Variation in the immuno-pathological responses of lambs after experimental infection with different strains of Mycobacterium avium subsp. paratuberculosis

Ruminant infection by Mycobacterium avium subsp. paratuberculosis (MAP) causes a granulomatous inflammatory response in the intestine and associated lymph nodes. Differences either in the affected organs or in the inflammatory infiltrate were observed between species and individuals. Such differences are usually attributed to variations in host immune responses or to inconsistent effects among different MAP strains. To evaluate if different MAP strains induce different immuno-pathological responses in lambs, 28 one-month-old individuals were divided into six groups and inoculated with different MAP strains. Groups 1 and 2 were inoculated with two bovine strains isolated in Argentina that showed different genetic patterns after BstEII-IS900-RFLP (hereafter strains E and A respectively). Group 3 was inoculated with a bovine strain isolated in Spain obtained after a previous step of culture (patterns C1). Group 4 was inoculated with a homogenate of intestinal mucosa of a clinical case affected by the same bovine strain as that of group 3. Group 5 was inoculated with an ovine strain that was directly purified from the intestinal mucosa of a clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral immune responses were assessed until 150 days post-infection (dpi), when lambs were humanely killed. Pathological studies were performed in tissues from the intestine and lymph nodes. Lesion types and inflammatory infiltrates were examined as indicators of pathogenicity. All the lambs infected with bovine MAP strains showed a common lesion pattern regardless of the strain type. Such pattern was characterized by focal lesions mainly in the mesenteric lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the granulomas as well as the presence of numerous giant cells. Differences in lesion severity were observed among groups: lambs from groups 1 and 2 had the highest number of granulomas and the largest lymph node area affected. Lesions in animals from group 5 (infected with an ovine strain) were more severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis or giant cells were never detected in this group. These results indicate that the MAP strain type induces different pathological responses in lambs.     

Relationships between clinical signs, pathological changes and tissue distribution of Mycobacterium avium subspecies paratuberculosis in 21 cows from herds affected by Johne's disease

Twenty-one cows from eight herds affected by Johne's disease were assigned to four groups: seven were not thriving and had persistent diarrhoea, six were not thriving and had intermittent diarrhoea, four were not thriving but did not have diarrhoea, and four were clinically normal. Postmortem, macroscopic lesions consistent with Johne's disease were identified in 17 of the cows and Mycobacterium avium subspecies paratuberculosis (MAP) was isolated from all of them. However, except for the fact that diarrhoea was correlated with the presence of lesions in the large intestine there was little correlation between the presence or absence of clinical signs and the lesions associated with Johne's disease. The tissue distribution of MAP was also poorly correlated with either the clinical signs or the lesions. The organism was widely distributed in 17 of the 21 cows, including three of the clinically normal animals, and was present in the mammary tissues of seven cows including two of the clinically normal animals. Three distinct histopathological patterns were observed in the affected intestines: infiltration of the lamina propria with giant cells, tuberculoid lesions, and lepromatous lesions; the lepromatous lesions were associated with extensive pathological changes.     

Clinical signs, imaging features, neuropathology, and outcome in cats and dogs with central nervous system cryptococcosis from California

Background: Cryptococcus spp. is a fungal pathogen with a predilection for the central nervous system (CNS). Objectives: To compare the clinical, advanced imaging, and neuropathologic findings in dogs and cats with CNS cryptococcosis, and to evaluate outcome of treatment in these animals. Animals: Twenty‐six cats and 21 dogs with CNS cryptococcosis. Methods: Medical records were reviewed for clinical findings and results of CNS imaging. Archived cerebrospinal fluid and CNS tissue specimens were reviewed for pathology. Findings in cats were compared with those in dogs and the effects of variables on survival were determined by survival curve analysis. Results: When present, pain was localized to the cervical region in dogs and was generalized or localized to the thoracolumbar spine or pelvic limbs in cats. Magnetic resonance imaging (MRI) findings were variable but correlated with CNS histopathological findings of meningitis, meningitis with gelatinous pseudocyst formation, and granulomatous mass lesions. Peripherally enhancing brain lesions were seen only in cats. Histopathologically, the inflammatory response was milder in cats compared with dogs. Remissions of ≥1 year occurred in 32% of treated animals. Altered mentation was associated with negative outcome. Glucocorticoid use after diagnosis was associated with improved survival in the first 10 days. Conclusions and Clinical Importance: Lesions seen on MRI reflected neuropathological findings and were similar to those reported in human patients. The immune response to infection may differ between cats and dogs, or relate to the infecting cryptococcal species. Long‐term (>6 month median survival time) survival may be possible in animals surviving ≥4 days after diagnosis.     

