Veterinary Pathology Laboratory Research Articles

Prevalence of nematode parasite, Contracaecum, in Nile tilapia, African catfish and Barbus species in Lake Hawassa, Ethiopia

A cross-sectional study was conducted from November 2017 to March 2018 at Lake Hawassa to determine the prevalence of larval Contracaecum infestation in Nile tilapia, (Oreochromis niloticus), African Catfish (Clarias gariepinus) and Barbus species (Barbus intermedius). Fifty-two point six per cent (52.6%) previous prevalence and 5% precision were used to estimate the sample size. Accordingly, a total of 383 randomly sampled fish species comprising of 163 (42.6%) C. gariepinus, 159 (41.5%) O. niloticus and 61(15.9%) B. intermedius were examined. The length and weight of each sampled fish were recorded. All the sampled fish were examined for the evidence of Contracaecum parasites in Hawassa University Veterinary Parasitology and Pathology Laboratory. Chi-square values and comparison of proportions were used to analyse the data. The overall prevalence of Contracaecum parasites of fish population was 31.6%. The distribution of parasite was significantly affected by fish species (p = .000), sexes (p = .018), length (p = .003) and weight classes of fish (p = .026). As a hygienic problem and gutting activity conducted at the sides of the Lake Hawassa and distribution of discarded fish wastes for surrounding piscivorous birds by butchers and other people, the life cycle of Contracaecum parasite was perpetuated. Thus, the parasite is of zoonotic significance. Therefore, awareness creation activities for societies and control of fish parasites should be conducted in the study area.

Gastric disorders of cattle in western Rio Grande do Sul State, Brazil

ABSTRACT: A retrospective study of gastric disorders in autopsied cattle in the Western region of Rio Grande do Sul State, was performed. The exam reports of bovine necropsy of the Veterinary Pathology Laboratory, Unipampa, were analyzed in the period from 2010 to 2018. All cases in which death was primarily caused by disturbance in the gastric chambers were included. During the period evaluated, 141 cattle were necropsied. Of those, 25 had gastric disorders. Of those, 53% had alterations in the rumen, followed by abomasum (17%), involvement of two chambers (13%) and reticulum (9%). Most cases corresponded to beef cattle raised in an extensive system and most them for calf production and fattening with an average age of approximately three years. The cases occurred in farms of four different municipalities. Bullous bloat by excessive Trifolium repens ingestion was the gastric disturbance with the highest number of dead cattle observed in this study, especially in irrigated áreas of livestock farms. Cases such as lactic acidosis, ruminal alkalosis due to excessive urea ingestion and Baccharis coridifolia poisoning were also important gastric disturbances in necropsied cattle, associated especially with poor management and period of scarcity of good quality fodder. Cases of Clostridium perfringens infection were also observed in young cattle suggesting that it is an important infectious agent in the evaluated cattle herds, also showing failures in vaccination of the herds. As observed, gastric disturbances in cattle in the western region of Rio Grande do Sul have several causes. Metabolic/toxic and infectious disturbances were important causes of mortality in the herds, inducing considerable economic losses. Based on this study, it is clear that the majority of outbreaks or isolated cases occurred due to errors in the management of the properties and the vast majority of them could have been avoided with improvements in the technical qualification of the workers and simple adjustments in the farming methods. It is also emphasized the importance of the conclusive diagnosis to control these disorders, once after the orientation to the producers, was observed significant decrease in cattle losses in the farms.

Epidemiological and pathological aspects of cardiomyopathies in cats in southern Brazil

ABSTRACT: Cardiomyopathies are considered one of the most important causes of heart failure in cats and are subdivided into three main morphological types: hypertrophic (HCM), dilated (DCM), and restrictive (RCM). This study aimed to determine the frequency and types of cardiomyopathies in cats diagnosed in southern Brazil, with an emphasis on their epidemiological and pathological aspects. Necropsy reports filed in a veterinary pathology laboratory were reviewed, and cats diagnosed with cardiomyopathy were selected for the study. Animal identification data, history and clinical signs, and gross lesions, were reviewed and compiled. During the study period, 1.594 cat necropsies were performed, of which 72 (4.5%) comprised a diagnosis of cardiomyopathy. HCM was the most frequent followed by CMR and CMD, representing 77.8%, 12.5% and 9.7%, respectively. Age ranged from three months to 18 years, with a median age of seven years. In relation to sex, 62.5% were males and 37.5% females. In 76.4% of the cases, it affected cats without a breed defined. Restrictive mixed dyspnea and hydrothorax were the main signs or findings of the clinical examination. Sudden death and acute paresis of the pelvic limbs due to aortic thromboembolism have also been described. In HCM, myocardial thickening was observed, with a reduction in the ventricular chamber. Hypertrophy, disarray, and fibrosis of the myofibers were the main histological findings. In RCM, whitish and thickened endocardium was seen in most cases. DCM was characterized by dilated cardiac chambers, and microscopic examination revealed no significant findings. The main extra cardiac lesions revealed pulmonary edema and congestion, hydrothorax and chronic passive congestion of the liver. Cardiomyopathies are important causes of death in cats and should be included in the differential diagnosis of patients with cardio respiratory clinical signs and in cases related to sudden death and acute paresis of the pelvic limbs.

