bluuebunny/crossref_metadata_2025 huggingface dataset:
Ameloblastoma and Keratinizing Ameloblastoma in Dogs
Authors: Dubielzig R. R. , Thrall D. E.
Published: March 2010

Ameloblastomas reviewed in this report were locally invasive neoplasms arising from the epithelial structures of the dental lamina, and were characterized histologically by features which are unique to dental lamina epithelium. These include the formation of epithelial sheets in which the cells nearest the stroma form a palisading row aligned perpendicularly to the basement membrane and the cells toward the center separate from each other except at desmosomal attachments. This is similar to the appearance of the stellate reticulum of the early enamel organ. Other features include epithelial cords which branch and interconnect, and the intimate association of epithelial structures and collagenous matrix. In our dogs, other important features were the deposition of inclusions similar in appearance to enamel matrix between the cells of the epithelium and various degrees of keratinization. All ameloblastomas studied were locally invasive tumors which occurred at various sites on the gingiva. The average age of the dogs was 8.7 years and the age range was three to 13 years. Radiographically, all of the tumors studied resulted in periodontal osteolysis. Six dogs were treated with radiation therapy, but details of the radiotherapy of two dogs could not be located. Of the other four dogs, one is alive 48 months after radiotherapy with no evidence of tumor regrowth. Regrowth of the oral tumor was apparent in the other three dogs six, 21, and 34 months after completion of the radiotherapy.

Three dogs were treated by radical mandibulectomy; all are alive with no evidence of tumor recurrence at two, 20, and 28 months postoperatively. Two dogs had local dissection (curettage) of tumors and the tumors recurred at 12 and 15 months after surgery. One dog was euthanatized after diagnosis of the oral tumor because of a progressive neuropathy.
Extracutaneous Mast-Cell Tumor in the Dog
Authors: Patnaik A. K. , MacEwen E. G. , Black A. P. , Luckow S.
Published: March 2010

Three neoplasms of extracutaneous mast-cell origin, arising from the nasopharynx, oral cavity, and hepatopancreatic lymph nodes respectively, were diagnosed in three dogs. The neoplasms had histologic features similar to those of cutaneous mast-cell tumors, but had limited metastasis mostly involving the regional lymph nodes. One dog had a perforating duodenal ulcer, suggesting that duodenal ulcers can occur with extracutaneous tumors as they do with some cutaneous mast-cell tumors in the dog.
Neoplasms in Calves (Bos taurus)
Authors: Schamber G. J. , Olson C. , Witt L. E.
Published: March 2010

From January 1, 1977 through December 31, 1978, 529,077 calves were slaughtered at a Wisconsin abattoir. Tissues from 36 calves found unfit for human consumption because of suspected neoplasia were examined histologically, and 19 lymphomas, seven mesotheliomas, one embryonal nephroma, one fibroma and one hemangiosarcoma were found.
Experimental Fecal Transmission of Human Cryptosporidia to Pigs, and Attempted Treatment with an Ornithine Decarboxylase Inhibitor
Authors: Moon H. W. , Schwartz A. , Welch M. J. , McCann P. P. , Runnels P. L.
Published: March 2010

Fecal material collected from an immunologically deficient man with persistent cryptosporidia infection was stored in potassium dichromate for two weeks and then fed (inoculated) to newborn pigs. The six inoculated newborn pigs shed the organism in their feces starting four to five days after inoculation and continuing for as long as 22 days after inoculation. Pigs which were killed and necropsied while shedding had cryptosporidia infection of ileum, cecum, and colon. Infected pigs had atrophied ileal villi and flattened irregular cecal and colonic epithelium. Uninoculated littermate controls remained free of the infection and had histologically normal intestinal tracts at necropsy. Treatment of three of the six inoculated pigs with the ornithine decarboxylase inhibitor, DL- α-difluoromethylornithine, orally for ten days had no apparent effect on the infection.
Ulcerative Duodenitis in Foals
Authors: Acland H. M. , Gunson D. E. , Gillette D. M.
Published: March 2010

Seven foals aged 18 days to 3 1/2 months had either single or multiple full-circumference segments or long antimesenteric bands of necrotizing duodenitis, sharply delineated from adjacent viable duodenum. Perforation of the necrotic wall had occurred in all foals, leading to acute fibrinous peritonitis. On the mucosal surface severe, diffuse, acute inflammation and ulceration involved the anterior half of the duodenum. Two further foals, aged 28 and 30 days, had lesions that are believed to be a chronic form of this disease. Both foals had a thickened duodenal wall, with large areas of mucosa replaced by granulation tissue. In addition one had several strictures associated with firm adhesions between the duodenal serosa and adjacent structures, together with ascending cholangiohepatitis and pancreatitis. Eight foals had gastric ulcers that were considered to be of less significance than the duodenal lesions. No etiologic agent could be found by aerobic or anaerobic bacterial culturing, negative contrast electron microscopy for viruses, or immunofluorescence staining for equine herpesvirus I, equine adenovirus, or equine coronavirus. The possible involvement of non-steroidal anti-inflammatory drugs is discussed.
Renal Medullary Crest Necrosis Associated with Phenylbutazone Therapy in Horses
Authors: Read W. K.
Published: March 2010

