Mycobacterium genavense granulomatous typhlocolitis in a horse.

A 23-y-old gelding was presented to a veterinary teaching hospital with a history of chronic, refractory diarrhea. Clinically, the horse was in poor body condition, with a thickened and corrugated large intestine identified by transcutaneous abdominal ultrasonography. At postmortem examination following euthanasia, the large colon and cecum had segmental thickening of the intestinal wall with innumerable mucosal ulcers and prominent polypoid mucosal masses. Many mesenteric and hepatic lymph nodes were enlarged. Histology revealed granulomatous and ulcerative typhlocolitis and granulomatous lymphadenitis with myriad acid-fast, variably gram-positive, intrahistiocytic bacilli that stained by immunohistochemistry for mycobacteria. Molecular testing by PCR and sequencing identified the causative agent as Mycobacterium genavense, which is an unusual presentation of infection in a horse.

Case report: Urbanized non-human primates as sentinels for human zoonotic diseases: a case of acute fatal toxoplasmosis in a free-ranging marmoset in coinfection with yellow fever virus.

Free-ranging non-human primates (NHP) can live in anthropized areas or urban environments in close contact with human populations. This condition can enable the emergence and transmission of high-impact zoonotic pathogens. For the first time, we detected a coinfection of the yellow fever (YF) virus with Toxoplasma gondii in a free-ranging NHP in a highly urbanized area of a metropolis in Brazil. Specifically, we observed this coinfection in a black-tufted marmoset found dead and taken for a necropsy by the local health surveillance service. After conducting an epidemiological investigation, characterizing the pathological features, and performing molecular assays, we confirmed that the marmoset developed an acute fatal infection caused by T. gondii in coinfection with a new YF virus South American-1 sub-lineage. As a result, we have raised concerns about the public health implications of these findings and discussed the importance of diagnosis and surveillance of zoonotic agents in urbanized NHPs. As competent hosts of zoonotic diseases such as YF and environmental sentinels for toxoplasmosis, NHPs play a crucial role in the One Health framework to predict and prevent the emergence of dangerous human pathogens.

Stillbirths and Neonatal Deaths Caused by Group B Streptococcus in Africa and South Asia Identified Through Child Health and Mortality Prevention Surveillance (CHAMPS).

Background: Invasive Group B Streptococcus (GBS) is a common cause of early-onset neonatal sepsis and is also associated with stillbirth. This study aimed to determine the proportion of stillborn infants and infants who died between 0 and 90 days attributable to GBS using postmortem minimally invasive tissue sampling (MITS) in 7 low- and middle-income countries (LMICs) participating in Child Health and Mortality Prevention Surveillance (CHAMPS). Methods: Deaths that occurred between December 2016 and December 2021 were investigated with MITS, including culture for bacteria of blood and cerebrospinal fluid (CSF), multipathogen polymerase chain reaction on blood, CSF, and lung tissue and histopathology of lung, liver, and brain. Data collection included clinical record review and verbal autopsy. Expert panels reviewed all information and assigned causes of death. Results: We evaluated 2966 deaths, including stillborn infants (n = 1322), infants who died during first day of life (0 to <24 hours, n = 597), early neonatal deaths (END) (1 day to <7 days; END; n = 593), and deaths from 7 to 90 days (n = 454). Group B Streptococcus was determined to be in the causal pathway of death for 2.7% of infants (79 of 2, 966; range, 0.3% in Sierra Leone to 7.2% in South Africa), including 2.3% (31 of 1322) of stillbirths, 4.7% (28 of 597) 0 to <24 hours, 1.9% (11 of 593) END, and 2.0% (9 of 454) of deaths from 7 to 90 days of age. Among deaths attributed to GBS with birth weight data available, 61.9% (39 of 63) of decedents weighed <2500 grams at birth. Group B Streptococcus sepsis was the postmortem diagnosis for 100% (31 of 31) of stillbirths. For deaths <90 days, postmortem diagnoses included GBS sepsis (83.3%, 40 of 48), GBS meningitis (4.2%, 2 of 48), and GBS pneumonia (2.1%, 1 of 48). Conclusions: Our study reveals significant heterogeneity in the contribution of invasive GBS disease to infant mortality across different countries, emphasizing the need for tailored prevention strategies. Moreover, our findings highlight the substantial impact of GBS on stillbirths, shedding light on a previously underestimated aspect in LMICs.