An analysis of time trends for canine heartworm disease in Grenada and its associated risk factors based on veterinary clinical pathology laboratory data base records between 2003 and 2015

Canine heartworm (CHW) disease is a common parasitic infection in dogs in the Caribbean islands. However, studies on temporal trends and risk factors are limited for this region. This study represents the time trends in laboratory prevalence and risk factors of canine heartworm infections between 2003 and 2015.In this case series, 662 cases of laboratory-diagnosed heartworm were compared to 662 dogs without a laboratory diagnosis of heartworm (controls). One hundred and seventy two frozen serum positive samples were later analyzed for heartworm antigens using Heska solo® Step CH, and all 172 cases of microfilariae were confirmed as Dirofilaria immitis. Annual prevalence, linear trends and odds ratios (OR) for CHW were estimated using EPIINFO version 7 at a significance level of α = 0.05. Logistic regression was used to assess the association of CHW with variables showing a statistically significant univariate relationship.Laboratory prevalence of CHW decreased from 72 cases per 1000 dogs per year in 2003 to 15 cases per 1000 dogs per year in 2015 [X2 for linear trend = 151.8, p < 0.0001], with the occurrence of an epidemic of CHW between 2008 and 2010.The odds of CHW were higher among adult dogs [(OR) = 3.9 (95% CI, 2.9–7.0)] and geriatric dogs [OR = 2.1 (95% CI, 1.1–4.3)] compared to puppies. The odds of CHW were higher [OR = 1.3 (95% CI, 1.1–1.6)] among male dogs than female dogs, but the odds for CHW were lower among neutered dogs [OR = 0.4 (95% CI, 0.2 – 0.6)] compared to intact dogs. The odds of a dog being diagnosed with CHW were elevated [OR = 4.1 (95% CI, 3.2–5.2)] during the dry season compared to the rainy season.Our findings show that canine heartworm is extensive in laboratory submissions in Grenada. However, the laboratory prevalence of CHW decreased between 2003 and 2015, with an epidemic occurring between 2008 and 2010. Age of the dog, sex, neutered status, and seasonality of diagnosis were significantly associated CHW in Grenada.

Feline oral cavity lesions diagnosed by histopathology: a 6-year retrospective study in Portugal.

The aim of this study was to analyse the frequency of oral cavity lesions in cats, their anatomical location and histological diagnosis, and the effect of life stage, breed and sex on different diagnoses. For this purpose, a retrospective study comprising 297 feline oral cavity lesions was performed over a 6-year period between 2010 and 2015. Histopathological records from the DNAtech Pathology Laboratory (Lisbon, Portugal) were analysed. The incidence of oral disease was higher in male cats (n = 173; 58.4%), mature adults (ranging from 7 to 10 years old [n = 88; 33.0%]) and in the European Shorthair breed (n = 206; 73.6%). The gingiva was the site where oral lesions were most commonly found, with 128 samples (43.1%). Incisional biopsies were used to obtain the majority of samples (n = 256; 86.2%), while excisional biopsies and punch biopsies were performed in 36 (12.1%) and five (1.7%) cases, respectively. Inflammatory and neoplastic lesions accounted for 187 (63%) and 110 (37%) of the studied cases, respectively. Malignancies were found in >80% of neoplastic cases. Feline chronic gingivostomatitis was the most common histological diagnosis (n = 116; 39.1%), followed by squamous cell carcinoma (n = 49; 16.5%) and eosinophilic granuloma complex (n = 33; 11.1%). The present work, involving a large series of samples of feline oral cavity lesions, from numerous geographically scattered practices and all examined at a reference veterinary pathology laboratory, adds important new understanding of the epidemiology of feline oral disease.

