bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifocal Myxedema and Mixed Thyroid Neoplasm in a Dog
Authors: Johnson J. A. , Patterson J. M.
Published: January 2017

An Old English Sheepdog developed multiple tumor-like masses bilaterally on the head, back, elbows, and hocks, and severe swelling of all digital pads. The gross lesions were the result of accumulation of myxedematous connective tissue in the dermis. Abundant glycosaminoglycan-rich ground substance was confirmed by colloidal iron, toluidine blue and alcian blue stains. The dog also had a mixed follicular-compact cellular carcinoma in the left thyroid gland. The right thyroid had a tumor composed of anaplastic mesenchymal cells forming myxomatous matrix and islands of abnormal cartilage closely integrated, and possibly contiguous, with a follicular-compact cellular carcinoma. The cellular atypism and numerous aberrant mitotic figures in the mesenchymal areas suggested malignancy, although pulmonary metastases derived only from the thyroid carcinoma. Clinically, the dog showed no signs of hypo- or hyperthyroidism, although a resting serum T-4 was slightly below normal.
Lesions Associated with Coccidiosis in Nursing Piglets
Authors: Eustis S. L. , Nelson D. T.
Published: January 2017

Of 45 piglets with diarrhea, 28 had coccidiosis, with no evidence of concurrent viral infection. Villous atrophy and necrotic enteritis were the characteristic lesions, and were more severe in piglets with combined viral and coccidial infections than with coccidiosis alone. Necrotic enteritis presumably was caused by bacterial invasion of the villous lamina propria at foci denuded of epithelium by coccidia, viruses or both. Consistent lesions associated with coccidia in piglets not infected by other primary enteric pathogens suggest that coccidia are the cause of significant clinical disease in nursing piglets 6 to 15 days old.
Congenital Defects of Squirrel Monkeys (Saimiri sciureus)
Authors: Stills H. F. , Bullock B. C.
Published: January 2017

Nine congenital defects were seen in six animals during necropsies of 27 aborted or stillborn and 25 neonatal squirrel monkeys ( Saimiri sciureus) during a two-year period. The defects were left diaphragmatic hypoplasia with herniation; right renal aplasia in conjunction with a right cleft lip and primary palate; supernumerary left kidney; skeletal defects, hydrocephalus, and thyroid anomalies consistent with the campomelic syndrome; atresia ani; and ultimobranchial gland remnants. The high incidence of congenital anomalies (4.9% of births and 11.5% of nonsurviving births) is consistent with a previous report of congenital defects in squirrel monkeys.
Acute Experimental Canine Ehrlichiosis
Authors: Reardon M. J. , Pierce K. R.
Published: January 2017

Dogs with acute Ehrlichia canis infection showed the established clinical features of acute ehrlichiosis and had thrombocytopenia, anemia, increased serum glutamic pyruvic transaminase activity, and decreased total serum protein and albumin concentrations during the first weeks after infection, and increasing gamma globulin concentrations after the third week.

Gross lesions in hemic and lymphoreticular tissues were transient lymphadenomegaly, splenomegaly, and increased red long-bone marrow. Lymphoreticular hyperplasia in the paracortical area of lymph nodes and in the splenic red pulp occurred during the second week of infection. Later, small lymphocytes were replaced by medium-sized lymphocytes and plasma cells. Activity of germinal centers increased initially, as shown by numerous mitotic figures and macrophages, but diminished later, and the follicles blended with interfollicular and paracortical tissue because of a decrease in small lymphocytes in the mantle layer. We saw splenic hemorrhages near the perifollicular sinus, and vasculitis, most often phlebitis, in the kidney between weeks 2 and 4. Multifocal reticuloendothelial hyperplasia occurred in the liver during the early stage and injured adjacent hepatocytes by compression.

Lesions typical of ehrlichiosis in these dogs were interstitial pneumonia, subendothelial aggregates of mononuclear cells in pulmonary blood vessels, renal periglomerular and perivenular plasmacytosis, hemopoietic hyperplasia, and perivascular cuffs of lymphocytes and plasma cells in many organs.
The Ultrastructure of Nephrocalcinosis Induced in Chicks by Cestrum diurnum Leaves
Authors: Sarkar K. , Narbaitz R. , Pokrupa R. , Uhthoff H. K.
Published: January 2017

Powdered Cestrum diurnum leaves, mixed with two diets differing in calcium and phosphorus contents, produced nephrocalcinosis in young chicks regardless of serum calcium elevation. The calcific deposits, found in both proximal and distal portions of cortical tubules, began either in the cytoplasm or in lysosomal bodies as a unilaminar spheroid structure containing apatite crystals. The ultrastructural characteristics of intraluminal concretions suggested that they were formed intracellularly but later were extruded into the lumen. The extent of calcific deposits increased with duration and with hypercalcemia. Although Cestrum contains an analog of 1,25-dihydroxycholecalciferol, neither mitochondria nor basal lamina contained calcific deposits described in nephrocalcinosis secondary to hypervitaminosis D.
The Influence of Dietary Fat and Non-Specific Immunotherapy on Carcinogen-induced Rat Mammary Adenocarcinoma
Authors: Kollmorgen G. M. , King M. M. , Roszel J. F. , Daggs B. J. , Longley R. E.
Published: January 2017

