An epidemic of early fetal loss (EFL), late fetal loss (LFL), fibrinous pericarditis, and unilate... more An epidemic of early fetal loss (EFL), late fetal loss (LFL), fibrinous pericarditis, and unilateral uveitis which occurred during the spring of 2001, are together now known as the mare reproductive loss syndrome (MRLS). A similar epidemic with less intensity was reported during the same period of time from southern Ohio, West Virginia, and Tennessee. The same syndrome with lesser intensity recurred in 2002. The estimated economic loss from the syndrome in 2001 and 2002 together was approximately $500 million. Both EFL and LFL were characterized by the absence of specific clinical signs in aborting mares. Nonhemolytic Streptococcus spp. and Actinobacillus spp. accounted for 65% of the organisms isolated from fetuses submitted for a postmortem during the MRLS period in 2001 and 2002. The pathologic findings in fetoplacental units of LFL included bronchopneumonia and funisitis, and there were no findings in EFL. Epidemiologic studies conducted in 2001 suggested an association between the presences of eastern tent caterpillars (ETC) in pastures with MRLS. Experimental studies in pregnant mares by exposure to ETC, or administration by stomach tube or with feed material, reproduced EFL and LFL. Similar experimental studies in mouse, rats, and goats with ETC were unsuccessful. Currently, 2 hypotheses are proposed for MRLS. One hypothesis proposes that an ETC-related toxin with secondary opportunistic bacterial invasion of the fetus leads to MRLS. The second hypothesis suggests that a breach of gastrointestinal mucosal integrity by hairs of ETC leads to a bacteremia and results in MRLS. In 2004, a similar equine abortion storm was reported from Australia and caterpillar exposure was identified as a risk factor for the abortion. In 2006, the syndrome was observed in Florida and New Jersey.
Aflatoxicosis was diagnosed in a small herd of cattle having access to moldy, unharvested sweet c... more Aflatoxicosis was diagnosed in a small herd of cattle having access to moldy, unharvested sweet corn. Necropsy of 1 cow that died revealed anasarca and a pale tan liver. In this cow, microscopic examination revealed edema of all soft tissues and liver lesions consistent with aflatoxicosis. Samples of corn taken from the field contained 2,365 ng of aflatoxin/g of corn. Weather conditions were conducive to the formation of aflatoxins by Aspergillus flavus and A parasiticus.
Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pieuropneumoni... more Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pieuropneumoniae, serotype 5. At three, six, 12, and 18 hours and one, two, four and seven days after exposure to haemophili a pair of animals were killed and necropsied. Pulmonary oedema with multifocal petechial haemorrhages and a diffuse neutrophilic bronchiolitis and alveolltis were observed at three and six hours after infection.•'ocal areas of coagulative necrosis developed in areas of intense suppuration at 12 and 18 hours after infection. At one and two days after infection, necrotic areas were surrounded by dense bands of degenerating leucocytes and contained unidentifiable round and elongated cells characteristic of this disease. In subacute lesions a thick layer of granulation tissue formed around the outer margin of developing abscesses. Most of the round and elongated cells in alveolar exudates could not be idelltified by enzyme histochemistry or electron microscopic examination. Neutrophils in various stages of degeneration and deterioration provided strong evidence that some of the cells were of this type. These findings suggest that neutrophils may play an early and significant role in development of lesions.
A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondar... more A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondary to dystocia. The foal developed a head tilt, seizures and watery diarrhoea during hospitalisation and died at 7 days of age. Histological examination of the brain and spinal cord revealed a suppurative meningoencephalomyelitis with vasculitis, and numerous intralesional, gram-negative bacilli. Similar microscopic lesions were noted in the lungs, renal medullary interstitium, and umbilicus. Bacilli in the brain, spinal cord and umbilicus were identified immunohistochemically as Salmonella group B. Salmonella agona was isolated in pure culture from the brain, lung, liver, kidney, and intestine. This is the first report of meningoencephalomyelitis and septicaemia due to Salmonella infection in an equine neonate.
-Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage ... more -Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses by Sweeney, CR; Hall, J.; Fisher, JRS; Leary, HJ III; Soma, LR; Spencer, PA (Oct 1988) in English
Respiratory syncytial virus was the cause of a severe epizootic of bovine respiratory tract disea... more Respiratory syncytial virus was the cause of a severe epizootic of bovine respiratory tract disease. The virus, isolated from a sick cow during the epizootic, produced cytopathic effect in a bovine turbinate cell line 14 days after it was inoculated. Additional support for the diagnosis came from the results of pathologic and serologic examinations. Lesions consistently present were severe necrotizing bronchiolitis and epithelial syncytia projecting from bronchiolar and alveolar walls. Also, in the cow from which the virus was isolated, there was tracheitis with a syncytial-like change involving the mucosal epithelium.
Ivermectin is a semisynthetic macrocyclic lactone anthelmintic of the avermectin family derived f... more Ivermectin is a semisynthetic macrocyclic lactone anthelmintic of the avermectin family derived from Streptomyces fermentation products. Avermectins are used as antiparasitic agents in domestic animals; although considered relatively safe, one must consider animal species, breed, weight, and age in dosage determinations. In January 2006, two canines were presented to the UK Livestock Disease Diagnostic Center after dying from suspected ivermectin overdoses [30-50 mg/kg body weight]. To confirm this clinical diagnosis we developed a rapid, sensitive semiquantitative ElectroSpray Ionization-Mass Spectrometry (ESI/MS) method for ivermectin in canine tissue samples. Pharmaceutical ivermectin contains two ivermectins differing by a single methyl group, and each compound forms interpretation-confounding adducts with tissue Na + and K + ions. We now report that ivermectin administration was clearly confirmed by comparison with standard and dosage forms of ivermectin, and simple proportionalities based on mass spectral intensity of respective molecular ions allowed semiquantitative estimates of injection site tissue concentrations of 20 and 40 µg/g tissue (wet weight) in these animals, consistent with the history of ivermectin administration and the clinical signs observed. There is a distinct need for both rapid detection and confirmation of toxic exposures in veterinary diagnostics, whether for interpretation of clinical cases antemortem or for forensic reasons postmortem. It is vital that interpreters of analytical results have appropriate guidance in the scientific literature and elsewhere so as to enable clear-cut answers. The method presented here is suitable for routine diagnostic work in that it allows rapid extraction of ivermectin from tissue samples, avoids the need for high-performance liquid chromatography and allows ready interpretation of the multiple ivermectin species seen by ESI + MS/MS in samples originating from veterinary dosage forms.
Actinobacillus equuli is a rare cause of peritonitis in adult horses. Septicemia and peritonitis ... more Actinobacillus equuli is a rare cause of peritonitis in adult horses. Septicemia and peritonitis due to A. equuli were diagnosed at necropsy in an 8-year-old Saddlebred mare. The origin of the infection was not known; however, small necrotic colonic mucosal lesions presumed to have been caused by phenylbutazone treatment may have allowed bacterial invasion. A good response to antimicrobial treatment has been documented in the small numbers of previously reported acute cases of peritonitis. Because it is potentially treatable, it is important for pathologists and clinicians to identify horses with A. equuli peritonitis.
Abstract. Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5... more Abstract. Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5 days after consuming corn screenings. These postmortem observations were reproduced in younger swine (16-24 kg) that died within 1 week when fed the corn screenings under experimental conditions. Additionally, pulmonary edema and hydrothorax occurred in a pig (7.1 kg) that died after receiving 4 daily intravenous injections of fumonisin B,. A fungus was isolated from the corn screenings that is identical to Fusarium moniliforme MRC-826 in colony morphology and under microscopic examination. Simultaneous epizootics occurred on 2 southwest Georgia farms, resulting in the deaths of 34 mature swine. Four cadavers representing both farms were submitted for diagnostic workup. At necropsy, the gross pathologic changes observed were remarkably similar. These changes included extremely marked pulmonary edema and massive hydrothorax. The thoracic cavities were overfilled with golden-yellow liquid...
-Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage ... more -Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses by Sweeney, CR; Hall, J.; Fisher, JRS; Leary, HJ III; Soma, LR; Spencer, PA (Oct 1988) in English
Pathological, entomological and avian investigations were conducted during the summer of 2002, in... more Pathological, entomological and avian investigations were conducted during the summer of 2002, in a horse farm that had four cases of West Nile virus (WNV) infection in horses. All the four horses had encephalitis and WNV infection was confirmed by RT-PCR and in situ hybridization procedure. Forty-seven per cent of house sparrows that resided on the farm were tested positive for WNV infection. Mosquitoes (98% Culex pipiens) collected by trapping at the farm, during this period were positive for WNV. The meteorological data for year 2002 were compared to previous 16 years. The precipitation and atmospheric temperature were found to be reduced and higher respectively, indicating a drier summer than the prior 16 years, which may have been a contributing factor for the outbreak. None of the horses on these premises had been vaccinated for WNV disease.