Outbreak of Rickets in Pigs in the West of Santa Catarina

Background: Rickets is a deficiency pathology that occurs in young and growing animals, leading to deficient bone mineralization. Rickets has been reported in several species producing numerous economic losses. The disease is caused by nutritional imbalance of calcium (Ca), phosphorus (P) and vitamin D. The aim of this work was to report two outbreaks of rickets in commercial weaning farms in the Seara city, in the western region of Santa Catarina State (SC), Brazil.Case: In August 2016, the Veterinary Pathology Laboratory (LPV) at the Concórdia Campus of the Catarinense Federal Institute (IFC) diagnosed two outbreaks of rickets in pigs in the weaning phase in Seara, SC. The clinical history was obtained by interviewing the field veterinarian and the farmers. In the anamnesis, both pig farmers stated having used a feed premix product from the same company, starting three months ago, and after that the pigs presented clinical signs of posterior paralysis and progressive weight loss. Six animals were submitted to necropsy and organs were collected from the abdominal and thoracic cavities; central nervous system and bones; fixed in 10% buffered formalin, routinely processed, paraffin embedded and stained with hematoxylin and eosin (HE) for histopathological analysis. Bone specimens were decalcified in nitric acid working solution 20 times their volume, during 5 days. In addition, samples of the premix product containing minerals and vitamins were sent to a specialized laboratory to analyze macroelements levels through the atomic absorption methodology. In property 1, there was a batch of 100 animals, the morbidity rate was 15% and lethality was 5%. In property 2, among 30 animals, the morbidity and lethality rate were 33%. Five animals from property 1 and one animal from property 2 underwent necropsy, that showed severe bone fragility and flexibility (6/6), growth plate discontinuity (2/6), as well as, increased volume of costochondral joints (rachitic rosary) and epiphyseal cartilage thickening (2/6). Regarding the premix used in both farms, the label showed manufactured guarantee of 110 g/kg of Ca (minimum), 62 g/kg of total P and 38,400 I.U./kg of vitamin D. Meanwhile the analysis of the product used in the feed mixture quantified 74.3 g/kg of Ca (minimum), 22.2 g/kg of total P and 40,098.9 I.U./kg of vitamin D. The diagnosis of rickets was established through the association of history, clinical signs, macroscopic, microscopic lesions and nutritional analyses.Discussion: The affected pigs weighed approximately 20 kg and consumed an average of 1.0 kg of feed per day. The recommended amount of feed consumption for pigs at this stage is approximately 953 g in American literature, while national recommendations described a consumption of 1,036 g/animal. Comparing information in the product label and laboratory analyses, the real level of Calcium was 32.4% (35.6 g/kg) lower in the product, as well as total Phosphorus level, 64.2% (39.8 g/kg) lower. On the other hand, Vitamin D levels were 4.4% (1,698.9 I.U.) above guarantee provided by the company. It is concluded that rickets in pigs raised intensively occurred due to non-observance of the minimum intake levels of Ca, P and Vitamin D in the diet. Although this is an evident conclusion, taking into account the industry's technification in Brazil, error in the formulation of the diet leading to animal mortality and serious economic losses to farmers should not be expected.

Polioencephalomalacia in Newborn Lamb

Background: Perinatal mortality in sheep is determined by death between 60 days of gestation and 28 days postpartum. The starvation / hypothermia complex was characterized by lambs that walked, but did not feed. Polioencephalomalacia (PEM) is a descriptive term that indicates the morphological diagnosis for necrosis with softening of the gray matter in the brain. There are no data available in the literature relating PEM to the starvation / hypoglycemia / hypothermia complex in small ruminants. Thus, the objective of this work is to report a case of polyioencephalomalacia related to the starvation / hypoglycemia / hypothermia and septicemia complex in a newborn sheep.Case: A 5-day-old sheep mixed race (Dorper x Santa Inês), female, 3.0 kg, from a rural property in the Federal District, was sent to the Veterinary Pathology Laboratory of the University of Brasilia, for a necropsy. Organ fragments were collected and fixed in a 10 % buffered formalin solution, routinely processed for histology and stained with Hematoxylin and Eosin (HE). Additionally, swabs from the meninges, eyeballs and navels were collected for bacteriology. The animal came from twin pregnancies and was weak since birth. With three days of life, it presented apathy, weakness, difficulty in breastfeeding, difficulty in walking, and decubitus in a self-auscultation position. After two days of evolution the lamb died. Macroscopically, eyeball opacity, omphalophlebitis and congested brain were observed. Microscopically in the frontal cortex, the leptomeninge was markedly thickened by a large number of neutrophils and, to a lesser extent, macrophages, lymphocytes and plasmocytes, associated with aggregates of free eosinophilic rods or in the cytoplasm of macrophages. In the underlying gray substance, the neurópilo was observed containing moderate amount of perineuronal vacuoles and distension of the perivascular space (perineuronal and perivascular edema), in addition to a large number of neurons with retracted and hypereosinophilic cytoplasm with the pycnotic and peripheral nucleus (neuronal necrosis). Moderate endothelial and astrocyte swelling was also observed. In the eyeball, they were seen in the anterior, posterior and vitreous chambers extending to the ciliary body, infiltrated by neutrophils, lymphocytes, plasmocytes and macrophages with a moderate amount of fibrin, which extended to the optic nerve papilla. In the vitreous chamber, a large number of free eosinophilic rods were found in the infiltrate and inside macrophages. The bulbar conjunctiva, the corneal limbus and the iridocorneal angle were slightly thickened by similar infiltrates. In the bacteriological examination of meninges, eyeballs and navels, pure Escherichia coli culture was isolated.Discussion: The diagnosis of PEM associated with meningitis and panuveitis in this study was based on clinical-pathological and microbiological findings. In small ruminants twin pregnancies occur more frequently, and it is common for puppies to be born weaker and not ingest colostrum properly, leading to a condition called failure in passive immunity transfer and thus developing some type of disease. Metabolic disorders that interfere with glycolysis and ATP production for neurons are among the causes of PEM, however there is little data in the literature relating PEM to the starvation / hypoglycemia / hypothermia complex. Another important factor related to inadequate colostrum intake and management is umbilical infections. Meningitis results from a septicemic manifestation of primary infection such as omphalophlebitis. The association of clinical and pathological data allowed the diagnosis of PEM associated with meningitis, which was confirmed by the isolation of Escherichia coli in pure culture.