The incidence of mammary adenocarcinoma in Sprague-Dawley female rats, caused by the carcinogen 7,12-dimethylbenz(α)anthracene, was influenced by the level of dietary fat fed after exposure to carcinogen. Carcinogen was given by stomach tube to 50-day-old rats, and tumors were evaluated when rats were 9 months old. Rats on diets containing 20% unsaturated fat had a tumor incidence of 97%, while rats changed to a low-fat diet (2% unsaturated fat) three or four weeks after exposure to the carcinogen had an incidence of 45%. Some rats on each diet were given two treatments with the methanol extraction residue of Bacillus Calmette-Guerin, either three and five weeks after carcinogen or four and six weeks after carcinogen. Tumor incidence in the treated group and the untreated group was the same when rats were maintained on the high-fat diet, but tumors in the treated group were larger and the disease was more severe by histological criteria. These tumors were more anaplastic and many were extensively infiltrated with lymphocytes compared to the untreated group. Tumor incidence was significantly lower in rats changed to the low-fat diet (45%) than in those on the high-fat diet (97%), and tumor incidence was reduced to 20% when rats changed to the low-fat diet were treated with methanol extraction residue. The treated group had less severe disease than the untreated group on the low-fat diet. Only half the tumor-bearing rats in this group had malignant tumors, and none were invasive. Methanol extraction residue protected most rats on the low-fat diet against mammary adenocarcinoma, and reduced the severity of disease in those rats that did develop tumors. Methanol extraction residue treatment provided no protection, and even increased the severity of disease, in rats on the high-fat diet.
Liquoid-Induced Renal Lesions in the Dog
Authors: Spencer A. J. , Wright N. G. , Macmillan I.
Published: January 2017

The role of fibrin in the pathogenesis of renal glomerular scarring in the dog was studied. Fibrin deposition, resulting from disseminated intravascular coagulation, was induced by intravenous injection of Liquoid (sodium polyanetholsulphonate). Thirty-eight puppies were killed from 30 minutes to 39 days after treatment, and the renal lesions examined by light, electron and immunofluorescence microscopy.

The major acute lesions in the glomeruli were capillary thrombosis, mesangial and endothelial cell swelling and phagocytosis of fibrin, polymorphonuclear leukocyte infiltration and necrosis. Animals that recovered from this acute phase had focal glomerular scars. Affected glomeruli showed combinations of mesangial enlargement, focal tuft hypercellularity, collagen formation, thickening, wrinkling and duplication of the glomerular basement membranes, and some capsular adhesions.

These observations indicate that fibrin deposition can be an important mechanism in glomerular scarring in the dog.
Red Cell Fragmentation in the Dog: An Editorial Review
Authors: Rebar A. H. , Lewis H. B. , Denicola D. B. , Halliwell W. H. , Boon G. D.
Published: January 2017

Red blood cell fragments in blood smears from dogs are described morphologically and pathogenetically. Categories include microangiopathic fragmentation, spherocytic fragmentation, Heinz body fragmentation, metabolic fragmentation associated with systemic disease, and artifactual fragmentation. Microangiopathic fragmentation is associated with direct physical damage to normal circulating red blood cells as they pass through abnormal capillary beds. Spherocytic fragmentation is a common feature of immune-mediated hemolytic anemia and results from the removal of portions of antibody-coated erythrocyte plasma membranes by phagocytes of the reticuloendothelial system. Heinz body fragmentation occurs when rigid particles of oxidized hemoglobin are torn from affected red cells as they circulate through the spleen. Metabolic fragmentation is an ill-defined syndrome most commonly associated with cholesterol loading of red cell membranes caused by lipid metabolism abnormalities. Resulting spiculated red cells are more susceptible to traumatic disruption. All the types of red cell fragmentation described in dogs have been observed and documented in man.
Canine Hepatocellular Carcinoma
Authors: Patnaik A. K. , Hurvitz A. I. , Lieberman P. H. , Johnson G. F.
Published: January 2017

In a study of 110 primary hepatic neoplasms in dogs, 55 hepatocellular carcinomas and two combined hepatocellular and cholangiocarcinomas were diagnosed. These neoplasms were classified into the following 11 groups based on histo-architectural pattern: trabecular, peliod, cobblestone, peritheliomatous, anaplastic, pseudoglandular, pleomorphic, scirrhous, clear cell, solid, and combined hepatocellular and cholangiocarcinoma. The neoplastic hepatocytes varied from almost normal to highly anaplastic spindle cells. Pleomorphic and giant cells were common in some groups, rare or absent in others. Metastasis was found in 61% (35 of 57 dogs), with varied frequencies in the different groups. Cirrhosis was found in only 7% (4 of 57), in contrast to a much higher percent in man, indicating the possibility of a different pathogenesis in the dog.
Canine Hepatic Carcinoids
Authors: Patnaik A. K. , Lieberman P. H. , Hurvitz A. I. , Johnson G. F.
Published: January 2017

In 110 primary hepatic neoplasms in the dog, 15 carcinoids were diagnosed. Diffuse involvement of all liver lobes with severe hemorrhage and necrosis was seen in all cases. The neoplasms had three distinct histologic patterns: solid nests; cords or ribbons; and an alveolar pattern with rosettes. In all three groups there was fibrovascular stroma that was hyalinized, mineralized, and thick in some places. The neoplastic cells were relatively uniform, polygonal to spindle-shaped, with eosinophilic, granular cytoplasm and vesiculated nuclei. Mitotic activity varied among the three groups. Argyrophilia was seen in all specimens stained with modified Grimelius stain. Metastasis occurred in 14 of 15 dogs (93.3%); the peritoneal wall and adjoining lymph nodes were the most common sites.
Hypercalcemia Associated with an Adenocarcinoma Derived from the Apocrine Glands of the Anal Sac
Authors: Meuten D. J. , Cooper B. J. , Capen C. C. , Chew D. J. , Kociba G. J.
Published: January 2017