Journal of Veterinary Diagnostic Investigation, 2005
During the spring and summer of 2001 and in association with the mare reproductive loss syndrome,... more During the spring and summer of 2001 and in association with the mare reproductive loss syndrome, 22 terminal and 12 clinical cases of equine pericarditis were diagnosed in central Kentucky. Actinobacillus species were the principal isolates from 8 of 10 nontreated, terminally affected and 3 of 10 clinically affected horses. Enterococcus faecalis and Streptococcus zooepidemicus were cultured from the remaining 2 nontreated terminal cases. No viruses were isolated in tissue culture. Nucleic acid of equine herpesvirus-2 was detected in pericardial and tracheal wash fluids of 3 and 1 individuals, respectively. Microscopic alterations in sections of heart and parietal pericardium were consistent with chronic fibrinous bacterial pericarditis. This report confirms a significant role of Actinobacillus species in equine pericarditis and describes an epidemic of this infrequently observed syndrome in the horse.
Journal of Veterinary Diagnostic Investigation, 1996
Proliferative enteropathy (proliferative enteritis, proliferative ileitis, intestinal adenomatosi... more Proliferative enteropathy (proliferative enteritis, proliferative ileitis, intestinal adenomatosis) has been reported in several animal species including the pig,1 2 dog, 2 foal, 3 blue fox, 5 guinea pig, 4 ferret, 6 hamster, 7 and rabbit. 13 The disease is characterized by adenomatous hyperplasia of crypt epithelial cells in the ileum and colon with intracytoplasmic curved bacteria resembling Campylobacter species. In the single case previously reported in a foal, Campylobacter-like organisms were demonstrated within the cytoplasm of enterocytes by spirochete stains and electron microscopy. 3 In a study using cloned DNA probes to isolated Campylobacter-like organisms, there was failure of the probes to hybridize with common porcine Campylobacter species, suggesting the causative agent to be an unidentified or uncultured species. 8 This finding, along with DNA sequencing and structural characteristics, resulted in this organism being named ileal symbiont intracellularis. 9 Subsequently, the organism was described and classified as a new genus and species, Lawsonia intracellularis. 1 1 An unweaned 5-month-old mixed-breed female foal with a history of anorexia, lethargy, and profuse watery diarrhea of greater than 1-week duration was presented to the University of Kentucky, Livestock Disease Diagnostic Center, for necropsy. Treatment had not been attempted. At necropsy, the foal was thin with readily apparent skeletal muscle atrophy. Gross lesions were confined to the small intestine. There was irregular thickening of the jejunum and ileum with the ileum being more severely affected. Lesions in the midjejunum were multifocal in nature and consisted of areas of discoid mucosal thickening, whereas the distal jejunum and ileum contained diffuse mucosal thickening resulting in a rugose pattern (Fig. 1). Samples of the small intestine, stomach, cecum, colon, brain, heart, lung, kidney, and spleen were placed in 10% neutral buffered formalin and, following fixation, were embedded in paraffin, sectioned at 5 µm, and stained with hematoxalin and eosin. In addition, selected sections of small intestine were stained by the Warthin-Starry silver impregnation method for bacteria. Pieces of formalinfixed small intestine were postfixed in osmium tetroxide and embedded in epoxy resin. Thin sections were stained with uranyl acetate and lead citrate. Histopathologically, the affected mucosa was thickened and consisted of hyperplastic glandular structures lined by immature epithelial cells (Fig. 2). The hyperplastic epithelium resulted in distortion of the normal villous structure. Some
Journal of Veterinary Diagnostic Investigation, 2004
During the 2002 and 2003 foaling seasons, Cellulosimicrobium ( Cellumonas) cellulans (formerly Oe... more During the 2002 and 2003 foaling seasons, Cellulosimicrobium ( Cellumonas) cellulans (formerly Oerskovia xanthineolytica) was the principal microorganism isolated from fetal tissues or placentas from cases of equine abortion, premature birth, and term pregnancies. Significant pathologic findings included chronic placentitis and pyogranulomatous pneumonia. In addition, microscopic and macroscopic alterations in the allantochorion from 4 of 7 cases of placentitis were similar to those caused by Crossiella equi and other nocardioform bacteria. This report confirms a causative role of C. cellulans infection in equine abortion.