Equine sarcoidosis: clinical signs,diagnosis, treatment and outcome of 22 cases

Background –  Equine sarcoidosis may present as a generalized or localized exfoliative dermatitis and/or as a granulomatous inflammation of multiple organs. Objectives –  To report the clinical signs, diagnosis, treatment and outcome for 22 horses with histologically confirmed sarcoidosis. Animals –  Twenty‐two horses of different breeds, between 3 and 17 years of age. Methods –  Diagnosis was based on clinical signs and histopathological findings. Results –  The following three forms of equine sarcoidosis were identified: generalized (13.6%), partially generalized (18.2%) and localized (68.2%). High‐dose systemic corticosteroids were used as the initial treatment in all three forms, followed by lower doses for a variable number of weeks. No local treatment was prescribed. Case outcome was variable; one of three cases of generalized sarcoidosis was euthanized immediately and the remaining two were euthanized after 2–3 months of unsuccessful treatment; all four cases of partially generalized sarcoidosis deteriorated despite treatment and were euthanized after 3.5–12 months; two cases with localized disease showed no response or insufficient response to treatment and were euthanized; four cases recovered fully with or without treatment, and one showed partial recovery without treatment; and eight cases improved whilst receiving prednisolone but required continuous low doses to maintain remission. Conclusions and clinical importance –  Recognition of the different forms of sarcoidosis based on history, clinical appearance and histopathology assisted in making an informed choice between treatment and euthanasia and prevented unnecessary local treatment. Equine sarcoidosis should be included in the differential diagnosis of a localized exfoliative dermatitis of unknown origin.     

Pathological findings in a natural outbreak of aflatoxicosis in dogs

The gross and histopathological lesions of 10 cases in a natural outbreak of aflatoxicosis amongst dogs in the Republic of South Africa are reported. The 10 cases were classified as acute (1 case), subacute (7 cases) and chronic (2 cases) on the basis of the nature, degree and extent of the following histopathological fractures: hepatocellular fatty degeneration, necrosis or regeneration; proliferation of bile ductules; accumulation of bile within the canaliculi; fibroplasia; and, mucoid degeneration, necrosis or segmental atrophy of the larger intrahepatic bile ducts. Fatty degeneration was noted grossly in the livers of all 10 cases and bile stasis in 4. Varying degrees of fibrosis were present depending on the stage of the disease. In the 2 chronic cases in which nodular regeneration was also observed fibrosis was pronounced. Other macroscopic findings included icterus, anaemia, ascites, hydrothorax, hydropericardium, anasarca, pulmonary oedema, gastro-enterorrhagia and nephrosis.     