Mechanisms of β-lactam resistance of Streptococcus uberis isolated from bovine mastitis cases

A number of veterinary clinical pathology laboratories in New Zealand have been reporting emergence of increased minimum in inhibitory concentrations for β-lactams in the common clinical bovine mastitis pathogen Streptococcus uberis. The objective of this study was to determine the genetic basis of this increase in MIC for β-lactams amongst S. uberis. Illumina sequencing and determination of oxacillin MIC was performed on 265 clinical isolates. Published sequences of the five penicillin binding proteins pbp1a, pbp1b, pbp2a, pbp2b, and pbp2x were used to identify, extract and align these sequences from the study isolates. Amino acid substitutions resulting from single nucleotide polymorphisms (SNP) within these genes were analysed for associations with elevated (≥ 0.5 mg/L) oxacillin MIC together with a genome wide association study. The population structure of the study isolates was approximated using a phylogenetic tree generated from an alignment of the core genome. A total of 53 % of isolates had MIC ≥ 0.5 mg/L for oxacillin. A total of 101 substitutions within the five pbp were identified, of which 11 were statistically associated with an MIC ≥ 0.5 mg/L. All 140 isolates which exhibited an increased β-lactam MIC had SNPs leading to pbp2x E381K and Q554E substitutions. The phylogenetic tree indicated that the genotype and phenotype associated with the increased MIC for oxacillin were present in several different lineages suggesting that acquisition of this increased β-lactam MIC had occurred in multiple geographically distinct regions. Reanalysis of the data from the intervention studies from which the isolates were originally drawn found a tendency for the pbp2x E381K substitution to be associated with lower cure rates. It is concluded that there is geographically and genetically widespread presence of pbp substitutions associated with reduced susceptibility to β-lactam antimicrobials. Additionally, presence of pbp substitutions tended to be associated with poorer cure rate outcomes following antimicrobial therapy for clinical mastitis.

Fatal lancehead pit viper (Bothrops spp.) envenomation in horses

Snake bite envenomations in farm animals are generally overestimated as the cause of mortality in rural areas in Latin America. However, most cases are based only on anecdotal information and assumptions, and lack diagnostic evidence. There are few proven reports of envenomation and death in horses caused by snakebites from members of the Bothrops genus (lancehead pit vipers). This study presents epidemiological and clinical-pathological findings of fatal bothropic envenomation in horses from Central Western Brazil in order to contribute to the correct diagnosis of this condition. A survey of the records of equine necropsies from the Veterinary Pathology Laboratories of the University of Brasilia, Federal University of Mato Grosso and Federal University of Mato Grosso do Sul, from January 2010 to February 2018, was performed. Five fatal cases of bothropic snakebite were identified in 755 necropsies of horses, corresponding to 0.66% of these cases, ranging annually from 0.33% to 0.89%. The main necropsy findings were marked swelling and diffuse subcutaneous hemorrhage, and identification of the fang marks in 2 out of five horses. Hemorrhage in most organs and tissues was the pathological hallmark of systemic envenomation. Myonecrosis, dermonecrosis, and moderate to severe kidney degeneration and necrosis were also observed. Fatal Bothrops snakebites in horses have a low occurrence in Central Western Brazil and most cases occur in the rainy season. The diagnosis of this condition may be substantiated by clinical signs and pathological findings. Local hemorrhage and necrosis, systemic hemorrhagic disorders and injuries related to acute kidney injury are the predominant clinical signs. These findings should be considered in the diagnosis and therapeutic management of these envenomations.

Breed and anatomical predisposition for canine cutaneous neoplasia in South Africa during 2013

Cutaneous neoplasia occurs commonly in dogs and owners in consultation with their veterinarian must decide when to perform surgery to obtain a histopathological diagnosis. The objective of this study was...