Neurological and gastrointestinal manifestations of spontaneous poisoning by Ricinus communis in goats.

An outbreak of Ricinus communis poisoning in goats with neurological and digestive changes was related to the ingestion of different vegetative parts of the plant. Two poisoned animals died within 5 h of the plant intake showing necrotic gastroenteritis and hepatocytes degeneration and necrosis. Toxicological analysis by HPLC-DAD assay demonstrated 21.1-25.1 µg/g of ricinine in samples of ruminal fluids and 10.1-10.9 µg/g in the liver of poisoned goats.

Poisoning by Nierembergia veitchii: Effects on vascular smooth muscle cells in the pathogenesis of enzootic calcinosis.

Vascular mineralization is a hallmark of enzootic calcinosis. Histopathological, ultrastructural, and immunohistochemical investigations were performed on the external carotid arteries of seven sheep naturally poisoned by Nierembergia veitchii. Histologically, moderate to marked hyperplasia of the tunica intima was observed without mineralization. The tunica media exhibited mild to severe mineralization and osteochondroid metaplasia. Sheep with enzootic calcinosis showed arterial overexpression of osteopontin and tissue-nonspecific alkaline phosphatase and immunolabeling for osteonectin and osteocalcin in both intima and media layers of the tested arteries. The main ultrastructural finding in the tunica media was a marked phenotypic change of vascular smooth muscle cells from a contractile phenotype (VSMC-C) into a synthetic phenotype (VSMC-S). In the tunica media, VSMC-S produced matrix and extracellular vesicles, forming mineralizable granules associated with arterial mineralization. VSMC-S were also present in the tunica intima, but matrix and extracellular vesicles and mineralization were not observed. The absence of matrix and extracellular vesicles in the intimal hyperplasia, even in the presence of noncollagenous bone proteins, tissue-nonspecific alkaline phosphatase, and vitamin D receptors, reinforces the hypothesis that the presence of matrix and extracellular vesicles are crucial for the development of vascular mineralization in enzootic calcinosis. It is proposed that the two different VSMC-S phenotypes in calcinosis are due to the expression of at least two genetically different types of these cells induced by the action of 1,25(OH)2D3.

Hepato-pathological hallmarks for the surveillance of Yellow Fever in South American non-human primates.

The early detection and diagnosis of deaths in free-ranging non-human primates (NHPs) are key points for the surveillance of Yellow Fever (YF) in Brazil. The histopathological identification of infectious diseases remains very useful and reliable in the screening and detection of emerging zoonotic diseases such as YF. We surveyed data records and liver slides stained with hematoxylin and eosin from the Epizootics Surveillance Network to control YF, Ministry of Health of Brazil, to evaluate histopathological hallmarks for the diagnosis of the YF virus infection. We selected natural fatal cases in NHPs from the genera Alouatta spp., Callithrix spp., and Sapajus spp. with a positive immunohistochemical assay for YF in liver samples. Our findings showed the full-spectrum YF-associated hepatic lesions in all NHPs, but some histopathological findings differed in the distribution and intensity between the three genera. In our study, South American NHPs showed significant differences in the YF-associated hepatic histopathological features compared to fatal cases reported in humans.