Chronic pancreatitis in dogs: A retrospective study of clinical,clinicopathological, and histopathological findings in 61 cases

The objective of this study was to characterize the clinical, clinicopathological, and histopathological findings of dogs with chronic pancreatitis. The necropsy database at Texas A&M University was searched for reports of dogs with histological evidence of chronic pancreatitis defined as irreversible histologic changes of the pancreas (i.e. fibrosis or atrophy). A reference necropsy population of 100 randomly selected dogs was used for signalment and concurrent disease comparisons. Cases were categorized as clinical or incidental chronic pancreatitis based on the presence of vomiting, decreased appetite, or both vs. neither of these signs. All archived pancreas samples were scored histologically using a published scoring system.Sixty-one dogs with chronic pancreatitis were included. The most frequent clinical signs were lethargy, decreased appetite, vomiting, and diarrhea. Compared to the reference necropsy population, chronic pancreatitis cases were more likely to be older, neutered, of the non-sporting/toy breed group, and to have concurrent endocrine, hepatobiliary, or neurological disease. Clinical cases had significantly higher histological scores for pancreatic necrosis and peripancreatic fat necrosis, and were significantly more likely to have hepatobiliary or endocrine disease as well as increased liver enzyme activities, or elevated cholesterol and bilirubin concentrations. In conclusion, clinical disease resulting from chronic pancreatitis might be related to the presence of pancreatic necrosis and pancreatic fat necrosis. The signalment, presentation, and concurrent diseases of dogs with chronic pancreatitis are similar to those previously reported for dogs with acute pancreatitis.     

Alterations of epidermal proliferation and cytokeratin expression in skin biopsies from heavy draught horses with chronic pastern dermatitis

We report the historical, clinical and histopathological characteristics of skin lesions in biopsies from 37 heavy draught horses with chronic pastern dermatitis. The skin lesions were divided into four macroscopic groups: scaling (group I, n=5), hyperkeratotic and hyperplastic plaque-like lesions (group II, n=14), nodular skin masses (group III, n=16) and verrucous skin lesions (group IV, n=2). The principal histological findings were hyperkeratosis and epidermal hyperplasia. There was a gradual increase in epidermal hyperplasia from groups I to IV, suggesting that the lesions represent different stages of disease. In all cases, there was perivascular dermatitis dominated by T lymphocytes with an increase in MHC class II-positive dendritic-like cells. Immunohistochemical labelling for cytokeratins CK5/6(4), CK10 and CK14 indicated a change in their expression pattern. This correlated with the degree of epidermal hyperplasia, indicating abnormal differentiation of keratinocytes. There was a statistically significant correlation between the severity of skin lesions and several other factors including increasing age, increasing cannon circumference, prominence of anatomical structures such as fetlock tufts of hairs, ergots and chestnuts, and bulges in the fetlock region.     

Necrotizing meningoencephalitis in five Chihuahua dogs

An acute to chronic idiopathic necrotizing meningoencephalitis was diagnosed in 5 Chihuahua dogs aged between 1.5 and 10 years. Presenting neurologic signs included seizures, blindness, mentation changes, and postural deficits occurring from 5 days to 5.5 months prior to presentation. Cerebrospinal fluid analyses from 2 of 3 dogs sampled were consistent with an inflammatory disease. Magnetic resonance imaging of the brain of 2 dogs demonstrated multifocal loss or collapse of cortical gray/white matter demarcation hypointense on T1-weighted images, with T2-weighted hyperintensity and slight postcontrast enhancement. Multifocal asymmetrical areas of necrosis or collapse in both gray and white matter of the cerebral hemispheres was seen grossly in 4 brains. Microscopically in all dogs, there was a severe, asymmetrical, intensely cellular, nonsuppurative meningoencephalitis usually with cystic necrosis in subcortical white matter. There were no lesions in the mesencephalon or metencephalon except in 1 dog. Immunophenotyping defined populations of CD3, CD11d, CD18, CD20, CD45, CD45 RA, and CD79a immunoreactive inflammatory cells varying in density and location but common to acute and chronic lesions. In fresh frozen lesions, both CD1b,c and CD11c immunoreactive dendritic antigen-presenting cells were also identified. Immunoreactivity for canine distemper viral (CDV) antigen was negative in all dogs. The clinical signs, distribution pattern, and histologic type of lesions bear close similarities to necrotizing meningoencephalitis as described in series of both Pug and Maltese breed dogs and less commonly in other breeds.     