Journal of Veterinary Diagnostic Investigation, 2003
Rhodococcus equi is a bacterial pathogen, ubiquitous in the soil, that infects many foals and is ... more Rhodococcus equi is a bacterial pathogen, ubiquitous in the soil, that infects many foals and is lethal to some. Transferrin is an iron-binding protein that has bacteriostatic properties in the blood. Transferrin is also highly polymorphic in most species, with 15 variants identified for horses using biochemical methods, and may be responsible for variation in susceptibility to bacterial pathogens. The objectives of this study were 1) to compare biochemical typing with DNA typing of transferrin, 2) to determine if transferrin DNA from archival paraffin-embedded tissue samples can be recovered and typed with molecular methods, and 3) to determine if there was an association between foal death caused by R. equi and transferrin type. Comparing biochemical methods and DNA sequencing for 41 horses demonstrated correspondence between the typing methods. The allele frequency of archival paraffin-embedded tissue samples from 34 Thoroughbred foals that succumbed to R. equi showed an excess o...
Journal of Veterinary Diagnostic Investigation, 2006
A 5-day-old Angus calf was submitted to the necropsy service at the University of Kentucky Livest... more A 5-day-old Angus calf was submitted to the necropsy service at the University of Kentucky Livestock Disease Diagnostic Center. At birth, the calf was noted to have 2 scrota. Five days post-calving the calf developed severe tenesmus and an umbilical infection. Clinical examination revealed atresia ani. At necropsy, complete diphallus, imperforate ani (type 2 atresia ani), and remnants of 2 scrota were identified. This report describes the gross pathologic appearance of a rare case of complete diphallia, imperforate ani (type 2 atresia ani), and an accessory scrotum in a 5-day-old calf.
An epidemic of early fetal loss (EFL), late fetal loss (LFL), fibrinous pericarditis, and unilate... more An epidemic of early fetal loss (EFL), late fetal loss (LFL), fibrinous pericarditis, and unilateral uveitis which occurred during the spring of 2001, are together now known as the mare reproductive loss syndrome (MRLS). A similar epidemic with less intensity was reported during the same period of time from southern Ohio, West Virginia, and Tennessee. The same syndrome with lesser intensity recurred in 2002. The estimated economic loss from the syndrome in 2001 and 2002 together was approximately $500 million. Both EFL and LFL were characterized by the absence of specific clinical signs in aborting mares. Nonhemolytic Streptococcus spp. and Actinobacillus spp. accounted for 65% of the organisms isolated from fetuses submitted for a postmortem during the MRLS period in 2001 and 2002. The pathologic findings in fetoplacental units of LFL included bronchopneumonia and funisitis, and there were no findings in EFL. Epidemiologic studies conducted in 2001 suggested an association between the presences of eastern tent caterpillars (ETC) in pastures with MRLS. Experimental studies in pregnant mares by exposure to ETC, or administration by stomach tube or with feed material, reproduced EFL and LFL. Similar experimental studies in mouse, rats, and goats with ETC were unsuccessful. Currently, 2 hypotheses are proposed for MRLS. One hypothesis proposes that an ETC-related toxin with secondary opportunistic bacterial invasion of the fetus leads to MRLS. The second hypothesis suggests that a breach of gastrointestinal mucosal integrity by hairs of ETC leads to a bacteremia and results in MRLS. In 2004, a similar equine abortion storm was reported from Australia and caterpillar exposure was identified as a risk factor for the abortion. In 2006, the syndrome was observed in Florida and New Jersey.
Aflatoxicosis was diagnosed in a small herd of cattle having access to moldy, unharvested sweet c... more Aflatoxicosis was diagnosed in a small herd of cattle having access to moldy, unharvested sweet corn. Necropsy of 1 cow that died revealed anasarca and a pale tan liver. In this cow, microscopic examination revealed edema of all soft tissues and liver lesions consistent with aflatoxicosis. Samples of corn taken from the field contained 2,365 ng of aflatoxin/g of corn. Weather conditions were conducive to the formation of aflatoxins by Aspergillus flavus and A parasiticus.
Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pieuropneumoni... more Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pieuropneumoniae, serotype 5. At three, six, 12, and 18 hours and one, two, four and seven days after exposure to haemophili a pair of animals were killed and necropsied. Pulmonary oedema with multifocal petechial haemorrhages and a diffuse neutrophilic bronchiolitis and alveolltis were observed at three and six hours after infection.•'ocal areas of coagulative necrosis developed in areas of intense suppuration at 12 and 18 hours after infection. At one and two days after infection, necrotic areas were surrounded by dense bands of degenerating leucocytes and contained unidentifiable round and elongated cells characteristic of this disease. In subacute lesions a thick layer of granulation tissue formed around the outer margin of developing abscesses. Most of the round and elongated cells in alveolar exudates could not be idelltified by enzyme histochemistry or electron microscopic examination. Neutrophils in various stages of degeneration and deterioration provided strong evidence that some of the cells were of this type. These findings suggest that neutrophils may play an early and significant role in development of lesions.
A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondar... more A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondary to dystocia. The foal developed a head tilt, seizures and watery diarrhoea during hospitalisation and died at 7 days of age. Histological examination of the brain and spinal cord revealed a suppurative meningoencephalomyelitis with vasculitis, and numerous intralesional, gram-negative bacilli. Similar microscopic lesions were noted in the lungs, renal medullary interstitium, and umbilicus. Bacilli in the brain, spinal cord and umbilicus were identified immunohistochemically as Salmonella group B. Salmonella agona was isolated in pure culture from the brain, lung, liver, kidney, and intestine. This is the first report of meningoencephalomyelitis and septicaemia due to Salmonella infection in an equine neonate.
-Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage ... more -Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses by Sweeney, CR; Hall, J.; Fisher, JRS; Leary, HJ III; Soma, LR; Spencer, PA (Oct 1988) in English
Respiratory syncytial virus was the cause of a severe epizootic of bovine respiratory tract disea... more Respiratory syncytial virus was the cause of a severe epizootic of bovine respiratory tract disease. The virus, isolated from a sick cow during the epizootic, produced cytopathic effect in a bovine turbinate cell line 14 days after it was inoculated. Additional support for the diagnosis came from the results of pathologic and serologic examinations. Lesions consistently present were severe necrotizing bronchiolitis and epithelial syncytia projecting from bronchiolar and alveolar walls. Also, in the cow from which the virus was isolated, there was tracheitis with a syncytial-like change involving the mucosal epithelium.
Ivermectin is a semisynthetic macrocyclic lactone anthelmintic of the avermectin family derived f... more Ivermectin is a semisynthetic macrocyclic lactone anthelmintic of the avermectin family derived from Streptomyces fermentation products. Avermectins are used as antiparasitic agents in domestic animals; although considered relatively safe, one must consider animal species, breed, weight, and age in dosage determinations. In January 2006, two canines were presented to the UK Livestock Disease Diagnostic Center after dying from suspected ivermectin overdoses [30-50 mg/kg body weight]. To confirm this clinical diagnosis we developed a rapid, sensitive semiquantitative ElectroSpray Ionization-Mass Spectrometry (ESI/MS) method for ivermectin in canine tissue samples. Pharmaceutical ivermectin contains two ivermectins differing by a single methyl group, and each compound forms interpretation-confounding adducts with tissue Na + and K + ions. We now report that ivermectin administration was clearly confirmed by comparison with standard and dosage forms of ivermectin, and simple proportionalities based on mass spectral intensity of respective molecular ions allowed semiquantitative estimates of injection site tissue concentrations of 20 and 40 µg/g tissue (wet weight) in these animals, consistent with the history of ivermectin administration and the clinical signs observed. There is a distinct need for both rapid detection and confirmation of toxic exposures in veterinary diagnostics, whether for interpretation of clinical cases antemortem or for forensic reasons postmortem. It is vital that interpreters of analytical results have appropriate guidance in the scientific literature and elsewhere so as to enable clear-cut answers. The method presented here is suitable for routine diagnostic work in that it allows rapid extraction of ivermectin from tissue samples, avoids the need for high-performance liquid chromatography and allows ready interpretation of the multiple ivermectin species seen by ESI + MS/MS in samples originating from veterinary dosage forms.