Thirty-five cases of renal medullary crest necrosis morphologically similar to the renal papillary necrosis of analgesic nephropathy as described in man and rats are reported in horses receiving maintenance dosages of phenylbutazone. The primary lesion is a well-demarcated focal medullary necrosis resulting in sequestration of fragments of the renal crest. Renal cortical lesions are considered secondary to the medullary necrosis and consist of segmental pallor as a result of tubular dilatation, filtrate retention, and interstitial edema. Ischemia in concert with phenylbutazone is suggested as the etiology. Renal medullary crest necrosis is presented as more appropriate morphological terminology for this lesion in the equine species than renal papillary necrosis as is used in man and rats.
Pathology of the Mononuclear Cell Leukemia of Fischer Rats. III. Clinical Chemistry
Authors: Stromberg P. C. , Vogtsberger L. M. , Marsh L. R.
Published: March 2010

Serum biochemical analyses were done on F344 rats in the early and late stages of mononuclear cell leukemia. There were marked increases in serum bilirubin, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and alkaline phosphatase. Increases in these parameters generally were more severe in the late stages of leukemia. Both direct and indirect-reacting bilirubin were increased with the unconjugated form predominating early and the conjugated form predominating late in the course of the disease. Lactate dehydrogenase isoenzyme determination correlated with histological examination indicated that liver damage was responsible for the observed changes. Urinalysis revealed marked hemoglobinuria, bilirubinuria and increased urine urobilinogen. Serum protein electrophoresis revealed marked reductions in the alpha globulin fractions.
The Effects of Dietary T-2 Toxin on Acute Herpes Simplex Virus Type 1 Infection in Mice
Authors: Friend S. C. E. , Schiefer H. B. , Babiuk L. A.
Published: March 2010

Young male white Swiss mice were fed control diet or diet supplemented with 20 or 10 parts per million (ppm) of T-2 toxin for two or three weeks. These mice then were inoculated with herpes simplex virus type 1 (HSV-1) (9.6 x 106 plaque forming units) intraperitoneally. To compare the effects of T-2 toxin against a known immunosuppressive drug, cyclophosphamide was injected intraperitoneally at 150 mg/kg, 24 hours after treatment with HSV-1, into mice fed the control diet. Mice were necropsied and tissues were collected for microscopic and virologic examination.

White Swiss mice which consumed a daily diet containing 20 ppm of T-2 toxin for two or three weeks were highly susceptible to HSV-1 infection and 27 of 36 (75%) died as a result of extensive hepatic and adrenal necrosis. Although HSV-1 was isolated from livers and brains of mice fed 20 ppm of T-2 toxin for two or three weeks, there was little or no inflammatory response found in the adrenals, livers, spinal cords, brains, or ganglia. The necrotizing encephalomyelitis observed in control mice was absent.

High levels of dietary T-2 toxin appeared to be more immunosuppressive than cyclophosphamide because only one mouse died after treatment with HSV-1 and cyclophosphamide. Mice treated with cyclophosphamide had changes in brain, spinal cord, spleens, thymus, and bone marrow which were similar to those fed 20 ppm of T-2 toxin and infected with HSV-1, however, liver lesions were much less severe.

HSV-1-infected mice on a diet with 10 ppm T-2 toxin had lesions of intermediate severity when compared with HSV-1-infected mice fed a diet with 20 ppm T-2 toxin and HSV-1-infected mice on control diets. Necrosis was less extensive in the livers and adrenals. The infrequent isolation of virus from liver and brain was consistent with the lack of intranuclear inclusion bodies and a more marked inflammatory response. Ten ppm of dietary T-2 toxin only depressed bone marrow and splenic red pulp to a mild or moderate degree. This may have enhanced the necrotizing encephalomyelitis observed in mice killed on days 6 and 8 after HSV-1 infection.

Liver lesions were mild and those of the adrenals were moderate in mice fed control diet. The rare isolation of HSV-1 from the liver and brain and the finding of a moderate to severe necrotizing encephalomyelitis in these mice was consistent with an essentially functional immune system.
Canine Laryngopharyngeal Rhabdomyoma Resembling an Oncocytoma: Light Microscopic, Ultrastructural and Comparative Studies
Authors: Liggett A. D. , Weiss R. , Thomas K. L.
Published: March 2010

A laryngopharyngeal rhabdomyoma was diagnosed in a four-year-old dog with clinical signs of upper respiratory obstruction. In people, rhabdomyomas have a predilection for the head and neck area. Features of this tumor were compared with an oncocytoma with which it may be confused.
Canine Laryngeal Rhabdomyoma
Authors: Meuten D. J. , Mays M. B. Calderwood , Dillman R. C. , Cooper B. J. , Valentine B. A. , Kuhajda F. P. , Pass D. A.
Published: March 2010

Three canine laryngeal tumors were diagnosed as oncocytomas by light microscopy, but were determined to be rhabdomyomas following ultrastructural and immunocytochemical examination. Tumors consisted of large eosinophilic cells interspersed with smaller dark cells. Large tumor cells had a granular, intensely eosinophilic cytoplasm. Scattered through the tumors were a few elongated cells with cytoplasmic cross striations and multiple nuclei. Tumor cells from all three dogs contained numerous mitochondria and bundles of myofibrils with electron-dense Z-lines typical of striated muscle cells. Intracellular myoglobin and desmin were detected in the tumors by immunocytochemistry. Comparisons are made with a previous report of canine laryngeal oncocytomas.
An Ultrastructural Study of Adenocarcinoma of the Small Intestine in Sheep
Authors: Ross A. D. , Day W. A.
Published: March 2010

The ultrastructural appearance at primary and metastatic sites of ten ovine small intestinal adenocarcinomas was that of scirrhous tubular adenocarcinoma. Polygonal undifferentiated tumor cells had desmosomes, folded nuclei, and moderate numbers of mitochondria but few other organelles. More differentiated cells were columnar with apical microvilli and basal nuclei. They contained granular endoplasmic reticulum, Golgi and secretory granules. Microvillus-lined intracytoplasmic lumina (5–10 μm diameter), fibrous filaments (10 nm diameter, up to 1.4 μm length) and tubular paracrystalline arrays (hexagonal symmetry, 37-nm periodicity) in lumina and secretory granules were seen in some tumor cells in all ten sheep.
Spongy Degeneration of the Central Nervous System in Two Canine Littermates
Authors: Zachary J. F. , O'Brien D. P.
Published: March 2010