Neurological disease in cattle in southern Brazil associated with Bovine herpesvirus infection.

The occurrence of neurological disease in cattle caused by Bovine herpesvirus in 11 farms from southern Brazil between 1987 and 2007 is described. Twenty-two animals were necropsied. Major clinical signs included excessive salivation, nasal and ocular discharge, circling, recumbency, depression, incoordination, grinding of teeth, and paddling movements. Necropsy findings in 10 of 22 cattle included hyperemia and softening of the rostral portions of the telencephalic cortex, with flattening of gyri, and malacia. Cattle in 10 cases did not show any gross lesions. Histological examination in most cases revealed nonsuppurative and necrotizing meningoencephalitis with acute neuronal necrosis, edema, eosinophilic intranuclear inclusion bodies in astrocytes and neurons, and infiltration of gitter cells. No histologic lesions could be detected in 4 cases. The initial diagnosis was based upon the clinical, epidemiological, and pathological findings. The diagnosis was confirmed by virus isolation in cell culture followed by virus identification by a glycoprotein C-based polymerase chain reaction. Seven isolates were identified as Bovine herpesvirus 5, and 4 were identified as Bovine herpesvirus 1.     

Evaluation of disease activity markers in dogs with idiopathic inflammatory bowel disease

OBJECTIVES: To evaluate the clinical utility of serum tumour necrosis factor-alpha, C-reactive protein and microalbuminuria as disease activity markers in canine idiopathic inflammatory bowel disease. METHODS: Dogs with chronic gastrointestinal disease for which no underlying cause could be identified were considered to have idiopathic inflammatory bowel disease and were included in the study. Serum tumour necrosis factor-alpha was assessed using a canine-specific ELISA, C-reactive protein by immunoturbidometric assay and quantitative microalbuminuria was analysed using a monoclonal antibody directed against canine albumin. The canine inflammatory bowel disease activity index and histopathologic grade were used to assess disease severity; biologic markers were then compared with the canine inflammatory bowel disease activity index and histopathologic grade. RESULTS: Sixteen dogs were included in the study. C-reactive protein level was mildly elevated in 15 dogs. Microalbuminuria was elevated in two of 15 dogs, and tumour necrosis factor-alpha was not detected in any dog tested. No correlation was found between the canine inflammatory bowel disease activity index and C-reactive protein or microalbuminuria or between histopathologic grade and C-reactive protein or microalbuminuria. There was no correlation between histopathologic grade and the canine inflammatory bowel disease activity index. CLINICAL SIGNIFICANCE: Although only a small number of dogs were evaluated, this study does not support the use of serum tumour necrosis factor-alpha measured by canine-specific ELISA or microalbuminuria in the evaluation of disease activity in dogs with idiopathic inflammatory bowel disease. Although mildly elevated in most dogs, C-reactive protein did not reflect disease severity as assessed by the canine inflammatory bowel disease activity index or histopathologic grade.     

Immunopathological studies on feline cutaneous and (muco)cutaneous mycobacteriosis

Eight cases of feline (muco)cutaneous mycobacteriosis were studied to identify the causative agent and examine for phenotype and functional characteristics (expression of interleukin (IL)-1beta, IL-6, IL-12, tumour necrosis factor-alpha and inducible nitric oxide synthase) of the inflammatory cells. Polymerase chain reaction and sequencing identified the causative agents as Mycobacterium tuberculosis or M. avium complex in each four cases. Lesions were characterised by pyogranulomatous infiltration, with variability in the presence and size of necrotic areas, the presence of multinucleated giant cells and the degree of lymphocyte infiltration. Macrophages were positive for myeloid/histiocyte antigen (calprotectin), suggesting they represented freshly recruited monocytes; further differentiation to epithelioid cells and multinucleated giant cells was associated with loss of the myeloid/histiocyte antigen. Lymphocytes were found disseminated in the infiltrate (predominantly T cells) and as B cell-dominated accumulations mainly in the periphery of the lesions. Acid-fast bacilli were numerous. In M. tuberculosis complex infection, extracellular bacilli were most prominent, whereas in M. avium complex infection, bacilli were mainly located intracellularly. All cytokines examined as well as inducible nitric oxide synthase (iNOS) were variably expressed by macrophages, epithelioid cells and multinucleated giant cells. Expression was most intense in degenerating macrophages loaded with intracellular bacilli, but was also seen cell-free within necrotic areas. The intense induction of cytokine and iNOS expression especially in infected macrophages suggests a relatively low virulence for these infectious agents in cats. Furthermore, the confinement of the bacilli to lesions indicates a successful response to infection.     

