Baylisascaris sp. found in a wild northern bobwhite (Colinus virginianus)

Fatal Aberrant Parasite Migration of Echinuria uncinata in Two African Pygmy Geese (Nettapus auritus)

Two adult African pygmy geese (Nettapus auritus) were found dead with minimal clinical disease signs. Necropsy revealed aberrant migration of the nematode parasite Echinuria uncinata, as confirmed morphologically and through DNA sequencing. This common waterfowl parasite typically lives in the proventriculus, burying headfirst into the mucosa and laying eggs into the gastrointestinal lumen. In these geese, the parasites tunneled through the gastrointestinal tract wall to invade the coelomic cavity; from which, a substantial quantity of eggs found their way into the coelomic space and into the air sacs and lungs. This potential parasite migration should be monitored for in Anseriformes species that present with similar disease conditions, and the use of Daphnia species, the intermediate host, as a waterfowl feed source is not recommended.

Cerebrospinal nematodiasis outbreak in an urban outdoor aviary of cockatiels (Nymphicus hollandicus) in southern California

An outbreak of cerebrospinal nematodiasis due to Baylisascaris sp. was documented in an urban outdoor aviary in southern California. Thirty-four out of 35 cockatiels (Nymphicus hollandicus, 97%) showed a variety of neurological signs including ataxia, lateral recumbency, opisthotonus, and torticollis. Thirteen carcasses were submitted for necropsy; the histological lesions were restricted to the central nervous system (brain and spinal cord) and were predominantly degenerative, characterized by multifocal white matter vacuolation, gliosis, axonal swelling, gitter cell infiltration, and mild hemorrhage, rarely accompanied by mild granulomatous inflammation and mild lymphocytic perivascular cuffs. Nematode larvae morphologically compatible with Baylisascaris sp. were observed in the brain of 5 birds, away from the lesion site.

Baylisascaris procyonis infection in a Moluccan cockatoo (Cacatua moluccensis)

An adult female Moluccan cockatoo (Cacatua moluccensis) was evaluated for a 10-day history of progressive ataxia and weakness. The bird had been exposed intermittently over a 3-day period to a cage that had previously housed juvenile raccoons. Results of diagnostic tests were inconclusive and, despite supportive care, the bird died 7 days after the initial presentation. Histopathologic examination revealed a single nematode larva in the midbrain that was consistent with Baylisascaris species and multifocal granulomas in the left ventricle of the heart. The neurologic disease in this bird was attributed to encephalitis caused by neural larval migration of the raccoon roundworm, Baylisascaris procyonis.

The avian neurologic examination and ancillary neurodiagnostic techniques: a review update

The purpose of this article is to guide the avian clinician in the assessment of neurologic function in birds. Physical and neurologic examinations that evaluate cranial nerves, postural reactions, and spinal reflexes identify neurologic dysfunction and the corresponding anatomic location of the lesion. Ancillary diagnostic tests, such as cerebrospinal fluid analysis, diagnostic imaging, muscle and nerve histology, and electrodiagnostics, are tools to confirm and clarify conclusions from the neurologic examination and to identify the cause of disease. Once the disease location and pathologic process have been identified, appropriate treatment and prognosis may be provided.

Baylisascaris procyonis: an emerging helminthic zoonosis

Baylisascaris procyonis, a roundworm infection of raccoons, is emerging as an important helminthic zoonosis, principally affecting young children. Raccoons have increasingly become peridomestic animals living in close proximity to human residences. When B. procyonis eggs are ingested by a host other than a raccoon, migration of larvae through tissue, termed larval migrans, ensues. This larval infection can invade the brain and eye, causing severe disease and death. The prevalence of B. procyonis infection in raccoons is often high, and infected animals can shed enormous numbers of eggs in their feces. These eggs can survive in the environment for extended periods of time, and the infectious dose of B. procyonis is relatively low. Therefore, the risk for human exposure and infection may be greater than is currently recognized.