Actinobacillus equuli is a rare cause of peritonitis in adult horses. Septicemia and peritonitis ... more Actinobacillus equuli is a rare cause of peritonitis in adult horses. Septicemia and peritonitis due to A. equuli were diagnosed at necropsy in an 8-year-old Saddlebred mare. The origin of the infection was not known; however, small necrotic colonic mucosal lesions presumed to have been caused by phenylbutazone treatment may have allowed bacterial invasion. A good response to antimicrobial treatment has been documented in the small numbers of previously reported acute cases of peritonitis. Because it is potentially treatable, it is important for pathologists and clinicians to identify horses with A. equuli peritonitis.
Abstract. Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5... more Abstract. Pulmonary edema and hydrothorax were observed in mature swine that died approximately 5 days after consuming corn screenings. These postmortem observations were reproduced in younger swine (16-24 kg) that died within 1 week when fed the corn screenings under experimental conditions. Additionally, pulmonary edema and hydrothorax occurred in a pig (7.1 kg) that died after receiving 4 daily intravenous injections of fumonisin B,. A fungus was isolated from the corn screenings that is identical to Fusarium moniliforme MRC-826 in colony morphology and under microscopic examination. Simultaneous epizootics occurred on 2 southwest Georgia farms, resulting in the deaths of 34 mature swine. Four cadavers representing both farms were submitted for diagnostic workup. At necropsy, the gross pathologic changes observed were remarkably similar. These changes included extremely marked pulmonary edema and massive hydrothorax. The thoracic cavities were overfilled with golden-yellow liquid...
-Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage ... more -Efficacy of water vapor-saturated air in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses by Sweeney, CR; Hall, J.; Fisher, JRS; Leary, HJ III; Soma, LR; Spencer, PA (Oct 1988) in English
Pathological, entomological and avian investigations were conducted during the summer of 2002, in... more Pathological, entomological and avian investigations were conducted during the summer of 2002, in a horse farm that had four cases of West Nile virus (WNV) infection in horses. All the four horses had encephalitis and WNV infection was confirmed by RT-PCR and in situ hybridization procedure. Forty-seven per cent of house sparrows that resided on the farm were tested positive for WNV infection. Mosquitoes (98% Culex pipiens) collected by trapping at the farm, during this period were positive for WNV. The meteorological data for year 2002 were compared to previous 16 years. The precipitation and atmospheric temperature were found to be reduced and higher respectively, indicating a drier summer than the prior 16 years, which may have been a contributing factor for the outbreak. None of the horses on these premises had been vaccinated for WNV disease.
Journal of Veterinary Diagnostic Investigation, 2005
During the spring and summer of 2001 and in association with the mare reproductive loss syndrome,... more During the spring and summer of 2001 and in association with the mare reproductive loss syndrome, 22 terminal and 12 clinical cases of equine pericarditis were diagnosed in central Kentucky. Actinobacillus species were the principal isolates from 8 of 10 nontreated, terminally affected and 3 of 10 clinically affected horses. Enterococcus faecalis and Streptococcus zooepidemicus were cultured from the remaining 2 nontreated terminal cases. No viruses were isolated in tissue culture. Nucleic acid of equine herpesvirus-2 was detected in pericardial and tracheal wash fluids of 3 and 1 individuals, respectively. Microscopic alterations in sections of heart and parietal pericardium were consistent with chronic fibrinous bacterial pericarditis. This report confirms a significant role of Actinobacillus species in equine pericarditis and describes an epidemic of this infrequently observed syndrome in the horse.