Progressive dysmetria was observed at four months and six months of age in two female Labrador retriever littermates. Neurological examinations indicated a cerebellar disorder. Laboratory analyses were normal. The dogs were studied clinically until they were killed for necropsy at nine months and eleven months of age. Both dogs had normal brain size, shape, and calvarial symmetry; the older dog had body weight loss, reduced brain weight, and muscle atrophy. Microscopically, there were vacuoles, hypertrophied fibrous astrocytes, myelin loss, and prominent blood vessels, distributed symmetrically in the subcortical and deep white matter of all lobes of the cerebrum; in the folial and deep white matter of the cerebellum; in the tracts of some cranial nerves; in the thalamic area, midbrain and brainstem; and in the white matter of the spinal cord. There was no significant myelinolysis, inflammation, or axonal degeneration. Ultrastructurally, there were intramyelinic vacuoles with separation of lamellae at intraperiod lines and larger spaces formed by coalescence of ruptured vacuoles. Hypertrophied fibrous astrocytes had abundant glial filaments, edematous cytosol, membrane-bound crystalline inclusions, dilated cytocavitary systems, and abnormal mitochondria. The clinical, histological, and ultrastructural findings resembled those reported for the juvenile form of Canavan's disease (van Bogaert and Bertrand type) in children.
Benign Melanoma of the Choroid in a Beagle: Ophthalmological, Light and Electron Microscopical Investigations
Authors: Weisse I. , Frese K. , Meyer D.
Published: March 2010

A pigmented choroidal tumor was diagnosed in a 13-month-old male beagle. The tumor was observed ophthalmoscopically over a period of seven years. Light and electron microscopical features are those of a benign melanocytic tumor with marked histological similarities to uveal nevus in man.
Pathology of Spontaneous Colibacillosis in a Broiler Flock
Authors: Nakamura K. , Maeda M. , Imada Y. , Imada T. , Sato K.
Published: March 2010

Forty-eight of 134 chickens collected from a flock on a broiler farm were diagnosed pathologically and microbiologically to have colibacillosis. Both acute septicemia (seven birds, 1 to 36 days old) and subacute serositis (41 birds, 5 to 57 days old) were found. The former consisted of necrosis with fibrinous exudates in the ellipsoids and lymphoid follicles of the spleen, and fibrinous thrombi in sinusoids of the liver with occasional necrosis of hepatic cells. The latter had fibrinopurulent inflammation with granulomatous changes in the serosal tissues—including the epicardium, pericardium, and hepatic peritoneal sac—accompanied by septicemic lesions in the spleen and liver. Respiratory lesions (airsacculitis, pneumonia, and tracheitis) were noted in most chickens affected with acute septicemia and subacute serositis. Degenerative changes also were observed in the bursa of Fabricius.
Testicular Degeneration and Necrosis Induced by Dietary Cobalt
Authors: Corrier D. E. , Mollenhauer H. H. , Clark D. E. , Hare M. F. , Elissalde M. H.
Published: March 2010

Dietary cobalt (265 ppm Co) induced polycythemia and consistent degenerative and necrotic lesions in the seminiferous tubules of rats. Cyanosis and engorgement of testicular vasculature on day 35 and thereafter was followed on day 70 by degenerative and necrotic changes in the germinal epithelium and Sertoli cells. Spermatogonia, primary spermatocytes and round spermatids were markedly affected, while elongated spermatids, spermatozoa, and Sertoli cells were more resistant. Damaged tubules, often present side by side with normal tubules, contained multinucleated giant cells composed of degenerated and necrotic spermatocytes and/or spermatids, sloughed germinal and Sertoli cells, and calcified necrotic debris. Necrotic tubules were frequently collapsed and devoid of epithelium except for occasional spermatogonia and surviving Sertoli cells. Lesions were not observed in the Leydig cells, cauda epididymis or seminal vesicles.
Pathogenesis of Canine Parvovirus Enteritis: Sequential Virus Distribution and Passive Immunization Studies
Authors: Meunier P. C. , Cooper B. J. , Appel M. J. G. , Lanieu M. E. , Slauson D. O.
Published: March 2010

After oral inoculation, the sequential distribution of canine parvovirus was studied in 14 nine-week-old seronegative beagle dogs. Two or three dogs were necropsied on days 1 through 6 after inoculation. Tissues were collected for virus isolation, immunofluorescence testing, and light microscopy. Virus was isolated from, and fluorescent cells were seen in the tonsil, retropharyngeal and mesenteric lymph nodes one and two days after inoculation. Virus infection of systemic and intestinal lymphoid tissues occurred as early as three days after inoculation and was associated with viremia. Intestinal epithelial infection was first seen four days after oral inoculation. All dogs were viremic before intestinal epithelial infection was found. Fecal virus excretion first occurred four days after oral virus inoculation. Intestinal virus infection and lesions became progressively more severe between four and six days after inoculation. The severity of intestinal lesions was variable and related to the severity of systemic lymphoid tissue lesions and the magnitude and duration of viremia. Four littermates of virus-infected dogs were passively immunized against canine parvovirus with convalescent canine serum 24 hours after oral virus inoculation. Neither clinical signs, lymphopenia, nor fecal virus excretion occurred in passively immunized dogs. Intestinal epithelial infection was not demonstrable by immunofluorescence testing when passively immunized dogs were necropsied four, five, and six days after virus inoculation.
Identification of Calcium Oxalate Monohydrate Crystals by X-ray Diffraction in Urine of Ethylene Glycol-Intoxicated Dogs
Authors: Thrall M. A. , Dial S. M. , Winder D. R.
Published: March 2010