Clinical, gross, and light microscopic findings are described for 36 dogs, 33 females and three males, with adenocarcinomas arising from the apocrine glands of the anal sac. All tumors had light microscopic features of malignancy and 22 of 23 metastasized to iliac and lumbar lymph nodes. Nine dogs had disseminated metastases, but bone metastases were found in only one dog. Differentiated neoplasms formed secretory acini and tubules lined by tall columnar or cuboidal epithelium. Most neoplasms were histologically bimorphic, with glandular areas and solid nests. Parathyroid glands were atrophic. Hypercalcemia (mean = 16.1 mg/dl) was present in 20 of 22 dogs (90%) and hypophosphatemia (mean = 3.2 mg/dl) in 12 of 17 (71%). Remission of hypercalcemia by tumor ablation and recurrence of hypercalcemia with tumor regrowth suggested that the tumor produced a substance that caused hypercalcemia. This unique clinicopathologic syndrome is characterized by hypercalcemia in old. predominantly female, dogs with an adenocarcinoma arising from the apocrine glands of the anal sac.
Canine Distemper Virus-Associated Cardiac Necrosis In The Dog
Authors: Higgins R. J. , Krakowka S. , Metzler A. E. , Koestner A.
Published: January 2017

An age-related canine distemper virus-associated cardiomyopathy characterized by multifocal myocardial degeneration, necrosis and mineralization with minimal inflammatory cell response was found in gnotobiotic Beagle pups. Of the 30 dogs infected experimentally at 5 to 7 days of age with virulent R252 strain of canine distemper virus. 11 had gross or microscopic cardiac involvement as early as 16 days post-infection. The 25 dogs similarly infected at 10 to 21 days of age. the uninfected age-matched controls, and pups infected at 5 to 7 days of age with avirulent R252 canine distemper virus had no cardiac lesions. Although the lesions are attributed to a direct viral effect, they occur against a background of other canine distemper virus-related changes including immunosuppression, anemia and encephalomyelitis. All these factors may have a modifying role in the development of this age-dependent susceptibility to virus-associated myocardial necrosis.
Canine Epidermotropic Lymphoproliferative Disease Resembling Pagetoid Reticulosis in Man
Authors: Johnson J. A. , Patterson J. M.
Published: January 2017

Gross lesions in a dog with cutaneous lymphoproliferative disease involved oral mucosa, and footpad and nasal epithelia. The lesions were vesicles, ulcers, erythematous papules, and plaques. The distinctive histologic feature was the predominantly intraepithelial proliferation of a monomorphous population of atypical mononuclear cells, many with bizarre convoluted nuclei. Ultrastructurally the mononuclear cells had few cytoplasmic organelles and resembled lymphocytes. These features distinguish the lesion from the usual canine cutaneous lymphosarcoma and from the canine equivalent of mycosis fungoides. The histology resembles that of pagetoid reticulosis in man.
Histocytology of Lymphoid Tumors in the Dog, Cat and Cow
Authors: Valli V. E. , Mcsherry B. J. , Dunham B. M. , Jacobs R. M. , Lumsden J. H.
Published: January 2017

In a retrospective study of lymphomas in animals, tumors in 72 dogs, 81 cats and 90 cows were classified on the basis of cell size (small, medium and large), nuclear cleavage (follicular center cells), and histologic architecture (nodular or diffuse). Each subtype was classified by age of animal at death, number of metastases, breed, and sex. As in man, nodular cleaved tumors are rare in animals, the cow having the most varied tumor types. There was one cleaved-cell tumor in 72 lymphomas in dogs, 23 of 81 in cats, and 33 of 90 in cows. There were six nodular tumors of 72 in dogs, two of 81 in cats, and eight of 90 in cows. Fifteen of 16 nodular lymphomas had noncleaved cells and twelve had small or predominantly small cells. Cats with nodular lymphomas were older at death than cats with diffuse lymphomas. Nodularity was not associated with greater age at death in dogs and cows. Animals with cleaved-cell lymphomas were older at death than those with noncleaved tumors; this difference was highly significant in cows. The number of metastases was greater with nodular tumors in all three species, and was equal in cleaved and noncleaved tumors. The biological behaviour of lymphoid tumors in animals is similar to those in man when the same criteria of classification are used.
Classification of Lung Carcinomas in the Dog and Cat
Authors: Moulton J. E. , Tscharner C. Von , Schneider R.
Published: January 2017

A total of 218 lung carcinomas from dogs and cats were examined histologically. The tumors were classified into adenocarcinoma, squamous-cell carcinoma, bronchial gland carcinoma, and alveolar-cell carcinoma. We believe that adenocarcinoma should be subdivided into differentiated and undifferentiated types because the two are distinct histologically and vary in frequency in the cat and dog. It is also important to recognize bronchial gland carcinoma, a distinct histological type, and to subdivide alveolar-cell carcinoma into three separate types: anaplastic small-cell and large-cell types, and adenomatosis type.
Olfactory Neuroblastoma in a Heifer
Authors: Anderson B. C. , Cordy D. R.
Published: January 2017

A nasal neuroblastoma (esthesioneuroblastoma) extending into the brain in a heifer produced mouth breathing and proptosis. The mass filled much of the left nasal cavity, palatine sinus and maxillary sinus, with turbinate atrophy and deviation of the septum. Caudally the neoplasm extended into the nasopharynx and olfactory bulb. It was a cellular neoplasm composed of small, undifferentiated piriform cells showing infrequent pseudorosettes and immature axonal processes. Mitosis was common in some areas.
Focal Mineralization and Nonspecific Granulomatous Inflammation of Respiratory Mucous Membranes in Pigs
Authors: Gilka F. , Sugden E. A.
Published: January 2017

