Parasitology and Pathogenesis of Geopetitia aspiculata (Nematoda: Spirurida) in Zebra Finches (Taeniopygia guttata): Experimental Infection and New Host Records

• Published in: Journal of zoo and wildlife medicine 1994-09, Vol.25 (3), p.403-422
• Main Authors: French, Richard A., Todd, Kenneth S., Meehan, Thomas P., Zachary, James F.
• Format: Article
• Language: English
• Subjects: Birds; Finches; Insect larvae; Larvae; Larval development; Nematode larvae; Nematodes; Proventriculus; Zebras; Zoos
• ISSN: 1042-7260; 1937-2825

Geopetitia aspiculata was isolated at the Lincoln Park Zoological Gardens, Chicago, Illinois. Infections in birds were determined by fecal analysis and/or postmortem examination. Feces from infected birds were fed as an exclusive diet to insects (potential intermediate hosts), including several species of cockroaches (Periplaneta americana, P. australasiae, Blattella germanica, Leucophaea maderae, Supella supellectilium), crickets (Gryllus pennsylvanicus, Acheta domestica), and mealworm beetles (Tenebrio molitor). Nematode larvae were identified in B. germanica, S. supellectilium, and A. domestica. In B. germanica (n = 35), the parasite developed to the infective stage in approximately 35 days. Zebra finches (Taeniopygia guttata) (n = 50) were inoculated p.o. with 15, 30, or 100 infective larvae recovered from experimentally infected insects. Infective third-stage larvae penetrated the proventricular mucosa, and 24 hr postinoculation, larvae were identified within the keratin layer at the proventricular-ventricular junction. At 4 days postinoculation, larvae were found encapsulated in the lamina propria of the superficial mucosa. Proventricular mucosal damage rendered the host susceptible to secondary bacterial and fungal invasion. The fourth-stage larvae penetrated the muscle layers of the proventriculus between 1 and 2 wk postinoculation. From 2 wk to 14 wk postinoculation, the fifth-stage worms developed to maturity. The prepatent period was 70-98 days (x̄ = 88 days). During the patent period, eggs were shed intermittently. The primary macroscopic lesion was a transmural and periproventricular mass of tightly coiled and intertwining nematodes. The mass originated from a single penetrating focus in the greater curvature of the distal proventriculus immediately proximal to the ventricular junction. The posterior end of the nematodes protruded 1-2 mm into the proventricular lumen. The mass was composed of fibrous connective tissue and granulation tissue which varied from thin and translucent to thick and opaque, depending on the duration of infection and the degree of host response.