bluuebunny/crossref_metadata_2025 huggingface dataset:
Akabane Disease in Cattle: Congenital Abnormalities caused by Viral Infection. Experimental Disease
Authors: Konno S. , Nakagawa M.
Published: March 2010

Nonpurulent encephalomyelitis and polymyositis were primary lesions of cattle and goats experimentally infected with Akabane virus. Two caprine fetuses, two months old, were infected placentally and examined 11 days after inoculation; twin caprine fetuses, three months old, were inoculated intramuscularly through the dam's uterus and examined nine days after inoculation. Both lesions were seen in each fetus.

Reactive proliferation of immature endothelial cells was a significant encephalitic change. Myositic changes included parenchymal degeneration and cell infiltration in fetuses in the myotubule phase and at the beginning of the myofiber phase.

Only nonpurulent encephalomyelitis was seen in six calves 14 days to one year old, inoculated intracerebrally and examined six to 47 days after inoculation. Nerve-cell degeneration, neuroglial mobilization, and perivascular cuffs were typical encephalitic changes in the calves.

Five fetuses were infected transplacentally and had polymyositis alone. The four bovine fetuses, two to six months old, were examined nine to 18 days after inoculation, and one caprine fetus, one month old, was examined 11 days after inoculation. Neither encephalomyelitis nor polymyositis was seen in four calves under one year old that were inoculated intravenously.
Mesangium in Rats after E. coli Neurotoxin Shock: A Morphometric and Light Microscopic Analysis
Authors: Queisser G. , Drommer W.
Published: March 2010

The renal corpuscles of 28 specific-pathogen-free Wistar rats fixed by perfusion were examined light microscopically and morphometrically following experimental protracted neurotoxin shock. The mean diameter of the center sections of 420 renal corpuscles was 113.0 μm. The mesangial portion occupied 9.5% of the total area of the renal corpuscle in control rats and increased to a maximum of 17.25% in experimental rats. The number of mesangial nuclei per renal corpuscle in rats with protracted shock showed that expansion of the mesangium with compression of capillary loops was not caused solely by an increase in the number of cells. Furthermore, there was an enlargement of the mesangial cytoplasm and matrix. Activation and proliferation of connective tissue in rats with protracted shock could be observed in the interstitium of various organs as well as in the mesangium of the glomerulus.
Canine Hypertrophic Osteodystrophy, A Study of the Spontaneous Disease in Littermates
Authors: Woodard J. C.
Published: March 2010

All members of a weimaraner litter had clinical and radiographic signs of hypertrophic osteodystrophy shortly after weaning. Three dogs were necropsied. Radiographic metaphyseal densities, which are used to make a clinical diagnosis of hypertrophic osteodystrophy, were found to result from elongation of the calcified cartilage lattice of the primary spongiosa. Intertrabecular acute inflammation was associated with necrosis, failure to deposit osseous tissue on the calcified-cartilage lattice, and trabecular microfractures. This process led to metaphyseal infraction and separation of the epiphysis. Defective bone formation (osteodystrophy) was considered a secondary process resulting from inflammation of osteochondral complexes, marrow, and periosteum. Enamel hypoplasia also was found to be associated with inflammation of the dental crypt, and abnormal enamel matrix was observed in the developing teeth. The histopathology of the bones and teeth was different from alterations which occur in infantile scurvy or congenital syphilis, although these diseases of man have radiographic similarities to canine hypertrophic osteodystrophy. Because the radiologic lesion is nonspecific, a clinical diagnosis of hypertrophic osteodystrophy is not necessarily diagnostic of a specific disease due to a single etiologic agent. Liver levels of ascorbic acid were within the normal range. Although an infectious agent could not be identified, the conditions may have an infectious origin with systemic manifestations.
The Pathogenesis of Vesicular Exanthema of Swine Virus and San Miguel Sea Lion Virus in Swine
Authors: Gelberg H. B. , Lewis R. M.
Published: March 2010

Vesicular exanthema of swine virus type A48 or San Miguel sea lion virus type 2, when inoculated intradermally into swine, resulted in fluid-filled vesicles at the sites of inoculation in the snout, coronary band, and tongue. Pigs that developed vesicles also had fevers. Secondary vesicle formation varied, depending on virus serotype. Viremia was found in one pig infected with San Miguel sea lion virus five days after infection. Virus was recovered from nasal-oral passages for up to five days after infection in both groups of pigs and from the gastrointestinal and urinary tracts of pigs infected with San Miguel sea lion virus. Neutralizing antibodies began to increase three days after inoculation and reached peak titers in seven to ten days. In the absence of secondary bacterial infection, healing was well advanced by ten days after inoculation.

Lesions usually were limited to nonhaired portions of the integument and tongue. Individual epithelial cells became infected when a break in the skin allowed virus access to susceptible epithelial cells from either exogenous or endogenous sources. Individual infected cells ruptured and adjacent cells were infected, resulting in the formation of multiple microvesicles. Centrifugal coalescence of microvesicles led to formation of grossly visible macrovesicles. Lesions rarely developed from viral contamination of intact hair follicles. A mild virus-induced encephalitis was seen in pigs infected with vesicular exanthema of swine virus, and virus was recovered from brain tissue of pigs infected with San Miguel sea lion virus.
Chronic Eosinophilic Gastroenteritis in the Horse
Authors: Pass D. A. , Bolton J. R.
Published: March 2010