Histopathology and localization of SARS-CoV-2 and its host cell entry receptor ACE2 in tissues from naturally infected US-farmed mink (Neovison vison).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes respiratory disease in mink similar to human COVID-19. We characterized the pathological findings in 72 mink from US farms with SARS-CoV-2 outbreaks, localized SARS-CoV-2 and its host cellular receptor angiotensin-converting enzyme 2 (ACE2) in mink respiratory tissues, and evaluated the utility of various test methods and specimens for SARS-CoV-2 detection in necropsy tissues. Of SARS-CoV-2-positive animals found dead, 74% had bronchiolitis and diffuse alveolar damage (DAD). Of euthanized SARS-CoV-2-positive animals, 72% had only mild interstitial pneumonia or minimal nonspecific lung changes (congestion, edema, macrophages); similar findings were seen in SARS-CoV-2-negative animals. Suppurative rhinitis, lymphocytic perivascular inflammation in the lungs, and lymphocytic infiltrates in other tissues were common in both SARS-CoV-2-positive and SARS-CoV-2-negative animals. In formalin-fixed paraffin-embedded (FFPE) upper respiratory tract (URT) specimens, conventional reverse transcription-polymerase chain reaction (cRT-PCR) was more sensitive than in situ hybridization (ISH) or immunohistochemistry (IHC) for detection of SARS-CoV-2. FFPE lung specimens yielded less detection of virus than FFPE URT specimens by all test methods. By IHC and ISH, virus localized extensively to epithelial cells in the nasal turbinates, and prominently within intact epithelium; olfactory mucosa was mostly spared. The SARS-CoV-2 receptor ACE2 was extensively detected by IHC within turbinate epithelium, with decreased detection in lower respiratory tract epithelium and alveolar macrophages. This study expands on the knowledge of the pathology and pathogenesis of natural SARS-CoV-2 infection in mink and supports their further investigation as a potential animal model of SARS-CoV-2 infection in humans.

Fatal Human Alphaherpesvirus 1 Infection in Free-Ranging Black-Tufted Marmosets in Anthropized Environments, Brazil, 2012-2019.

Human alphaherpesvirus 1 (HuAHV1) causes fatal neurologic infections in captive New World primates. To determine risks for interspecies transmission, we examined data for 13 free-ranging, black-tufted marmosets (Callithrix penicillata) that died of HuAHV1 infection and had been in close contact with humans in anthropized areas in Brazil during 2012-2019. We evaluated pathologic changes in the marmosets, localized virus and antigen, and assessed epidemiologic features. The main clinical findings were neurologic signs, necrotizing meningoencephalitis, and ulcerative glossitis; 1 animal had necrotizing hepatitis. Transmission electron microscopy revealed intranuclear herpetic inclusions, and immunostaining revealed HuAHV1 and herpesvirus particles in neurons, glial cells, tongue mucosal epithelium, and hepatocytes. PCR confirmed HuAHV1 infection. These findings illustrate how disruption of the One Health equilibrium in anthropized environments poses risks for interspecies virus transmission with potential spillover not only from animals to humans but also from humans to free-ranging nonhuman primates or other animals.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Pathology and One Health implications of fatal Leptospira interrogans infection in an urbanized, free-ranging, black-tufted marmoset (Callithrix penicillata) in Brazil.

Leptospirosis is a zoonotic neglected disease of worldwide public health concern. Leptospira species can infect a wide range of wild and domestic mammals and lead to a spectrum of disease, including severe and fatal forms. Herein, we report for the first time a fatal Leptospira interrogans infection in a free-ranging nonhuman primate (NHP), a black-tufted marmoset. Icterus, pulmonary haemorrhage, interstitial nephritis, and hepatocellular dissociation were the main findings raising the suspicion of leptospirosis. Diagnostic confirmation was based on specific immunohistochemical and PCR assays for Leptospira species. Immunolocalization of leptospiral antigens and identification of pathogenic species (L. interrogans species) were important for better understanding the pathogenesis of the disease. One Health-related implications of free-ranging NHPs in anthropized areas and transmission dynamics of human and animal leptospirosis are discussed.