Journal of Veterinary Diagnostic Investigation, 1996
Proliferative enteropathy (proliferative enteritis, proliferative ileitis, intestinal adenomatosi... more Proliferative enteropathy (proliferative enteritis, proliferative ileitis, intestinal adenomatosis) has been reported in several animal species including the pig,1 2 dog, 2 foal, 3 blue fox, 5 guinea pig, 4 ferret, 6 hamster, 7 and rabbit. 13 The disease is characterized by adenomatous hyperplasia of crypt epithelial cells in the ileum and colon with intracytoplasmic curved bacteria resembling Campylobacter species. In the single case previously reported in a foal, Campylobacter-like organisms were demonstrated within the cytoplasm of enterocytes by spirochete stains and electron microscopy. 3 In a study using cloned DNA probes to isolated Campylobacter-like organisms, there was failure of the probes to hybridize with common porcine Campylobacter species, suggesting the causative agent to be an unidentified or uncultured species. 8 This finding, along with DNA sequencing and structural characteristics, resulted in this organism being named ileal symbiont intracellularis. 9 Subsequently, the organism was described and classified as a new genus and species, Lawsonia intracellularis. 1 1 An unweaned 5-month-old mixed-breed female foal with a history of anorexia, lethargy, and profuse watery diarrhea of greater than 1-week duration was presented to the University of Kentucky, Livestock Disease Diagnostic Center, for necropsy. Treatment had not been attempted. At necropsy, the foal was thin with readily apparent skeletal muscle atrophy. Gross lesions were confined to the small intestine. There was irregular thickening of the jejunum and ileum with the ileum being more severely affected. Lesions in the midjejunum were multifocal in nature and consisted of areas of discoid mucosal thickening, whereas the distal jejunum and ileum contained diffuse mucosal thickening resulting in a rugose pattern (Fig. 1). Samples of the small intestine, stomach, cecum, colon, brain, heart, lung, kidney, and spleen were placed in 10% neutral buffered formalin and, following fixation, were embedded in paraffin, sectioned at 5 µm, and stained with hematoxalin and eosin. In addition, selected sections of small intestine were stained by the Warthin-Starry silver impregnation method for bacteria. Pieces of formalinfixed small intestine were postfixed in osmium tetroxide and embedded in epoxy resin. Thin sections were stained with uranyl acetate and lead citrate. Histopathologically, the affected mucosa was thickened and consisted of hyperplastic glandular structures lined by immature epithelial cells (Fig. 2). The hyperplastic epithelium resulted in distortion of the normal villous structure. Some
Journal of Veterinary Diagnostic Investigation, 2004
During the 2002 and 2003 foaling seasons, Cellulosimicrobium ( Cellumonas) cellulans (formerly Oe... more During the 2002 and 2003 foaling seasons, Cellulosimicrobium ( Cellumonas) cellulans (formerly Oerskovia xanthineolytica) was the principal microorganism isolated from fetal tissues or placentas from cases of equine abortion, premature birth, and term pregnancies. Significant pathologic findings included chronic placentitis and pyogranulomatous pneumonia. In addition, microscopic and macroscopic alterations in the allantochorion from 4 of 7 cases of placentitis were similar to those caused by Crossiella equi and other nocardioform bacteria. This report confirms a causative role of C. cellulans infection in equine abortion.
Journal of Veterinary Diagnostic Investigation, 2003
Rhodococcus equi is a bacterial pathogen, ubiquitous in the soil, that infects many foals and is ... more Rhodococcus equi is a bacterial pathogen, ubiquitous in the soil, that infects many foals and is lethal to some. Transferrin is an iron-binding protein that has bacteriostatic properties in the blood. Transferrin is also highly polymorphic in most species, with 15 variants identified for horses using biochemical methods, and may be responsible for variation in susceptibility to bacterial pathogens. The objectives of this study were 1) to compare biochemical typing with DNA typing of transferrin, 2) to determine if transferrin DNA from archival paraffin-embedded tissue samples can be recovered and typed with molecular methods, and 3) to determine if there was an association between foal death caused by R. equi and transferrin type. Comparing biochemical methods and DNA sequencing for 41 horses demonstrated correspondence between the typing methods. The allele frequency of archival paraffin-embedded tissue samples from 34 Thoroughbred foals that succumbed to R. equi showed an excess o...
Journal of Veterinary Diagnostic Investigation, 2006
A 5-day-old Angus calf was submitted to the necropsy service at the University of Kentucky Livest... more A 5-day-old Angus calf was submitted to the necropsy service at the University of Kentucky Livestock Disease Diagnostic Center. At birth, the calf was noted to have 2 scrota. Five days post-calving the calf developed severe tenesmus and an umbilical infection. Clinical examination revealed atresia ani. At necropsy, complete diphallus, imperforate ani (type 2 atresia ani), and remnants of 2 scrota were identified. This report describes the gross pathologic appearance of a rare case of complete diphallia, imperforate ani (type 2 atresia ani), and an accessory scrotum in a 5-day-old calf.
Uploads
Papers by Lenn Harrison