Feline esophagitis secondary to gastroesophageal reflux disease: clinical signs and radiographic,endoscopic, and histopathological findings

Chronic esophagitis due to gastroesophageal reflux (GER) is rarely reported in the cat. This paper describes the clinical signs and diagnostic findings, including radiographic, endoscopic, and histopathological abnormalities, in three young, purebred, male cats with esophagitis presumed to be secondary to GER. Clinical signs included regurgitation, dysphagia, and weight loss. Contrast radiography revealed GER, esophageal dilatation, and decreased motility. Endoscopy showed hyperemia, increased vascularity, ulcers, erosion, and an abnormal lower esophageal sphincter. Histopathological lesions included squamous hyperplasia and dysplasia, erosions, ulcers, and an inflammatory infiltrate of lymphocytes, plasma cells, and neutrophils. Long-term follow-up demonstrated progression of the disease in two of the cats.     

Correlation between fine-needle aspiration cytopathology and histopathology of the lung in dogs and cats

Medical records from 28 patients having fine-needle aspiration (FNA) cytopathology and histopathology of pulmonary lesions were reviewed. Clinical signs, thoracic radiographs, cytopathology, histopathology, and complications associated with FNA were evaluated. Correlation between cytopathological and histopathological diagnoses was determined. Cytopathological specimens were classified as neoplastic, inflammatory, or nondiagnostic. Histopathological diagnoses were categorized as neoplastic or inflammatory. No complications were observed following FNA. Diagnoses obtained by FNA cytopathology accurately reflected the diagnosis obtained on histopathological examination in 82% of cases. Fine-needle aspiration cytopathology of the lung is a useful and safe diagnostic tool in dogs and cats with pulmonary parenchymal lesions.     

Inflammation induced by subcutaneous turpentine inoculation of young American alligators (Alligator mississippiensis)

Turpentine-induced skin lesions in young American alligators (Alligator mississippiensis) kept at 25 C were used to study inflammatory response in a reptile. Skin harvested at intervals between 4 hours and 30 days after inoculations were done had no gross changes until days 24 to 26, when superficial skin necrosis was evident. Early responses of congestion and dermal edema (4 to 8 hours) were seen by light microscopy, and these were followed by necrosis and granulocyte migration (1 to 3 days). Later, there was predominance of monocytic cells, including vacuolated macrophages (7 to 30 days). Evident at 14 days and prominent by day 30 were central dermal zones of necrotic debris surrounded by orderly palisades of vacuolated multinucleated giant cells and capillary-laden immature fibrous connective tissue. Systemic illness or visceral lesions were not observed. Controls, given inoculations of sterile saline solution, had no gross or microscopic changes.     