Discrete mineralized foci and granulomatous inflammation occurred in the lamina propria mucosae of respiratory mucous membranes of adult pigs. Lesions were present in clinically healthy pigs of both sexes, including castrated males, fed various pelleted or non-pelleted diets. They were mainly in longitudinally corrugated mucosae of the dorsal wall of the trachea. Identical mineralization and inflammation occurred in the nasal cavity and, in decreasing frequency and intensity, in the thoracic trachea and bronchi. The lesions in respiratory mucous membranes occurred in pigs with and without mineralization in other organs. The distribution of lesions in the respiratory tract, and the higher frequency in pigs fed non-pelleted dusty feeds, suggest that focal mineralization was caused by inhaled particles of calcium salts.
Short-Term Effects of Dietary Nitrilotriacetic Acid in the Male Charles River Rat Kidney
Authors: Alden C. L. , Kanerva R. L. , Anderson R. L. , Adkins A. G.
Published: January 2017

Trisodium nitrilotriacetate monohydrate was fed to male weanling Charles River rats for 28 days. Clinical evidence of urinary tract toxicity included hydronephrosis and nephromegaly. Microscopically, severe renal injury was recognized specifically as convoluted tubular cytoplasmic vacuolation and pelvic epithelial erosion. Hyperplasia occurred as a sequela to these specific cytotoxic alterations.
Progressive Retinal Degeneration in Ranch Mink
Authors: Hadlow W. J.
Published: January 2017

Retinal degeneration was prevalent in a large group of sapphire and pastel mink (Mustela vison) kept for studies on slow viral diseases. Nearly 78% of those two to eight years old were affected. The retinopathy was equally common in both sexes but more frequent in sapphires (85%) than in pastels (63%), and it was severe more often in sapphires than in pastels. By light microscopy, the primary change appeared to be progressive degeneration of fully developed photoreceptors, beginning in their outer segments. In many mink, including some younger ones, the rods and cones and outer nuclear layer had disappeared from all but the far periphery of the fundus. The inner retinal layers were spared until late in the disease, and the pigment epithelium remained essentially unchanged. The cause of the retinopathy was not established. It may represent an abiotrophy in which the structural integrity of the photoreceptors began to wane in many mink after they reached two years of age. Apart from reducing visual acuity, the retinopathy has implications for the photoperiodic control of fur growth and reproduction in this highly light-sensitive carnivore.
Pathology of Naturally Occurring Chlamydiosis in African Clawed Frogs (Xenopus laevis)
Authors: Howerth E. W.
Published: January 2017

Chlamydiosis was diagnosed in six African clawed frogs (Xenopus laevis) from a tank of laboratory-bred frogs experiencing sudden deaths. Gross findings were hepatomegaly, distention of the gall bladder, and splenomegaly.

Hepatic lesions were present in each frog and were characterized by mononuclear cell infiltrates, necrosis of hepatocytes, Kupffer's cell proliferation, and sinusoidal fibrin thrombi. Cholestasis, hemosiderin-laden Kupffer's cells, parenchymal infarction, and multinucleated hepatocytes were less common findings. Other lesions included degenerative and inflammatory changes in the kidneys, epicarditis and myocarditis, and reticuloendothelial cell proliferation, lymphoid depletion, and necrosis in the spleens. Intracytoplasmic inclusions typical of chlamydiae were seen by light microscopy in hepatocytes and reticuloendothelial cells of the spleen. Electron microscopy demonstrated that these inclusions were composed of three distinct types of particles consistent with the life stages described for chlamydiae.
Familial Renal Amyloidosis in Abyssinian Cats
Authors: Boyce J. T. , DiBartola S. P. , Chew D. J. , Gasper P. W.
Published: January 2017

Medullary and glomerular amyloidosis, papillary necrosis, and secondary interstitial disease were diagnosed in eight related adult Abyssinian cats from two catteries. The lesions were similar to those in two unrelated mongrel cats with renal amyloidosis. Ultrastructurally, the patterns of amyloid deposition were as described in other species, although medullary deposition predominated. Potassium permanganate oxidation blocked Congo red staining of the deposits suggesting that they contained amyloid A protein (secondary amyloid). The disease may be a model of familial secondary amyloidosis and offers an opportunity to study the pathogenesis of both amyloid deposition and papillary necrosis.

The histochemical characteristics of feline renal amyloid require careful attention to technique. Section thickness affects Congo red affinity and both dichroism as well as birefringence should be considered when interpreting staining reactions. Thioflavine-T may be the preferred stain for identification of small deposits of amyloid. Variation in section thickness markedly affected the degree of potassium permanganate oxidation.
Canine Transmissible Venereal Sarcoma: Tumor Cell and Infiltrating Leukocyte Ultrastructure at Different Growth Stages
Authors: Hill D. L. , Yang T. J. , Wachtel A.
Published: January 2017

Electron microscopic study of the canine transmissible venereal sarcoma (N = 26) at different stages of growth showed that tumors in a progressive phase of growth (N = 12) were comprised mostly of large, round cells with prominent nuclei and nucleoli, a few spindle-shaped cells and collagen fibers, focal areas of necrosis, and lymphocyte infiltrates. Regressing tumors (N = 9) had the fewest viable round cells, greater numbers of infiltrating leukocytes, and were comprised almost entirely of connective tissue (collagen bundles) in the latest stages of regression. The infiltrating leukocytes consisted primarily of lymphocytes, some eosinophils, and neutrophils, but very few macrophages.

