Pale Areas Research Articles

A Rare Complication in the Oral Local Infiltration Anesthesia.

The present report describes a rare complication named Kuhn anemia, which happened during local infiltration anesthesia of maxillary wisdom tooth. A 24-year-old male was referred for residual crown of left maxillary wisdom tooth and therefore required extraction. Oral examination revealed a buccal impacted left maxillary wisdom tooth (28), severe caries affecting the dental pulp, and pain with percussion. This case was diagnosed as impacted wisdom tooth 28 and pulpitis. Thus, the authors performed an extraction of the 28. After injection of articaine hydrochloride (68mg:1.7mL) containing epinephrine (1:100,000) as local anesthetic, the patient felt pain and heat in the left cheek, and an irregularly shaped pale area appeared on the left cheek. The authors stopped the surgery and comforted him. After a 30-minute break, the cheek turned normal, and abnormal sensation was no longer felt.

Role of Vitamin E And Selenium as an Anti-Stressant in Translocation of Captive Ungulates

Wild ungulates especially in captivity face high stress in translocation that may cause even mortality. Chemical immobilization is employed to minimize stress by using sedatives. Vitamin E and Selenium may have impact on reducing stress. Objectives: To estimate the impact of Vitamin E and Selenium treatment in translocation of captive ungulates. Methods: The study was carried out while planned translocation of 40 ungulates from different zoological gardens of four districts of Punjab to Safari Zoo, Lahore, Punjab, Pakistan was performed. The animals were divided into two equal groups i.e., A and B. Both groups were anesthetized with combination of Ketamine and Xylazine while Vitamin E and Selenium was also injected in group B after anesthesia. Blood samples were also drawn for hemato-chemical analysis in both groups. The necropsy of the dead animals was also done for internal organs and skeletal muscles examination. Results: In the group A, two chinkaras and two spotted deer were found dead at the time of release. The pale areas, hemorrhages and clotted blood were observed in necropsy. The values of Hemoglobin, Total Erythrocyte Count and Packed Cell Volume were moderately varied from the normal in both groups. The group A had greater lymphocyte count and lower neutrophils while in group B, lymphocyte count was lower, neutrophils were higher and Aspartate transaminase (AST), Alanine transaminase (ALT), and cortisol levels were quite higher than normal. Conclusions: Vitamin E and Selenium has positive impact to reduce stress level in translocation of captive ungulates.

The occurrence of myopathies and meat abnormalities in modern broiler farming

Over the past few decades, there has been a significant increase in the production and consumption of poultry meat due to its high-quality nutritional profile, relatively low production costs, and ease of meat processing. This growing demand has led to progressive improvements in genetic selection for fast-growing broilers, triggering several spontaneous idiopathic muscle abnormalities along with an increased susceptibility to stress-induced myopathy. These muscle abnormalities have a negative impact on the quality of both fresh and processed chicken meat, primarily affecting the large breast muscle (m. pectoralis major) of broilers, which is also the most valuable part of the carcass. Frequent meat abnormalities include the occurrence of pale, soft, and exudative meat, primarily characterized by reduced water-holding capacity, while Deep Pectoral Myopathy results in a change in colour and a significant reduction in the attractive appearance of the small breast muscle (m. pectoralis minor). Myopathies labelled as "White Striping" are characterized by superficial white stripes, "Wooden Breast" is marked by pale and bulging areas of significant hardness, while "Spaghetti Meat" is described by the separation of muscle fibres resembling spaghetti pasta. These mentioned abnormalities and myopathies negatively impact the economic aspect of the poultry industry during the removal of affected parts and, furthermore, reduce the qualitative and nutritional value of the meat, posing challenges during technological processes. This paper describes recent findings on the occurrence, characteristics, and prevalence of the most common myopathies affecting modern broiler farming.

Monensin poisoning outbreak in free-ranging and captive birds.