Four cases of chronic eosinophilic gastroenteritis in horses are described. The disease was manifested clinically by weight loss, malabsorption and diarrhea or soft, formless feces. A chronic inflammatory reaction, with diffuse and focal eosinophilic infiltrates, was present in the esophagus, stomach, small and large intestine, and mesenteric lymph nodes. The cause of the lesion was not determined but was thought to be due to an ingested allergen, as the lesion is indicative of an on-going, immediate hypersensitivity reaction. One horse had generalized acanthosis, hyperkeratosis, and ulcerative coronitis.
Heinz Body Anemia and Methemoglobinemia in Ponies Given Red Maple (Acer rubrum L.) Leaves
Authors: George L. W. , Divers T. J. , Mahaffey E. A. , Suarez M. J. H.
Published: March 2010

Ponies given dried red maple ( Acer rubrum L.) leaves at a dose of 3.0 gm/kg body weight became ill and died one to five days after administration of the leaves. Two clinical patterns of disease were seen. Ponies given dried leaves collected after September 15 died by 18 hours, while ponies given dried leaves collected before September 15 became ill with a hemolytic syndrome and died by three to five days. Freshly harvested leaves administered immediately after collection did not produce disease in ponies, but when dried, they became toxic and remained so for at least 30 days. Overnight freezing did not alter the toxicity of the leaves. Leaves were toxic when administered at doses of 1.5 gm/kg of body weight. The clinical signs of ponies with the hemolytic syndrome included polypnea, tachycardia, icterus, cyanosis, scleral petechiation, and brownish discoloration of the urine and blood.

Blood changes of ponies with the hemolytic syndrome included anemia, hemoglobinemia, Heinz bodies, depletion of erythrocyte reduced glutathione, increased erythrocyte fragility, and increased serum levels of aspartate amino transferase, sorbitol dehydrogenase, plasma protein, and bilirubin.

Lesions of ponies that died from the hemolytic syndrome included icterus, centrilobular hepatic degeneration, hemoglobinemic nephrosis, and erythrophagocytosis by splenic, adrenal, and hepatic phagocytes. Only brownish discoloration of the blood and mild centrilobular hepatic degeneration were observed in the four ponies that died peracutely.
Morphometry of Equine Neutrophils Isolated at Different Temperatures
Authors: Bertram T. A. , Coignoul F. L.
Published: March 2010

Equine neutrophils were evaluated ultrastructurally and by morphometric analysis. Homogeneous populations of neutrophils were isolated from peripheral blood at 4° and 22°C by centrifugation on two sequential Ficoll-Hypaque density gradients. Isolation procedures at both temperatures resulted in neutrophil degranulation but not cell swelling. Degranulation was more extensive in cells isolated at 22°C. Isolation temperature affected the neutrophil content of secondary granules more than primary granules. A granule similar to immature specific granules of human neutrophils was observed. Granules with a flocculent matrix were more frequent in cells processed at 22°C. These granules were considered to be involved in the degranulation process.
A Suspected New Storage Disease in Cattle
Authors: Hartley W. J. , Webb R. F.
Published: March 2010

A suspected storage disease occurred in 50% of a group of five- to seven-month-old Hereford calves in one of four years following the same mating procedure. Lesions were confined to the central nervous system and consisted of multiple intraneuronal, cytoplasmic laminated cytosomes in restricted areas of the brain stem, together with extensive loss of myelinated nerve fibers in the motor columns of the cord.
Ectopic Thyroid Carcinoma with Metastases in a Beagle Dog
Authors: Stephens L. C. , Saunders W. J. , Jaenke R. S.
Published: March 2010

A 10.25-year-old female beagle had an invasive neoplasm at the base of the heart which metastasized to the lungs, pancreas, and kidney. The neoplasm in these locations was composed of clusters of polyhedral cells surrounded by fine fibrovascular stroma. The differential diagnoses were malignant chemodectoma, ectopic parathyroid carcinoma, and ectopic thyroid carcinoma. Based on ultrastructural features, this tumor was an ectopic thyroid carcinoma.
Congenital Heart Diseases in Swine
Authors: Hsu F. S. , Du S. J.
Published: March 2010

One hundred twenty-two congenital cardiac anomalies were diagnosed in 83 pigs (4.35%) during necropsies of 1906 pigs from one day to four years of age during an 11-month period.

The incidence of cardiac malformation was highest at 29 to 56 days of age. Of the 83 pigs with cardiac anomalies, 47 (56%) were male and 36 (44%) were female, and of these, 15 (18%) were purebred and 68 (82%) were crossbred pigs. Of the 15 purebred pigs with cardiac malformation, there were seven Landrace pigs, four Large White pigs, three Duroc Jersey pigs, and one Yorkshire pig; whereas 94% of the 68 crossbred pigs were crossbred among Landrace, Duroc Jersey, and Large White.

The 122 cardiac anomalies found in the 83 pigs were: dysplasia of the tricuspid valve in 42 pigs, atrial septal defect in 31 pigs, subaortic stenosis in 22 pigs, ventricular septal defect in nine pigs, persistent common atrioventricular canal in eight pigs, malformation of the moderator band in seven pigs, persistent vena cava in one pig, persistent truncus arteriosus in one pig, and pulmonary stenosis in one pig.

