Abstract.A novel plant-induced lysosomal storage disease was observed in goats from a village in Mozambique. Affected animals were ataxic, with head tremors and nystagmus. Because of a lack of suitable feed, the animals consumed an exotic hedge plant growing in the village that was identified as Ipomoea carnea (shrubby morning glory, Convolvulaceae). The toxicosis was reproduced by feeding I. carnea plant material to goats. In acute cases, histologic changes in the brain and spinal cord comprised widespread cytoplasmic vacuolation of neurons and glial cells in association with axonal spheroid formation. Ultrastructurally, cytoplasmic storage vacuoles in neurons were membrane bound and consistent with lysosomes. Cytoplasmic vacuolation was also found in neurons in the submucosal and mesenteric plexuses in the small intestine, in renal tubular epithelial cells, and in macrophage-phagocytic cells in the spleen and lymph nodes in acute cases. Residual alterations in the brain in chronic cases revealed predominantly cerebellar lesions characterized by loss of Purkinje neurons and gliosis of the Purkinje cell layer. Analysis of I. carnea plant material by gas chromatography-mass spectrometry established the presence of the mannosidase inhibitor swainsonine and 2 glycosidase inhibitors, calystegine B 2 and calystegine C 1 , consistent with a plant-induced ␣-mannosidosis in the goats. The described storage disorder is analogous to the lysosomal storage diseases induced by ingestion of locoweeds (Astragalus and Oxytropis) and poison peas (Swainsona).Most lysosomal storage diseases are genetic disorders, 32 but a few are induced by the ingestion of toxic plants such as the locoweeds (Astragalus and Oxytropis spp.) from North America, South America, and China 36 and the poison peas (Swainsona spp.) found in Australia. 13,15,25 These plants belong to the family Fabaceae (Leguminosae) and contain the indolizidine alkaloid swainsonine, an inhibitor of lysosomal ␣-mannosidase and mannosidase II. 12,28 The action of swainsonine results in a lysosomal storage disorder that closely mimics ␣-mannosidosis, characterized by the accumulation of incompletely processed oligosaccharides rich in ␣-mannosyl and ␤-N-acetyl glucosamine moieties. 2,12 Histologically, there are cytoplasmic vacuoles in cells of the nervous system and other tissues. Neurons, as is the case in most lysosomal storage diseases, are most consistently affected because

Evaluation of canine renal biopsy tissue has generally relied on light microscopic (LM) evaluation of hematoxylin and eosin-stained sections ranging in thickness from 3 to 5 µm. Advanced modalities, such as transmission electron microscopy (TEM) and immunofluorescence (IF), have been used sporadically or retrospectively. Diagnostic algorithms of glomerular diseases have been extrapolated from the World Health Organization classification scheme for human glomerular disease. With the recent establishment of 2 veterinary nephropathology services that evaluate 3-µm sections with a panel of histochemical stains and routinely perform TEM and IF, a standardized objective species-specific approach for the diagnosis of canine glomerular disease was needed. Eight veterinary pathologists evaluated 114 parameters (lesions) in renal biopsy specimens from 89 dogs. Hierarchical cluster analysis of the data revealed 2 large categories of glomerular disease based on the presence or absence of immune complex deposition: The immune complex-mediated glomerulonephritis (ICGN) category included cases with histologic lesions of membranoproliferative or membranous patterns. The second category included control dogs and dogs with non-ICGN (glomerular amyloidosis or focal segmental glomerulosclerosis). Cluster analysis performed on only the LM parameters led to misdiagnosis of 22 of the 89 cases-that is, ICGN cases moved to the non-ICGN branch of the dendrogram or vice versa, thereby emphasizing the importance of advanced diagnostic modalities in the evaluation of canine glomerular disease. Salient LM, TEM, and IF features for each pattern of disease were identified, and a preliminary investigation of related clinicopathologic data was performed.

