RADIOGRAPHIC AND ULTRASONOGRAPHIC EVALUATION OF THE PATELLAR LIGAMENT FOLLOWING TIBIAL TUBEROSITY ADVANCEMENT

Effect of tibial tuberosity advancement (TTA) on the patellar ligament has not been described. Our purpose was to evaluate the patellar ligament radiographically and ultrasonographically before and after a TTA. Twenty‐one stifles (20 dogs) were evaluated preoperatively (T0), and at six (n=18) (T1) and 16 weeks (n=17) (T2) postTTA. Radiographically, proximal and distal thickness of the patellar ligament was assessed and a ratio to the total length of the ligament was calculated to compensate for the magnification. Ultrasound evaluation included measurements of the transverse thickness and cross‐sectional area at three different levels, as well as a subjective score of ligament changes. In comparison with T0, all radiographic and ultrasonographic measurements increased significantly, 6 weeks postoperatively (P≤0.04), and did not change 16 weeks postoperatively compared with T1. The subjective score worsened significantly from T0 to T1 and T0 to T2 (P<0.0001), and improved significantly from T1 to T2 (P=0.02). Larger cage size was associated with a more severe increase in radiographic proximal thickness to total length ratio and ultrasonographic middle transverse area at both follow‐up examinations (P0.02). Dogs in which arthrotomy was not performed appeared to have ultrasonographically less changes. In conclusion, patellar desmopathy was a common postoperative sequel to TTA. Surgical trauma, arthrotomy, perfusion injury, complete vs. partial cranial cruciate ligament rupture, larger tibial advancement, postoperative activity or altered insertion angle of the patellar ligament at the tibial tuberosity are suggested causes, that should be elucidated in a larger study cohort.     

EFFECT OF CONTRAST MEDIUM INJECTION DURATION ON PEAK ENHANCEMENT AND TIME TO PEAK ENHANCEMENT OF CANINE PULMONARY ARTERIES

Our goal was to investigate the effect of contrast medium injection duration on pulmonary artery peak enhancement and time to peak enhancement. Fourteen dogs were allocated into one of seven predefined weight categories, each category contained two dogs. Dogs in each weight category were assigned to group A or B. Animals in each group received a different contrast medium injection protocol. In group A, a fixed injection rate of 5 ml/s was used. In group B, the contrast injection rate was calculated as follows: flow rate=contrast volume/scan duration+10 s. Time to peak enhancement and peak enhancement of the main left and right pulmonary arteries were measured on single‐level, dynamic CT images for a fixed time of 30 s. Rank correlation (Spearman's) coefficients between injection duration and time to peak enhancement and between body weight and peak enhancement were calculated. For group A, there was a significant negative correlation between peak enhancement and weight (r=?0.94; P=0.005), while for group B, there was no significant correlation (r=?0.64 and P=0.18). There was a significant correlation between time to peak enhancement and injection duration in both groups (group A: r=0.99; P=0.006 and group B: r=0.85; P=0.02). In conclusion, injection duration is a key feature in a CT angiography injection protocol. A protocol with an injection duration adjusted to the scan duration seems to be particularly suitable for veterinary applications where a population with great weight variability is studied.     

IMAGING DIAGNOSIS—TRANSCRANIAL COLOR‐CODED DUPLEX SONOGRAPHY IN A DOG WITH HEPATIC ENCEPHALOPATHY

We report the use of transcranial Doppler ultrasonography in a dog with hepatic encephalopathy secondary to a congenital portosystemic shunt. A severe increase in the pulsatility index was measured in the right middle cerebral artery, left middle cerebral artery, and basilar artery. These values returned to normal following medical stabilization of the patient and resolution of the neurologic signs. Transcranial Doppler ultrasonography appears to have value for monitoring the status of intracranial hypertension in patients with hepatic encephalopathy.     

Anchovy (Engraulis ringens) and sardine (Sardinops sagax) spatial dynamics and aggregation patterns in the Humboldt Current ecosystem, Peru, from 1983–2003

Three indexes of spatial aggregation are developed and used to examine the aggregation pattern of sardine (Sardinops sagax) and anchovy (Engraulis ringens) in the Peruvian Humboldt Current System, determined from 36 acoustic surveys conducted from 1983 through 2003 by the Peruvian Marine Institute (IMARPE). Each index assesses a different aspect of aggregation: the concentration, the percent occupancy of space and the clustering of high‐fish abundance. Both time‐series correlation and tree‐based clustering‐regression method, classification and regression trees (CART), were used to relate each of the indexes to environmental variables (season, temperature anomaly and year). Additionally, a measure of onshore–offshore distribution, the average distance from the coast, and abundance variables (the average acoustic backscatter per occupied sampling unit, and the acoustically estimated total abundance of sardine and anchovy from IMARPE) were related to environmental factors by using CART. We show that the 1983–2003 time series can be divided into three different periods: with shifts in 1992 and in 1997–98. Sardine and anchovy showed large differences in both abundance and aggregation among these periods. Although upwelling ecosystems support dramatic and sudden changes in environmental conditions, fish responses are sometimes smoother than usually suggested and there are transition periods with concomitant high biomasses of anchovy and sardine, but with different spatial aggregation patterns. Observed relationships between environmental proxies and aggregation patterns support the habitat‐based hypothesis that environmentally mediated alterations in range lead to population changes.     