The pathological features of the anomalies in swine were similar to those described in small animals and in man. The findings indicate that spontaneous porcine cardiac anomalies might provide models for cardiovascular investigators to study the etiology and pathogenesis of congenital heart diseases in man and other mammals.
Tumors Involving Bone in the Domestic Cat: A Review of Fifty-eight Cases
Authors: Quigley P. J. , Leedale A. H.
Published: March 2010

This account of 58 spontaneous tumors involving bone in domestic cats compares and contrasts the pathological findings with previous surveys. Of the tumors described, only one was diagnosed as benign. Squamous cell carcinoma was the most common tumor of the series; osteosarcoma was the most common primary tumor. Only two tumors metastasized to the lungs (one hemangiosarcoma and one osteosarcoma), and only three metastasized to a regional node (two squamous cell carcinomas and one lymphosarcoma).
Erythrocyte Macrocytosis in Feline Leukemia Virus Associated Anemia
Authors: Weiser M. G. , Kociba G. J.
Published: March 2010

Using erythrocyte volume distribution histograms (erythrograms), erythrocyte macrocytosis and anisocytosis were quantitated in 139 cats tested for feline leukemia virus group-specific antigen. Feline leukemia virus-negative cats with non-regenerative anemia or normal packed cell volumes had normal mean corpuscular volume values. Uninfected cats with regenerative anemia had prominent, significantly increased macrocytosis and anisocytosis (p < 0.01). Ninety percent of 62 feline leukemia virus-positive cats had altered erythrograms. Thirty-three feline leukemia virus-positive cats with non-regenerative anemia had marked macrocytosis. Their mean corpuscular volume values (mean 60 fl ± 2 fl standard error, reference range of 37-49 fl) were significantly greater than those of feline leukemia virus-negative cats except for those with regenerative anemia. Feline leukemia virus-positive, non-anemic cats had significantly increased mean corpuscular volume values of intermediate magnitude. Nine adult cats experimentally infected with feline leukemia virus developed non-regenerative anemia with significant increases in mean corpuscular volume and anisocytosis. However, the macrocytosis observed in these cats was considerably less than in naturally occurring feline leukemia virus-positive cats with non-regenerative anemia. These observations indicate there are events in the pathogenesis of feline leukemia virus-associated anemia other than simple erythroid hypoplasia. We suggest that hemolysis and erythrocyte regeneration occur before erythroid hypoplasia and may partially account for macrocytosis observed in the face of non-regenerative anemia.
Pathology of the Mononuclear Cell Leukemia of Fischer Rats. I. Morphologic Studies
Authors: Stromberg P. C. , Vogtsberger L. M.
Published: March 2010

Pathological evaluations were done on 205 rats with mononuclear cell leukemia. Leukemia was diagnosed in 22.2% of males and 20.4% of females with significant risk beginning at 20 months of age. Mononuclear cell leukemia was responsible for 50% of early deaths in two-year studies. Clinically, rats became depressed, pale, icteric and had palpably enlarged spleens. Gross lesions included splenomegaly, enlarged mesenteric lymph nodes, and mottled livers. Hemorrhages occurred in the lungs, brain, and lymph nodes. Histological examination demonstrated that spleen and liver were most consistently and seriously involved, although numerous other organs contained leukemic infiltrates of variable severity. Spleens exhibited diffuse leukemic infiltration of the red pulp, follicular lymphoid depletion, and decrease in both extramedullary hematopoiesis and hemosiderin. Liver lesions consisted of diffuse centrilobular degeneration and necrosis. Erythrophagocytosis by tumor cells was common in the spleen and observed in liver, lymph nodes, and adrenals. The disease appeared to originate in the spleen. Bone marrow infiltration occurred late relative to spleen involvement and was present in less than half of the rats.
Nephrotic Syndrome and Collagenizing Glomerulopathy in PVG/c Rats Treated with the α-mannosidase Inhibitor “Swainsonine”
Authors: Huxtable C. R. , Dorling P. R.
Published: March 2010

Weanling PVG/c rats treated with the α-mannosidase inhibitor swainsonine developed increasing proteinuria which terminated as a severe nephrotic syndrome after 35 to 45 days. This was associated with a glomerulopathy characterized by the production of collagen fibrils adjacent to endothelial and mesangial cells, foot process expansion, subepithelial projections of the basement membrane, and splitting of the lamina densa. The swainsonine-induced glomerulopathy appeared to be an exacerbation of a spontaneous abnormality in this strain of rat.
The Pathology of DisseminatedAspergillus terreusInfection in Dogs
Authors: Kabay M. J. , Robinson W. F. , Huxtable C. R. R. , McAleer R.
Published: March 2010

Disseminated Aspergillus terreus infection was diagnosed in ten previously healthy adult dogs—nine German shepherds and one dalmatian. The disease was characterized by the presence of multiple granulomas and infarcts in a wide range of organs. The kidney, spleen, and skeletal system were most commonly and severely affected. Fungal hyphae were demonstrated in large numbers within granulomas and thrombi, and A. terreus was readily isolated by culture. This disseminated mycosis appears unique; in this series of cases there was no apparent predisposing factor, portal of entry, or primary focus for dissemination of the infection.
Mannosidosis in Galloway Calves
Authors: Embury D. H. , Jerrett I. V.
Published: March 2010

Mannosidosis was diagnosed in four stillborn Galloway calves and an autolyzed full-term fetus from experimental matings of carrier animals. Gross lesions were moderate internal hydrocephalus, and pallor and enlargement of the liver and kidneys and arthrogryposis. Histologic changes in the central nervous system of each calf were marked foamy vacuolation of the cytoplasm of neurones in the cerebral cortex, thalamus and brainstem, and vacuolation of the Purkinje cells of the cerebellum. Spheroids were common throughout the brain and there was also consistent severe foamy cytoplasmic vacuolation of renal tubular epithelial cells and hepatocytes. The activities of α-mannosidase, the lysosomal enzyme whose activity is deficient in mannosidosis, and activities of five other lysosomal enzymes were compared in brain, liver, and kidney tissues of three mannosidosis-affected calves and normal calf tissues. Tissues from the affected calves had a marked deficiency of α-mannosidase activity compared with the normal tissues; the greatest deficiency was in the liver (99%) and brain (98%). Activities of the other lysosomal enzymes were elevated in the affected tissues compared with normal.