Endemic Xanthium strumarium poisoning in cattle in flooded areas of the Araguari River, Minas Gerais, Brazil.

In this paper, we describe poisoning outbreaks of Xanthium strumarium in cattle on the borders of the Araguari River, Southeastern Brazil. In this region, several hydroelectric plants promote transient flooding, which creates a favorable environment for the invasion of X. strumarium in extensive areas, often as the predominant species in those areas. The outbreaks occurred between July and September (dry season). Bovines of all ages were affected, including suckling animals. Mortality varied from 2% to 5.5%. The animals exhibited ataxia, weakness, loss of balance, recumbency, and the majority were found dead. Laboratory results showed a marked increase in the serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase. Histological and ultrastructural changes in the liver consisted of centrilobular necrosis and hemorrhage. On toxicological evaluation, the dicotyledons contained 0.30 µg/mg of atractyloside and 0.37 µg/mg of carboxyatractyloside. Considerable economic loss has occurred in this region due to the lack of knowledge regarding X. strumarium as a toxic plant and its adaptation to the environmental and climatic conditions of the region, which have made the condition endemic.

Crotalaria spectabilis poisoning in horses fed contaminating oats.

The present report describes the clinical and pathological changes induced by the consumption of oats contaminated with Crotalaria spectabilis seeds by horses. Eighty horses were exposed to oats containing 10 g/kg of C. spectabilis seeds with 0.46% pyrrolizidine alkaloids, and 21 horses died within a 6-month period. Clinical signs included jaundice, apathy, a hypotonic tongue, ataxia, hyporexia, weight loss, aimless wandering, violent behavior, and proprioceptive deficits. Pathological findings were predominant in the liver and included periportal bridging fibrosis, megalocytosis, centrilobular necrosis, and bile stasis. Other findings were Alzheimer's type II astrocytes in the cortex, midbrain, basal nuclei, brainstem and pons; multifocal edema and hemorrhage in the lungs; and degeneration and necrosis of the tubular epithelium of kidneys. Horses are highly sensitive to pyrrolizidine alkaloid-containing plants, and the observed clinical and pathological findings are typical of this poisoning. The seeds were planted, and botanical identification of the adult plants confirmed the diagnosis of C. spectabilis poisoning.

Intersecting Paths of Emerging and Reemerging Infectious Diseases.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shares common clinicopathologic features with other severe pulmonary illnesses. Hantavirus pulmonary syndrome was diagnosed in 2 patients in Arizona, USA, suspected of dying from infection with SARS-CoV-2. Differential diagnoses and possible co-infections should be considered for cases of respiratory distress during the SARS-CoV-2 pandemic.

Eurytrema coelomaticum natural infection in small ruminants: a neglected condition.

Pancreatic eurytrematosis (PE) is an under diagnosed and neglected parasitosis in goats and sheep in the Americas. Clinical and pathological features of PE are not well defined in small ruminants worldwide. Natural cases of PE in small ruminants were detected in the Federal District, Brazil. A survey of necropsy records, including epidemiological and clinicopathological data, in goats and sheep was conducted. Most cases of PE occurred during the rainy season in adult females, with an incidence of 12.9% in goats and 0.8% in sheep. Clinical signs varied from asymptomatic infections to anorexia, lethargy, weakness, marked weight loss and death in some goats. Overall, most cases of PE in goats and sheep were incidental necropsy findings with minor pancreatic lesions. Three goats, however, showed severe chronic pancreatitis, dilation of major pancreatic ducts with numerous trematodes present and marked abdominal fat necrosis. Morphological and molecular characterization of flukes detected Eurytrema coelomaticum. Our findings shed light on the prevalence of E. coelomaticum infections in small ruminants in the region and highlight the possibility of severe and lethal cases in goats. PE must be further investigated in small ruminant populations in relevant livestock production regions of the Americas.

Uraemic Encephalopathy in a Persian Cat with Chronic Kidney Disease.