Monensin poisoning is uncommon and has been rarely reported in birds. This work aimed to described clinical-pathological aspects of an outbreak of monensin poisoning in captive and free-ranging birds. Thirty-seven of 600 captive birds fed a diet containing 893.19mg/kg of monensin died within 10 days (mortality 6.17%). There was no ionophore antibiotics on the feed label supplied to captive birds, which established an error in feed production. Necropsies were performed on twelve animals: Muscovy duck (Cairina moschata) (2/12), greater rhea (Rhea americana) (2/12), black-necked swan(Cygnus melancoryphus) (2/12), garganey (Anas querquedula) (1/12), ostrich (Struthio camelus) (1/12), and common pigeon (Columbus livia) (4/12). These four common pigeons were free-ranging birds and died after eating the same contaminated feed. Birds were mainly found dead, however in animals which clinical signs were observed (Columba livia, Rhea americana, Cairina moschata, Anas querquedula, and Struthio camelus), they included incoordination, inability to stand, and intense prostration, that ranged from 24 to 72h until death. Grossly, five birds had focally extensive pale firm areas in the myocardium and two had in the skeletal muscles, one being concomitant lesions. Histologically, muscle necrosis and degeneration were observed in striated musculature (skeletal and/or heart) in all birds analyzed. Monensin poisoning outbreaks can affect free-ranging birds that are fed on external feeders, as well as captive birds, due to an error in the feed formulation.

Amyloid goiter secondary to familial Mediterranean fever with E148Q mutation: A unique case.

Amyloid goiter secondary to familial Mediterranean fever with E148Q mutation: A unique case.

Factors associated with detection of hereditary diffuse gastric cancer on endoscopy in individuals with germline CDH1 mutations

Individuals with germline pathogenic CDH1 variants have a high risk of hereditary diffuse gastric cancer. The sensitivity of EGD in detecting signet ring cell carcinoma (SRCC) in this population is low. We aimed to identify endoscopic findings and biopsy practices associated with detection of SRCC. This retrospective cohort included individuals with a germline pathogenic/likely pathogenic CDH1 variant undergoing at least 1 EGD at Memorial Sloan Kettering Cancer Center between January 1, 2006, and March 25, 2022. The primary outcome was detection of SRCC on EGD. Findings on gastrectomy were also assessed. The study included periods before and after implementation of the Cambridge protocol for endoscopic surveillance, allowing for assessment of a spectrum of biopsy practices. Ninety-eight CDH1 patients underwent at least 1 EGD at our institution. SRCC was detected in 20 (20%) individuals on EGD overall and in 50 (86%) of the 58 patients undergoing gastrectomy. Most SRCC foci were detected in the gastric cardia/fundus (EGD, 50%; gastrectomy, 62%) and body/transition zone (EGD, 60%; gastrectomy, 62%). Biopsy results of gastric pale mucosal areas were associated with detection of SRCC (P< .01). The total number of biopsy samples taken on EGD was associated with increased detection of SRCC (P= .01), with 43% detected when≥40 samples were taken. Targeted biopsy sampling of gastric pale mucosal areas and increasing number of biopsy samples taken on EGD were associated with detection of SRCC. SRCC foci were mostly detected in the proximal stomach, supporting updated endoscopic surveillance guidelines. Further studies are needed to refine endoscopic protocols to improve SRCC detection in this high-risk population.

MicroRNAs: Emerging players in the pathogenesis of vitiligo.

Vitiligo is an autoimmune skin disease characterized by presence of pale patchy areas of depigmentation. MicroRNAs (miRNAs) are important regulators of gene expression and play significant roles in diverse biological and pathological processes. Accumulating evidence has shown that miRNAs were differentially expressed in skin lesions and peripheral blood mononuclear cells of patients with vitiligo. In particular, miRNAs are significantly correlated with the development and progression of vitiligo. The abundance of some miRNAs in serum was also correlated with the vitiligo lesion severity, indicating that miRNAs might serve as prognostic biomarkers. Importantly, the direct involvement of miRNAs in the pathogenesis of vitiligo has been demonstrated. For example, increased expression of miR-25 contributes to vitiligo through promoting the dysfunction and oxidative stress-induced destruction of melanocytes. However, there are limited studies on the function and mechanism of deregulated miRNAs in vitiligo. Further studies are required to establish clinical applications of miRNAs for vitiligo. More in-depth investigations of miRNAs are needed for the understanding of the pathogenesis of vitiligo and the development of novel therapeutic targets. This present review summarizes the current literature on the deregulation and pathogenic roles of miRNAs in vitiligo. We also highlight the potential clinical applications of miRNAs in patients with vitiligo.