Mannosidosis is a lysosomal storage disease that results from a defect in glycoprotein metabolism and affects man,18 Angus and Angus-related breeds of cattle, such as Murray greys,12,21 and the cat.4 The congenital disease is caused by an inherited deficiency of the lysosomal enzyme α-mannosidase,14 and is inherited in an autosomal recessive manner.

Mannosidosis was recently reported in a number of aborted and stillborn Australian Galloway calves3 from an experimental breeding trial. This is more detailed account of the histological and biochemical results obtained during the trial.
Immunohistochemical Staining For S100 Protein in the Diagnosis of Canine Amelanotic Melanoma
Authors: Sandusky G. E. , Carlton W. W. , Wightman K. A.
Published: March 2010

Formalin-fixed, paraffin-embedded tissue samples of canine amelanotic melanomas and normal canine tissues were studied immunohistochemically for the presence of S100 protein. Use of the avidin-biotin complex procedure demonstrated variable amounts of S100 protein in the tumor cell cytoplasm and nuclei in 26 of 31 tumors. S100 protein was not observed in some other common canine skin tumors stained by the avidin-biotin complex technique. These were a mast cell tumor, fibrosarcoma, mammary gland adenocarcinoma, histiocytoma, transmissible venereal tumor, and a thyroid gland adenocarcinoma. Among normal tissues the presence of S100 protein was demonstrated in chondrocytes in the trachea, myoepithelial cells in the breast, melanocytes in the skin, some sweat glands and ducts in the skin, stellate cells in the pituitary, and interdigitating reticulum cells in the lymph node and in Peyer's patches. These results indicate that the avidin-biotin complex procedure for demonstrating S100 protein is a useful diagnostic tool in the diagnosis of canine amelanotic melanoma.
Induction and Reversibility of Thyroid Proliferative Changes in Rats Given an Antithyroid Compound
Authors: Todd G. C.
Published: March 2010

Sixty Fischer 344 rats were fed a diet containing 90 ppm methimazole, a known antithyroid compound. Following exposure to the test compound, groups of ten animals were terminated at 1, 3, and 6 months. Similar groups of ten treated animals were given control diet for a reversibility period of 2, 3, and 6 months, respectively. Groups of ten control rats were terminated after 1, 3, 6, and 12 months. Except for the expected effect on body weight, the treated animals had no physical signs of toxicity. The weight of thyroids increased with the duration of exposure, becoming in males after 6 months about ten times the weight of thyroids from control rats. Thyroids of treated rats after 1 and 3 months had a diffuse homogeneous hypertrophy and hyperplasia of follicular cells, decreased colloid, and increased vascularity. After 6 months' exposure to the antithyroid compound, there was diffuse hyperplasia but also a heterogeneity in the size and morphology of follicles, protrusion of follicular tissue through the gland capsule and into vascular spaces, and the development of follicular nodules. Treated rats placed on control diet, allowing for reversibility, had thyroids which were decreased in size with large follicles and flattened epithelium, and a complete remodeling of most nodules with no evidence of progression. Although the nodules produced after prolonged administration of the antithyroid compound had many of the characteristics of neoplasia, the biologic behavior supports the diagnosis of nodular hyperplasia.
A Clinicopathologic and Ultrastructural Study of Undifferentiated Malignant Tumors of the Oral Cavity in Dogs
Authors: Patnaik A. K. , Lieberman P. H. , Erlandson R. A. , Macewen E. G. , Hurvitz A. I.
Published: March 2010

Undifferentiated malignant tumors of the oral cavity were diagnosed in six dogs under 2 years of age. The dogs were examined because of pain and swelling of the upper molar or premolar areas. In all six dogs, the tumors were initially misdiagnosed as infections or carnasal abscesses. The differential diagnosis included malignant lymphoma, osteosarcoma, mesenchymal chondrosarcoma, embryonal rhabdomyosarcoma, and malignant melanoma. Electron microscopy of three neoplasms showed that there were no specific features characteristic of carcinoma or sarcoma. Immunoperoxidase studies for cytokeratins, epithelial membrane antigen, actin, myosin, desmin, and vimentin were also negative. We conclude that these tumors be designated undifferentiated malignant tumors of the oral cavity until histogenesis is established.
Ultrastructure and Frequency of Mastitis Caused by Ovine Progressive Pneumonia Virus Infection in Sheep
Authors: Deng P. , Cutlip R. C. , Lehmkuhl H. D. , Brogden K. A.
Published: March 2010

