RESUMEN
The Rhynonyssid mesostigmatic mite, Sternostoma tracheacolum, is a well-documented endoparasitic hematophagous arthropod of the respiratory tracts of multiple avian species, particularly Estrildid finches and canaries. In this retrospective study, 175 medical and 278 pathology records for the Gouldian finch (Chloebia gouldiae) population (N = 377) at the San Diego Zoo between 2013 and 2021 were analyzed to evaluate the effectiveness of ivermectin-based prophylaxis. A multivariable negative binomial regression model was constructed to evaluate the population effects of monthly treatments on morbidity or mortality associated with respiratory mites. While controlling for other factors in the model, the prophylactic treatment did not significantly reduce the monthly rate of mite-associated morbidity or mortality (IRR = 1.017, 95% CI: 0.997-1.036, P = 0.0759); however, low proportions of the population were prophylactically treated over time. Different factors were significant when separately evaluating adjusted associations with respiratory morbidity and mortality. The findings suggest increased rates of respiratory morbidity for each successive year of the study period (IRR = 1.180, 95% CI: 1.046-1.342, P = 0.0090) and increased rates of mite-associated mortality occurring annually between May and October (IRR = 1.697, 95% CI: 1.034-2.855, P = 0.0404) compared to the wet winter season. Our findings highlight the need to continually evaluate and optimize treatment regimens in zoological collections. Further investigations into this host-parasite relationship and potential treatments and preventive therapies are warranted.
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Pinzones , Passeriformes , Animales , Estudios Retrospectivos , Sistema RespiratorioRESUMEN
Northern Canada is warming at 3 times the global rate. Thus, changing diversity and distribution of vectors and pathogens is an increasing health concern. California serogroup (CSG) viruses are mosquitoborne arboviruses; wildlife reservoirs in northern ecosystems have not been identified. We detected CSG virus antibodies in 63% (95% CI 58%-67%) of caribou (n = 517), 4% (95% CI 2%-7%) of Arctic foxes (n = 297), 12% (95% CI 6%-21%) of red foxes (n = 77), and 28% (95% CI 24%-33%) of polar bears (n = 377). Sex, age, and summer temperatures were positively associated with polar bear exposure; location, year, and ecotype were associated with caribou exposure. Exposure was highest in boreal caribou and increased from baseline in polar bears after warmer summers. CSG virus exposure of wildlife is linked to climate change in northern Canada and sustained surveillance could be used to measure human health risks.
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Virus de la Encefalitis de California , Reno , Ursidae , Animales , Humanos , Zorros , Ecosistema , Serogrupo , Animales Salvajes , Canadá/epidemiologíaRESUMEN
Anurans can display a host of intriguing sexual syndromes, including hermaphroditism and sex reversal. Using a multifaceted approach for diagnosing and characterising hermaphroditism in the endangered anuran species Rana mucosa, we tracked changes in female reproductive status using hormone monitoring, ultrasound examinations, individual life history, fertilisation records and post-mortem findings. Seven individuals originally sexed as females developed secondary male sexual characteristics, behaviour and hormone profiles and, in some cases, had testicular tissue despite having previously laid eggs. Our results suggest that reproductive technologies can shed light on life history patterns and reproductive anomalies that may affect endangered anuran survival.
RESUMEN
Recent reports have highlighted a lower-than-expected prevalence of neoplasia in elephants and suggested mechanisms for cancer resistance. But despite infrequent reports in the literature, uterine neoplasia is common in managed Asian elephants (Elephas maximus). This study is an archival review of reproductive tract neoplasia in 80 adult female Asian elephant mortalities in managed care facilities in the United States from 1988 to 2019. Neoplasms occurred in 64/80 (80%) of cases. Most were in the uterus (63/64; 98%) with only a single case of ovarian neoplasia. Myometrial leiomyomas were present in 57/63 (90%) cases with uterine neoplasia. Uterine adenocarcinoma was present in 8/63 (13%) cases. Remaining cases included endometrial adenoma (2), focal carcinoma in situ in endometrial polyps (1), anaplastic carcinoma (1), endometrial hemangioma (1), primitive neuroectodermal tumor (PNET; 1), and angiosarcoma (1). One case with uterine adenocarcinoma had a separate pelvic mass histologically characterized as an anaplastic sarcoma. Distant metastases were documented in 5/8 (63%) cases of uterine adenocarcinoma, and in the uterine anaplastic carcinoma, PNET, and angiosarcoma. Four uterine adenocarcinomas and one carcinoma in situ were examined immunohistochemically for pan-cytokeratin, vimentin, and estrogen receptor. In all, neoplastic cells were pan-cytokeratin positive and vimentin negative, and in 2 cases were immunoreactive for estrogen receptor. Results show that female reproductive tract neoplasia, particularly of the uterus, is common in Asian elephants and is not limited to leiomyomas. Importantly, uterine neoplasms have the potential to impact fecundity and may represent obstacles to conservation in managed care.
