Comparative histological analysis of the alae nasi in French bulldogs with brachycephalic obstructive airway syndrome and unaffected non-brachycephalic dogs.

BACKGROUND: Brachycephalic dogs are characterised by a short and flat nose. This cranial conformation is associated with brachycephalic obstructive airway syndrome, a respiratory syndrome primarily characterised by stenotic nares, a hyperplastic soft palate and a hypoplastic trachea, among other malformations, with secondary abnormalities resulting in upper airway obstruction METHODS: In this study, we aimed to characterise and compare the histological features of tissue samples harvested from the alae nasi of French bulldogs and non-brachycephalic dogs. Samples from the alae nasi of 11 French bulldogs and 13 non-brachycephalic dogs were collected. Four-µm-thick, paraffin-embedded sections were obtained from each tissue sample and mounted on glass slides, followed by staining with haematoxylin and eosin, periodic acid-Schiff and toluidine blue for histological examination. RESULTS: The only variation observed between the samples obtained from French bulldogs and those obtained from non-brachycephalic dogs concerned the presence of cartilage in the specimens. Cartilage was absent in 10 of 11 French bulldogs but present in nine of 13 non-brachycephalic dogs; this difference was statistically significant (p < 0.05). LIMITATIONS: The findings of this study need further validation in future prospective studies. It would be useful to examine the entire nostril wing, to include additional brachycephalic breeds, a larger number of subjects spanning a wider age range and degree of stenotic nares severity, a larger tissue sample, and a broadening of the control group to include dolichocephalic and mesaticephalic dogs. CONCLUSION: This study found an absence of cartilage in French bulldog nare specimens compared to those from non-brachycephalic dogs. This absence of cartilage may contribute to brachycephalic obstructive airway syndrome, although histological examination of the entire wing of the nostrils is needed to confirm this hypothesis.

Feline progressive histiocytosis: a retrospective investigation of 26 cases and preliminary study of Ki67 as a prognostic marker.

Feline progressive histiocytosis (FPH) is an uncommon and infrequently reported cutaneous histiocytic proliferative disorder, whose clinical presentation is solitary or multiple cutaneous nodules and papules, with late-course internal metastasis. We describe herein the clinical, epidemiologic, histologic, and immunohistochemical features of this entity, and document the outcome of FPH based on a retrospective study of 26 cases. Female and male cats were affected equally. Lesions were evident either as solitary (16 of 26 cases) or multiple (10 of 26 cases) nonpruritic and alopecic nodules or plaques, preferentially located on the legs and extremities (73%). Follow-up was complete for 19 cats, and ranged from 41 to 1,449 d. Nine died of FPH with a median overall survival of 96 d (range: 41-238 d). The disease recurred in 14 cats after surgical excision of the nodules, and the median disease-free survival was 175 d (range: 21-1,449 d). Five of the 26 cats were alive at the end of the study, and 4 had no progression of the disease. Histologically, lesions were characterized by poorly circumscribed, unencapsulated histiocytic infiltration of dermis and subcutis. Epitheliotropism was observed in 11 (42%) cats. Atypical histiocytes diffusely and consistently expressed MHC II, CD18, and Iba1. Statistically significant higher E-cadherin expression was observed in epitheliotropic cases compared to non-epitheliotropic cases. A negative correlation between overall survival and proliferation index was evident, thus suggesting Ki67 as a promising prognostic marker.

Significance of a common extended mucosal interface observed in transverse small intestine sonograms.

An echogenic stripe can be seen through the mucosal layer on either side of the ultrasonographic image of a bowel loop in cross-section. The mucosa is a continuous layer surrounding the intestinal lumen; thus it should appear as a continuous hypoechoic band with no bright stripe in it. The purpose of this study was to investigate the origin of this stripe and to determine whether it is an artifact. Intestinal cross-sectional images were obtained using different transducer types and frequencies. In vivo and in vitro, different angles of insonification were used and, in vitro, bowel loops were also fluid filled during an ultrasonographic examination, to assess the potential influence of intestinal shape and position on this stripe. Some of these loops were evaluated histologically to determine if the echogenic stripe had a histologic basis. The echogenic stripe was present only when the loop was flattened. It remained on each side of the maximal cross-sectional width and disappeared when this width was parallel to the ultrasound beam, or when the bowel loop had a completely round shape and was dilated. There was no influence of transducer type, shape, or frequency on the appearance of the line. Histologically, uneven and larger distance between the mucosal villi could be seen on either side of the bowel loop corresponding to the location of the echogenic stripe seen on the ultrasonographic images. In conclusion, the occasional echogenic stripe represents an interface within the mucosa due to altered position of villi on either side of the maximal intestinal cross-sectional width in collapsed bowel segment.

Spinal subarachnoid cysts in 13 dogs.

Thirteen dogs, including 6 Rottweiler dogs, exhibiting clinical signs of spinal cord dysfunction and myelographically confirmed subarachnoid space enlargement were investigated. To characterize the lesions and to get a better understanding of their pathogenesis, different imaging techniques were used in association with explorative surgical procedures (12 dogs) and histopathologic techniques (5 dogs). All subjects underwent preoperative myelography, five of which were examined by computed tomography (CT) scanning and one by magnetic resonance imaging (MRI) as well as cerebrospinal fluid (CSF) flow measurement (velocimetry). Most animals were <12 months old (7/13 dogs) and Rottweilers were over-represented (6/13 dogs). The lesions were mainly located dorsally with respect to the spinal cord (10/13 dogs) and in the cranial cervical area (8/13 dogs). MRI suggested spinal cord deviation with signs of ventral leptomeningeal adhesion opposite the enlarged space. In one dog, velocimetry confirmed that the "cyst" was freely communicating with the surrounding CSF space. Surgical investigation confirmed leptomeninges-induced ventral adhesion in 4/5 dogs. Follow-up studies, carried out from 6 months to 2.5 years postoperatively, showed there was full recovery in 8/13 dogs. This study suggests that the compression of the spinal cord is possibly not caused by a cyst. Adhesion resulting from a combination of microtrauma and chronic inflammatory processes induces a secondary enlargement of the subarachnoid space and may be a significant causative factor in spinal cord compression and dysfunction. The over-representation of Rottweilers and the young age of the animals in the study suggest a possible genetic predisposition and an inherited etiology.