Evidence of porcine circovirus infection in pigs with wasting disease syndrome from 1985 to 1999 in Hokkaido, Japan

An epizootiological survey with histopathological methods was conducted for porcine circovirus in 220 diseased pigs (1-200 days old) in 49 farms from 1985 to 1999. Histopathological lesions containing PCV antigen were detected mainly in the lymphoid tissues from 42 of 189 diseased pigs (22.2%) in 4 of 45 farms (8.9%) from 1990 to 1999. The rate of positive pigs gradually increased from 1997 onward and PCV infection was found in 50% of diseased pigs in 1999. Histopathologically, the lesions in the lymphoid tissues (including lymph nodes, Peyer's patches, tonsil and spleen) were highly correlated with the presence of numerous spherical basophilic intracytoplasmic inclusion bodies with PCV antigen, and consisted of lymphocellular depletion and infiltration of macrophages. Although most affected cells showed cytoplasmic reactivity for PCV, intranuclear antigen was also seen in the lymphocytes, macrophages and ileal epithelial cells. Ultrastructurally, macrophages and giant cells contained electron-dense, round to ovoid lysosomal bodies, in which there were concentric circle or paracrystalline arrays of small nonenveloped icosahedral viral particles, approximately 15-17 nm in diameter. Other consistent infectious agents were present in 90.5% of cases, and porcine reproductive and respiratory syndrome virus infection was in 52.4% of the cases with PCV. The histopathological findings suggested that PCV induced systemic immunosuppression in the infected pigs and made them more susceptible to infection of the organisms. Because of the presence of PCV antigens in the intestinal epithelium, feces may play a significant role in dissemination of PCV.     

CLINICAL AND MAGNETIC RESONANCE IMAGING FEATURES OF INFLAMMATORY VERSUS NEOPLASTIC MEDIAL RETROPHARYNGEAL LYMPH NODE MASS LESIONS IN DOGS AND CATS

Medial retropharyngeal lymph node (MRLN) mass lesions are a common cause of cranial cervical masses in dogs and cats, and are predominantly due to metastatic neoplasia, primary neoplasia, or inflammatory lymphadenitis. The purpose of this retrospective cross‐sectional study was to test the hypothesis that clinical and magnetic resonance imaging (MRI) characteristics for dogs and cats with MRLN mass lesions would differ for inflammatory vs. neoplastic etiologies. Dogs and cats with MRLN mass lesions that had undergone MRI and had a confirmed cytological or histopathological diagnosis were recruited from medical record archives. Clinical findings were recorded by one observer and MRI characteristics were recorded by two other observers who were unaware of clinical findings. A total of 31 patients were sampled, with 15 in the inflammatory lymphadenitis group and 16 in the neoplasia group. Patients with inflammatory lymphadenitis were more likely to be younger and present with lethargy (P = 0.001), pyrexia (P = 0.000), and neck pain (P = 0.006). Patients with inflammatory lymphadenitis were also more likely to have a leukocystosis (P = 0.02) and segmental neutrophilia (P = 0.001). Inflammatory masses were more likely to have moderate or marked MRI perinodal contrast enhancement (P = 0.021) and local muscle contrast enhancement (P = 0.03) whereas the neoplastic masses were more likely to have greater MRI width (P = 0.002) and height (P = 0.009). In conclusion, findings indicated that some clinical and MRI characteristics differed for dogs and cats with inflammatory vs. neoplastic medial retropharyngeal lymph node masses. Although histopathological or cytological diagnosis remains necessary for confirmation, these findings may help with the ranking of differential diagnoses of future cases.     

Epizootic cutaneous pythiosis in beef calves

Enzootic bovine granulomatosis (EBG) is a disease that affects beef calves in the flooded Savanna regions of Venezuela. Although Pythium insidiosum was originally the suspected etiologic agent, nothing was done to demonstrate its presence in the infected animals. The objective of this study was to investigate the etiologic agent causing cutaneous lesions in a group of 63 calves diagnosed with EBG. The collected samples were analyzed by histopathology, immunohistochemistry, serology, and mycological techniques. The clinical manifestations of BEG included ulcerated and swollen granulomatous lesions on the limbs of young calves. Histopathological studies revealed an eosinophilic inflammatory reaction with neutrophils, giant cells and branching hyphae with the Splendore-Hoeppli phenomenon. Immunofluorescence analysis identified the branching hyphae as elements of the fungal-like organism P. insidiosum. Wet mounts in 10% KOH revealed hyaline slender branching hyaline coenocytic hyphae, but cultures from those samples were negative. Anti-P. insidiosum immunoglobulins were also demonstrated in the collected sera of the affected bovines using latex agglutination, immunodiffusion, ELISA, and Western Blot. The histopathological, immunohistochemical, and serological tests showed for the first time that P. insidiosum could be involved in epizootic bovine pythiosis.     

