional culture methods and phenotypic and molecular tests were used for bacterial isolation and identification, respectively. None of the isolates could be identified phenotypically. As a result, four of the five isolates obtained from the right eye were considered to belong to putative novel bacterial species and taxa as their similarity to GenBank data was below 98.75%. The isolates were considered to be Pasteurellaceae bacterium, Corynebacterium ciconiae, Cardiobacteriaceae bacterium, Actinomyces sp., and Dermabacteraceae bacterium. The only isolate from the left eye was identified as Psychrobacter pygoscelis. The cytological analysis demonstrated cell infiltrates composed mostly of degenerate heterophils, reactive macrophages, plasma cells, lymphocytes, and eosinophils. Based on histopathological findings, the lesion was defined as a typical pyogranulomatous lesion. Immunohistochemistry demonstrated that the granuloma was positive for TNF-α, IL-4, MMP-9, IL-1β, and IL-6. This is the first documented report of the unilateral pyogranulomatous ocular lesion in a Gentoo penguin chick, living in its natural habitat in Antarctica. This report also describes the isolation of four bacteria from the infected eye, which are considered to belong to novel Genus, species, or taxa. The primary bacterial pathogen that caused the ocular lesion was not able to be detected and remains unclear.

Marek's disease virus associated ocular lymphoma in Roulroul partridges (Rollulus rouloul)

Two 1-year old Roulroul partridges (Rollulus rouloul), one male and one female, were presented because of eye problems and anorexia. Twenty of the 30 Roulroul partridges in the owner's collection had already died. The affected birds stopped eating, became thinner, and eventually died. Antibiotic treatment, which started because of the suspicion of a septicaemic process, was unsuccessful. At clinical examination of the two partridges it was found that in both birds, one eye ball was filled with a whitish yellow amorphous material and the other eye ball of the female showed a distinct corneal opacity. Both presented birds were euthanized. Necropsy revealed no significant abnormalities in addition to the eye lesions. Histology and immunohistochemistry of the female's eye revealed an infiltrate of T-lymphocytes corresponding to ocular lymphoma. Herpesvirus genus-specific PCR, followed by Sanger sequencing confirmed the presumptive diagnosis of Marek's disease in both birds. To our knowledge, this is the first confirmed case of infection with Gallid Herpesvirus 2 (Marek's disease virus) in partridges and the first case in this specific species.

Aspergillus and aspergilloses in wild and domestic animals: a global health concern with parallels to human disease

The importance of aspergillosis in humans and various animal species has increased over the last decades. Aspergillus species are found worldwide in humans and in almost all domestic animals and birds as well as in many wild species, causing a wide range of diseases from localized infections to fatal disseminated diseases, as well as allergic responses to inhaled conidia. Some prevalent forms of animal aspergillosis are invasive fatal infections in sea fan corals, stonebrood mummification in honey bees, pulmonary and air sac infection in birds, mycotic abortion and mammary gland infections in cattle, guttural pouch mycoses in horses, sinonasal infections in dogs and cats, and invasive pulmonary and cerebral infections in marine mammals and nonhuman primates. This article represents a comprehensive overview of the most common infections reported by Aspergillus species and the corresponding diseases in various types of animals.

Articular aspergillosis of hip joints in turkeys

Aspergillosis is an important cause of morbidity and mortality in birds. Turkey poults are known to be particularly susceptible to fungal infection. Although the respiratory tract is the most commonly affected, dissemination can occur into virtually any organ. Here, we report an unusual outbreak of articular aspergillosis in a flock of meat turkeys with clinical signs of lameness. Between 7 and 11 weeks of age, turkeys had severe granulomatous osteoarthritis of the hip joints with necrosis of the femur head. Fungal morphology and PCR amplification and sequencing of the first ITS1-5.8S-ITS2 rDNA region identified Aspergillus fumigatus as the infectious agent. Concurrently, Staphylococcus spp. was isolated from the hip joints, which may have promoted the tropism of the fungus. Mild respiratory tract aspergillosis was observed in only one case. The findings suggest that fungal arthritis may present a specific disease entity in turkeys and should be considered as further cause of lameness in turkeys.

Observations of aspergillosis in the brains of turkey poults using different histopathological staining techniques

Different staining methods were evaluated for studying aspergillosis of the central nervous system (CNS). The pathological changes and fungal elements in cerebrum and cerebellum of 17 turkey poults with aspergillosis were examined and described. Tissue sections were stained with hematoxylin-eosin (HE), Kluver-Barrera's and Grocott's methods, and periodic acid-Schiff (PAS). Focal granulomatous reactions with central necrosis were observed in the HE stained slides. Fungal hyphae were easily demonstrated using Grocott's method and PAS. These two methods, however, were not suitable for describing detailed histopathological changes. The Kluver-Barrera method was used to demonstrate the neural tissue reaction. Neurons were found to be sensitive to aspergillosis, in contrast to glial cells that showed fewer pathological changes. The fungal elements were clearly visible with the Kluver-Barrera method, resulting in better information about the interactions of neural tissue, the inflammatory response, and the fungus. The use of the Kluver-Barrera method for this purpose has not been documented previously.

Fungal diseases of birds of prey

Aspergillosis and candidiasis are ranked among the most common infectious diseases in birds of prey. The prevention of these fungal diseases is often easier than treatment. Thus the clinician should strive to prevent infection by minimizing stress, maintaining a healthy environment, limiting long-term use of antibiotics and corticosteroids, and reducing exposure to fungal organisms. Although less commonly diagnosed among wild, free-ranging birds of prey, a high incidence in a free-ranging population should make the clinician think of an immunocompromising factor (i.e., toxins, human encroachment or low prey base) that may be contributing to infection. The diagnosis of aspergillosis and candidiasis often requires more than just the identification of the agent, as these ubiquitous organisms often are cultured from healthy birds of prey. In those birds of prey in which a fungal infection is highly suspected or proven, antifungal drugs remain the mainstay of treatment, although available drugs and modes of delivery have improved in recent years.

Conjunctivitis in birds

There are numerous causative agents of avian conjunctivitis, many of which are associated with systemic disease. A thorough evaluation of the patient's history and habitat is mandatory, and a complete physical examination and ophthalmic examination are required. The owner should be informed at the initial visit that an orderly sequential approach for obtaining diagnostic specimens is required and that a protracted course of treatment may be required to bring about complete, long-lasting resolution of clinical signs.

A case of aspergillosis in a broiler breeder flock

A case of aspergillosis in a broiler breeder flock having respiratory and nervous system problems caused by Aspergillus fumigatus and Aspergillus niger is documented. Dyspnea, hyperpnea, blindness, torticollis, lack of equilibrium, and stunting were observed clinically. On postmortem examination of the affected birds, white to yellow caseous nodules were observed on lungs, thoracic air sacs, eyes, and cerebellum. Histopathologic examination of lungs and cerebellum revealed classic granulomatous inflammation and cerebellar lesions, necrotic meningoencephalitis, respectively. No lesions were noted in the cerebrum histopathologically. Aspergillus hyphae were observed in stained sections prepared from lesioned organs. Fungal spores and branched septate hyphae were observed in direct microscopy. Aspergillus fumigatus and A. niger were isolated from the inoculations prepared from the suspensions of organs showing lesions.

Respiratory diseases of gallinaceous birds

Respiratory conditions constitute many of the diseases affecting all avian species, including gallinaceous birds. Clinical signs and gross lesions of different respiratory diseases are often similar, and establishing a definitive diagnosis may require ancillary laboratory testing. Determination of a specific diagnosis allows practitioners to select the most effective therapies and to prescribe a management program that prevents recurrence.