Uraemic encephalopathy (UE) is rarely associated with acute kidney injury or chronic kidney disease in domestic animals, and we now report the first case in a cat. The animal presented with hypothermia, apathy, lethargy, depression, severe dehydration, uraemic breath, elevated serum urea nitrogen and creatine concentrations, and eventual seizures and coma prior to death. Gross necropsy findings included severe bilateral renal scarring, ulcerative stomatitis and glossitis, and uraemic gastropathy. Microscopic lesions of diffuse interstitial fibrosis, multifocal mineralization and lymphoplasmacytic interstitial nephritis were seen in the kidneys. There was symmetrical, bilateral spongy vacuolation of the white matter of the basal nuclei and cerebellum and Alzheimer type II astrocytes in the cerebral cortex and hippocampus. Glial fibrillary acid protein immunolabelling was absent or faint in astrocytes of the cerebral grey matter. UE should be included in the differential diagnosis in animals with chronic kidney disease and neurological signs.

Squamous cell carcinoma of the footpad with systemic metastasis in a captive crowned solitary eagle (Buteogallus coronatus).

Squamous cell carcinomas (SCC) are one of the most common tumors of the tegument that can have a misdiagnosis of chronic skin wounds. An adult captive crowned solitary eagle presented an indolent wound-like ulcer on the footpad and a fatal outcome. An infiltrating tumoral mass in the foot and multiple tumoral metastatic nodules in visceral organs were detected. The neoplasm was composed of atypical squamous cells with strong positivity for cytokeratin, "keratin pearl" structures, and marked invasion of tissues confirming a diagnosis of metastatic SCC. This might be the first report of an SSC with metastasis on the footpad in a captive Chaco eagle, which is one of the endangered species of birds of prey.

Paraganglioma of the Tongue in a Chow Chow Dog: A Comparison With the Human Counterpart and Literature Review.

Over the last 20 years, substantial knowledge has been developed in Veterinary oncology, and tumors previously reported only in humans have been identified in animals. Primary paragangliomas of the tongue are extremely rare tumors in human beings and have never been reported in animals. A Chow Chow dog showed an ulcerated nodule at the lingual body, deeply infiltrated, which extended to the base of the tongue. A full clinical and pathological investigation was conducted, and a post-surgical follow-up of 6 months did not detect recurrence. Cytological, histological, and immunohistochemical features are presented and support the diagnosis of lingual paraganglioma. The paraganglioma of the tongue reported in this Chow Chow dog shares many similarities with the human counterpart.

An undescribed species of Sarcocystis associated with necrotizing meningoencephalitis in naturally infected backyard chickens in the Midwest of Brazil.

Sarcocistys -associated menigoencephalitis is virtually an unrecognized cause of neurological disease in chickens. An undescribed species of Sarcocystis cause fatal infection in two backyard chickens in the Midwest of Brazil. Infected chickens presented anorexia, weight loss, incoordination, ataxia and opisthotonos. Yellow necrotic foci in the gray and white matter of the telencephalon were the main gross lesion. Microscopically, necrotizing granulomatous and heterophilic meningoencephalitis with intralesional Sarcocystis -like schizonts and mezoites were observed in the central nervous system. Molecular analysis of frozen brain samples of the two chickens was identical and the protozoan was named Sarcocystis sp. Chicken-2016-DF-BR. Complete nested PCR- sequence of Sarcocystis sp. Chicken-2016-DF-BR was equally similar to Sarcocystis anasi (EU553477) and Sarcocystis albifronsi (EU502868). This is the first report of Sarcocistys -associated meningoencephalitis with molecular characterization in backyard chickens.