Urine sediments of dogs with experimentally induced ethylene glycol poisoning were examined by light microscopy and X-ray diffraction. Massive calcium oxalate crystalluria was observed in all poisoned dogs. By light microscopy, the frequency with which six-sided hippurate-like prisms and envelope forms of calcium oxalate dihydrate occurred was approximately equal. The hippurate-like crystals were shown to be calcium oxalate monohydrate by X-ray diffractometry.
Cytochemical Reactions in Cells from Leukemic Dogs
Authors: Grindem C. B. , Stevens J. B. , Perman V.
Published: March 2010

Leukemic cells from 17 dogs with spontaneous leukemia were stained with leukocyte alkaline phosphatase, alpha naphthyl acetate esterase with and without fluoride, peroxidase, and periodic acid-Schiff. Cytochemistry was necessary for identification or confirmation of leukemic cell type in most dogs and resulted in changing the light microscopic morphologic diagnosis in eight of 17 dogs. Leukemic cell types diagnosed were myclomonocytic leukemia in seven dogs, monocytic leukemia in five dogs, lymphocytic leukemia in four dogs, and myelocytic leukemia in one dog.
Enzyme Histochemistry of the Small Intestinal Mucosa in Experimental Infections of Calves with Rotavirus and EnterotoxigenicEscherichia coli
Authors: Stiglmair-Herb M. T. , Pospiscihl A. , Hess R. G. , Bachmann P. A. , Baljer G.
Published: March 2010

The effect of rotavirus and enterotoxigenic Escherichia coli, administered in different sequences, on alkaline and acid phosphatase, leucinaminopeptidase, β-galactosidase, and succinicdehydrogenase of the intestinal mucosa of cesarian-derived, colostrum-deprived calves was investigated. Decrease in enzyme activity was most prominent in dual infections; it also occurred in parts of the small intestine in monoinfected animals. Increases in enzyme activity involved totally either one or all tissue compartments (crypt, basal villus area. villus tips). Increased activity was present in enteric mucosae that were either not affected or were only slightly affected by rotavirus or enterotoxigenic E. coli. We interpret the increase in enzyme activity as an adaptation of the enteric mucosa to maintain the absorptive function.
Focal Mucinosis in Dogs: Seven Cases and Review of Cutaneous Mucinoses of Man and Animals
Authors: Dillberger J. E. , Altman N. H.
Published: March 2010

Seven dogs had one or more asymptomatic nodules, papules, or plaques on the skin or oral mucosa. The primary histologic feature was the accumulation of excess mucin within the dermis or submucosa. Based upon the clinical presentation and the histopathologic changes, it was proposed that these lesions represent the canine analogue of focal mucinosis in man, and that the same name be applied to the lesion in dogs. The criteria for the diagnosis of focal mucinosis were: (1) the presence of a single (rarely multiple) papule, nodule, or plaque which may be firm, rubbery, or soft, (2) the accumulation of mucin which disrupts and separates collagen fibers, (3) mild to extensive fibroblast proliferation, and (4) a mild mononuclear cell infiltration. The mucinoses of man and animals were reviewed.
Hereditary Copper Toxicosis in West Highland White Terriers
Authors: Thornburg L. P. , Shaw D. , Dolan M. , Raisbeck M. , Crawford S. , Dennis G. L. , Olwin D. B.
Published: March 2010

Histologic, histochemical and atomic absorption studies on liver tissue from 71 West Highland white terriers are reported. Twenty-seven dogs had histologically normal liver and copper concentration comparable to mongrel control dogs. Forty-four dogs had hepatic copper concentrations up to 22 limes the mean copper concentration found in clinically normal mongrel dogs. Hepatitis, hepatic necrosis and cirrhosis were associated with the increased copper concentration in some dogs. Matings between dogs with high liver copper concentration produced pups with high liver concentration. The copper storage defect is inherited.
Carotid Body Tumor: An Incidental Finding in Older Ranch Mink
Authors: Hadlow W. J.
Published: March 2010

Carotid body tumors were found incidentally at necropsy in 15 ranch mink ( Mustela vison), mostly royal pastels, kept for studies on slow viral diseases. The mink, five males and ten females, were 77 to 135 months old (mean age 107 months). Loosely or firmly attached at the bifurcation of the common carotid artery, and 11 larger tumors were smooth-surfaced, discrete, pale brown, globoid masses that varied from 2.5 to 16 mm in diameter. Four tumors of microscopic size occurred in otherwise normal-looking carotid bodies. All were composed of densely packed polygonal cells disposed in sheets and cords or arranged in clusters by a reticulin meshwork rich in blood vessels. Always unilateral, the tumors had not invaded locally or metastasized. As seen in the smallest tumors, the neoplastic cells usually arose centrally in the carotid body and formed an expansive growth that replaced much of the normal parenchyma without necessarily enlarging the organ beyond normal limits. The cause of the tumors was not apparent. All tumor-bearing mink had lived at an elevation of 1,100 meters, and none had suffered from any obvious chronic cardiopulmonary disease.
Spermatid Giant Cells, Tubular Hypospermatogenesis, Spermatogonial Swelling, Cytoplasmic Vacuoles, and Tubular Dilatation in the Testes of Normal Rabbits
Authors: Morton D. , Weisbrode S. E. , Wyder W. E. , Maurer J. K. , Capen C. C.
Published: March 2010