Eosinophilic Granulomatous Myocarditis in Two Pigs

Eosinophilic myocarditis is a human condition that has been rarely documented in animals. We now report two unrelated porcine cases of idiopathic eosinophilic granulomatous myocarditis that resembled the human disease and which were associated with sudden death. The most relevant gross finding in both cases was marked cardiomegaly, accompanied by raised, multifocal to coalescent small white nodules (1-2mm) and poorly demarcated multifocal pale areas in the epicardium. Histologically, there were multifocal to coalescent areas of cardiomyocyte loss with replacement by an intense inflammatory infiltrate of eosinophils and epithelioid macrophages, and proliferation of fibrous connective tissue. Immunohistochemistry for porcine circovirus type 2 (PCV2) and Toxoplasma gondii, in-situhybridization and quantitative polymerase chain reaction tests for PCV2 and porcine circovirus type 3 and aerobic bacterial culture on myocardium samples were negative.

HYDROPERICARDIUM HEPATITIS SYNDROME IN CHICKENS/ARTICLE REVIEW

Hydropericardium hepatitis syndrome is an acute infectious disease of broiler chickens characterized by high mortality, accumulation of fluids in the pericardial sac and necrosis of hepatocytes, during 1987 the virus was isolated from chickens in Angara near Karachi city in Pakistan and the disease takes it is name of this city. It is reported in China in 2015 in birds of 3-6 weeks in broiler chickens causing sudden death with high mortality reaches up to 75%. Avian adenovirus divided into 3genrea: Atadodenovirus, Siadenovirus, and Aviadenovirus the last one divided in to 5 species A to E subgroup1 strain 4 causing (Hydropericardium hepatitis syndrome). Subgroup 2 causing turkey (hemorrhagic enteritis, marble spleen disease). Subgroup 3 causing (Egg drop syndrome EDS). strain D and E produce inclusion body hepatitis while strain 1 causing (quill bronchitis). outbreaks of the disease producing economic losses for the poultry industry. Both vertical and horizontal transmission have an important role in the spreading of the disease. gross examination of the liver showing friable, enlargement, paleness of the liver. the kidney is swelling and hemorrhage with pale areas of necrosis in the parenchyma, pericardium is filled with clear or jelly fluids but histological changes showing hepatitis, nephritis and presence of basophilic intranuclear inclusion bodies. There are many tests can be used for the diagnosis such as PCR, ELISA, neutralization test. We concluded that the disease has economic importance due to high mortality and high losses of chicken’s meat production, so, biosecurity and vaccination are essential for preventing the infection.

Outbreak of toxoplasmosis associated with muscular lesions in finishing pigs caused by an atypical Toxoplasma gondii genotype.

Toxoplasma gondii infections are usually asymptomatic in pigs, and an acute clinical disease is rare in this host. This study aimed to determine the pathological and molecular aspects of an outbreak of fatal systemic toxoplasmosis in finishing pigs in Brazil. The outbreak occurred on a commercial finishing pig farm in the state of Santa Catarina in southern Brazil. The farm had 1500 pigs and 3.8% of mortality rate during the outbreak. The pigs had fever, anorexia, apathy, and locomotor deficits. Seven pigs were necropsied. Gross findings included multifocal to coalescent pale areas in skeletal muscles, lymphadenomegaly, hepatosplenomegaly, and non-colapsed lungs. The histological findings included granulomatous lymphadenitis, hepatitis and splenitis, necrotizing myositis, and lymphoplasmacytic interstitial pneumonia. Lung and liver lesions were occasionally accompanied by T. gondii parasitic structures. Positive immunolabeling for T. gondii tachyzoites and encysted bradyzoites was detected in all examined pigs. PCR-RFLP (11 markers) and microsatellite analysis (15 markers) identified the non-archetypal genotype #278 in pigs. This is the first report of systemic toxoplasmosis in pigs with muscle lesions and additionally shows the diversity of disease-causing T. gondii genotypes circulating in animals in Brazil.