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Carcinoma , Elefantes , Leiomioma , Neoplasias Uterinas , Animales , Carcinoma/veterinaria , Femenino , Leiomioma/epidemiología , Leiomioma/veterinaria , Neoplasias Uterinas/veterinaria , ÚteroRESUMEN
Pathologic amyloid accumulates in the CNS or in peripheral organs, yet the mechanism underlying the targeting of systemic amyloid deposits is unclear. Serum amyloid A (SAA) 1 and 2 are produced predominantly by the liver and form amyloid most commonly in the spleen, liver, and kidney. In contrast, SAA3 is produced primarily extrahepatically and has no causal link to amyloid formation. Here, we identified 8 amyloidosis cases with amyloid composed of SAA3 expanding the uterine wall of goats with near-term fetuses. Uterine amyloid accumulated in the endometrium, only at the site of placental attachment, compromising maternal-fetal gas and nutrient exchange and leading to fetal ischemia and death. No other organ contained amyloid. SAA3 mRNA levels in the uterine endometrium were as high as SAA2 in the liver, yet mass spectrometry of the insoluble uterine peptides identified SAA3 as the predominant protein, and not SAA1 or SAA2. These findings suggest that high local SAA3 production led to deposition at this unusual site. Although amyloid A (AA) amyloid deposits typically consist of an N-terminal fragment of SAA1 or SAA2, here, abundant C-terminal peptides indicated that the uterine amyloid was largely composed of full-length SAA3. The exclusive deposition of SAA3 amyloid in the uterus, together with elevated uterine SAA3 transcripts, suggests that the uterine amyloid deposits were due to locally produced SAA3. This is the first report of SAA3 as a cause of amyloidosis and of AA amyloid deposited exclusively in the uterus.
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Amiloide/metabolismo , Amiloidosis/patología , Apoptosis , Muerte Fetal , Proteoma/análisis , Proteína Amiloide A Sérica/metabolismo , Útero/patología , Secuencia de Aminoácidos , Amiloidosis/metabolismo , Animales , Western Blotting , Proliferación Celular , Células Cultivadas , Cromatografía Liquida , Femenino , Cabras , Técnicas para Inmunoenzimas , Datos de Secuencia Molecular , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Útero/metabolismoRESUMEN
Polymorphism is a wide-spread feature of amyloid-like fibrils formed inâ vitro, but it has so far remained unclear whether the fibrils formed within a patient are also affected by this phenomenon. In this study we show that the amyloid fibrils within a diseased individual can vary considerably in their three-dimensional architecture. We demonstrate this heterogeneity with amyloid fibrils deposited within different organs, formed from sequentially non-homologous polypeptide chains and affecting human or animals. Irrespective of amyloid type or source, we found inâ vivo fibrils to be polymorphic. These data imply that the chemical principles of fibril assembly that lead to such polymorphism are fundamentally conserved inâ vivo and inâ vitro.