Pasteurellosis Outbreak Due to Pasteurella multocida Type A in Rabbits (Oryctolagus cuniculus)

Background: Pasteurellosis is a common disease of cattle, pigs, and poultry, which rarely affects humans. In rabbits, the respiratory presentation of the disease is frequently reported. Clinical signs related to bronchopneumonia include sneezing, lung stertors, oculonasal discharge, dyspnea and cyanosis. Infection may lead to otitis, conjunctivitis, abscesses and sepsis. Furthermore, Pasteurella multocida infection may lead to sudden death without clinical manifestations. Reports of pasteurellosis in rabbits are scarce in Brazil. Therefore, the objective of this article is to describe an outbreak of pasteurellosis with high mortality in a rabbity in the State of Santa Catarina, Brazil.Cases: Two adult rabbits were submitted for necropsy at the Veterinary Pathology Laboratory of the Instituto Federal Catarinense - Campus Concórdia, within an interval of twenty days. Herd was represented by 40 animals, of which six fattening rabbits and three breeders died. Animals were kept in suspended cages with slatted floor. Clinical signs were represented by prostration, sneezing, and mucopurulent nasal discharge. In addition, wounds were observed in the distal portion of the limbs. Death occurred up to two days after the onset of clinical signs. Necropsies were performed and tissue samples were collected for histopathologic, immunohistochemical and microbiologic (bacterial culture and antibiogram) exams. At the necropsy, severe diffuse fibrinous exudate covering the pericardium sac, visceral and parietal pleural surfaces was noted, as well as multiple diaphragm adhesions. In addition, the lungs presented diffuse red coloration and showed multiple abscesses ranging from 0.3 to 1cm in diameter. The nasal sinus and the tracheal mucosa showed diffuse reddening (rabbits 1 and 2). Abscesses up to 2 cm in diameter were observed in the mammary glands (rabbit 1), heart and kidneys (rabbit 2). The urinary bladder was distended by cloudy urine and moderate amount of purulent exudate (rabbits 1 and 2). Histopathological evaluation revealed diffuse marked fibrinosuppurative pleuritis associated with severe multifocal suppurative bronchopneumonia (rabbits 1 and 2), as well as multifocal marked mastitis (rabbit 1), nephritis and myocarditis (rabbit 2). Also, intralesional bacterial aggregates and thrombosis were observed in both cases. Pasteurella multocida type A was isolated through bacterial culture, and antibiogram showed sensitivity to all tested antibiotics. Immunohistochemistry showed mild multifocal positive staining for P. multocida in the visceral pleura in both cases.Discussion: In the present case, P. multocida type A led to suppurative bronchopneumonia, pulmonary abscesses and fibrinosuppurative pleuritis in both rabbits. In addition, abscesses affecting the kidneys, heart and mammary glands were observed. These findings are typically seen in this condition in rabbits, and similar lesions may be noted in pigs. It is believed that nutritional, climatic and hierarchical changes may predispose to the development of the disease. In the present outbreak, the disease may have initially affected fattening rabbits, which are more exposed to stressful events, and then bacterial spread to breeders sharing the same facility may have occurred. Furthermore, contributing factors include concomitant bacterial infections, and the level of virulence of the bacterial strain involved in the outbreak. In the present study, the diagnosis of pasteurellosis in rabbits was based on the epidemiological, gross, histopathological, bacterial and immunohistochemical findings. It is believed that the present report will improve the understanding of the disease in rabbits in Brazil, since rare descriptions of the condition are currently available nationwide.

Clinical-epidemiological, anatomic-pathological, histochemical and immunohistochemical characterization of renal cystadenocarcinoma-nodular dermatofibrosis syndrome in 11 German Shepherd dogs

ABSTRACT: Eleven cases of renal cystadenoma/cystadenocarcinoma-nodular dermatofibrosis syndrome (RCND) are described in German Shepherd dogs diagnosed from January 1994 to January 2018 at the Veterinary Pathology Laboratory of the “Universidade Federal de Santa Maria” (LPV-UFSM). The study sample was composed of eight male and three female dogs at a ratio of 2.67:1. Age ranged from six to 12 years (mean=8.7 years). The main clinical signs reported in descending order of frequency were multiple cutaneous nodules (nodular dermatofibrosis), dyspnea, anorexia, weight loss, recurrent hematuria, vomiting, and polydipsia. Results demonstrated that it is not always easy to clinically recognize this syndrome, but its peculiar anatomical-pathological characteristics allow safe diagnosis. Histologically, it was possible to detect all phases (cysts, papillary intratubular hyperplasia, and cystadenomas or cystadenocarcinomas) of a possible pathological continuum of the renal lesions. Uterine leiomyomas were observed in only one of the cases. Through histochemical techniques, it was possible to identify the presence of type I collagen in both cutaneous and renal lesions and consider its possible involvement in the pathogenesis of renal cystadenocarcinoma. Immunohistochemistry (IHC) showed partially satisfactory results in the staining of epithelial cells of renal cysts and neoplasms for pan-cytokeratin.