An Outbreak of Gout in Kadaknath Birds: A Pathomorphological Study

The present study is an investigation to ascertain the cause of death of 40 Kadaknath birds whose carcass es were brought for the post mortem to the Department of Veterinary Pathology, College of Veterinary Science, GADVASU, Ludhiana in October, 2021 with a history of dull appearance, reduced feed and water intake. Detailed necropsy examination was carried out and the tissues were collected for histopathological examination. Gross pathological findings revealed dry and white chalky patches of urate crystals on the serosal surface of various tissues viz. liver, heart, lungs, kidney, spleen, intestine and joints. Both the kidneys were enlarged and congested showing nephropathy. Ureters were filled with urate crystals. Haematoxylin & Eosin stained tissues of liver, heart, lungs, kidney, spleen and intestine revealed acellular pale area with empty spaces in radiating pattern which represent the space left over by the dissolved uric acid crystals during processing. Deglantha staining of the tissues revealed sharp needle shaped black coloured uric acid crystals. Therefore, it was concluded that the birds died due to visceral gout as these uric acid crystals are toxic and damage the organs.

A new species of stone loach of the genus Mustura (Teleostei: Nemacheilidae) from Chindwin River drainage, Manipur, north-eastern India.

Mustura taretensis, a new nemacheilid loach, is described from the Taret River, a tributary of the Yu River, Chindwin River drainage, Manipur, India. The new species is distinguished from all its congeners by a unique combination of the following characters: body with 1213 irregular dark-brown blotches or bars on flank, alternating with 1116 irregular dark-brown saddles on the back; dorsum of head with a distinctly visible rhomboid dark-brown mark encircling a pale oval area on the nape; dorsal fin with 9 or 10 branched rays; lateral line complete; a well-developed free posterior chamber of air bladder, the halves of air bladder capsules connected by a manubrium; poorly developed processus dentiformis; suborbital flap present in males; and body depth 12.816.0 % SL. The generic status of Mustura chindwinensis, M. dikrongensis, M. tigrina and M. tuivaiensis are also discussed in the paper.

Histology and clinical imaging lifecycle of black pigment in fibrosis secondary to neovascular age-related macular degeneration

PurposeMelanotic cells with large spherical melanosomes, thought to originate from retinal pigment epithelium (RPE), are found in eyes with neovascular age-related macular degeneration (nvAMD). To generate hypotheses about RPE participation in fibrosis, we correlate histology to clinical imaging in an eye with prominent black pigment in fibrotic scar secondary to nvAMD. MethodsMacular findings in a white woman with untreated inactive subretinal fibrosis due to nvAMD in her right eye were documented over 9 years with color fundus photography (CFP), fundus autofluorescence (FAF) imaging, and optical coherence tomography (OCT). After death (age 90 years), this index eye was prepared for light and electron microscopy to analyze 7 discrete zones of pigmentation in the fibrotic scar. In additional donor eyes with nvAMD, we determined the frequency of black pigment (n = 36 eyes) and immuno-labeled for retinoid, immunologic, and microglial markers (RPE65, CD68, Iba1, TMEM119; n = 3 eyes). ResultsDuring follow-up of the index eye, black pigment appeared and expanded within a hypoautofluorescent fibrotic scar. The blackest areas correlated to melanotic cells (containing large spherical melanosomes), some in multiple layers. Pale areas had sparse pigmented cells. Gray areas correlated to cells with RPE organelles entombed in the scar and multinucleate cells containing sparse large spherical melanosomes. In 94% of nvAMD donor eyes, hyperpigmentation was visible. Certain melanotic cells expressed some RPE65 and mostly CD68. Iba1 and TMEM119 immunoreactivity, found both in retina and scar, did not co-localize with melanotic cells. ConclusionHyperpigmentation in CFP results from both organelle content and optical superimposition effects. Black fundus pigment in nvAMD is common and corresponds to cells containing numerous large spherical melanosomes and superimposition of cells containing sparse large melanosomes, respectively. Melanotic cells are molecularly distinct from RPE, consistent with a process of transdifferentiation. The subcellular source of spherical melanosomes remains to be determined. Detailed histology of nvAMD eyes will inform future studies using technologies for spatially resolved molecular discovery to generate new therapies for fibrosis. The potential of black pigment as a biomarker for fibrosis can be investigated in clinical multimodal imaging datasets.