Twenty-five sheep, experimentally ( n = 15) or naturally ( n = 6) infected with ovine progressive pneumonia virus and noninfected controls ( n = 4), were evaluated for histological and ultrastructural lesions of mastitis. Histologically, nine of 15 experimentally infected sheep and all six naturally infected sheep had lympho-plasmacytic mastitis. Severity of the lesion increased with length of time after infection. Periductal lymphatic nodules were seen in five sheep experimentally infected for 2.8 years or longer and in five naturally infected sheep that wore 3.7 years old or older. Ultrastructurally, responses to ovine progressive pneumonia virus were diffuse lympho-plasmacytic infiltrates in glandular interstitium, lymphocytic and occasional plasmacytic infiltrates in ductal walls and lumens, lymphoblasts surrounded by small lymphocytes in glandular interstitium, and degeneration of epithelium releasing cells and cellular debris into the lumen. Based on the prevalence of lesions, the mammary tissue was more susceptible to ovine progressive pneumonia virus than other target organs: lung, brain, and synovium. Lesions did not differ between breeds of sheep. Ovine progressive pneumonia virus was not seen in the mammary tissue but was isolated from 15 of 17 mammary glands.
Henneguya exilis Kudo Associated with Granulomatous Branchitis of Channel Catfish Ictalurus punctatus (Rafinesque)
Authors: Duhamel G. E. , Kent M. L. , Dybdal N. O. , Hedrick R. P.
Published: March 2010

Outbreaks of a chronic branchitis in channel catfish Ictalurus punctatus (Rafinesque) were observed on four fish farms throughout the state of California from November 1982 to April 1984. Severe granulomatous inflammation of the gill filaments with necrosis of the cartilage of the gill ray and diffuse epithelial hyperplasia, resulting in extensive fusion of gill lamellae, was present on histologic examination of gill specimens from 35 out of 44 fish examined. Numerous, small trophozoites morphologically consistent with presporogonic myxosporean parasites were consistently associated with the inflammatory process. Mature spores of Henneguya exilis Kudo were present in large numbers in gill specimens from two fish and only occasionally in 22 others. Similar cases referred to as “Hamburger Gill Disease” or “proliferative gill disease” have been known to occur in the south-central United States. This report describes the morphologic changes of this condition and discusses its possible pathogenesis.
Paranasal Meningioma in the Dog: A Clinicopathologic Study of Ten Cases
Authors: Patnaik A. K. , Lieberman P. H. , Erlandson R. A. , Shaker E. , Hurvitz A. I.
Published: March 2010

Paranasal meningiomas were diagnosed in ten dogs based on gross and light microscopic examinations of tissue specimens, and, in one case, electron microscopic examination. Seven of ten dogs were female (average age was 13 years). Most dogs (7/10) had seizures on examination. Two dogs with meningioma located in the nasal cavity had nasal discharge, and one had epistaxis. Tumors originated in the nasoparanasal region (eight) and frontal region of the cranial cavity (two). The histologic types of meningioma included psammomatous (two), transitional (three), meningotheliomatous (two), fibroblastic (two), and angioblastic (one). Tumors were malignant and extended to the brain in eight cases. These tumors differed from intracranial meningiomas mainly in their more anaplastic nature and aggressive behavior.
Distinctive Peripheral Lymph Node Hyperplasia of Young Cats
Authors: Moore F. M. , Emerson W. E. , Cotter S. M. , DeLellis R. A.
Published: March 2010

Peripheral lymph node enlargement was found in 14 of a series of 132 feline lymph node biopsy specimens. Six of nine cats tested had antibodies for feline leukemia virus (FeLV). Half of the cats were clinically normal while the remainder had fever, lethargy, anorexia, and hepatosplenomegaly. There was severe distortion of lymph nodal architecture with variable loss of discernible follicles and sinuses. Histiocytes, lymphocytes, immunoblasts, and plasma cells were present in expanded paracortical regions which encroached on, and occasionally effaced, lymphoid follicles. Postcapillary venules were numerous and prominent throughout the paracortex. The lymphadenopathy was most commonly transient (86% of cases) with subsequent development of lymphoma in one cat. Lymph nodes from seven kittens with experimental FeLV infection were compared with spontaneously enlarged lymph nodes; four of seven had B and T lymphocyte hyperplasia with normal nodal architecture. Three had partial loss of nodal architecture as a result of expanded paracortical regions populated largely by histiocytes and lymphocytes. Proliferation of postcapillary venules was not prominent in nodes from FeLV-infected cats. The cause of spontaneous lymph node hyperplasia of young cats was not determined. However, the similarity of lesions to those of kittens with experimental FeLV infection and the association with FeLV by serologic tests in six of nine cats suggest that this retrovirus may be involved in the pathogenesis of the lesion.
Pathology of the Vertebral Column of Horses with Cervical Static Stenosis
Authors: Powers B. E. , Stashak T. S. , Nixon A. J. , Yovich J. V. , Norrdin R. W.
Published: March 2010

Specimens of ligamentum flavum, joint capsule, and dorsal lamina were collected at surgery or necropsy from 25 horses with cervical static stenosis. All horses had myelographic evidence of dorsal compression of the spinal cord caused by soft tissue and/or bone in the caudal cervical area, primarily at C6-7. Most horses also had radiographic evidence of degenerative joint disease of articular facets. Histologically 19 horses had osteosclerosis and cartilage retention in the dorsal lamina, and 24 horses had increased fibrocartilage at the ligamentum flavum attachment to dorsal lamina. The ligamentum flavum and joint capsule had fibrovascular tissue in 20 horses. Fibrocartilaginous tissue, old hemorrhage, and fat necrosis were not unusual. One horse each had a synovial cyst, eosinophilic granulomas in the joint capsule, and osteochondrosis of articular facets. These findings indicate that abnormal biomechanical forces or instability of articulations result in stretching and tearing of the ligamentum flavum and joint capsule with subsequent fibrovascular and fibrocartilaginous proliferation, osteosclerosis of the dorsal lamina, and osteophyte formation on the articular facets.
Morphology and Behavior of Primary Ocular Melanomas in 91 Dogs
Authors: Wilcock B. P. , Peiffer R. L.
Published: March 2010