Incidence of skin tumors in dogs in Salvador, Bahia state, Brazil (2007-2016)

ABSTRACT: This study aimed to establish the incidence of skin tumors (cutaneous proliferative lesions of neoplastic or non-neoplastic nature) in dogs diagnosed by histopathological evaluation at the Veterinary Pathology Laboratory (LPV) of the Federal University of Bahia (UFBA) in a 10-year (2007-2016) historical series. Of the 1945 histopathological diagnoses made in this period, 503 were skin biopsies, and 617 dermatological problems (87 dogs, 17.3%, presented more than one positive diagnosis) were found. Of the 617 diagnoses of dermatopathy, 546 (88.49%) were tumors and 71 (11.51%) were non-tumorous alterations. The 546 conditions more profoundly studied were from 453 dogs, 468 (85.7%) neoplastic and 78 (14.3%) non-neoplastic tumors. The 468 neoplasms were classified as follows: 230 benign (49.14%), 215 malignant (45.94%), 23 borderline (epitheliomas) (4.91%), 51.92% (243/468) mesenchymal, 42.74% (200/468) epithelial, 4.91% (23/468) melanocytic, and 0.43% (2/468) metastatic (mammary gland). The most commonly diagnosed neoplastic dermatopathies were mastocytoma (14.7%) and lipoma (7.48%). Among the 78 non-neoplastic conditions (14.3%), epidermal inclusion cyst (39.74%) and trichogranuloma (15.38%) were the most frequent. Canine dermatopathies accounted for 26% of the biopsy files of the LPV-UFBA. Distinct simultaneous dermatological problems were frequently found in the dogs assessed (one in six). Considering that these conditions can present with different cellular origin and biological behavior, it is crucial that histopathological evaluation be performed in fragments from the different cutaneous lesions.

Lung biopsy with guillotine cutting needle and biopsy forceps though transdiaphragmatic thoracoscopy in dogs with pulmonary alterations

ABSTRACT: Lung diseases are common in small animal clinical routine. Diagnosis is usually affected due to nonspecific symptoms. Imaging features such as radiography and chest ultrasound are acceptable screening tests, although lung biopsy can provides a precise diagnosis. Thus thoracoscopy provides a minimally invasive diagnostic assessment for chest diseases and offers the benefits such as improved illumination and magnification of the image when compared with thoracotomy. In this study we evaluated the transdiaphragmatic thoracoscopic-assisted techniques of lung biopsy with a the guillotine cutting needle and biopsy forceps, in dogs presenting radiographic suspicion on pulmonary tumors. Fourteen dogs regardless of breed, gender, age and body weight admitted at the Hospital of Veterinary Clinics (HCV) of the Veterinary College (FAVET) of Universidade Federal do Rio Grande do Sul (UFRGS), were assessed. Inclusion criteria were presence of nodules on chest radiography and triage tests without changes that could hinder general anesthesia and surgical approach. The animals were positioned in dorsal recumbence and two thoracoscopic ports were established: the first port for working instruments; the second paraxyphoid port for the telescope. Three samples were collected using each sampling method from each lesion or from tumors macroscopically similar whenever their size was less than one centimeter. The samples were sent for histopathological examination in the Veterinary Pathology Laboratory of FAVET/UFRGS. Surgical time was recorded from first incision to wound closure and surgical complications were reported. The dogs were evaluated for the presence of subcutaneous emphysema, hematoma, seroma, local infection and dehiscence. No conversion to open surgery was necessary during the thoracoscopic procedure in any patient. Thoracoscopic assisted biopsy using guillotine needle and biopsy forceps was a safe and fast technique, without perioperative complications. Both devices provided good quality samples for histopathological analysis of lung abnormalities. However the cutting guillotine needle was more efficient especially in larger pulmonary nodules. The transdiaphragmatic access provided optimal approach for both hemithoraces.

Gross and histopathological pitfalls found in the examination of 3,338 cattle brains submitted to the BSE surveillance program in Brazil