Schmallenberg virus infection suspected in a calf born to an imported heifer.

Schmallenberg virus infection suspected in a calf born to an imported heifer.

How to Manage the Large Nonpedunculated Colorectal Polyp

How to Manage the Large Nonpedunculated Colorectal Polyp

Sepse por Yersinia enterocolitica em um feto equino abortado: relato de caso

ABSTRACT Yersinia enterocolitica is a bacterium with zoonotic potential and there are no previous records of this bacteria being isolated from aborted foals. This report aims to describe a case of sepsis due to Y. enterocolitica in a seven month old aborted equine. The fequinoetus was submitted to necropsy and samples of all the organs were collected for the histological exam. Samples of liver, lung, placenta, and stomach contents were collected for bacterial culture. Macroscopically, the liver was enlarged with yellowish heterogeneous color, heart with pale myocardial areas; lungs not collapsed, heavy and shiny, thickened umbilical cord covered with fibrin and pus. Histopathologically, there was moderate multifocal necrosuppurative myocarditis and thrombosis, moderate diffuse suppurative bronchopneumonia, mild multifocal fibrinonecrotic hepatitis, and moderate diffuse necrosuppurative omphalitis with intralesional bacterial myriads and thrombosis. Mild multifocal suppurative placentitis, nephritis, myositis, cystitis, and dermatitis were also observed, in addition to mild diffuse lymphoid rarefaction. The microbiological evaluation identified Y. enterocolitica in the liver, lung, and stomach fluid. This is the first report of sepsis due to Y. enterocolitica causing an abortion in a horse. This bacterium has zoonotic importance; therefore, it should be investigated in abortion in this species, serving as a differential diagnosis in reproductive disorders.

Chagas disease in urban and peri‑urban environment in the Amazon: Sentinel hosts, vectors, and the environment

Chagas disease is an anthropozoonosis, caused by a flagellated protozoan, Trypanosoma cruzi, in which the enzootic cycle occurs between mammals and triatomines. Two dogs with a history of sudden death were necropsied at the Federal University of Pará (UFPA). One dog had a pale area in the myocardium, which on histopathological examination showed a T. cruzi amastigote nest; immunohistochemistry (IHC) analysis characterized it as acute Chagas disease (ACD). The second dog showed no macroscopic changes. Microscopically, a few cardiomyocytes were replaced by adipocytes, and IHC result was negative for T. cruzi. However, results of polymerase chain reaction (PCR) of the cardiac tissue of both dogs was positive for T. cruzi DNA. After that, an epidemiological study was conducted in the region. For this study, we selected four areas in Castanhal. One of the four areas (Area 1) is where one of the dogs lived. The other three areas were chosen because they were recently deforested for housing. Blood samples were collected from dogs, cats, wild small mammals (marsupials and rodents), and the digestive tract of triatomines. Nested PCR was performed on all the blood samples and the triatomine digestive tracts. In Area 1, T. cruzi DNA was detected in 50% (12/24) of the tested dogs, in the only tested cat (1/1), 50% (1/2) of the tested marsupials (Didelphis marsupials), and 100% of the captured triatomines (Rhodnius pictipes) (2/2). In Area 2, T. cruzi DNA was not detected in any of the 11 (0/11) dogs and two marsupials tested (0/2), and no triatomines were found in this area. In Area 3, T. cruzi DNA was detected in 42.25% (30/71) of the dogs, in 66,6% (2/3) of the cats, the only captured marsupial (D. marsupialis) (1/1), and all three triatomines (3/3) (R. pictipes) tested. In Area 4, the two dogs tested were negative (0/2), 25% (1/4) of the captured marsupials (D. marsupialis) was positive, and no triatomine was captured in this area. The data demonstrate the importance of detecting T. cruzi in dogs, cats, small rodents, and marsupials in the Amazon metropolitan areas, where ecotopes carry reservoirs and vectors capable of participating in the Chagas disease cycle. The proximity between humans and T. cruzi vectors in these places might contribute to increased disease transmission risk and maintenance of agents. It was noted that high-standard condominiums, previously thought to reduce the risk for this disease, presented a new epidemiological risk. The presence of T. cruzi DNA in a dog who, a year earlier had tested negative, when another dog in the same house died of ACD, shows that the transmission cycle is present and active, with a high possibility of disease transmission to animals and humans.

