RESUMEN
A novel foot disease in free-ranging elk ( Cervus elaphus) in southwestern Washington State emerged in 2008 and spread throughout the region. Initial studies showed adult elk had chronic hoof overgrowth, sole ulcers, and sloughed hoof capsules, but no cause was determined. To identify possible causes and characterize the earliest lesions, 9-, 7-, and 3-month-old elk were collected. Nine-month-old elk had sole ulcers (3/9 elk) and sloughed/overgrown hoof capsules (4/9 elk) similar to adults. Histologically, lesions consisted of coronary, heel bulb, and interdigital ulcers with suppurative inflammation, epithelial hyperplasia, deeply invasive spirochetes, and underrunning of the hoof capsule and heel-sole junction. Spirochetes were identified as Treponema via immunohistochemistry and polymerase chain reaction (PCR). Seven-month-old elk had similar underrunning foot ulcers (6/8 elk) with Treponema identified in all lesions but no chronic overgrowth or sloughed hoof capsules. Three-month-old calves had superficial coronary erosions with no inflammation or identifiable spirochetes (3/5 elk) but were culture/PCR positive for Treponema, suggesting possible early lesions. Lesions from 9- and 7-month-old elk included aerobic and anaerobic bacteria, many of which are associated with infectious foot disease in livestock. Antibody enzyme-linked immunosorbent assay of 7- and 3-month-old elk from the enzootic region showed a trend toward increased Treponema antibody titers compared to normal control elk from outside the region, further supporting the significance of Treponema in the pathogenesis of foot disease. Treponeme-associated hoof disease (TAHD) in elk, a debilitating and progressive condition, shares similarities to bovine digital dermatitis and contagious ovine digital dermatitis.
Asunto(s)
Ciervos , Enfermedades del Pie/veterinaria , Pezuñas y Garras/microbiología , Treponema/aislamiento & purificación , Infecciones por Treponema/veterinaria , Envejecimiento , Animales , Femenino , Enfermedades del Pie/microbiología , Pezuñas y Garras/patología , Masculino , Infecciones por Treponema/microbiología , Infecciones por Treponema/patologíaRESUMEN
OBJECTIVE: To determine major causes of death and the anatomic location of musculoskeletal injuries in Quarter Horse racehorses in California. DESIGN: Retrospective case series. ANIMALS: 314 Quarter Horse racehorses with musculoskeletal injuries that were necropsied through the California Horse Racing Board Postmortem Program from 1990 to 2007. PROCEDURES: Postmortem pathology reports were retrospectively reviewed. Musculoskeletal injuries were categorized by anatomic region and described. The number of Quarter Horse starts and starters for the same period of time were obtained from a commercial database for determination of fatal injury incidence. RESULTS: Musculoskeletal injuries accounted for 314 of the 443 (71 %) Quarter Horse racehorses that died during the 18-year study period. Fatal musculoskeletal injuries occurred at a rate of 2.0 deaths/1,000 race starts and 18.6 deaths/1,000 horses that started a race. Musculoskeletal injuries occurred predominantly during racing (84%) and in the forelimbs (81%). The most common fatal musculoskeletal injuries were metacarpophalangeal and metatarsophalangeal joint (fetlock) support injuries (40%) and carpal (24%), vertebral (10%), and scapular (8%) fractures. Proximal interphalangeal (pastern) joint luxations resulted in death of 3% of horses. Fracture configurations of some bones were consistent with those of Thoroughbred racehorses. Evidence of preexisting stress remodeling of bone was reported for some fractures. CONCLUSIONS AND CLINICAL RELEVANCE: Knowledge of common locations and types of fatal musculoskeletal injuries in racing Quarter Horses may enhance practitioners' ability to detect mild injuries early, rest horses, and help prevent catastrophic injuries.