Sporotrichosis: the main differential diagnosis with tegumentary leishmaniosis in dogs from Rio de Janeiro, Brazil

Seventy-four dogs from the State of Rio de Janeiro with ulcerated cutaneous lesions were submitted to clinical, dermatological, parasitological, mycological, histopathological and cytopathological exams, a leishmanin skin test, an indirect immunofluorescence (IIF) test for leishmaniosis, and nonspecific laboratory tests such as blood count and serum biochemistry. Sporothrix schenckii was isolated from 41 dogs and Leishmania (Viannia) braziliensis was isolated from 33 animals. Most dogs with sporotrichosis were from the municipality of Rio de Janeiro (53.7%) and presented ulcerated cutaneous lesions on the head (68.3%). Laboratory alterations in these animals included anemia (58.5%), hypoalbuminemia (83%) and hyperglobulinemia (75.6%). Histopathology revealed the predominance of a chronic granulomatous inflammatory infiltrate (70.7%), and yeast-like structures were detected in 17% of the histopathological exams and in 32% of the cytological exams. Three of 41 dogs with sporotrichosis were seropositive by IIF for leishmaniosis and 2 of 20 animals tested within this group had a positive leishmanin skin test. Similarly, most of the 33 dogs with leishmaniosis were from the municipality of Rio de Janeiro (69.7%) and had ulcerated cutaneous lesions on the head (84.8%). Laboratory alterations in these animals included anemia (66.7%), hypoalbuminemia (100%) and hyperglobulinemia (91%). Histopathology showed the predominance of a chronic granulomatous inflammatory infiltrate (63.6%) and amastigote forms were detected in 30.3% of the histopathological exams and in 31.8% of the 22 cytological exams performed. About 72.7% of the dogs were seropositive by IIF and five of seven animals had a positive skin test. Due to the clinical similarities, histopathological and nonspecific laboratory results similarities, the serological and skin tests for leishmaniosis positive in dogs with sporotrichosis, and the overlapping endemic areas in Rio de Janeiro, the differential diagnosis between the two diseases requires the demonstration of their respective etiological agents.     

Multidisciplinary approach in the diagnosis of acute leptospirosis in dogs naturally infected by Leptospira interrogans serogroup Icterohaemorrhagiae: A prospective study

Leptospirosis, a zoonotic disease with worldwide distribution, is caused by spirochetes of the genus Leptospira. In dogs, this disease is frequently misdiagnosed. Few studies have attempted to associate the detection of Leptospira spp. infection with clinicopathological and renal histopathological findings using a multidisciplinary approach. The present study isolated and characterized Leptospira spp. obtained from naturally infected dogs and described relevant clinical and histopathological findings. Blood and urine were collected from 57 dogs with clinical symptomatology suggestive of leptospirosis; 38 cases were confirmed by PCR in urine or by culture or microscopic agglutination testing (titers ≥800). A total of 12 strains of pathogenic Leptospira were isolated from the studied dogs (seven in blood, four in urine and one in both blood and urine samples). All isolates were characterized as Leptospira interrogans serogroup Icterohaemorrhagiae. Of the confirmed cases, almost one-third of the animals had been vaccinated. Our analysis of laboratory testing revealed that azotemia and proteinuria were statistically significant predictors of infection. The main histopathological findings seen in kidney tissues were necrosis, degeneration, tubular regeneration, mononuclear inflammatory infiltrate and congestion. A multidisciplinary approach involving clinicopathological and histopathological characterization of renal involvement can aid in the identification of acute leptospirosis infection.