Primary ocular melanocytic neoplasms from 91 dogs were divided into two groups by histologic criteria. Seventy-five were benign and composed of spindle-shaped and large polyhedral melanocytes similar to those of human ocular melanocytomas. Fifty-nine of these originated in the uvea where most resulted in uveitis, glaucoma, or hyphema prior to enucleation. None metastasized. Nineteen melanocytomas were limbal tumors. None metastasized, but three of nine incompletely excised tumors were found within the anterior chamber 2 to 3 years after the initial removal. Sixteen uveal melanocytic neoplasms were histologically malignant. Three had confirmed metastases, all within 3 months of enucleation. Cell type or pattern of growth within the globe were not predictive of biologic behavior. Our data suggest that the mitotic index is the best criterion for histologic identification of ocular melanomas with high metastatic potential. We propose that the classification of primary ocular melanomas be simplified to include only two categories: melanocytoma (benign) and melanoma (potentially malignant). Further behavioral data may justify a grading scheme for melanomas based upon mitotic index.
A Nephrotic-like Syndrome with an Associated Mesangio-proliferative Glomerulopathy in a Cow
Authors: White M. R. , Crowell W. A. , Blue J. L.
Published: March 2010

A 3-year-old Limousin cow was admitted to the University of Georgia Teaching Hospital with a history of chronic weight loss and diarrhea of more than 1 year's duration. Clinical laboratory findings included proteinuria and hypoproteinemia and were suggestive of a nephrotic-like syndrome. Necropsy findings included generalized edema of the visceral organs and diffuse red glistening foci on the capsular and cut surfaces of the cortex of both kidneys. Microscopically, the kidney had hypercellular and hypersegmented glomeruli, focal glomerulosclerosis, periglomerular fibrosis, and tubular nephrosis. The glomerular hypercellularity was confirmed by electron microscopy to be due to increased mesangial cells.
A Scanning and Transmission Electron Microscopic Study of Rotavirus-Induced Intestinal Lesions in Neonatal Gnotobiotic Dogs
Authors: Johnson C. A. , Snider T. G. , Henk W. G. , Fulton R. W.
Published: March 2010

Neonatal gnotobiotic dogs orally inoculated with canine rotavirus had ultrastructural changes limited to the jejunal and ileal regions of the small intestine. Early scanning electron microscopic findings consisted of swollen villus epithelial cells, denuded foci on intestinal villi, and slight to moderate villus atrophy. Later changes were slight villus atrophy with no denuded intestinal villi. Transmission electron microscopic changes in villus epithelial cells from 12 to 48 hours post-inoculation included: rotavirus particles associated with intracytoplasmic vacuoles near the terminal web and apical tubules; viral particles in dilated cisternae of rough endoplasmic reticulum; and moderate numbers of necrotic cells having no microvilli, swollen mitochondria, membrane-bound lipid-like material in the cytoplasm, clumped chromatin around the periphery of the nucleus, and disruption of the cytoplasmic membrane. In jejunum and ileum at 72 to 154 hours post-inoculation, there were fewer necrotic villus epithelial cells and fewer virus particles. In addition, the ultrastructural morphology of the majority of the villus epithelial cells was similar to crypt epithelium. These studies showed that rotavirus infected the villus epithelial cells with subsequent propagation of the rotavirus and destruction of villus epithelial cells.
Neuropathology of Experimental 3-nitro-4-hydroxyphenylarsonic Acid Toxicosis in Pigs
Authors: Kennedy S. , Rice D. A. , Cush P. F.
Published: March 2010

Twenty pigs were fed a diet containing 187.5 mg kg−1 of 3-nitro-4-hydroxyphenylarsonic acid (3-nitro). Ten pigs were euthanized at intervals up to 29 days, 3-nitro was withdrawn from the diet of the remaining pigs on day 30, and these animals were subsequently euthanized at intervals up to 49 days after commencement of the experiment. A nervous syndrome characterized by clonic convulsive episodes inducible by exercise, developed at day 11. Paraparesis was apparent at day 22 progressing to paraplegia by day 33 (3 days after cessation of 3-nitro feeding). Histopathologic examination revealed myelin and axonal degeneration in the white matter of the spinal cord coincident with the onset of nervous signs. Marchi-positive degeneration was present in the dorsal funiculus at cervical level at day 22. Lesions intensified with increasing duration of toxicosis and while degenerate fibers were seen in all funiculi, there was preferential involvement of the fasciculi gracilis and cuneatus, the peripheral regions of the ventral and lateral funiculi, and a discrete area of the dorsal region of the lateral funiculus. Peripheral and optic neuropathies were evident from day 32 but were always mild and focal. The experiment establishes 3-nitro as a central-peripheral neurotoxicant of pigs.
Histopathological and Hematological Findings in Myeloid Leukemia Induced by a New Feline Leukemia Virus Isolate
Authors: Toth S. R. , Onions D. E. , Jarrett O.
Published: March 2010