Asunto(s)
Enfermedades de los Caballos/mortalidad , Caballos/lesiones , Deportes , Heridas y Lesiones/veterinaria , Animales , Miembro Anterior , Fracturas Óseas/mortalidad , Fracturas Óseas/veterinaria , Artropatías/mortalidad , Artropatías/veterinaria , Estudios Retrospectivos , Heridas y Lesiones/mortalidadRESUMEN
The objective of this study was to observe the dynamics of clinical cure and recurrence of the lesions of bovine digital dermatitis for 11 months after treatment with topical lincomycin HCl. The study was a clinical follow-up of 39 active bovine digital dermatitis lesions (from 29 cows). Cows with active, painful bovine digital dermatitis (BDD) lesions on the interdigital commissure of the rear feet were identified on day 0. On day 1, lesions in all cows were photographed and full-skin thickness 6mm punch biopsies were obtained for histological evaluation. All lesions on all cows were treated with topical lincomycin paste under a light bandage. On days 12 and 23, a subsample of 10 lesions was randomly selected, photographed, and biopsied. On day 37, all lesions on all cows were photographed and biopsied. After day 37, lesions were evaluated on a monthly basis. All lesions were photographed at each observation until day 341 (end of study) but only cows that had macroscopically active lesions were biopsied. Of the 39 lesions treated on day 1, 21 (54%) required re-treatment on at least one occasion before day 341. Macroscopic classification agreed well with histological classification when lesions were small, focal and active (M1 lesions) or large, ulcerative and active (M2), but agreement was variable for lesions that had healed macroscopically (M5) or that were chronic (M4). A transition model showed that M1 and M2 lesions were 27 times more likely to be an M2 lesion on the next observation than to be a healed (M5) lesion.
Asunto(s)
Antibacterianos/administración & dosificación , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Bovinos/patología , Dermatitis Digital/tratamiento farmacológico , Dermatitis Digital/patología , Enfermedades del Pie/veterinaria , Lincomicina/administración & dosificación , Administración Tópica , Animales , Baños/veterinaria , Biopsia/veterinaria , California , Bovinos , Femenino , Estudios de Seguimiento , Enfermedades del Pie/tratamiento farmacológico , Enfermedades del Pie/patología , Histocitoquímica , Análisis de RegresiónRESUMEN
OBJECTIVE: To compare the effectiveness of lincomycin and oxytetracycline for treatment of digital dermatitis (DD) in dairy cows through gross visual examination, histologic evaluation, and bacteriologic evaluation. DESIGN: Randomized controlled clinical trial. ANIMALS: 25 cows with DD lesions from a commercial Holstein dairy herd. PROCEDURES: Cows with DD lesions were randomly assigned to 1 of 3 groups: topical treatment with 10 g of lincomycin hydrochloride (n = 11), topical treatment with 10 g of oxytetracycline hydrochloride (11), and no treatment (3) on days 1 and 2 (d1). Biopsy specimens were obtained for histologic examination from DD lesions prior to treatment and 28 or 31 days (d30) after treatment for histologic examination. Cows were clinically examined on d1, days 12 or 14 (d14), and d30. RESULTS: No difference was evident in clinical responses to lincomycin and oxytetracycline, so data were pooled; at d30, 8 of 11 of lincomycin-treated lesions and 7 of 11 oxytetracycline-treated lesions appeared visually healed, respectively. Gross visual examination suggested 73% (16/22) of treated cows were healed at d14 and 68% (15/22) of treated cows were healed on d30. Of the 15 lesions that appeared healed on d30, 7 of 15 were classified histologically as active (ulceration and bacterial invasion; 2/15) or incipient (5/15). CONCLUSIONS AND CLINICAL RELEVANCE: Clinical responses to lincomycin and oxytetracycline did not differ. Agreement was good between gross visual and histologic assessments of DD lesions before treatment; agreement 1 month after treatment was variable. Histologic evaluation could not distinguish incomplete healing from lesion recurrence.
Asunto(s)
Enfermedades de los Bovinos/tratamiento farmacológico , Dermatitis/veterinaria , Dermatosis del Pie/veterinaria , Lincomicina/uso terapéutico , Oxitetraciclina/uso terapéutico , Administración Tópica , Animales , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Bovinos , Industria Lechera , Dermatitis/tratamiento farmacológico , Femenino , Dermatosis del Pie/tratamiento farmacológico , Pezuñas y Garras , Lincomicina/administración & dosificación , Oxitetraciclina/administración & dosificación , Papiloma/tratamiento farmacológico , Papiloma/veterinariaRESUMEN
This article describes amebic infections in 4 horses: granulomatous amebic encephalitis caused by Balamuthia mandrillaris and Acanthamoeba culbertsoni and systemic infections caused by Acanthamoeba sp. The former infection occurred in 1 of 4 horses spontaneously without any underlying conditions; the latter amebic infection was perhaps "opportunistic" considering the visceral involvement by this protozoan in association with Aspergillus sp. and/or Escherichia coli and Pseudomonas sp. The clinicopathologic findings and demonstration of the amebic organisms using immunohistochemical techniques, culture, polymerase chain reactions, and electron microscopy are presented.