Round-cell nuclei contained numerous perichromatin and interchromatin granules. Their cytoplasm often had annulate lamellae complexes and large deposits of glycogen. Loosely packed tumor cells had extensive proliferation and elongation of cytoplasmic extensions (filopodia). Evidence for cell-mediated tumor cell lysis was demonstrated by degenerative changes in tumor cells which were closely apposed to lymphocytes. Spindle-shaped cells in regressing tumors had intravacuolar collagen fragments, suggesting a possible degradative capacity by these cells.
Cytochemical Detection of Inherited Copper Toxicosis of Bedlington Terriers
Authors: Johnson G. F. , Gilbertson S. R. , Goldfischer S. , Grushoff P. S. , Sternlieb I.
Published: January 2017

Sections of paraffin-embedded specimens of liver obtained from Bedlington terriers were stained with rhodanine for copper and examined and graded by two pathologists. Their results correlated well with each other, as well as with the results of quantitative determinations of hepatic copper content. Copper toxicosis was established by cytochemistry in 20 of 21 specimens, indicating a sensitivity of 95%. The method is highly specific—none of the 19 specimens obtained from unaffected dogs displayed copper-containing granules suggestive of copper toxicosis. Copper cytochemistry appears to be a satisfactory substitute for chemical analysis of hepatic copper content.
Visceral Leishmaniasis in the German Shepherd Dog. I. Infection, Clinical Disease, and Clinical Pathology
Authors: Keenan C. M. , Hendricks L. D. , Lightner L. , Webster H. K. , Johnson A. J.
Published: January 2017

Two groups of three German shepherd dogs each were inoculated with Leishmania chagasi or Leishmania donovani amastigotes and the infection was followed for 82 days. The dogs developed a persistent infection, became thin, and developed splenomegaly and lymphadenomegaly by 55 days after inoculation. All dogs developed a normocytic, normochromic anemia of increasing severity. Thrombocytopenia and leukopenia occasionally occurred. Blood tryptophan levels were decreased significantly in infected dogs. Increased total serum protein, with hypergammaglobulinemia and hypoalbuminemia, was present in all dogs to various degrees. There was a marked increase in gamma globulins, with smaller increases in alpha and beta globulins. Many of the clinicopathologic changes observed in these dogs were similar to the disease as it occurs in man. The German shepherd dog may be a useful laboratory model for the study of visceral leishmaniasis.
Effect of Ivermectin Treatment on Eosinophilic Pneumonia and Other Extra vascular Lesions of Late Strongylus vulgaris Larval Migration in Foals
Authors: Turk M. A. M. , Klei T. R.
Published: January 2017

Eighteen parasite-free pony foals were infected orally with 500 third stage larvae of Strongylus vulgaris. At 56 days after infection, six ponies were treated with intramuscular ivermectin (22,23-dihydroavermectin B1); six were treated with oral ivermectin; and six were not treated. Necropsy was done 91 days after infection to study the pathologic effects of migrating S. vulgaris larvae and to determine the efficacy of ivermectin in attenuation of 5. vulgaris-induced lesions.

Larval migration induced eosinophilic inflammation of the liver, spleen, mesenteric, colic and cecal lymph nodes, and small and large intestine. Previously unreported parasitic lesions included eosinophilic pneumonia with eosinophilic granulomas and pulmonary lymphoid nodules. S. vulgaris larvae were observed in eosinophilic granulomas in the lung, epicardium, liver, and intestinal serosa. Injectable and oral ivermectin formulations were equally effective in reduction of these lesions.
Acute Pathological Effects of Inorganic Mercury and Copper in Gills of Rainbow Trout
Authors: Daoust P.-Y. , Wobeser G. , Newstead J. D.
Published: January 2017

Lesions induced in the gills of rainbow trout (Salmo gairdneri) by exposure to acutely lethal aqueous concentrations of inorganic mercury and copper were examined by light and electron microscopy. Lesions were most severe during the first 48 hours of exposure to the metals and were characterized primarily by apoptosis of lamellar epithelial cells and lamellar fusion. The latter process occurred either by simple apposition of adjacent lamellae to each other or through epithelial hypertrophy and hyperplasia. Except for hypertrophy of and increased number of primary lysosomes in lamellar epithelial cells of animals exposed to mercury, branchial lesions were not prominent in fish collected between 48 and 96 hours. The branchial lesions observed in this study are compared with pathological processes occurring in mammals.
Clinical and Pathological Changes in Sheep Experimentally Poisoned by the Blue-Green Alga Microcystis aeruginosa
Authors: Jackson A. R. B. , Mcinnes A. , Falconer I. R. , Runnegar M. T. C.
Published: January 2017

Fifteen young sheep were inoculated intraruminally with various doses of an algal bloom of Microcystis aeruginosa. Lethally poisoned sheep died between 18 and 48 hours after inoculation. Findings included marked elevation of serum concentrations of certain enzymes and bilirubin, mild elevations of blood urea nitrogen and serum inorganic phosphorus with marked reduction in blood glucose, a mild neutrophilia with a marked left shift and marked changes in coagulation parameters. Necropsy findings included pale swollen, sometimes hemorrhagic, livers, edema involving the body cavities and widespread small hemorrhages. The primary site of toxicity was the liver which had centrilobular to near massive hepatocyte necrosis. Electron microscopic lesions were aggregation of endoplasmic reticulum with displacement of subcellular organelles towards the periphery of the hepatocyte, and vacuolation of the contents of more severely affected cells.
Hyperplastic Endometrial Polyps in the Dog and Cat
Authors: Gelberg H. B. , McEntee K.
Published: January 2017