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Amiloide/química , Microscopía Electrónica de Transmisión , Conformación ProteicaRESUMEN
A 24-year-old female blue and gold macaw (Ara ararauna) was presented for an acute onset of left head tilt. On examination, the macaw was dehydrated and had a 120-degree left head tilt, decreased proprioception of the left pelvic limb, and intermittent vertical nystagmus. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with lymphopenia and heterophilia and a high uric acid concentration. Radiographs showed bilateral intertarsal joint osteoarthritis and a healed ulnar fracture. Magnetic resonance imaging of the brain revealed focal T2 and fluid-attenuated inversion recovery hyperintense lesions in the right cerebral hemisphere and in the midbrain. The midbrain lesion showed susceptibility artifact on the T2* sequence, suggesting hemorrhage. In the T2* sequence, iron accumulation (as seen with hemorrhage) distorts the magnetic signal, resulting in the production of a susceptibility artifact, which can then be visualized as a region of hypointensity. The bird was hospitalized but died despite intensive care. Necropsy revealed multiple cerebral vascular lesions including an acute cerebral infarct, a ruptured midbrain aneurysm, and multifocal systemic atherosclerosis. To our knowledge, this is the first report of a cerebral aneurysm in a bird. This report correlates the clinical presentation, imaging, and histopathologic findings in a macaw with central vestibular disease and demonstrates how advanced imaging techniques can identify hemorrhagic lesions through the T2* sequence.
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Enfermedades de las Aves/patología , Hemorragia Cerebral/veterinaria , Infarto Cerebral/veterinaria , Psittaciformes , Animales , Hemorragia Cerebral/patología , Infarto Cerebral/patología , Resultado Fatal , Femenino , Imagen por Resonancia MagnéticaRESUMEN
We characterized the complete genome of a novel dog circovirus (DogCV) from the liver of a dog with severe hemorrhagic gastroenteritis, vasculitis, and granulomatous lymphadenitis. DogCV was detected by PCR in fecal samples from 19/168 (11.3%) dogs with diarrhea and 14/204 (6.9%) healthy dogs and in blood from 19/409 (3.3%) of dogs with thrombocytopenia and neutropenia, fever of unknown origin, or past tick bite. Co-infection with other canine pathogens was detected for 13/19 (68%) DogCV-positive dogs with diarrhea. DogCV capsid proteins from different dogs varied by up to 8%. In situ hybridization and transmission electron microscopy detected DogCV in the lymph nodes and spleens of 4 dogs with vascular compromise and histiocytic inflammation. The detection of a circovirus in tissues of dogs expands the known tropism of these viruses to a second mammalian host. Our results indicate that circovirus, alone or in co-infection with other pathogens, might contribute to illness and death in dogs.
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Infecciones por Circoviridae/veterinaria , Circovirus/genética , ADN Viral/genética , Diarrea/veterinaria , Enfermedades de los Perros/epidemiología , Hemorragia Gastrointestinal/veterinaria , Genoma Viral , Vasculitis/veterinaria , Animales , California/epidemiología , Infecciones por Circoviridae/complicaciones , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/virología , Circovirus/clasificación , Circovirus/aislamiento & purificación , ADN Viral/clasificación , ADN Viral/aislamiento & purificación , Diarrea/complicaciones , Diarrea/epidemiología , Diarrea/virología , Enfermedades de los Perros/virología , Perros , Heces/virología , Femenino , Hemorragia Gastrointestinal/complicaciones , Hemorragia Gastrointestinal/epidemiología , Hemorragia Gastrointestinal/virología , Humanos , Hibridación in Situ , Hígado/patología , Hígado/virología , Ganglios Linfáticos/patología , Ganglios Linfáticos/virología , Masculino , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Bazo/patología , Bazo/virología , Vasculitis/complicaciones , Vasculitis/epidemiología , Vasculitis/virologíaRESUMEN
A 25-yr-old spayed female spotted hyena (Crocuta crocuta) developed intermittent right pelvic limb lameness that persisted following conservative medical therapy. No obvious musculoskeletal lesions were noted on initial physical exam; however, spinal radiography was suspicious for possible intervertebral degenerative joint disease or discospondylitis. Despite prolonged medical therapy, the lameness progressed to minimal weight bearing and marked muscle atrophy of the right pelvic limb. Electromyography showed spontaneous activity in the muscles of right sciatic nerve distribution. Sensory and motor nerve conduction velocities in the right tibial and peroneal nerves were undetectable and markedly reduced, respectively. A magnetic resonance imaging (MRI) scan revealed a large, space-occupying mass on the right side of the sacrum and pelvis. Antemortem fine-needle aspiration of the mass and postmortem histopathology resulted in diagnosis of a high-grade squamous cell carcinoma of the anal sac. Squamous cell carcinoma of the anal sac is very rare in domestic dogs and previously unreported in spotted hyenas.