Asunto(s)
Acanthamoeba/aislamiento & purificación , Amebiasis/veterinaria , Encefalopatías/veterinaria , Enfermedades de los Caballos/parasitología , Enfermedades Pulmonares Parasitarias/veterinaria , Acanthamoeba/genética , Amebiasis/parasitología , Animales , Encefalopatías/parasitología , ADN Protozoario/química , ADN Protozoario/genética , Resultado Fatal , Femenino , Caballos , Inmunohistoquímica/veterinaria , Enfermedades Pulmonares Parasitarias/parasitología , Masculino , Reacción en Cadena de la Polimerasa/veterinariaRESUMEN
Three diagnostic assays for detecting West Nile virus (WNV) in avian oral swabs were evaluated in California in 2004 and 2005: two commercial antigen-capture assays, VecTest and Rapid Analyte Measurement Platform (RAMP), and reverse transcriptase-polymerase chain reaction (RT-PCR) of oral swabs in a specialized viral transport medium (VTM). Results from this study demonstrated that VTM was excellent for transportation and maintenance of WNV in avian oral swab samples and allowed for detection by RT-PCR and subsequent confirmation by virus isolation. Oral swabs and kidney tissue in VTM tested by RT-PCR were found to have similar accuracy in detecting WNV in corvids. The two antigen-capture assays, VecTest and RAMP, provided few false positives for corvids, with over 95% specificity. When performed by multiple local agencies throughout the state, VecTest and RAMP were similarly sensitive for oral swabs of American Crows (Corvus brachyrhynchos) (70% and 64%, respectively). Data from known WNV positive corvid oral swabs in VTM tested by antigen-capture assays at a diagnostic laboratory suggested that RAMP was more sensitive than VecTest. Due to high probability of false negatives, neither test is recommended for use on non-corvids. While WNV antigen-capture assays were effective screening tools for corvids, they were markedly less sensitive for Western Scrub Jays (Aphelocoma californica).
Asunto(s)
Enfermedades de las Aves/diagnóstico , Orofaringe/virología , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo Occidental/aislamiento & purificación , Animales , Antígenos Virales/inmunología , Enfermedades de las Aves/virología , Aves , Reacciones Falso Negativas , Reacciones Falso Positivas , Reproducibilidad de los Resultados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Sensibilidad y Especificidad , Especificidad de la Especie , Fiebre del Nilo Occidental/diagnóstico , Virus del Nilo Occidental/inmunologíaRESUMEN
OBJECTIVE: To determine the distribution for limbs and bones in horses with fractures of the proximal sesamoid bones and relationships with findings on palmarodorsal radiographic images. SAMPLE POPULATION: Proximal sesamoid bones obtained from both forelimbs of cadavers of 328 racing Thoroughbreds. PROCEDURE: Osteophytes; large vascular channels; and fracture location, orientation, configuration, and margin distinctness were categorized by use of high-detail contact palmarodorsal radiographs. Distributions of findings were determined. Relationships between radiographic findings and fracture characteristics were examined by use of chi2 and logistic regression techniques. RESULTS: Fractures were detected in 136 (41.5%) horses. Biaxial fractures were evident in 109 (80%) horses with a fracture. Osteophytes and large vascular channels were evident in 266 (81%) and 325 (99%) horses, respectively. Medial bones typically had complete transverse or split transverse simple fractures, indistinct fracture margins, > 1 vascular channel that was > 1 mm in width, and osteophytes in abaxial wing and basilar middle or basilar abaxial locations. Lateral bones typically had an oblique fracture and distinct fracture margins. Odds of proximal sesamoid bone fracture were approximately 2 to 5 times higher in bones without radiographic evidence of osteophytes or large vascular channels, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Biaxial fractures of proximal sesamoid bones were common in cadavers of racing Thoroughbreds. Differences between medial and lateral bones for characteristics associated with fracture may relate to differences in fracture pathogeneses for these bones. Osteophytes and vascular channels were common findings; however, fractures were less likely to occur in bones with these features.