Hyperplastic endometrial polyps from 17 dogs and 14 cats are described. These growths were pedunculated to broad-based and projected into the uterine lumen. They were lined by endometrial epithelium and contained cystic endometrial glands surrounded by a well-vascularized connective tissue stroma. The morphologic evidence suggests that endometrial polyps arise from focal areas of cystic endometrial hyperplasia.
Some Unusual Features of Mesangioproliferative Glomerulonephritis in Horses
Authors: Sabnis S. G. , Gunson D. E. , Antonovych T. T.
Published: January 2017

Seven horses ranging from three to 15 years of age had nephrotic syndrome; at necropsy, renal tissue of all seven horses had the morphologic lesions of mesangioproliferative glomerulonephritis (membranoproliferative glomerulonephritis). Homogeneous eosinophilic material which filled the glomerular capillary lumina was found in five horses. Ultrastructurally, this material primarily consisted of electron-dense deposits with a fibrillar pattern in five horses and in one horse, rhomboid crystalline deposits which resembled deposits seen in human cryoglobulinemia. The association of mesangioproliferative glomerulonephritis with cryoglobulinemia is well documented in man. The presence of intracapillary deposits, with the histologic and ultrastructural lesion of mesangioproliferative glomerulonephritis, suggests a similar association in these horses.
Ovine Abortion and Stillbirth due to Purulent Placentitis caused by Yersinia pseudotuberculosis
Authors: Karbe E. , Erickson E. D.
Published: January 2017

Yersinia pseudotuberculosis was isolated from an aborted placenta and stillborn lamb from a sheep flock having multiple abortions. Given intravenously, it caused elevated body temperatures and purulent placentitis in eight of nine ewes. Two ewes died following infection at 2.5 months of gestation. Two ewes infected at 3.5 months gestation aborted; three infected at four months gave birth to weak, premature, or moribund lambs. One ewe infected at 4.5 months gave birth to a healthy lamb. One lamb which died minutes after birth had focal necrotizing hepatitis, a lesion observed in a stillborn lamb during the original disease outbreak. Y. pseudotuberculosis was reisolated from endometrial, placental, and fetal lesions of experimentally infected animals.
“Shaker” Calf Syndrome: A Newly Recognized Inherited Neurodegenerative Disorder of Horned Hereford Calves
Authors: Rousseaux C. G. , Klavano G. G. , Johnson E. S. , Shnitka T. K. , Harries W. N. , Snyder F. F.
Published: January 2017

The clinical and pathological features of a newly recognized, inherited neurodegenerative disorder in horned Hereford calves are described. The disorder is expressed in newborns by tremulous shaking of the head, body and tail, difficulty in rising, a wobbly spastic gait, and aphonia. Transient improvement is followed by deterioration and progressive spastic paraplegia. Generalized tremors can be induced easily by a variety of stimuli, and spinal reflexes may be exaggerated or depressed. The major pathological finding is an excessive accumulation of neurofilaments within neurons of the central, peripheral, and autonomic nervous systems. The involvement of multiple systems of neurons and the similarity with some forms of human motor neuron disease and spinocerebellar degeneration suggest that this unique bovine disease may serve as a suitable animal model for these human neurodegenerative disorders.
Canine Ovarian Tumors of Germ Cell Origin
Authors: Greenlee P. G. , Patnaik A. K.
Published: January 2017

Fourteen ovarian germ cell tumors were diagnosed in the dog—seven dysgerminomas and seven teratomas. Six of the teratomas had immature components and were judged malignant; three had metastasized. One dysgerminoma had metastasized. The dysgerminomas developed in dogs ten years of age and older, and the teratomas developed in dogs nine years old and younger.
Primary Intestinal Lymphangiectasia in Three Dogs: A Morphological and Immunopathological Investigation
Authors: Suter M. M. , Palmer D. G. , Schenk H.
Published: January 2017

Morphological and immunological findings of three dogs with primary lymphangiectasia are described and compared with three normal dogs. Scanning electron microscopy showed distended and fused intestinal villi in dogs with intestinal lymphangiectasia, and morphometric evaluation revealed deeper crypts in the small intestine of dogs with intestinal lymphangiectasia. Although plasma cells of all classes were diminished in the cranial parts of the small intestine, there was an absolute and relative increase of immunoglobulin G-containing plasma cells in the caudal small intestine in dogs with intestinal lymphangiectasia.
Microscopic Lesions Associated with the Isolation of Haemophilus somnus from Pneumonic Bovine Lungs
Authors: Andrews J. J. , Anderson T. D. , Slife L. N. , Stevenson G. W.
Published: January 2017

Sixty-one of 68 sets of bovine lungs from which only Haemophilus somnus was isolated had microscopic lesions of purulent bronchiolitis and bronchopneumonia. In 37 of 61 lungs, the bronchiolar exudates were markedly necrotic with accompanying necrosis of the adjacent bronchiolar epithelium. Bronchiolitis obliterans was prominent in 23 of 28 lungs affected with chronic lesions with abscesses present in seven. Alveolar filling with inflammatory cells (neutrophils with fewer macrophages) was limited to peribronchiolar alveoli in 25 of 61 lungs and was multifocal to diffuse in the other 36. Lesions in the remaining lungs (7 of 68) were classified as fibrinous pneumonia with bronchiolitis (2), fibrinous pleuritis (2), suppurative interstitial pneumonia with vasculitis (2), and diffuse congestion (1).
Ultrastructural Morphology of Leukemic Cells in the Cat
Authors: Grindem C. B.
Published: January 2017