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Neoplasias de las Glándulas Anales/diagnóstico , Sacos Anales/patología , Carcinoma de Células Escamosas/veterinaria , Hyaenidae , Neoplasias de las Glándulas Anales/diagnóstico por imagen , Animales , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/diagnóstico por imagen , Femenino , RadiografíaRESUMEN
Cheetahs (Acinonyx jubatus) are a highly threatened species because of habitat loss, human conflict, and high prevalence of disease in captivity. An epidemic of feline infectious peritonitis and concern for spread of infectious disease resulted in decreased movement of cheetahs between U.S. zoological facilities for managed captive breeding. Identifying the true feline coronavirus (FCoV) infection status of cheetahs is challenging because of inconsistent correlation between seropositivity and fecal viral shedding. Because the pattern of fecal shedding of FCoV is unknown in cheetahs, this study aimed to assess the frequency of detectable fecal viral shedding in a 30-day period and to determine the most efficient fecal sampling strategy to identify cheetahs shedding FCoV. Fecal samples were collected from 16 cheetahs housed at seven zoological facilities for 30 to 46 consecutive days; the samples were evaluated for the presence of FCoV by reverse transcription-nested polymerase chain reaction (RT-nPCR). Forty-four percent (7/16) of cheetahs had detectable FCoV in feces, and the proportion of positive samples for individual animals ranged from 13 to 93%. Cheetahs shed virus persistently, intermittently, or rarely over 30-46 days. Fecal RT-nPCR results were used to calculate the probability of correctly identifying a cheetah known to shed virus given multiple hypothetical fecal collection schedules. The most efficient hypothetical fecal sample collection schedule was evaluation of five individual consecutive fecal samples, resulting in a 90% probability of identifying a known shedder. Demographic and management risk factors were not significantly associated (P < or = 0.05) with fecal viral shedding. Because some cheetahs shed virus intermittently to rarely, fecal sampling schedules meant to identify all known shedders would be impractical with current tests and eradication of virus from the population unreasonable. Managing the captive population as endemically infected with FCoV may be a more feasible approach.
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Acinonyx , Coronavirus Felino/aislamiento & purificación , Heces/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Esparcimiento de Virus/fisiología , Animales , Femenino , Masculino , ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodosRESUMEN
A 5-year-old Thoroughbred-cross mare was diagnosed with insulin-dependent diabetes mellitus. Partial glycemic control and clinical improvement were achieved with daily insulin administration for 18 mo. The mare subsequently developed evidence of hypoadrenocorticism and died. Necropsy findings included lymphocytic infiltration of the pancreas, adrenal cortex, adrenal medulla, and thyroid glands, suggestive of an immune-mediated polyendocrinopathy.
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Diabetes Mellitus Tipo 1/veterinaria , Enfermedades de los Caballos/tratamiento farmacológico , Poliendocrinopatías Autoinmunes/veterinaria , Animales , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Resultado Fatal , Femenino , Enfermedades de los Caballos/diagnóstico , Caballos , Poliendocrinopatías Autoinmunes/complicaciones , Poliendocrinopatías Autoinmunes/diagnóstico , Poliendocrinopatías Autoinmunes/tratamiento farmacológicoRESUMEN
West Nile virus (WNV) was first documented in North America in New York City in 1999. Several deaths attributable to WNV have been reported in captive thick-billed parrots (Rhynchopsitta pachyrhyncha), an endangered psittacine native to North America. The serologic responses in 12 captive adult thick-billed parrots after a series of three initial WNV vaccine injections with annual boosters over 6 yr was evaluated. In addition, the serologic responses of 11 thick-billed parrot chicks following an initial vaccination series to determine if there were seroconversions were also reported. Most adults (67%) had seroconverted after 5 yr of annual vaccination, with a median titer of 1:80 (range 1:40-1:160) for those that seroconverted. After the first year, birds were likely naturally exposed to WNV, which limited interpretation of titers. None of the chicks seroconverted during the initial three-vaccine series; only two of four chicks (50%) had seroconverted when tested at the 1-yr yearly booster, and at 2 yr, three of four chicks had seroconverted. Although some birds had detectable antibody titers, it is unclear whether this vaccine can reliably provide protection against WNV in thick-billed parrots.
