New Insights on the Neglected Avian Nematode Hystrichis tricolor: Hystrichiosis-Induced Proventriculitis in Synanthropic Egyptian Geese (Alopochen aegyptiaca Linnaeus, 1766) in Germany.

Hystrichis tricolor is a neglected avian enoplid nematode (superfamiliy Dioctophymatoidea) and known to parasitize various species of the Anatidae (Anas spp. and Mergus spp.) from the northern hemisphere, inducing mainly proventriculitis in domestic and wild waterfowl. Here, we focus on the pathological findings of naturally H. tricholor-infected Egyptian geese (Alopochen aegyptiaca) and a neozoan shelduck (Tandorninae) of Germany. Nowadays, this species is considered the fastest-spreading alien waterfowl species within Western Europe. Additionally, molecular sequencing coupled with phylogenetic characterization of H. tricolor is reported. Post mortem analyses unveiled patent gastric H. tricolor infections in eight of twelve infected birds (8/12; 66.7%), inducing proventriculitis resulting in large visible nodular lesions. Histopathological findings point to chronic host pro-inflammatory immune reactions. These results demonstrate the potential role of Egyptian geese as natural reservoir hosts of H. tricholor and highlight their possible role in parasite transmission (i.e., spillback) into endemic waterfowl species. Due to avian health concerns, the occurrence of hystrichiosis should be monitored in native waterfowl in the future, introducing appropriate management practices in conservation strategies of endemic wild birds not only in Germany but elsewhere in Europe.

Periodontal structures in horses with pituitary pars intermedia dysfunction: A histological evaluation.

Introduction: Pituitary pars intermedia dysfunction (PPID) and dental disorders are of major concern in horses older than 15 years. Although PPID in geriatric horses and dental disorders in all age groups are well described, a connection between this endocrine disease and pathological changes in equine dental structures has not yet been investigated. In humans, periodontitis is considered to be a complication of systemic diseases like diabetes mellitus type 2, obesity and various conditions leading to an impaired immune response. In PPID, cross links to insulin and immune dysregulations are proven. The aim of this study was to compare histological findings of the gingiva and the sub gingival periodontal ligament of PPID affected horses with control horses. Methods: In a case-control morphometric descriptive study, 145 dental locations of 10 PPID affected horses (27.3 ± 2.06 years) were compared with 147 dental locations of 10 controls (21.4 ± 4.12 years). Histological parameters were leukocyte infiltration, keratinization of gingival epithelium, blood vessel supply of the periodontium and structure of cementum. Results: The distribution and localization of gingival leukocyte infiltrations (LI) in PPID affected horses was more often multifocal to coalescing (p = 0.002) and reached into deeper parts of the periodontium, sometimes down to the sub gingival periodontal ligament (PDL). Aged animals of both groups showed higher prevalence (PPID: OR 1.66; controls: OR 1.15) for severe leukocyte infiltration in the PDL. PPID was not significantly associated with increased LI. The cementum bordering the soft tissue in interdental locations showed four times more irregularities in PPID affected horses than in controls which predisposes for interdental food impaction and periodontal diseases. Discussion: In summary, multifocal to coalescing leukocytes and irregular cementum are seen more often in PPID than in controls - however our findings mainly reflect an association of older age with periodontal disease.

The Gingiva of Horses With Pituitary Pars Intermedia Dysfunction: A Macroscopic Anatomical Evaluation.

Pituitary pars intermedia dysfunction (PPID) is a common neurodegenerative disease mainly in horses older than 15 years. The domestic equine population is following the same demographic change as that seen in humans; it is aging and veterinarians are asked to attend to geriatric horses more frequently. Common problems seen regularly in older equines are dental disorders and especially periodontal disease. As a systemic and endocrine disease, associated with delayed wound healing and impaired immune function, PPID should be considered before major dental treatment in aged equines is started. Possible negative effects of PPID on epithelial tissues could also affect the periodontium. Therefore, the aim of the present study was to identify gross changes in the gingiva associated with PPID. Fourteen horses with clinical signs of PPID and adenoma in the pituitary pars intermedia and 13 controls showing neither clinical signs nor PPID-associated histological changes in the pituitary gland were included. PPID-affected horses (26.9 ± 0.73 years) were significantly older than controls (20.0 ± 1.24 years). In the PPID-affected group, significantly more often an irregular and bulky appearance of the gingival texture was observed, as well as an irregular shape of the gingival margin. Furthermore, the sulcus gingivalis of cheek teeth frequently was deeper than 1 mm. These findings indicate a possible association between age, soft tissue alterations, and PPID and suggest a potential predisposition of PPID-affected horses for periodontal diseases.