Myeloid leukemia was induced by a new feline leukemia virus isolate FeLV-AB/GM-1 in a high proportion of cats. The latency period was short. Three to 5 weeks after infection early changes were detectable in the bone marrow, and cats developed leukemia 5 to 8 weeks after infection. The results of the present histological and cytological studies suggested that there were two stages in the development of leukemia. The first stage appeared to be equivalent to the syndrome of bone marrow dysplasia or preleukemia which, however, converted rapidly to leukemia. Cytopenia(s) were the main hematological findings in all preleukemic and leukemic cats. White blood cell counts were low or normal, but the number of leukemic and abnormal cells increased in the peripheral blood with the progression of the disease. This reliable model system lends itself to further studies to elucidate the pathogenesis of myeloproliferative disorders.
Enterocolitis Caused by Ehrlichia sp. in the Horse (Potomac Horse Fever)
Authors: Cordes D. O. , Perry B. D. , Rikihisa Y. , Chickering W. R.
Published: March 2010

Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae of both small and large intestines. Multifocal areas of necrosis occurred in mucous membranes. Ehrlichial organisms were most common in the cytoplasm of epithelial cells, macrophages, and mast cells of the large colon.
Polysaccharide Storage Myopathy in Canine Phosphofructokinase Deficiency (Type VII Glycogen Storage Disease)
Authors: Harvey J. W. , Calderwood Mays M. B. , Gropp K. E. , Denaro F. J.
Published: March 2010

A severe, progressive myopathy developed in an 11-year-old, phosphofructokinase (PFK)-deficient, male, English Springer Spaniel dog. Results from a routine neurological examination were normal. Examination of histologic sections of skeletal muscle revealed large accumulations of material in some myofibers. These deposits were pale, basophilic, somewhat flocculent, and slightly granular with hematoxylin and eosin stain. Most fascicles examined in sections of limb and trunk muscles were affected to some degree, with up to 10% of muscle fibers being involved. Deposits stained strongly with periodic acid-Schiff and were resistant to digestion by alpha amylase but were removed by incubation with gamma amylase. Deposits were faintly positive with Gomori's methenamine silver technique and alcian blue (pH 2.5) and were brown-gray with Lugol's iodine solution but were negative with other stains. Based on staining characteristics, the deposits seemed to consist primarily of an amylopectin-like polysaccharide(s). Alcian blue staining (pH 2.5) was removed by treatment with neuraminidase but not with hyaluronidase, indicating that some sialic acid residues were also present. Electron microscopically, the deposits were composed of short granular filaments, small granules and amorphous material. They were not membrane bound. The morphologic appearance and staining characteristics of the deposits were remarkably similar to deposits previously described in human PFK-deficient myopathy. As expected, total PFK activities were markedly reduced when assayed in skeletal muscles of this dog. In contrast with other PFK-deficient dogs, muscle glycogen in this animal was not increased above that of normal dogs.
The Causes of Glaucoma in Cats
Authors: Wilcock B. P. , Peoffer R. L. , Davidson M. G.
Published: March 2010

The cause of glaucoma in 131 enucleated eyes from 128 cats was determined in a retrospective histologic study. Obliteration of the ciliary cleft by diffuse iridal melanoma (38 eyes), or other neoplasms (14 eyes), or by the presence of idiopathic lymphocytic-plasmacytic anterior uveitis (53 eyes) were the most frequent lesions likely to explain the development of glaucoma. Secondary changes of inner retinal atrophy, optic disc cupping, scleral thinning with megaglobus, and atrophy of ciliary processes were similar to those described in dogs and human beings with chronic glaucoma. In light of the duration and severity of the glaucoma, the degree of inner retinal atrophy was often less than expected. Diffuse corneal edema and breaks in Descemet's membrane, changes typical of glaucoma in other species, were rarely detected. Eyes with chronic uveitis and glaucoma had collapsed ciliary clefts, iridoscleral adhesions, and posterior displacement of the iris. We were unable to determine whether these changes were consequences of the uveitis and thus responsible for the development of glaucoma, or if they were merely the result of the chronic glaucoma itself.
Characteristics of Canine Melanomas and Comparison of Histology and DNA Ploidy to Their Biologic Behavior
Authors: Bolon B. , Mays M. B. Calderwood , Hall B. J.
Published: March 2010

The biologic behavior of 179 formalin-fixed, paraffin-embedded canine melanomas was correlated with their histologic appearance. In addition, flow cytometric analysis of DNA content was performed on 54 of these tumors. Histologic examination accurately predicted clinical course in 89% of the melanomas with known behavior. Flow cytometry accurately predicted behavior in 93% of tumors with diagnostic histograms and demonstrated malignant features in 100% of metastases from malignant oral tumors; histograms were nondiagnostic for 15% of tumors tested. Histologic examination, flow cytometry, and biologic behavior were in agreement for 93% of the tumors with diagnostic histograms. Interpretive problems were encountered in analyzing heavily pigmented melanomas using this flow cytometery technique.
Ultrastructural Morphogenesis of 4-ipomeanol-induced Bronchiolitis and Interstitial Pneumonia in Calves
Authors: Li X. , Castleman W. L.
Published: March 2010