Testes of 36 normal New Zealand white rabbits (8, 15, 18, 26, and greater than 52 weeks of age) were examined by light and electron microscopy. The incidence and number of affected tubules were determined for spermatid giant cells, focal tubular hypospermatogenesis, cytoplasmic swelling of spermatogonia, intracytoplasmic vacuoles in seminiferous epithelium, and tubular dilatation. Spermatogenesis commenced at 15–18 weeks of age and was present in all rabbits by 18 weeks. Spermatid giant cells occurred in 96% of rabbits 15 weeks of age and older. Focal hypospermatogenesis was present in 14–57% of testes once active spermatogenesis began. Ninety-seven percent of testes in all age groups combined had spermatogonial swelling. Infrequent dilated seminiferous tubules were present in five rabbits. Ultrastructurally, spermatid giant cells were round cells with multiple nuclei that appeared to arise by widening of narrow intercellular bridges that normally connect spermatogenic epithelial cells. Pale-staining spermatogonia consisted of cytoplasmic and nuclear swelling with disruption of plasma and nuclear membranes. Tubules with spermatogonial swelling were more numerous in 15- and 18-week-old rabbits. There were no significant differences in incidence or extent of spermatid giant cells, focal hypospermatogenesis, cytoplasmic vacuoles, or tubular dilatation between age groups after spermatogenesis commenced. Although the cause of these changes is not known, they were frequent findings in normal rabbits 15 weeks of age and older.
Intracranial Meningioma: A Comparative Pathologic Study of 28 Dogs
Authors: Patnaik A. K. , Kay W. J. , Hurvitz A. I.
Published: March 2010

Intracranial meningiomas were identified in 28 dogs based on histologic examination of tissue. The average age of the dogs was 11 years, and 83% (20/24) were 10 years old or older. German shepherd and mixed breed were most common (31% each, 8/26). Grossly, meningiomas were oval, dome-shaped and flattened masses adherent to the dura and compressing the brain. Forty-eight percent (15/26) of the tumors affected the dorsal surface of the brain, and two thirds of these were located in the anterior half. Histologically, tumor types were transitional (13), meningiotheliomatous (11), angioblastic (three), and fibroblastic (one). There was direct invasion of the brain in 27% (6/22) although we observed neurologic signs and pathologic changes in 88% (23/26) and 90% (18/20) of the dogs, respectively. Intracranial menigioma can be compared and contrasted with this tumor in man and cats.
Cerebellar Vermian Hypoplasia in Dogs
Authors: Kornegay J. N.
Published: March 2010

Six dogs with cerebellar dysplasia, in which the cerebellar vermis was hypoplastic, are described. Clinical signs in these dogs were noted around 2 weeks of age and included ataxia, dysmetria, and intention tremors. A variable portion of the caudal cerebellar vermis was absent in each dog; portions of the cerebellar hemispheres and flocculus also were absent in some of them. Neurons in certain brain stem nuclei that project to the cerebellum were either chromatolytic or vacuolated. Cerebellar vermian hypoplasia of dogs is analogous to the Dandy-Walker syndrome of human beings.
Hereditary Myopathy in Labrador Retrievers: A Morphologic Study
Authors: McKerrell R. E. , Braund K. G.
Published: March 2010

Skeletal muscle and peripheral nerve were obtained over several years from 12 Labrador retrievers with signs of hereditary myopathy. Biopsy and necropsy samples were examined by histology and histochemistry. Despite normal findings in peripheral nerves, a wide range of morphologic changes were observed in muscle including features generally considered characteristic of neurogenic disease. These included small and large muscle fiber group atrophy, presence of small angular fibers, and occasional fiber type grouping. Other prominent changes in muscle were increased numbers of internal nuclei, architectural disturbances, type II fiber deficiency, necrosis, regeneration, and fibrosis—all of which are more usually associated with destructive myopathies or muscular dystrophies. The pathology of this condition, therefore, includes features of both neurogenic and myopathic disease, while the underlying pathophysiology remains unclear.
Generalized Amyloidosis in Rhesus Monkeys
Authors: Blanchard J. L. , Baskin G. B. , Watson E. A.
Published: March 2010

Necropsy materials from 57 cases of generalized amyloidosis in rhesus monkeys were reviewed. Clinically, animals with the disease were characterized by cachexia with muscle wasting, recurrent diarrhea, and arthritis. Gross lesions included hepatomegaly, splenomegaly, chronic/active colitis, fibrous strictures of the cecocolic junction, osteoarthritis, and generalized muscle atrophy. Histologic examination revealed minimal to severe deposits of amyloid in the small intestine (100%), spleen (93%), large intestine (67%), liver (40%), lymph nodes (71%), stomach and/or adrenal gland (32%). More amyloid was deposited in the spleen, liver, and small intestine than in other organs. Shigella sp. were isolated from feces in 23% of the cases and 84% had histologic evidence of colitis. Other findings indicated that 100% of the animals had lung mites, 25% had strictures of the cecocolic junction, and 40% had osteoarthritis. Thirty percent of the cases occurred in animals 10 months to 5 years of age, 10% in ages 6 to 10 years, and 60% in animals greater than 10 years old.
Immunohistochemical Detection of Canine Adenovirus in Paraffin Sections of Liver
Authors: Rakich P. M. , Prasse K. W. , Lukert P. D. , Cornelius L. M.
Published: March 2010