A uniquely patterned new species of Emesis from Honduras (Riodinidae).

Emesis eleanorae Gallardo & Grishin n. sp. is described from western Honduras. It differs from other species of Emesis Fabricius, 1807 in having a row of prominent iron-gray crescent-shaped postdiscal spots on both wings above, outlined by paler areas basad and mirrored as merlot-colored spots below, with the largest by the forewing costa, and in its females being bright golden-orange in color. Genomic sequence analysis of Emesis reveals that the new species belongs to the subgenus Aphacitis Hübner, [1819] and is sister to the clade containing Emesis diogenia Prittwitz, 1865 and Emesis heteroclita Stichel, 1929, and the clade of these three species is sister to Emesis vulpina Godman & Salvin, 1886.

Abortion in Captive Gray Brocket Deer (Mazama gouazoubira) Associated with Colloid Goiter, Hemonchosis and Necrotizing Rumenitis

Background: The gray brocket deer (Mazama gouazoubira) is a specie that shows great adaptability in different habitats and it is the most abundant deer specie in South America. The present work describes for the first time a case of abortion followed by death associated with colloid goiter, massive hemonchosis and necrotizing rumenitis in a captive female gray brocket deer. Case: A 4-year-old female gray brocket deer (M. gouazoubira) raised in captivity had a history of abortion during the last third of gestation. The animal was kept in an enclosure together with 3 other gray brockets deers, being 1 male of the same age and 2 juvenile brocket deer of approximately 1 and 2 years old. The animals were fed with concentrated used as cattle feed and dewormed annually with 1% Ivermectin. The animals' enclosure had vegetation cover formed by grasses and soil. The animals appeared healthy with no behavioral changes. The day after the stillbirth, the mother was found dead in the enclosure and sent to the animal pathology sector of the University of Vila Velha (UVV), Brazil. Necropsy revealed that thyroid lobules were highly increased in volume and histopathological findings were compatible with colloid goiter. A large number of nematodes were found in the abomasal content,totalizing 11,626 helminths, which were morphologically characterized as Haemonchus contortus. Grossly, the serous and ruminal mucosa exhibited an extensively reddish focal area with irregular contour, surface ulceration and a firm consistency. Microscopically, a severe necrotizing rumenitis was diagnosed. The liver showed pale multifocal areas on the subcapsular surface,friable to the touch which deepened when cut. Histopathological analysis revealed an accentuated multifocal panlobular coagulative necrosis, characterizing an acute liver necrosis.Discussion: Iodine is a mineral of great importance for thyroid hormones synthesis and your requirements are higher during pregnancy and lactation. Diets deficient in iodine causes a reduction in the basal activity of the hormones triiodothyronine (T3) and thyroxine (T4) and over-stimulation of the thyroid by thyroid stimulating hormone (TSH), resulting in goiter. In the present case, it is possible that the shortage of iodine in diet caused a goiter and, as a consequence, triggered the abortion. Haemonchus contortus is a pathogenic nematode of small ruminants, leading to decreased productivity and death in some cases as a result of anemia and hypoxia. The contact between domestic and wild animals, resulting in the emergence of infectious diseases and the spread of pathogens among species. In the present case, manual counting accounted for 11,626 H. contortus larvae, characterizing a massive infection and justifying the condition of severe anemia. The high parasitic load shown in this case points out this parasite's importance related to this species in captivity. In general, inflammatory lesions in the rumen are results of excessive intake of fermentable carbohydrates, which leads to a considerable decrease in ruminal pH and leads to a high proliferation of lactic acid bacteria. This lesion has been previously reported in cervids. This case of comorbidities demonstrates that failures in nutritional and health handling, may cause simultaneous multiple diseases leading to death. Preventive measures for helminth parasite control and a proper feeding management with an adequate diet must be provided in order to preserve the species in captivity. Keywords: colloid goiter, abortion, cervids, Haemonchus contortus.