Background: Human renal biopsies are routinely evaluated with light microscopy (LM) using a panel of histologic stains, transmission electron microscopy (TEM), and immunofluorescence (IF) microscopy to obtain a diagnosis. In contrast, the pathologic evaluation of glomerular disease in veterinary medicine has relied mostly on LM and was of limited utility. To address this problem, recently established veterinary renal diagnostic centers have adopted methods used in human nephropathology for evaluation of renal biopsies. Three broad categories of disease, which have the greatest implications for clinical management of proteinuric dogs, have been established and include amyloidosis, immune complex-mediated glomerulonephritis (ICGN), and non-ICGN.Objective: To demonstrate histopathologic, ultrastructural, and IF findings in renal biopsy specimens that experienced veterinary nephropathologists utilize to make accurate and clinically useful diagnoses in dogs with proteinuric glomerular disease and to provide guidelines for the proper evaluation of renal biopsies.Methods: Renal biopsy specimens were routinely examined by LM, IF, and TEM. Samples were reviewed by members of the World Small Animal Veterinary Association Renal Standardization Study Group to identify lesions that were diagnostic for, or suggestive of, the presence of immune complexes (IC) or amyloidosis in all modalities. Ten guidelines for renal biopsy evaluation were formulated.Results: Each method of investigation contributed important findings that were integrated to make an accurate final morphological diagnosis. The guidelines were validated by an independent group of veterinary pathologists.Conclusions and Clinical Importance: Routine evaluation of renal biopsies with LM, TEM, and IF is feasible and necessary for making accurate, morphologic diagnoses that can be used to guide clinical management of dogs with glomerular disease.

SummaryToxicity of closantel, a halogenated salicylanilide anthelmintic, is described in 11 sheep and a goat, humanely killed 4-70 days after accidental overdosage. Status spongiosis of the cerebrum and cerebellum was present, its severity decreasing with time after treatment. Ultrastructurally, vacuoles in the cerebral white matter were seen to be intramyelinic due to splitting of myelin lamellae at the intraperiod lines, indicating myelin oedema. In the optic nerves, Wallerian degeneration and eventual fibrosis and atrophy of the nerves followed myelin vacuolation. Lesions in the optic nerves were particularly advanced in the intracanalicular portion, indicating a compressive neuropathy within the optic canal. Acute retinal lesions consisted of papilloedema, necrosis of the outer retinal layers (especially the photoreceptor layer), and retinal separation in tapetal and non-tapetal areas. In more chronic cases, the outer nuclear layer was diffusely attenuated and generally reduced to a single row of cells.

An extreme form of abnormal development, dwarfism, is common in man and some animals, but has not been officially reported in horses. Within the Friesian horse breed, congenital dwarfism has been recognised for many years, but no detailed report exists on its phenotype. The most salient feature of the dwarf syndrome is the physeal growth retardation in both limbs and ribs. Affected animals have approximately 25% shorter fore- and hindlimbs and approximately 50% reduced bodyweight. Postnatal growth is still possible in these animals, albeit at a slower rate: the head and back grow faster than the limbs and ribs leading to the characteristic disproportional growth disturbance. Thus, adult dwarfs exhibit a normal, but a relatively larger head conformation, a broader chest with narrowing at the costochondral junction, a disproportionally long back, abnormally short limbs, hyperextension of the fetlocks and narrow long-toed hooves. Furthermore, a dysplastic metaphysis of the distal metacarpus and metatarsus is radiographically evident. Microscopic analysis of the growth plates at the costochondral junction shows an irregular transition from cartilage to bone, and thickening and disturbed formation of chondrocyte columns, which is similar to findings in osteochondrodysplasia.