Transmission and scanning electron microscopic characteristics of leukemic cells from eight cats with spontaneous leukemia are described. Nuclear blebs, myelin figures, cytoplasmic microfibrils and C-type virus were seen more frequently in leukemic cells. Surface ridges and ruffles seen with the scanning electron microscopy were helpful in distinguishing myelogenous from lymphogenous leukemia.
Megakaryocytic Infection and Thrombocytopenia in African Swine Fever
Authors: Edwards J. F. , Dodds W. J. , Slauson D. O.
Published: January 2017

Pigs infected with an African swine fever field isolate of modified virulence became acutely thrombocytopenic four to five days after the onset of fever and viremia. By eight days after inoculation, all pigs were thrombocytopenic. Immunofluorescence microscopy demonstrated that 2 to 10% of the megakaryocytes were infected. By 13 days after inoculation, platelet counts returned to within normal limits, and there was megakaryocytic hyperplasia despite a continued viremia. Secondary complications delayed the return of normal circulating platelet levels in some pigs. The clinical findings of African swine fever are discussed in light of the gross and histologic lesions.
A Retrospective Study of Proliferative Interstitial Lung Disease of Horses in Florida
Authors: Buergelt C. D. , Hines S. A. , Cantor G. , Stirk A. , Wilson J. H.
Published: January 2017

Proliferative and fibrosing interstitial lung disease was diagnosed in 20 horses submitted for necropsy between 1982 and 1985. Most of the horses were foals ranging from 3 days to 6 months in age. Six adult horses were affected. The macroscopic and microscopic characteristics of the lesions consisted of proliferative interstitial pneumonia and were similar to those of atypical interstitial pneumonia of ruminants. Based on morphologic features of the lesions, a toxic etiology is suspected for the induction of this naturally acquired primary equine lung disorder, but could not be specifically discovered by historical information.
Choroid Plexitis in White-tailed Deer (Odocoileus virginianus) in Southern New York State
Authors: Levine S. , Fish D. , Magnarelli L. A. , Anderson J. F.
Published: January 2017

Brains, spinal cords, nerve roots, nerves and muscle tissues were removed from deer in southern New York State and examined for histologic evidence of infection by the causative agent of Lyme disease, Borrelia burgdorferi. There was no histologic evidence of this infection and only four of 26 deer had serologic evidence of past infection despite the fact that all were parasitized by the tick vector, Ixodes dammini. Of these ticks, 21% were carrying B. burgdorferi. In contrast, most of the deer had choroid plexitis. All but one of 48 deer tested were infected with Trypanosoma cervi, 20 of 24 deer had sarcocystis in skeletal muscles and two had dural lesions probably due to the nematode Pneumostrongylus tenuis. The causal relationship between choroid plexitis and trypanosomiasis is discussed.
Immunohistochemical Demonstration of Desmin in Canine Smooth Muscle Tumors
Authors: Andreasen C. B. , Mahaffey E. A.
Published: January 2017

Sections of formalin-fixed, paraffin-embedded canine leiomyomas, leiomyosarcomas, or fibrosarcomas were examined by immunohistochemical methods for the presence of desmin. Twenty-two leiomyomas and leiomyosarcomas were stained using the avidin-biotin complex technique, and 14 samples demonstrated positive staining for desmin. The eight negative results obtained may reflect differences in fixation or the affinity of the primary antibody for the tissues examined. Desmin was specific for myogenic tissues. Five canine fibrosarcomas examined immunohistochemically were all negative for desmin staining. The results indicate that desmin is a useful marker for immunohistochemical identification of canine leiomyomas and leiomyosarcomas.
Spontaneous Nonneoplastic Gastric Lesions in Female Han: NMRI Mice, and Influence of Food Restriction Throughout Life
Authors: Rehm S. , Sommer R. , Deerberg F.
Published: January 2017

A life span study of 900 female virgin Han:NMRI mice (300 outbred controls, 300 of a fat subline, and 300 of a lean subline) was done to determine the occurrence of spontaneous disease with ad libitum or restricted feeding. Major nonneoplastic lesions in the glandular stomach were erosions, ulcers and adenomatous hyperplasia of the fundus. Ulcers, ranging in incidence with ad libitum feeding from 5 to 9% and with food restriction from 13 to 34%, either occurred secondary to other diseases or were due to stress associated with food restriction, causing death mainly in the lean subline. Adenomatous hyperplasia was most common in the control group (41%); the frequency increased with age and was significantly reduced by food restriction. The etiology of adenomatous gastric hyperplasia is yet unknown. However, a lack of antiparietal cell antibodies, as determined by an immunofluorescent technique, indicates that an autoimmune disorder is not involved and an increase in antral gastrin cells, as determined by avidin-biotin peroxidase immunocytochemistry, suggests a hormonal involvement in pathogenesis.
Equine Testicular Interstitial Cell Tumors
Authors: Gelberg H. B. , McEntee K.
Published: January 2017

Interstitial cell tumors from nine stallions were described. In all but one horse the tumors were found in undescended testes. Five animals had bilateral tumors. Two animals showed increased aggression. Tumors contained two cell types. The first type were large distinctly bordered eosinophilic cells interpreted to be hyperplastic and hypertrophic interstitial cells. They blended with pleomorphic often spindloid neoplastic cells which had fibrillar, vacuolated cytoplasm and indistinct cell borders. This latter cell population was arranged in nodules or broad sheets as endocrine-like packets or interweaving fascicles. Biologic behavior of the neoplasms could not be ascertained from histologic examination.
Renal Lesions in Cattle Fed Sodium Hydroxide-treated Barley
Authors: Kennedy S. , Rice D. A.
Published: January 2017