The two objectives of this research were 1) to describe the ultrastructural morphogenesis of pulmonary damage and repair induced in calves after treatment with 4-ipomeanol and 2) to characterize infiltrating pulmonary inflammatory cells by bronchoalveolar lavage. Interstitial edema was observed as early as 4 hours after intravenous injection of 4-ipomeanol (5 mg/kg body weight) and progressed to severe alveolar edema by 72 hours. Damage to type I alveolar epithelial cells and terminal bronchiolar nonciliated cells included dilation of endoplasmic reticulum and perinuclear envelopes and was present at 4 hours after treatment. Necrosis and sloughing of these cells from basement membranes occurred at times from 12 to 96 hours after treatment. Alveolar capillary endothelial cells had mild dilation of endoplasmic reticulum at times from 12 to 72 hours after treatment. Necrosis of endothelial cells was not observed. Inflammatory cell infiltrates in bronchioles and alveoli were dominated by macrophages and neutrophils. Significant elevations ( P < 0.05) in numbers of neutrophils and macrophages were recovered by bronchoalveolar lavage at times from 24 to 96 hours after 4-ipomeanol-treatment. Hyperplasia of nonciliated bronchiolar epithelial cells and of type II alveolar epithelial cells were observed at 72 and 96 hours after treatment. The results indicate that type I alveolar epithelial cells and nonciliated bronchiolar epithelial cells are most susceptible to 4-ipomeanol-induced damage and necrosis in calves. 4-ipomeanol-induced pulmonary edema in calves occurs prior to ultrastructurally-demonstrable, mild, alveolar capillary endothelial cell damage.
Erythrocyte Pathology and Mechanisms of Heinz Body-mediated Hemolysis in Cats
Authors: Christopher M. M. , White J. G. , Eaton J. W.
Published: March 2010

Despite the frequency of both oxidant drug-induced and spontaneous Heinz body formation in cats, the cellular and biochemical mechanisms by which Heinz bodies result in red blood cell (RBC) destruction and hemolytic anemia in this species remain unknown. Feline spleens are non-sinusoidal and inefficient at removing Heinz body-containing RBC from the circulation; therefore, alternative mechanisms must be involved in accelerated RBC destruction. Propylene glycol (PG) ingestion causes dose-dependent Heinz body formation and decreased RBC survival in cats. We investigated several aspects of Heinz body-containing RBC from three cats ingesting diets that provided 8.0 g PG/kg body weight for up to 3 weeks, in order to characterize cellular lesions that are associated with the presence of Heinz bodies and that might contribute to chronic, accelerated RBC destruction, as well as to gain insight into the mechanism by which PG induces Heinz body formation. Erythrocytes with PG-induced Heinz bodies had decreased levels of reduced glutathione and adenosine triphosphate and reduced deformability. There was no change in hemoglobin isoelectric focusing or membrane lipid peroxidation. Electrophoretic patterns of Heinz body-containing RBC membranes were significantly altered, and membrane surface charge distribution was disturbed. Progressively protruding Heinz bodies suggested that extrusion of Heinz bodies may be a means of cell healing and/or destruction in the absence of splenic pitting. When compared to results obtained using RBC from cats treated with the oxidant drug phenylhydrazine, significant differences were noted in packed cell volume, turbidity index, membrane heme, and morphologic appearance of Heinz bodies. Our results indicate that multiple cellular abnormalities develop in RBC with PG-induced Heinz bodies that do not cause acute hemolysis but that may shorten RBC survival. Propylene glycol-induced Heinz bodies provide an ideal model for studying the chronic effects of Heinz bodies on RBC structure and function and may be useful in understanding the mechanisms of formation and the consequences of endogenous Heinz bodies in cats.
Pathologic Changes of the Small Intestinal Mucosa of Pigs after Feeding Phaseolus vulgaris Beans
Authors: Kik M. J. L. , Huisman J. , van der Poel A. F. B. , Mouwen J. M. V. M.
Published: March 2010

The jejunal mucosa of pigs fed diets containing Phaseolus vulgaris beans was characterized grossly as mucosal atrophy and microscopically as atrophy and blunting of the villus in association with elongation of crypts with cells with increased mitotic activity. These morphologic findings were most severe in the proximal and middle parts of the jejunum. Compared to controls, goblet cells were significantly decreased in the villus but markedly increased in the crypt region. The activity of aminopeptidase and sucrase-isomaltase in the test animals was also significantly lower than in the controls. The findings in this study suggested that feeding Phaseolus vulgaris beans reduced the digestive and absorptive capacity of the mucosa, resulting in weight loss and diarrhea of affected pigs.
Histopathologic and Immunocytochemical Studies of Distemper in Harbor Porpoises
Authors: Kennedy S. , Smyth J. A. , Cush P. F. , McAliskey M. , McCullough S. J. , Rima B. K.
Published: March 2010

During 1988 thousands of harbor seals ( Phoca vitulina) died in European seas as a result of morbillivirus infection. Six harbor porpoises ( Phocoena phocoena) found stranded on the coast of Northern Ireland in late 1988 were submitted to our laboratory for necropsy. Pneumonia was the main necropsy finding in three of these animals. Microscopic lung lesions characterized by necrosis of bronchial and bronchiolar epithelium and infiltration of alveoli with leukocytes, lymphoid cells, macrophages, and multinucleate syncytia were seen in all six porpoises. Cytoplasmic and nuclear acidophilic inclusions characteristic of morbillivirus infection were common in bronchial and bronchiolar epithelial cells and in alveolar macrophages and syncytia. Brain alterations included degeneration and necrosis of neurons, microglial infiltration, and perivascular cuffing. There were cytoplasmic and nuclear acidophilic inclusions in many neurons. Immunoperoxidase staining of morbillivirus antigen was seen in many tissues including lung, brain, spleen, and urinary bladder. Alterations in our porpoises were similar to those seen in distemper in seals and many species of terrestrial mammals. Systemic viral disease has not previously been documented in Cetacea.