Asunto(s)
Miembro Anterior/diagnóstico por imagen , Miembro Anterior/lesiones , Fracturas Óseas/veterinaria , Enfermedades de los Caballos/diagnóstico por imagen , Huesos Sesamoideos/diagnóstico por imagen , Huesos Sesamoideos/lesiones , Distribución por Edad , Animales , Cadáver , Femenino , Fracturas Óseas/diagnóstico por imagen , Caballos , Masculino , Radiografía , Distribución por SexoRESUMEN
Primary amoebic meningoencephalitis is a fulminant infection of the human central nervous system caused by Naegleria fowleri, a free-living amoeba that thrives in artificially or naturally heated water. The infection usually is acquired while bathing or swimming in such waters. The portal of entry is the olfactory neuroepithelium. This report describes fatal meningoencephalitis caused by N. fowleri in Holstein cattle that consumed untreated surface water in an area of California where summer temperatures at times exceed 42 degrees C. In the summers of 1998 and 1999, severe multifocal necrosuppurative hemorrhagic meningoencephalitis was observed in brain samples from nine 10-20-month-old heifers with clinical histories of acute central nervous system disease. Olfactory lobes and cerebella were most severely affected. Lesions were also evident in periventricular and submeningeal neuropil as well as olfactory nerves. Naegleria fowleri was demonstrated by immunohistochemistry in brain and olfactory nerve lesions and was isolated from one brain. Even though cultures of drinking water did not yield N. fowleri, drinking water was the likely source of the amoeba. The disease in cattle closely resembles primary amoebic meningoencephalitis in humans. Naegleria meningoencephalitis should be included among differential diagnoses of central nervous system disease in cattle during the summer season in areas with high ambient temperatures.
Asunto(s)
Amebiasis/parasitología , Amebiasis/veterinaria , Enfermedades de los Bovinos/parasitología , Meningoencefalitis/parasitología , Meningoencefalitis/veterinaria , Naegleria fowleri/aislamiento & purificación , Estaciones del Año , Animales , Encéfalo/parasitología , Encéfalo/patología , Bovinos , Brotes de Enfermedades/veterinariaRESUMEN
Three outbreaks of late-gestation abortions in does and ulcerative posthitis in bucks, associated with caprine herpes virus-1 (CHV-1), in California are described. In herd A, 10 of 17 does aborted in a 7-day period, whereas in herd B, 4 of 130 does aborted in a 45-day period and in herd C, 100 of 300 does aborted in a 3-week period. Most fetuses had multifocal pinpoint depressed foci with a zone of hyperemia on external and cut surfaces of the kidneys, liver, lungs, and adrenal glands. Histologically, scattered multifocal areas of necrosis with mild neutrophilic infiltrate were observed in kidneys, brain, liver, adrenal glands, and lungs of most fetuses of the 3 herds. Large amphophilic intranuclear inclusion bodies, which displaced the chromatin, were observed in cells within and around the necrotic foci in kidneys and adrenal glands. Particles 85-113 nm in size with morphology compatible with herpes virus were observed in the nuclei of these cells when examined by electron microscopy. Irregular, shallow, red ulcers were observed in the prepuce of 1 buck from herd C. Prepuce biopsies from this animal had necrosis of the superficial mucosal epithelium and severe submucosal lymphoplasmocytic infiltrates. Large intranuclear amphophilic inclusion bodies were observed in most cells of the stratum spinosum of the preputial epithelium, but no viral particles were observed in these cells. Caprine herpes virus-1 was isolated from tissue pools of fetuses from the 3 herds but not from prepuce biopsies. Positive results were obtained when tissues of a fetus from herd C were processed by a polymerase chain reaction technique to amplify the amino terminus of the glycoprotein C gene of CHV-1. Sera from aborted does from herds B and C and from the 3 bucks from herd C had high antibody titers to CHV-1. The results presented here support the hypothesis that the male goat is involved in the transmission of CHV-1. However, other forms of transmission cannot be ruled out.