Anatomopathological changes in canine distemper seropositive dogs and virus detection in sinoatrial nodes / Alterações anatomopatológicas em cães soropositivos para cinomose e detecção de vírus em nódulos sinoatriais

Canine distemper is a viral disease that affects several systems on dogs, among them, the cardiovascular system. The aim of this study was to identify canine distemper virus (CDV) in the sinoatrial node (SAN) of dogs serologically positive for distemper by Polymerase Chain Reaction preceded by reverse transcription (RT-PCR), and to analyze gross and microscopic changes of distemper in the heart and other tissues. SAN and tissue fragments were collected from 17 serologically positive dead animals, necropsied from October 2015 to December 2016. In the heart, right heart dilatation was observed in 13 dogs (76.47%) and left concentric hypertrophy in two dogs (11.76%). Microscopically, lymphocytic myocarditis was observed in four (23.53%) dogs and 41.18% presented viral inclusion corpuscles of CDV in the bladder epithelium. Only one (5.88%) dog presented a 319 bp target fragment for distemper virus using primers CDV 1 and CDV 2 at the sinoatrial node. In conclusion, CDV can be located in the sinoatrial node of naturally infected dogs, as demonstrated in this study by the RT-PCR technique, reinforcing the hypothesis that CDV is capable of causing inflammatory lesions in the sinoatrial node of this species. Macroscopic and microscopic cardiac changes are frequently observed in dogs with distemper, mainly cardiac dilatation and myocarditis. Viral inclusions of CDV in bladder epithelial cells are an important microscopic finding for the diagnosis of distemper.

A cinomose canina é uma doença viral que afeta vários sistemas, dentre eles o cardiovascular. Objetivou-se identificar o vírus da cinomose canina no nó sinoatrial (NSA) de cães sorologicamente positivos para cinomose, através da reação em cadeia da polimerase, precedida de transcrição reversa (RT-PCR), além de analisar os achados macroscópicos e histológicos da cinomose no coração e outros tecidos. Foram coletados fragmentos de tecidos e do NSA de 17 cães sorologicamente positivos para cinomose que vieram a óbito e foram necropsiados no período de outubro de 2015 a dezembro de 2016. No coração observou-se dilatação cardíaca direita em 76,47% dos cães e hipertrofia concêntrica esquerda em 11,76% dos cães. Microscopicamente observou-se miocardite linfocítica em 23,53% dos cães e 41,18% apresentou corpúsculos de inclusão viral no epitélio vesical. Somente um (5,88%) cão apresentou fragmento alvo de 319 bp para cinomose utilizando os primers VCC1 e VCC2, no nó sinoatrial. Conclui-se que o VCC pode localizar-se no nó sinoatrial de cães naturalmente infectados, como demonstrados neste estudo pela técnica de RT-PCR, reforçando a hipótese de que o VCC é capaz de provocar lesões inflamatórias no nó sinoatrial dessa espécie. Alterações cardíacas macroscópicas e microscópicas, principalmente dilatação cardíaca e miocardite, são frequentemente observadas em cães com cinomose. Inclusões virais nas células epiteliais da bexiga são importantes achados microscópicos para diagnóstico da cinomose.

Electrocutions in free-living black-tufted marmosets (Callithrix penicillata) in anthropogenic environments in the Federal District and surrounding areas, Brazil.

Shrinking natural habitats exposes some non-human primates to the risk of accidents associated with electrical transmission lines. We examined dead marmosets (Callithrix penicillata) collected in the region from January 2015 to April 2018 to determine the animals' cause of death and for electrocuted animals we examined the locations the animals had died as well as the configuration of the power lines at these sites. We also recorded the sex of the animal, the body region affected, and characteristics of the injuries. We diagnosed electrocutions in 11% (n = 34) of the marmosets studied. Most of the affected animals were male (n = 22) with single or double sites of injury on the limbs. Animals were injured in urban (n = 26) and peri-urban (n = 8) areas on lower-voltage alternate current lines, and we detected no seasonality or hotspots of electrocution. Our findings suggest that movement along transmission lines composed of bundled conductors is a major factor in electrocutions of marmosets in the Federal District and surrounding areas. The planning of electrical power grid infrastructure should consider arboreal primates to prevent electrocutions.