ABSTRACT: This study stems from the findings during the gross and histopathological exam of 3,338 cattle brains as part of the bovine spongiform encephalopathy (BSE) active surveillance program of the Brazilian Ministry of Agriculture, Livestock, and Supply from 2001 to 2005. The work was carried out in the Veterinary Pathology Laboratory of the Federal University of Santa Maria which at the time (2001-2007) was the national reference laboratory for the diagnosis of BSE and other transmissible spongiform encephalopathies. Both gross and histopathological aspects are described. Several gross aspects were annotated: anatomic normal structures not commonly recognized (non-lesions), lesions of no clinical significance, postmortem changes and artifacts; all these can amount to important pitfalls that distract the pathologist during the routine gross examination of the central nervous system (CNS). Accordingly, equivalent pitfalls were described in the histological examination. Non-lesions observed were the pineal body, embryo remnants such as the external germinal layer of the cerebellum, subependymal plates, and clusters of neuroblasts in the basal ganglia; or circumventricular structures such as area postrema, subcomisural organ, and melanosis in the leptomeninges and vessel walls. Lesions with little or no clinical importance included age-related changes as lipofuscin, hemosiderin, mineralization and hyalinization of vessel walls within the brain and meninges. Corpora amylacea and corpora arenacea were detected respectively in astrocyte processes and the pineal body. Cytoplasmic neuronal vacuolization was observed in the red nucleus and habenular nucleus. Sarcocystis sp. without a correspondent inflammatory reaction was rarely observed. Included within findings with no clinical manifestation were axonal spheroids and perivascular mononuclear cuffings. Changes in the CNS due to killing, sampling and fixation methods can obscure or distract from the more critical lesions. The ones related to the process of killing included hemorrhages caused in cattle destroyed by a captive bolt. Artifacts related to sampling and handling of CNS tissue consisted of inclusion of bone sand in the neural tissue from sawing the calvarium; dark neurons produced by excessive handling of the brain, and micro-organisms that contaminated the tissues during sampling or histological processing. Postmortem autolytic or putrefactive changes observed included vacuolar changes in the myelin sheath, clear halos surrounding neurons and oligodendrocytes, clusters of putrefaction bacilli within vessels or dispersed throughout the brain tissue associated or not to clear halos. One interesting, and somewhat frequent, postmortem autolytic change found in the bovine brain was the partial dissolution of the granule cell layer (GCL) of the cerebellum, also referred to as conglutination of the GCL or as the French denomination “état glace”. Due to the shortage of comprehensive publications in the subject, this review is intended to address the main pitfalls that can be observed in the brain of cattle hoping to help other pathologists avoiding misinterpret them.

Linfossarcoma de células B multicêntrico em uma ovelha

Background : : : Lymphosarcoma is a malignant tumor from tumoral cells similar to lymphocytes and its spontaneous development in small ruminants is unusual in Brazil. In cattle, the lymphosarcomas are often associated with infection by bovine leukemia virus (BLV), although sheep are considered as a very susceptible specie to BLV. Spontaneously lymphosarcoma is rare and in most cases it is observed in apparently healthy animals in slaughterhouses. There is no report of this tumor in sheep in southern Brazil. We describe a case of spontaneous multicentric B-cells lymphosarcoma in an ewe. Case : In June 2007, a 4-years-old mixed breed ewe was necropsied after clinical signs as anorexia, weight loss and death in few weeks. This ewe was purchased in September 2006 with another 44 sheep, most females of the same age. Dairy cattle were also raised together with sheep at the same farm. Fragments of liver, lung, spleen, kidneys, brain and parotid lymph node were sent to the Veterinary Pathology Laboratory - Universidade Federal de Santa Maria, Brazil, for histopathological evaluation. Multiply white to yellow nodules, with 0.5 to 2 cm of diameter, were observed in the liver, kidneys, and the parotid lymph node. The nodules were soft and some coalesced and infiltrating the hepatic parenchyma. The kidneys nodules were similar to those of the liver but prominent in the capsule. They were observed infiltrating more intensely the cortical region. The parotid lymph node was 6 x 4 x 3.5 cm size, whitish, multilobulated and the cut surface was totally obliterated by the tumor mass. Histologically, the neoplasm showed intense proliferation of neoplastic lymphoid cells arranged in sheets and a poor fibrovascular stroma, with round small and hyperchromatic nuclei, and scarce eosinophilic cytoplasm compressing the adjacent parenchyma. Immunohistochemistrily, neoplastic cells were strongly positive for anti-CD79a antibody and negative for anti-CD3 antibody, indicating neoplastic cells derived from B lymphocytes. Discussion : The diagnostic of multicentric B-cell lymphosarcoma was made based on gross, histological, and immunohistochemical findings. Spontaneous development of this tumor is uncommon in sheep in Brazil. The multicentric presentation seen in this case is the most common form of lymphosarcoma in sheep, although the thymic and cutaneous forms also occur. Sheep affected by multicentric lymphosarcomas may have symmetrical lymphadenopathy, not observed in this case, and involvement of various organs including liver, kidney, spleen, intestine, skeletal muscle and heart. However, under experimental conditions, these tumors are easily induced after inoculation of bovine retrovirus (BLV) in sheep, by its high sensitivity. Possibly, the spontaneous transmission of BLV from cattle developing the disease in sheep may occur in Brazil as well as in other countries. Epidemiological factors of the disease are not established yet. Despite this, some correlation must exist for the low occurrence of this disease in sheep in properties of southern Brazil, where cattle and sheep are commonly raised together, and the frequency of lymphosarcoma in sheep is low. In this case, the association of BLV with development of the neoplasm could not be confirmed. This is the first report of multicentric B-cell lymphosarcoma in sheep diagnosed in southern Brazil.

Diagnóstico imuno-histoquímico de pitiose cutânea em equinos

This report describes five cases of equine cutaneos pythiosis submitted to the Veterinary Pathology Laboratory - Universidade Federal do Rio Grande do Sul, B...