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Anticuerpos Antivirales/sangre , Enfermedades de las Aves/prevención & control , Loros , Vacunas Virales/inmunología , Fiebre del Nilo Occidental/veterinaria , Animales , Esquemas de Inmunización , Fiebre del Nilo Occidental/prevención & controlRESUMEN
Purpose: To investigate the use of an amyloid-targeting fluorescent probe, ARCAM-1, to identify amyloid-containing deposits in the retina of a transgenic mouse model of Alzheimer's disease (AD) and in human postmortem AD patients. Methods: Aged APP/PS1 transgenic AD and wild-type (WT) mice were given an intraperitoneal (IP) injection of ARCAM-1 and their retinas imaged in vivo using a fluorescence ophthalmoscope. Eyes were enucleated and dissected for ex vivo inspection of retinal amyloid deposits. Additionally, formalin-fixed eyes from human AD and control patients were dissected, and the retinas were stained using ARCAM-1 or with an anti-amyloid-ß antibody. Confocal microscopy was used to image amyloid-containing deposits stained with ARCAM-1 or with immunostaining. Results: Four out of eight APP/PS1 mice showed the presence of amyloid aggregates in the retina during antemortem imaging. Retinas from three human AD patients stained with ARCAM-1 showed an apparent increased density of fluorescently labeled amyloid-containing deposits compared to the retinas from two healthy, cognitively normal (CN) patients. Immunolabeling confirmed the presence of amyloid deposits in both the retinal neuronal layers and in retinal vasculature. Conclusions: ARCAM-1 facilitates antemortem detection of amyloid aggregates in the retina of a mouse model for AD, and postmortem detection of amyloid-containing deposits in human retinal tissues from AD patients. These results support the hypothesis of AD pathology manifesting in the eye and highlight a novel area for fluorophore development for the optical detection of retinal amyloid in AD patients. Translational Relevance: This paper represents an initial examination for potential translation of an amyloid-targeting fluorescent probe to a retinal imaging agent for aiding in the diagnosis of Alzheimer's disease.
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Enfermedad de Alzheimer , Placa Amiloide , Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides , Animales , Humanos , Ratones , Ratones Transgénicos , Retina/diagnóstico por imagenRESUMEN
A 3-year-old, intact female guinea pig (Cavia porcellus) was presented for anorexia and abdominal distention of 24 hours' duration. Radiographs revealed a severely distended stomach, suggestive of severe gastric dilatation or gastric dilatation-volvulus (GDV). Exploratory surgery was recommended, but the owners elected euthanasia. On necropsy, the guinea pig was found to have GDV. No underlying conditions were identified that could have predisposed this guinea pig to the development of GDV.
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Dilatación Gástrica/veterinaria , Cobayas , Enfermedades de los Roedores/diagnóstico , Vólvulo Gástrico/veterinaria , Animales , Eutanasia Animal , Femenino , Dilatación Gástrica/diagnóstico , Dilatación Gástrica/cirugía , Enfermedades de los Roedores/cirugía , Vólvulo Gástrico/diagnóstico , Vólvulo Gástrico/cirugíaRESUMEN
Radio telemetry has greatly advanced the understanding of wild animal ecology. Telemetry studies must ensure that placement of transmitters does not influence the health and behavior of study animals. Here, 10 American badgers (Taxidea taxus) were implanted with beeswax-coated abdominal radio transmitters under general anesthesia and tracked for an average of 14 mo. Behavior and movements of all badgers indicated successful short-term recovery from implantation; however, three mortalities were observed between 5 mo and 15 mo after capture. Cause of death could not be determined for two badgers due to decomposition of the carcasses. A third badger that was recovered in good postmortem condition died from sepsis secondary to a transmitter-related omental torsion. This study indicates that there is some risk associated with abdominally implanted radio transmitters in badgers. Future studies involving implanted transmitters in mammals should focus on identifying safe and effective telemetry devices that do not affect the health of study animals. American badger, omental adhesion, peritoneal implant, telemetry, Taxidea taxus.
