Six dogs, five males and one hermaphrodite, were diagnosed with hypospadias. Two of the five males had the penile form of the condition, two had the perineal form and one had the glandular form; the hermaphrodite had the scrotal form. The hermaphrodite had no prostate gland and no right testicle; it had a normal right ovary and horn of the uterus but the left horn was joined to the testicle. Its karyotype showed 78 chromosomes, all in metaphase, and two typical sex chromosomes X and Y.

Hypoglycemia is frequently found in dogs suffering from portosystemic shunt (PSS). However, the mechanisms leading to abnormal blood glucose concentration in such dogs have not been studied. Therefore, investigations were undertaken to study the structure of pancreatic islets in 25 patients with congenital PSS (cPSS). Material for morphometry and histopathology was taken during the surgical closing of the abnormal blood vessel. A total of 75 islets (3 randomly chosen from each patient) were analyzed, and their average size was compared to reference values for dogs that were considered as 50-325 μm. The average size of 47 (63%) islets was below 50 μm, whereas the mean dimension of the largest islet did not exceeded 80 μm. The average islet size in all patients was 46 (SD 13.3) μm and in only 2 dogs (8%) all 3 analyzed islets were bigger than the lower reference value. Histopathological examination revealed cytoplasmic vesicles in pancreatic cells, as well as extracellular, homogenous, acidophilic deposits in pancreatic islets. These results indicate that in dogs suffering from cPSS the pancreatic islets are smaller than the reference values and their cells may contain abnormal structures.

Lipomas are common, usually slow-growing, benign tumours of mesenchymal origin that most commonly occur on the proximal limb and trunk of middle-aged to older dogs. They are rarely associated with either local invasion or malignancy, unlike infiltrative lipomas and liposarcomas, respectively. Three dogs, a 10-year-old mixed-breed female of 35 kg body weight, a 10-yearold mixed-breed male of 30 kg body weight, and an 11-year old female German shepherd of 38 kg body weight, were presented with a 3-6 month (median, 5 months) history of progressive left pelvic limb lameness and thigh swelling. A lesion affecting the soft tissue of the thigh and the left sciatic nerve was suspected in all dogs. A left thigh magnetic resonance (MR) revealed a homogenous, well circumscribed tumour in the mixed-breed dogs and two similar tumours in the German shepherd. The tumours were interposed between the semimembranosus and semitendinosus muscles. The treatment involved surgical extirpation of the tumours. A follow-up examination 12 months post operation showed mild lameness and proprioceptive deficits in the operated limb in all the dogs. The withdrawal reflex and the cranial tibial reflex were normal. Neither mass nor thickening were palpable in the thigh region. Although intermuscular lipoma is rare, it should be suspected in dogs with progressive monoparesis. Magnetic resonance is a valuable imaging method for diagnostic precision and pre-operative planning. Quick diagnosis and decompressive surgery are required to allow recovery. Canine, benign tumour, sciatic nerve

Hepatic stellate cells play a crucial role in the development of liver fibrosis. In a damaged liver, stellate cells undergo activation, which is manifested as a change of their phenotype: differentiation of stellate cells to myofibroblast-type cells, expression of alpha-Smooth Muscle Actin, their proliferation and a reduction in the size of cytoplasmic lipid droplets. The aim of this study was to determine the number and morphology of stellate cells in the canine liver affected by congenital portosystemic shunt (PSS) and portal vein hypoplasia – hepatic microvascular dysplasia (PVH-HMD). The material for investigation were archived paraffin blocks with liver samples collected supravitally from six dogs with PSS, six dogs with PVH-HMD and six healthy dogs. On the HE-stained sections, the number of stellate cells per 100 hepatocytes was counted (Sztark method) and the diameter of veins in the hepatic triads was measured (light microscope Olympus BX 43, SC30 camera, CellSens Entry 2011 Olympus). In addition, the diameter of lipid droplets in stellate cells was measured (computed image analysis system LUCIA 4.21). The results were analysed statistically (the Kruskal-Wallis test followed by Dunn’s post-hoc procedure; significance level (α) at 0.05; Statistica 12 StatSoft Inc.). The degree of liver fibrosis was determined (Masson’s method of slide stain; Scheuer scale). The liver samples from the dogs with PSS and PVH-HMD were stained immunohistochemically with Monoclonal Mouse Anti-Human Smooth Muscle Actin (α-SMA), clone 1A4, antibodies (DAKO). Portosystemic shunt and primary portal vein hypoplasia in the dog results in a reduction in the diameter of portal vein branches and in insufficient portal blood flow through the liver. In the material investigated, this was particularly evident in the animals affected by PSS: such dogs had a significantly smaller diameter of the veins than did the healthy dogs (p<0.001) or the dogs with PVH-HMD (p=0.023). Fibrosis and the expression of α-SMA were stronger in the dogs with PSS than in those with PVH-HMD. Moreover, the dogs with PSS had a significantly higher average number of stellate cells than the healthy animals (p=0.007) did. However, the examination of the material revealed an enlargement of cytoplasmic lipid droplets: the dogs with PSS had a significantly larger diameter of lipid vacuoles in the cytoplasm of stellate cells than did the healthy animals (p<0.001) or the dogs with PVH-HMD (p=0.043); the dogs with PVH-HMD had lipid droplets with a significantly larger diameter than the healthy animals (p<0.001) did. Hypoperfusion of the liver and the accompanying regressive lesions in hepatocytes result mainly in an increased number of stellate cells and stronger expression of α-SMA, while cytoplasmic lipid droplets in the stellate cells are not reduced in size. The present study indicates the need for detailed analyses of clinical cases and warrants further comprehensive studies of comparative hepatopathology because it demonstrates differences between humans and dogs in the morphological indicators of hepatic stellate cell activation in chronic liver damage.

Introduction: The clinical symptoms of portosystemic shunts (PSSs) and hepatic microvascular dysplasia (HMD) – portal vein hypoplasia (PVH) in dogs are similar. PSSs are abnormal vascular connections between the portal vein system and systemic veins. HMD is a very rare developmental vascular anomaly, recognisable during histopathological examination. The study aim was to assess the prevalence of HMD–PVH and hepatocellular and vascular pathologies in the liver. Material and Methods: Liver biopsies from 140 dogs (of different breeds and both sexes) arousing clinical suspicion of PSS were examined histopathologically. Results: An initial PSS diagnosis was confirmed in 125 dogs (89.29%). HMD–PVH was found in 12.32% of dogs, as an isolated disease in 9.29%, especially in Yorkshire terriers, and with extrahepatic PSS in 6.67%. Histopathological analysis of muscles around sublobular veins showed that HMD cases presented hypertrophy or hypertrophy with fibrosis. In 2.17% of all dogs with liver vascular developmental disorders calcification was visible around vessels (without correlation by degenerative changes in those vessels), suggesting prior onset of deep metabolic disorders. Clinical suspicion of PSS was also formed upon quite different pathological processes in young dogs. Conclusion: Histopathological findings diagnosed the type of vascular anomalies (PSS or HMD–PVH) or other pathological changes conclusively, therefore detailed hepatic histopathology is an indispensable component of the clinical diagnostic process.