An avidin-biotin immunoperoxidase procedure was optimized for detection of canine adenoviral antigens in formalin-fixed, paraffin-embedded liver. Long-term stability of viral antigen was shown by successful demonstration of virus in liver tissue preserved up to six years from dogs with infectious canine hepatitis. This immunohistochemical stain was applied to sections from livers with a wide range of inflammatory lesions. Examination of sections from 53 dogs yielded five livers with small amounts of adenovirus. An additional virus-positive liver was identified from a dog with no hepatic inflammation. Although a cause and effect relationship remains to be determined, these findings suggest a possible connection between canine adenovirus and spontaneous chronic hepatitis.
Pathology of Vitamin D Deficiency in Growing Turkeys
Authors: Hedstrom O. R. , Cheville N. F. , Horst R. L.
Published: March 2010

Turkey poults were fed a vitamin D-deficient diet and examined for clinical signs and structural changes of bone and parathyroid glands. Vitamin D-deficient poults developed ricketic changes during days 10 to 14. Control poults (deficient diet plus vitamin D) did not develop rickets. In deficient poults, lengths of proliferating-prehypertrophied zones of growth plates increased significantly in the proximal tibiotarsus but were only slightly elongated in the distal tibiotarsus. Unmineralized hypertrophic chondrocyte zones increased in length rapidly in conjunction with a decrease in the length of mineralized hypertrophic degenerative zones; this occurred more rapidly in proximal than in distal tibiotarsus. Other ricketic changes included decreases in bone ash, total femoral bone ash (calcium, phosphorus, magnesium), bone length, and body weight. Plasma alkaline phosphatase was increased, calcium was normal, and phosphorus was normal or elevated. Parathyroids were hyperplastic and had foci of degeneration. Vitamin D3 metabolites 25OHD3, 1,25(OH)2D3, and 24,25(OH)2D3 were rapidly depleted. Increase in bone ash Ca/P ratios in deficient poults suggests that phosphorus may be selectively released from ricketic bone. Low 25OHD3 and 1,25(OH)2D3 of control poults early in the experiment suggests that 1,400 IU of vitamin D3/kg of feed may not be an adequate level of vitamin D3 for growing turkey poults.
Microcystin-LR-induced Ultrastructural Changes in Rats
Authors: Hooser S. B. , Beasley V. R. , Basgall E. J. , Carmichael W. W. , Haschek W. M.
Published: March 2010

The ultrastructure of hepatic, pulmonary, and renal lesions was evaluated in rats injected intraperitoneally with a lethal dose of microcystin-LR (MCLR, 160 μg/kg), a cyclic heptapeptide hepatotoxin produced by the blue-green algae, Microcystis aeruginosa. Hepatic lesions were first Seen at 10 minutes post-dosing and consisted of mild widening of hepatocyte intercellular spaces centrilobularly. At 20 minutes post-dosing, hepatocyte plasma membrane alterations were more pronounced, consisting of plasma membrane invagination with formation of variably sized and shaped intracytoplasmic vacuoles, loss of microvilli along the sinusoidal face, and widespread, pronounced hepatocyte separation. By 30 minutes, the space of Disse was markedly widened. At 60 minutes post-dosing, centrilobular areas contained necrotic cells and apparently intact, isolated, organelles intermingled with erythrocytes and platelets. In less severely affected regions there was prominent hepatocyte rounding, and erythrocytes and platelets were present in the widened space of Disse. Large amounts of hepatocellular debris and intact hepatocytes were present in the pulmonary vasculature, while smaller amounts of debris were also seen in the glomerular and peritubular capillaries of the renal cortex. This study shows that initial lesions are confined to Shape changes in the plasma membrane of hepatocytes. These changes are consistent with the hypothesis that microcystin-LR induces alterations in the hepatocyte cytoskeleton. Later changes consist of hepatocyte disassociation and necrosis, as well as endothelial damage, which allow release of hepatocytes and debris into the circulation with microembolism in lungs and kidneys.
Congenital Spinal Stenosis in Beef Calves in Western Canada
Authors: Doige C. E. , Townsend H. G. G. , Janzen E. D. , McGowan M.
Published: March 2010

Nineteen calves with a clinical history of posterior weakness or ataxia were examined at necropsy. Dorsoventral narrowing of the vertebral canal and myelopathy were found in the thoracic and lumbar areas of the spinal cord; vertebral metaphyseal growth plates had focal areas of premature closure. Malformation of the cranial base and hydrocephalus were also observed. Shortening of lung bones and malformation of long bone epiphyses were prominent findings and were associated with focal premature closure of metaphyseal growth plates. The cause of these lesions is unknown; possible causes, including a maternal deficiency of manganese, are discussed.
Ovine Mesangiocapillary Glomerulonephritis Type I and Crescent Formation
Authors: Frelier P. F. , Armstrong D. L. , Pritchard J.
Published: March 2010

Morphologic examination of four Finnish Landrace mixed-breed lambs, 27 to 35 days of age, affected with mesangiocapillary glomerulonephritis type 1, demonstrated a progressive glomerulonephritis. By 27 days of age, three lambs had crescents in 58 to 93% of glomeruli. These three lambs were also uremic. The accelerated rate of crescent formation was attributed to infiltrating polymorphonuclear leukocytes and monocytes, the result of discontinuities (gaps) in the glomerular basement membrane, and to the loss of the integrity of Bowman's capsule. In the three lambs, platelets were identified adjacent to the endothelium or denuded glomerular basement membrane. Two distinctly different types of crescents were noted, apparently dependent on the integrity of Bowman's capsule. One type resulted from the influx of inflammatory cells and dissociation of parietal epithelial cells from Bowman's capsule. The other type was more extensive and contained collagen and was associated with damage to Bowman's capsule resulting in cellular infiltration from the interstitium and sclerosis. Based on morphologic similarities, ovine mesangiocapillary glomerulonephritis is a suitable model for studying the pathogenesis and treatment of mesangiocapillary glomerulonephritis type 1 in human beings.
Enterocecocolitis Associated with IntraepithelialCampylobacter-like Bacteria in Rabbits (Oryctolagus cuniculus)
Authors: Schoeb T. R. , Fox J. G.
Published: March 2010