Pathological and parasitological characterization of Prosthenorchis elegans in a free-ranging marmoset Callithrix geofroyi from the Brazilian Atlantic Forest

ABSTRACT: Prosthenorchis elegans is an acanthocephalan intestinal parasite reported in neotropical primates. Despite parasitism by P. elegans having already been described in wild marmosets in the Brazilian Atlantic Forest, there are no reports of this infection in wild Geoffroy’s marmoset (Callithrix geofroyi). The aim of this study is to report one case of P. elegans parasitism in a free-ranging C. geoffroyi from Brazilian Atlantic Forest in Espírito Santo state, and characterize the pathological and parasitological findings of this infection. One Geoffroy’s marmoset necropsied at the Vila Velha University’s Veterinary Pathology Laboratory presented intense chronic transmural ulcerative enteritis associated with twenty cylindrical helminths present in the jejunum and ileum. We can conclude that parasitism by P. elegans occurs in free-ranging groups of Geoffroy’s marmosets. Its infection produced severe intestinal lesions even in free-ranging marmoset and therefore is a threat to this animal’s survival in wildlife and can have some impact on primate conservation in the Brazilian Atlantic Forest.

Feline leprosy due to Candidatus 'Mycobacterium lepraefelis': Further clinical and molecular characterisation of eight previously reported cases and an additional 30 cases.

This paper, the last in a series of three on 'feline leprosy', provides a detailed description of disease referable to the previously unnamed species, Candidatus 'Mycobacterium lepraefelis', a close relative of the human pathogens Mycobacterium leprae and Mycobacterium lepromatosis. Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with Candidatus 'M lepraefelis' infection. A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory (VIDRL) records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Thirty-eight cats were definitively diagnosed with Candidatus 'M lepraefelis' infection. Typically, cats tended to be middle-aged or older when first infected, with a male predilection. Affected cats typically had widespread cutaneous lesions, in some cases after initially localised disease. Advanced cases were often systemically unwell. All cats had outdoor access. The histological picture was lepromatous in the majority of patients, although two cases had tuberculoid disease. In one case that underwent necropsy, lesions were evident in the liver, spleen and lungs. Treatment was varied, although most cats received a combination of oral clarithromycin and rifampicin. Prognosis for recovery was variable, but typically poor. Candidatus 'M lepraefelis' typically causes high bacterial index (lepromatous) feline leprosy that in some cases progresses to systemic mycobacteriosis. The disease has a variable clinical course and prognosis. Many cases either died or were euthanased due to the infection. Multilocus sequence analysis reveals a heterogeneous picture and further analysis of draft genome sequencing may give clues to the taxonomy and epidemiology of this organism. Prospective treatment trials and/or additional drug susceptibility testing in specialised systems would further inform treatment recommendations. Comparative aspects: This paper finishes with a discussion of comparative aspects of infection caused by the three feline leproid disease agents that have been the subject of this series: Candidatus 'Mycobacterium tarwinense', Mycobacterium lepraemurium and Candidatus 'M lepraefelis'.

Feline leprosy due to Mycobacterium lepraemurium.

This paper, the second in a series of three on 'feline leprosy', provides a detailed description of disease referable to Mycobacterium lepraemurium, the most common cause of feline leprosy worldwide. Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with M lepraemurium infection. A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Sixty-five cats were definitively diagnosed with M lepraemurium infection. Typically, cats were 1-3 years of age when first infected, with a male gender predilection. Affected cats were generally systemically well. All had outdoor access. Lesions tended to consist of one or more cutaneous/subcutaneous nodules, typically located on the head and/or forelimbs, possibly reflecting the most likely locations for a rodent bite as the site of inoculation for organisms. Nodules had the propensity to ulcerate at some stage in the clinical course. The cytological and histological picture varied from tuberculoid, with relatively low bacterial numbers, to lepromatous with moderate to high bacterial numbers. Treatment was varied, although most cats underwent surgical resection of lesions with adjunctive medical therapy, most often using a combination of oral clarithromycin and rifampicin. Prognosis for recovery was generally good, and in two cases there was spontaneous remission without the requirement for medical intervention. Untreated cats continued to enjoy an acceptable quality of life despite persistence of the disease, which extended locally but had no apparent tendency to disseminate to internal organs. M lepraemurium causes high bacterial index (lepromatous) or low bacterial index (tuberculoid) feline leprosy. The infection typically causes nodules of the skin and/or subcutis (which tend towards ulceration) on the head and/or forelimbs. The disease usually has an indolent clinical course and infected cats have a generally favourable response to therapeutic interventions, with rare cases undergoing spontaneous resolution. Genomic analysis may yield clues as to the environmental niche and culture requirements of this elusive organism. Prospective treatment trials and/or additional drug susceptibility testing in specialised systems would further inform treatment recommendations.