BackgroundThe European Veterinary Renal Pathology Service (EVRPS) is the first Web‐based registry for canine renal biopsy specimens in Europe.Hypothesis/ObjectivesThe aim was to verify whether differences exist between the clinical and laboratory presentation of dogs with nephropathy according to renal pathological findings, as defined by light and electron microscopy of renal biopsy specimens submitted to EVRPS.AnimalsRenal biopsy specimens of dogs were collected from the archive of the service (n = 254). Cases were included if both light and electron microscopy were available (n = 162).MethodsRenal biopsy specimens were classified based on the morphological diagnoses. Thereafter, they were grouped into 3 disease categories, including immune‐complex‐mediated glomerulonephritis (ICGN), non‐immune‐complex‐mediated GN (non‐ICGN), and renal lesions not otherwise specified (RL‐NOS). Differences among morphological diagnoses and among disease categories were investigated for clinical and laboratory variables.ResultsSerum albumin concentration was lower in dogs with ICGN than in those with non‐ICGN (P = 0.006) or RL‐NOS (P = 0.000), and the urine protein‐to‐creatinine ratio (UPC) was significantly higher in ICGN than in the other 2 disease categories. Regarding morphological diagnoses, albumin was significantly lower in amyloidosis (AMY) and membranous (MGN), membranoproliferative (MPGN) or mixed glomerulonephritis (MixGN) than in minimal change disease, primary (FSGS I) or secondary (FSGS II) focal and segmental glomerulosclerosis and juvenile nephropathies (JN). The UPC was higher in MPGN than in FSGS I and FSGS II.Conclusions and clinical importanceDogs with ICGN, in particular MPGN, had higher protein loss than those with non‐ICGN or RL‐NOS, leading to more severe hypoalbuminemia. Clinical and laboratory differentiation among dogs with the different morphological diagnoses and among dogs with different disease categories was difficult due to overlapping results.

This retrospective study describes 4 cases of canine babesiosis with histologically confirmed acute pancreatitis. In addition, 16 dogs with babesiosis are reported with serum amylase (>3500 U/l ) and/or lipase (>650 U/l ) activity elevations of a magnitude that would support a diagnosis of probable acute pancreatitis, although extra-pancreatic sources of the enzymes could not be excluded in these cases. Median time of pancreatitis diagnosis was 2.5 days post-admission, with primarily young (median age 3 years), sexually intact dogs affected. The development of pancreatitis was unrelated to the degree of anaemia at time of admission. In addition to pancreatitis, 80 % of cases suffered from other babesial complications, namely icterus (13), acute respiratory distress syndrome (6), immune-mediated haemolytic anaemia (6), renal failure (3), haemoconcentration (2) and cerebral syndrome (2). Acute respiratory distress syndrome, renal failure and cerebral syndrome were associated with a poor prognosis, with 4 of the 5 dogs included in the overall 26 % mortality rate having at least 1 of these complications. Haemolytic anaemia with ischaemia-reperfusion injury to the pancreas is proposed as a possible primary pathophysiological mechanism in babesial pancreatitis. Hypotensive shock, immune-mediated haemolytic anaemia, haemoconcentration and possibly altered lipid metabolism in babesiosis may also be involved. The previously postulated pro-inflammatory cytokine milieu of complicated babesiosis may underlie the progression, if not the primary initiation, of pancreatic pathology. Acute pancreatitis may represent the previously reported 'gut' form of babesiosis

A case of chronic idiopathic intestinal pseudo-obstruction in an English bulldog is described. The dog was presented with chronic weight loss and vomiting. An intestinal obstruction was suspected based on clinical and radiological findings. A diagnosis of chronic idiopathic intestinal pseudo-obstruction was made on the basis of full thickness intestinal biopsies. The dog was refractory to any antiemetic therapy. Necropsy revealed marked atrophy and fibrosis of the tunica muscularis, together with a mononuclear cell infiltrate extending from the duodenum to the colon. This case was presented with clinical findings consistent with visceral myopathy in humans--namely, atony and dilatation of the whole gut--but the histological findings resembled sclerosis limited to the gastrointestinal tract.