We examined 28 suckling, weanling, and young adult rabbits with lethargy, inappetence, and mucinous, semifluid feces. Sixteen of the rabbits had intestinal lesions. In eight of these rabbits, the primary changes were multifocal to diffuse epithelial proliferation and accumulation of lymphocytes, macrophages, or both in the lamina propria of the small intestine, cecum, and sacculated colon. In two of these rabbits, the accumulation of macrophages in the lamina propria was extensive. The other eight rabbits had erosive and suppurative cecocolitis, and four of the rabbits with proliferative lesions also had suppurative cecocolitis. In Warthin-Starry-stained sections of affected intestine, curved or spiral bacteria were visible within degenerated or hyperplastic epithelium, in luminal exudate, or in both. Such organisms were sparse or not found in the other 12 rabbits, which did not have intestinal lesions. The bacteria ultrastructurally resembled intraepithelial Campylobacter-like bacteria previously observed in proliferative enteritis in a variety of species and in acute typhlitis in young rabbits. In immunofluorescence tests, Campylobacter-like bacteria in epithelial cells, crypt lumina, and in luminal exudates in both proliferative and erosive lesions bound monoclonal antibodies and polyclonal antisera prepared against intracellular bacteria found in proliferative enteritis in pigs, hamsters, and ferrets. These observations indicate that a condition similar to proliferative enteritis of swine, hamsters, and other species also occurs in laboratory rabbits.
Hepatic Copper Concentrations in Purebred and Mixed-breed Dogs
Authors: Thornburg L. P. , Rottinghaus G. , McGowan M. , Kupka K. , Crawford S. , Forbes S.
Published: March 2010

Histomorphologic, histochemical, and atomic absorption analysis studies were performed on liver tissue from 623 clinically normal purebred and mixed-breed dogs to assess the range of hepatic copper concentrations, the histologic distribution of copper, and the histomorphologic changes associated with the various copper concentrations that were found. Atomic absorption analysis revealed a continuous numerical spectrum ranging from less than 100 parts per million on a dry weight basis (ppm dw) to more than 2,000. No decisive numerical criterion was found that could be used to separate normal from abnormal copper concentrations because of this continuous array. The threshold for histochemical demonstration of copper-containing granules using rhodanine or rubeanic acid staining was 400 ppm dw. At this concentration the copper-containing granules were located in the centrilobular hepatocytes (zone 3 of Rappaport). Copper-containing granules were found in the midzonal and periportal hepatocytes (zones 2 and 1 of Rappaport) in livers with 1,000 ppm dw and higher copper concentrations. The majority of the 623 livers were normal histomorphologically. Multifocal hepatitis characterized by mixed inflammatory cell accumulation and centrilobular distribution was found to be associated with copper concentrations in the range of 2,000 ppm dw or higher. An appropriate upper limit for normal hepatic copper concentration in the dog was not determined based on the present study.
Purine Metabolism in Feline Lymphomas
Authors: Copelan E. A. , Waddell K. S. , Johnson S. C. , Mathes L.
Published: March 2010

Deficiency of the purine metabolic enzyme adenosine deaminase causes severe immunodeficiency. Retroviruses have been reported to decrease the activity of adenosine deaminase, and many retroviruses, including feline leukemia virus, cause immunodeficiency. Levels of purine metabolic enzymes including adenosine deaminase and consequences of adenosine deaminase inhibition were investigated in feline leukemia virus-infected fresh tumor cells and infected and uninfected cell lines. No evidence of virus effect on levels of adenosine deaminase or other purine metabolic enzymes was detected. Neoplastic cells demonstrated considerable heterogeneity of activity levels of purine metabolic enzymes.
Immunohistochemical Localization ofPasteurella haemolyticaAl-derived Endotoxin, Leukotoxin, and Capsular Polysaccharide in Experimental Bovine Pasteurella Pneumonia
Authors: Whiteley L. O. , Maheswaran S. K. , Weiss D. J. , Ames T. R.
Published: March 2010

Six, 5- to 10-week-old male Holstein calves were inoculated intratracheally with 5 × 10′ logarithmic growth phase Pasteurella haemolytica biotype A serotype 1 (A1). Immunohistochemical techniques in conjunction with the use of monoclonal antibodies directed against P. haemolytica A1-derived lipopolysaccharide (LPS), capsular polysaccharide, and a polyclonal rabbit anti-leukotoxin antibody were used to localize their respective antigens in tissue sections of pneumonic lung at the light and electron microscopic levels. We found the following: 1) LPS, capsular polysaccharide, and leukotoxin were released into the inflammatory exudate; 2) LPS was found within the cytoplasm of neutrophils (located in the alveolus and alveolar wall), alveolar macrophages, endothelial cells, pulmonary intravascular macrophages, and on epithelial cell surfaces; 3) capsular polysaccharide was found in the alveolus and alveolar macrophages but not in cells of the alveolar wall; and 4) leukotoxin was associated with cell membranes of degenerating inflammatory cells located in the alveolus. This is the first study that demonstrates the presence of leukotoxin in the pulmonary inflammatory lesions caused by P. haemolytica A1 and implicates endotoxin as an important factor in the genesis of the pulmonary lesions.
Diphenylamine-induced Renal Papillary Necrosis and Necrosis of the Pars Recta in Laboratory Rodents
Authors: Lenz S. D. , Carlton W. W.
Published: March 2010