Generalized Apocrine Cystomatosis in an Old English Sheepdog

Résumé— Les kystes sudoripares multicentriques sont des affections rares chez le chien caractérisées par une hyperplasie multifocale kystique des glandes apocrines au niveau du cou et de la tête. Dans ce cas, nous décrivons un cas sévére de kystes sudoripares multicentriques généralisés chez un Bobtail. Bien que cette affection soit considérée comme un processus non-néoplasique, le comportement et l'histologie des lésions sont compatibles avec révolution d'une tumeur bénigne. En outre nous avons mis en évidence l'expression de récepteurs pour un facteur de croissance épidermique, puissant mitogéne de l'épithélium glandulaire. [Generalized apocrine cystamatosis in an Old English Sheepdog. (Kystes sudoripares généralisés chez un Bobtail.) Zusammenfassung— Apokrine Zystomatose ist eine seltene Erkrankung beim Hund, die durch eine multifokale zystische Hyperplasie der apokrinen Drüsen über Kopf und Hals gekennzeichnet. In diesem Bericht wird der Fall einer schweren generalisierten apokrinen Zystomatose bei einem Bobtail beschrieben. Obwohl dieser Zustand gewöhnlich als nicht-neoplastisches Geschehen eigenstuft wird, war das Verhalten und die Histologie der Veränderungen in diesem Fall mit einem gutartigen Tumor vergleichbar. Weiterhin wurde die Expression eines Rezeptors für den epidermalen Wachstumsfaktor entdeckt, der ein potentes Mitogen für die Drüsenepithelien darstellt und in sekretorischen Zellen apokrine Zysten umgibt. [Generalized aprocrine cystomatosis in an Old English Sheepdog (Generlisierte apokrine Zystomatose bei einem Bobtail). Abstract— Apocrine cystomatosis is an uncommon disorder in the dog characterized by multifocal cystic hyperplasia of apocrine glands over the head and neck. In this report, we describe a case of severe generalized apocrine cystomatosis in an Old English Sheepdog. Although the condition is usually regarded as a non-neoplastic process, the behaviour and histology of the lesions in our case are compatible with a benign tumor. Furthermore, we detected the expression of the receptor for epidermal growth factor, a potent mitogen for glandular epithelia, in secretory cells lining apocrine cysts.     

THORACIC COMPUTED TOMOGRAPHY FINDINGS IN DOGS EXPERIMENTALLY INFECTED WITH ANGIOSTRONGYLUS VASORUM

To characterize the computed tomography (CT) features of thoracic lesions caused by infection with Angiostrongylus vasorum, pre‐ and postcontrast CT was performed in six experimentally infected Beagles 13 weeks postinoculation and in four of these 9 weeks postchemotherapy. Findings were compared with survey radiographs and necropsy findings. A multicentric bronchoalveolar pattern more pronounced at the lung periphery was present radiographically. On CT, the predominant abnormality underlying this alveolar pattern was multiple large nodules merging to areas of consolidation, and containing air bronchograms of varying extent. These nodular changes corresponded to histopathologic granulomata, consisting mainly of macrophages, multinucleated giant cells, and lymphocytes that had accumulated around larvae and eggs. Morphologically, no bronchial changes were observed on CT or histologically. Quantitatively, however, on CT there was evidence of bronchial thickening at 13 weeks postinoculation and mild very peripheral bronchiectasia 9 weeks postchemotherapy. Regional lymph nodes were enlarged after infection, and smaller after treatment. On postcontrast CT, several suspicious intraluminal filling defects suggestive of thrombosis were found; however, the tortuosity of some pulmonary arteries seen radiographically was not present in CT images. After treatment, the consolidations and large nodules had almost completely disappeared. A remaining radiographic interstitial pattern was characterized on CT as ground‐glass opacifications, subpleural interstitial thickening, subpleural lines, and interface signs. These interstitial changes reflected fibrosis as documented histopathologically. CT allowed very detailed and accurate characterization of pulmonary parenchymal lesions, bronchi, and lymphnodes and closely reflected histopathological changes.     

Skin lesions in canine leishmaniasis

Forty-three dogs affected by canine leishmaniasis (CL) with skin lesions have been studied clinically and histopathologically. Identification of leishmaniads in tissues was achieved using indirect immunoperoxidase staining. According to both macroscopic and microscopic lesions, four different dermatological patterns have been observed. Twenty-six dogs showed alopecia and desquamation as the main skin lesions. Histologically a diffuse non-suppurative dermatitis, with numerous leishmaniads inside macrophages was present. Ten animals showed skin ulcerations on limbs, especially over articulations. Histologically, the number of leishmaniads was very reduced. Five animals presented a generalised nodular disease. Each nodule corresponded with a focal accumulation of macrophages, multinucleated giant cells and lymphocytes, with a high number of parasites. Finally, two dogs presented generalised skin pustules. The possible pathogenesis and the differential diagnosis of each form is discussed.