Ten 14-week-old calves were fed a diet containing 87.5% NaOH-treated barley, and killed after 29, 65, 71, 117, 140, 179, 314, 338, and 408 days. Eight control calves were fed a diet in which untreated rolled barley was substituted for alkali-treated grain. Calves receiving NaOH-treated barley became polyuric with urine pH ranging from 9.0 to 9.5, and had significantly raised plasma creatinine levels on day 29. Other clinical findings were normal, and there were no other significant alterations in blood. At necropsy, bilateral renal lesions consisted of white cortical foci, medullary stippling, and the presence of uroliths in the renal papillae and calyces. Microscopic changes included tubular dilatation, atrophy, necrosis, and mineralization, interstitial fibrosis with mononuclear cell invasion and consequent glomerular changes. It appeared that glomerular and interstitial changes were secondary to primary tubular damage. No abnormalities were detected in control calves. Feeding of NaOH-treated barley can result in nephrotoxicosis in cattle.
Pathogenesis of Corneal Lesions Caused by Moraxella bovis in Gnotobiotic Calves
Authors: Rogers D. G. , Cheville N. F. , Pugh G. W.
Published: January 2017

Moraxella bovis was instilled into the conjunctival sac of gnotobiotic calves and corneas were sampled serially after infection. Lesions developed in seven of eight infected calves, but were absent in a noninfected control calf. Histologically, M. bovis was first seen in foci of swollen epithelium and within basal epithelial cells adjacent to ulcers. Corneal ulcers were severe in later stages of infection; fibrin deposits, neutrophils, and bacteria were present in the stromas. Examination of early lesions by scanning electron microscopy showed M. bovis in pits on the surfaces of dark epithelial cells, enmeshed in degenerate epithelial cells and within erosions and an ulcer; in later samples, bacteria were rare. Ultrastructurally, M. bovis was seen in surface pits in superficial epithelial cell processes and within swollen epithelial cells. In stroma, M. bovis was frequently seen among collagen fibrils, within neutrophil phagosomes, and associated with cellular debris. This study demonstrates that a virulent strain of M. bovis can invade bovine corneal epithelial cells and can cause keratitis in the absence of injurious ultraviolet irradiation or other known predisposing environmental factors.
Subcellular Location of Corticosteroid-induced Alkaline Phosphatase in Canine Hepatocytes
Authors: Sanecki R. K. , Hoffmann W. E. , Gelberg H. B. , Dorner J. L.
Published: January 2017

Dogs received either 4 mg/kg of prednisone or sterile saline daily for 32 days. Serum samples were assayed every 4 days for total alkaline phosphatase (ALP) and corticosteroid-induced ALP isoenzyme (CIALP) activity. The initial and major increase of serum ALP was attributed to the liver isoenzyme of ALP (LALP), however, CIALP began to increase by day 8 and was significantly increased by day 24. Prior to treatment and on day 32, sections of liver from control and prednisone-treated dogs were stained for ALP activity after blocking the staining activity of LALP with levamisole. The staining activity of CIALP was compared to the staining activity of LALP in liver sections from control dogs and from dogs in which the bile duct was ligated. It was determined that CIALP was located in that area of the hepatocyte membranes which comprise the bile canaliculi.
Pathology of Experimental Ureaplasma Mastitis in Ewes
Authors: Kennedy S. , Ball H. J.
Published: January 2017

One mammary gland of each of nine primum partum suckling ewes was inoculated with ureaplasma 8 weeks post-partum. Infected glands were swollen, hot, and painful from 16 hours post-infection. Subsequently there was agalactia and reduction in gland size. Histopathologic and ultrastructural examination indicated that the acute phase of the induced mastitis was characterized by necrosis of secretory epithelium with a neutrophil, eosinophil, and macrophage response. Subsequently there was lymphoid infiltration, acinar involution, and fibrosis. This report confirms the pathogenicity of ureaplasma for the ovine mammary gland, and is the first description of the pathologic features of ureaplasmal mastitis in sheep.
Canine Pancreatic Endocrine Tumors: Immunohistochemical Analysis of Hormone Content and Amyloid
Authors: O'Brien T. D. , Hayden D. W. , O'Leary T. P. , Caywood D. D. , Johnson K. H.
Published: January 2017

Thirty-one primary canine pancreatic endocrine tumors and their metastases were studied histologically and immunohistochemically for the presence of insulin, glucagon, somatostatin, pancreatic polypeptide (PP), gastrin, and adrenocorticotrophic hormone (ACTH). Tumors were also evaluated for the presence of amyloid. The cytoarchitectural pattern of 25 of 31 primary tumors was predominantly solid, whereas three tumors were mostly glandular, two were unclassified, and one had a gyriform pattern. Cells with insulin immunoreactivity were found in 30 of 31 tumors and were found in all cases in which there was clinical evidence of inappropriate insulin secretion. Insulin was the only hormone demonstrable in three of the 30 tumors, but cells immunoreactive for other hormones were also present in various combinations in most tumors [i.e., glucagon (13 of 30), somatostatin (17 of 30), PP (25 of 30), and gastrin (2 of 30)]. One tumor contained only cells with glucagon and PP immunoreactivity. Amyloid was found in ten of 31 primary tumors but was not detected in metastases. Cells with insulin immunoreactivity were the only cell type consistently present in tumors containing amyloid. Amyloid deposits did not immunoreact with any of the antisera. Seventeen of 31 dogs had metastasis of the pancreatic endocrine tumor to regional lymph nodes, liver, or both. All metastases available for study (15 of 17) contained cells with insulin immunoreactivity and some contained cells with PP or somatostatin immunoreactivity. No statistically significant ( P > 0.05) differences in tendency to metastasize were found when pancreatic endocrine tumors were compared by region of origin, cytoarchitectural pattern, presence of amyloid, or by number of hormones contained within the tumor.