Lasalocid Poisoning in Buffalo Calves in the State of Pará, Brazil

Background: Ionophore antibiotics are food additives with coccidiostatic or antimicrobial action; they are also used as growth promoters, ruminal pH regulators, volatile fatty acid molar modifiers, and methanogenesis reducers. However, these compounds have the potential to cause microbial resistance, in addition to the risk of intoxication. Ionophore poisoning may be caused by excessive intake, sensitivity of certain animal species, and concomitant use with other drugs. In Brazil, cases of ionophore poisoning in buffalos are rare. This study aims to describe the epidemiological, clinical, and pathological findings of lasalocid poisoning in buffalo calves.Case: A visit was made to a farm in the municipality of Mojú, Pará state to care for Murrah buffalo calves. After weaning, the buffalos were grazed in paddocks with Panicum spp., and received a supplement of mineral, protein, and vitamin. This supplement contained, per kg, 250 g PB, 50 g Ca, 20 g P, 8 g S, 39 g Na, 20 mg Co, 557 mg Cu, 200 mg Fe, 12.4 mg Se, 2040 mg Zn, 0.19 mg biotin, 26750 IU of vitamin A, 4175 IU of vitamin D, 155 IU of vitamin E and 300 mg/kg of lasalocid. The product was made available to all calves, at 1-2 g/kg body weight (BW), according to the manufacturer's recommendations. Older calves were raised together with those less than 30 days old; as a result, the older calves tended to eat more, which could lead to a supplementation consumption of more than 1 kg body weight per animal per day. It was reported that between 40 and 60 days after the introduction of this supplement, 16 calves fell ill and died due to apathy, motor instability, tremors, and distended neck. The herd had a mortality rate of 33.3%. Two calves underwent a necroscopic examination at the Pathology Section of the Veterinary Institute of the Federal University of Pará. Macroscopic examination revealed extensive pale areas in the skeletal muscles, myocardium, and tongue. Fragments of these muscles and various organs were collected, fixed in 10% buffered formalin, processed according to the routine histological technique, and stained with hematoxylin-eosin and Masson's trichrome stain. Microscopic examination of the histologic samples revealed foci of muscle atrophy and necrosis characterized by an increase in cytoplasmic eosinophilia associated with the loss of stretch marks, and hyperchromatic nuclei that were displaced to the periphery. The necrosis of the muscle fibers was highlighted by Masson's trichrome staining.Discussion: The diagnosis of lasalocid poisoning in buffalo calves was based on epidemiological data, clinical findings, results of macroscopic and histopathological examination, and based on the estimated ionophore intake, obtained directly from the supplement label and by the calf's handler. Based on the absence of stratification of the calves by similarity of age and because the buffalo calves older than 30 days could eat more than 1 kg of the supplement (containing 300 mg/kg of lasalocid), it was possible to estimate the intake of lasalocid per kg CP (body weight). Therefore, the intake of lasalocid by a 70-kg buffalo calf in approximately 90 days and daily supplement consumption between 1 and 1.5 kg would be between 4.2 and 6.4 mg/kg of body weight. This report reinforces that notion that buffalo calves should never ingest ionophores; however, if necessary, strict protocols must be followed to avoid poisoning in these animals. This study highlighted the fact that stratification of buffaloes by different age groups during feeding became a risk factor that allowed greater consumption by older animals; this led to the estimated consumption of 4.2-6.4 mg/kg of lasalocid.Keywords: ionophores, ruminants, buffalo calves, muscle necrosis.Descritores: ionóforos, ruminantes, bezerros búfalos, necrose muscular.Título: Intoxicação por lasalocida em bezerros búfalos no Estado do Pará, Brasil