Asunto(s)
Aborto Veterinario/virología , Brotes de Enfermedades/veterinaria , Enfermedades de las Cabras/virología , Infecciones por Herpesviridae/veterinaria , Enfermedades del Pene/veterinaria , Varicellovirus/aislamiento & purificación , Feto Abortado/patología , Feto Abortado/virología , Animales , California/epidemiología , ADN Viral/química , ADN Viral/genética , Femenino , Enfermedades de las Cabras/patología , Enfermedades de las Cabras/transmisión , Cabras , Infecciones por Herpesviridae/patología , Infecciones por Herpesviridae/transmisión , Infecciones por Herpesviridae/virología , Histocitoquímica/veterinaria , Masculino , Microscopía Electrónica de Transmisión/veterinaria , Enfermedades del Pene/patología , Enfermedades del Pene/virología , Reacción en Cadena de la Polimerasa/veterinaria , Embarazo , Varicellovirus/genéticaRESUMEN
Between February 2000 and February 2002, the California Animal Health and Food Safety Laboratory System diagnosed 26 cases of low-pathogenic H6N2 avian influenza from 12 commercial egg-laying farms. The most common gross and histologic lesions observed in infected chickens were fibrinous yolk peritonitis, salpingitis, oophoritis, and nephritis. Edema of the mesentery of the oviduct and pale, swollen kidneys were also observed. Mortality in infected flocks ranged from 0.25% to 3%, and egg production dropped 7% to 40%.
Asunto(s)
Pollos/virología , Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Oviposición/fisiología , Animales , California/epidemiología , Brotes de Enfermedades/veterinaria , Femenino , Gripe Aviar/patología , Peritonitis/veterinaria , Peritonitis/virologíaRESUMEN
OBJECTIVE: To determine sensitivity and specificity of western blot testing (WBT) of CSF and serum for diagnosis of equine protozoal myeloencephalitis (EPM) in horses with and without neurologic abnormalities. DESIGN: Prospective investigation. ANIMALS: 65 horses with and 169 horses without neurologic abnormalities. PROCEDURE: CSF and serum from horses submitted for necropsy were tested for Sarcocystis neurona-specific antibody with a WBT. Results of postmortem examination were used as the gold standard against which results of the WBT were compared. RESULTS: Sensitivity of WBT of CSF was 87% for horses with and 88% for horses without neurologic abnormalities. Specificity of WBT of CSF was 44% for horses with and 60% for horses without neurologic abnormalities. Regardless of whether horses did or did not have neurologic abnormalities, sensitivity and specificity of WBT of serum were not significantly different from values for WBT of CSF. Ninety-four horses without EPM had histologic evidence of slight CNS inflammation. CONCLUSIONS AND CLINICAL RELEVANCE: The low specificity of WBT of CSF indicated that it is inappropriate to diagnose EPM on the basis of a positive test result alone because of the possibility of false-positive test results. The high sensitivity, however, means that a negative result is useful in ruling out EPM. There was no advantage in testing CSF versus serum in horses without neurologic abnormalities. Slight CNS inflammation was common in horses with and without S neurona-specific antibodies in the CSF and should not be considered an indication of CNS infection with S neurona.
Asunto(s)
Western Blotting/veterinaria , Encefalomielitis/veterinaria , Enfermedades de los Caballos/diagnóstico , Sarcocystis/inmunología , Sarcocistosis/veterinaria , Animales , Western Blotting/métodos , Encefalomielitis/sangre , Encefalomielitis/líquido cefalorraquídeo , Encefalomielitis/diagnóstico , Reacciones Falso Positivas , Femenino , Enfermedades de los Caballos/sangre , Enfermedades de los Caballos/líquido cefalorraquídeo , Caballos , Masculino , Estudios Prospectivos , Sarcocistosis/sangre , Sarcocistosis/líquido cefalorraquídeo , Sarcocistosis/diagnóstico , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To determine risk factors for Clostridium piliforme infection in neonatal foals on a Thoroughbred breeding farm in California. DESIGN: Case-control and retrospective cohort studies. ANIMALS: 322 neonatal Thoroughbred foals either born on the study farm or born elsewhere but traveled to the farm with their dam during the 1998, 1999, and 2000 breeding seasons. PROCEDURE: Mare and foal records from 1998, 1999, and 2000 were examined, using case-control design methods to determine variables associated with increased risk of C. piliforme infection in foals. Important risk factors identified in the case-control study were then reevaluated by use of a retrospective cohort design, using data from all neonatal foals present on the farm during the 3-year study period. RESULTS: Foals born between March 13 and April 13 were 7.2 times as likely to develop C. piliforme infection as were those born at any other time of the foaling season. Foals of nonresident (visiting) mares were 3.4 times as likely to develop disease as were foals born to mares that were permanent residents of the study farm. Foals of mares < 6 years of age were 2.9 times as likely to develop disease as were foals born to older mares. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this research can be used to better understand the epidemiologic factors of C. piliforme infection in horses. High-risk foals can be closely monitored to aid in early diagnosis and treatment, resulting in the best possible clinical outcome for affected individuals.