Pathology of the Proximal Radius in Juvenile Pugs.

The aim of this study was to describe the physeal pathology of the proximal radius in four skeletally immature male Pugs. Physical examination, radiography, and computed tomography (CT) of the thoracic limbs were performed in all four dogs. Two Pugs were available for long-term follow-up and two Pugs were euthanatized after the diagnostic imaging results. Four male Pugs, aged between 6 and 7 months, were presented with a history of thoracic limb lameness lasting 2 to 3 months. Radiography and CT of the thoracic limbs showed irregularity of the proximal radial physes with varying degrees of radiolucency within the adjacent metaphyses. The pathology was associated with elbow joint incongruity and angular deformity of the antebrachium. Two dogs were euthanatized, one of which was autopsied, and histopathology of the proximal radius revealed bilateral physeal dysplasia. At long-term follow-up of the two surviving dogs, lameness had resolved. Radiography and CT scans of the thoracic limbs revealed normal bone opacity within the proximal radius and resolution of the radiolucent areas of the proximal radial physes. However, incongruity of the radioulnar joint remained. In this report, the resolution of identified physeal pathology at the proximal radius in juvenile Pugs demonstrates the potential for spontaneous remission despite the presence of notable radiographic changes.

Mutations in the CYP27B1 gene cause vitamin D dependent rickets in pugs.

Rickets is a disorder of bone development and can be the result of either dietary or genetic causes. Here, related pugs from 2 litters were included. Three pugs had clinical signs including, lameness, bone deformities, and dyspnea. One other pug was found dead. Radiographs of 2 affected pugs, 5 and 6 months old, showed generalized widening, and irregular margination of the physes of both the appendicular and the axial skeleton with generalized decrease in bone opacity and bulbous swelling of the costochondral junctions. Two pugs had low serum calcium and 1,25 (OH)2 D3 concentrations. Test results further indicated secondary hyperparathyroidism with adequate concentrations of 25-hydroxyvitamin D. Necropsy revealed tongue-like projections of cartilage extending into the metaphysis consistent with rickets, loss of metaphyseal mineralization and lung pathology. Vitamin D-dependent rickets was diagnosed. A truncating mutation in the 1α-hydroxylase gene (CYP27B1) was identified by genome sequence analysis of the pugs with VDDR type 1A. Vitamin D-dependent rickets type 1A can occur in young pugs, and if left untreated is a life-threatening condition. Early medical intervention can reverse clinical signs and should be instituted as soon as possible.

Asymmetric nasal mucosal thickening in healthy dogs consistent with the nasal cycle as demonstrated by MRI and CT.

The nasal cycle is a physiological phenomenon that causes regular cyclical congestion and decongestion of the venous sinusoids lining the nasal mucosa. The purpose of this prospective study was to describe magnetic resonance imaging (MRI) and computed tomographic (CT) features of the normal nasal cycle in a group of dogs. Five dogs were recruited that met the following criteria: 8 to 15 months old, nonbrachiocephalic breed, no clinical signs or history of nasal disease, and undergoing anesthesia for problems unrelated to the nasal cavity. Nasal MRI (n = 5) and CT scans (pre- and postcontrast, n = 5) were acquired. Images were evaluated subjectively by two board-certified radiologists and objectively by a diagnostic imaging intern using regions of interest placed on each side of the nasal cavity. Findings were compared using Cohen's kappa coefficient and Students t-test on log-transformed data. All dogs showed diffuse unilateral mucosal thickening of the rostral part of the nasal cavity in both MRI and CT studies. This mucosal thickening shifted sides between examinations in three dogs. Changes appeared most marked on T2-weighted scans. No asymmetric mucosal changes were seen in the mucosa of the ethmoturbinates, vomer-nasal septum, hard palate or the frontal sinuses in any patient on MRI or CT. Computed tomographic contrast enhancement of the thickened mucosa was not statistically significant (P-value < 0.08). In conclusion, the normal nasal cycle may cause asymmetrical mucosal changes in the rostral part of the nasal cavity that mimic MRI and CT characteristics previously reported for inflammatory disease in dogs.