The nephrotoxicity of diphenylamine, the parent compound of the mefenamate family of non-steroidal anti-inflammatory drugs, was evaluated in male Syrian hamsters, male Sprague-Dawley rats, and male Mongolian gerbils. Total renal papillary necrosis was observed in four of ten, seven of ten, and six of ten male Syrian hamsters orally treated with diphenylamine at respective doses of 400 mg/kg body weight/day, 600 mg/kg body weight/day, and 800 mg/kg body weight/day. Total renal papillary necrosis was also observed in five of ten and four of ten male Syrian hamsters intraperitoneally treated with diphenylamine at respective doses of 600 mg/kg body weight/day and 800 mg/kg body weight/day. Focal intermediate renal papillary necrosis was induced in two hamsters orally given diphenylamine at 600 mg/kg body weight/day and in two of ten hamsters intraperitoneally given diphenylamine at 800 mg/kg body weight/day. Apex-limited necrosis of the medullary interstitial cells and vasa recta and degeneration of the renal interstitial matrix occurred in two Sprague-Dawley rats orally administered diphenylamine at 800 mg/kg body weight/day. Degeneration and necrosis of the pars recta was induced in seven of ten hamsters intraperitoneally given diphenylamine at 400 mg/kg body weight/day. Gross and microscopic renal lesions were not observed in any Mongolian gerbils. It was concluded that the Syrian hamster is more susceptible to the papillotoxic effects of diphenylamine than the Sprague-Dawley rat and the Mongolian gerbil. Renal papillary necrosis in the Syrian hamster treated orally with diphenylamine is reproducible, is of short onset, and is induced in a high proportion of the hamsters (70-90%). When administered diphenylamine, the male Syrian hamster may prove useful as an alternative experimental rodent model of non-steroidal, anti-inflammatory, drug-induced renal papillary necrosis.
Morphometric Analyses of the Skin of Dogs with Atopic Dermatitis and Correlations with Cutaneous and Plasma Histamine and Total Serum IgE
Authors: Nimmo Wilkie J. S. , Yager J. A. , Eyre P. , Parker W. M.
Published: March 2010

In order to improve the diagnostic value of histopathologic examination of skin biopsy samples from dogs with atopic dermatitis and, perhaps, to identify any differences from the normal state that may predispose to this skin condition, we compared the anatomic and cellular morphology of skin from three standard sites in 21 normal and 15 atopic dogs. The standard sites were lateral neck, dorsal rump, and craniolateral abdomen. No differences between the two groups were found in the means of area or thickness of the stratum corneum or the remainder of the epidermis at any site. The area of sebaceous glands, but not apocrine sweat glands, was larger in the atopic group ( P ≤ 0.05 for the lateral neck skin and P < 0.1 for the dorsal rump skin). The mean number of non-metachromatic mononuclear cells in combined skin samples (126 μm2) in atopic dogs (91.0 ± 28.7) was significantly greater ( P ≤ 0.01) than for the control normal dogs (65.3 ± 19.3); the mean number of mast cells in atopic dogs (12.39 ± 6.44) was similarly greater than in the controls (8.48 ± 5.14; P ≤ 0.1). Eosinophils were significantly increased in atopic dog skin ( P ≤ 0.01), with the mean for all three sites combined of 0.81 ± 0.90 compared with a mean of 0.06 ± 0.15 for normal dogs. Numbers of circulating blood eosinophils were not significantly different in the atopic and normal group. Plasma histamine concentrations of 15.3 ± 7.8 for the atopics and 14.3 ± 4.1 for the normal dogs were not significantly different, although they were very high when compared to human values. Cutaneous histamine concentrations were always greater in the atopic dogs, although the difference was significant for only two of the three skin sites ( P ≤ 0.05). Plasma histamine concentrations did not correlate with those of cutaneous histamine. There was a very good correlation between mast cell numbers and cutaneous histamine concentrations ( r = 0.84). Total serum IgE levels were not significantly different in atopic and normal dogs, although the means, 182.6 ± 112.4 (normal) and 195.4 ± 108.8 (atopic), are high when compared to serum concentrations in human beings. There was no correlation between serum IgE concentrations and those of plasma histamine. By confirming that numbers of cutaneous mast cells, non-metachromatic mononuclear cells, and eosinophils are significantly increased in the skin of atopic dogs in comparison to that of normal dogs, these data increase the validity of using such criteria for diagnostic purposes.
Islet Amyloid Polypeptide and Calcitonin Gene-related Peptide Immunoreactivity in Amyloid and Tumor Cells of Canine Pancreatic Endocrine Tumors
Authors: O'Brien T. D. , Westermark P. , Johnson K. H.
Published: March 2010

Seven canine pancreatic endocrine tumors were evaluated immunohistochemically for the presence of islet amyloid polypeptide (IAPP), calcitonin gene-related peptide (CGRP), and several other pancreatic hormones. Four tumors contained cells with IAPP immunoreactivity, and four had cells with CGRP immunoreactivity. IAPP and CGRP immunoreactivities were localized to distinctly different cell populations in three tumors in which both peptides were detected; however, IAPP immunoreactivity consistently was found in cells that also contained insulin immunoreactivity. Amyloid deposits, which were found in three of the seven tumors, showed strong immunoreactivity with antiserum against IAPP and weaker immunoreactivity with antiserum to CGRP. These results indicate that amyloid deposits in canine pancreatic endocrine tumors are likely derived from IAPP, as is amyloid found in human pancreatic endocrine tumors and pancreatic islet amyloid in aged and diabetic persons and cats.