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Sistemas de Identificación Animal , Mustelidae , Sepsis/veterinaria , Procedimientos Quirúrgicos Operativos/veterinaria , Animales , Resultado Fatal , Femenino , Epiplón/patología , Sepsis/etiología , Procedimientos Quirúrgicos Operativos/efectos adversos , Torsión MecánicaRESUMEN
Prevalence and disease caused by isosporoid coccidia in passerine birds are well recognized, but confusion about the life cycles of the parasites has led to taxonomic inconsistencies. In this study, we characterized segments of the chromosomal small and large-subunit ribosomal RNA (rRNA) genes of coccidial parasites from 23 species of passerine birds, as well as heat shock protein 70, apicoplast rRNA, and chromosomal 5.8s rRNA genes from a subgroup of these animals, and we correlated genetic data with morphologic findings for different parasite developmental stages, host phylogeny, and overall taxonomic relations within the phylum Apicomplexa. Our findings indicate that isosporoid coccidia of passerine birds are monophyletic but exhibit substantial diversity, with most avian species having one or several unique parasite lineages that underwent synchronous speciation with their hosts, interrupted by sporadic episodes of lateral transmission across species and families. Molecular analyses support a homoxenous life cycle, with sexual forms occurring chiefly in the intestines and asexual merozoites present systemically. Rarely, extraintestinal sexual stages can occur. The passerine coccidia are genetically most closely related to species of Eimeria rather than Isospora. We suggest that these parasites, whether identified from blood merozoite stages or fecal oocysts, be provisionally grouped as a homogeneous clade of individual species in a single taxon and formally named when reliable criteria allowing reclassification of related genera in the suborder Eimeriina are clarified.
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Enfermedades de las Aves/parasitología , Coccidiosis/veterinaria , Eimeriidae/genética , Isospora/genética , Passeriformes/parasitología , Animales , Secuencia de Bases , Coccidiosis/parasitología , ADN Protozoario/química , ADN Protozoario/aislamiento & purificación , Eimeriidae/clasificación , Eimeriidae/ultraestructura , Genotipo , Proteínas HSP70 de Choque Térmico/genética , Isospora/clasificación , Isospora/ultraestructura , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico/genética , Alineación de SecuenciaRESUMEN
In this study, we examined the prevalence, pathology, and epidemiology of tumors in free-ranging island foxes occurring on three islands in the California Channel Islands, USA. We found a remarkably high prevalence of ceruminous gland tumors in endangered foxes (Urocyon littoralis catalinae) occurring on Santa Catalina Island (SCA)--48.9% of the dead foxes examined from 2001-2008 had tumors in their ears, and tumors were found in 52.2% of randomly-selected mature (≥ 4 years) foxes captured in 2007-2008, representing one of the highest prevalences of tumors ever documented in a wildlife population. In contrast, no tumors were detected in foxes from San Nicolas Island or San Clemente Island, although ear mites (Otodectes cynotis), a predisposing factor for ceruminous gland tumors in dogs and cats, were highly prevalent on all three islands. On SCA, otitis externa secondary to ear mite infection was highly correlated with ceruminous gland hyperplasia (CGH), and tumors were significantly associated with the severity of CGH, ceruminous gland dysplasia, and age group (older foxes). We propose a conceptual model for the formation of ceruminous gland tumors in foxes on SCA that is based on persistent, ubiquitous infection with ear mites, and an innate, over exuberant inflammatory and hyperplastic response of SCA foxes to these mites. Foxes on SCA are now opportunistically treated with acaricides in an attempt to reduce mite infections and the morbidity and mortality associated with this highly prevalent tumor.
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Neoplasias del Oído/epidemiología , Especies en Peligro de Extinción , Zorros/fisiología , Tumores Neuroendocrinos/epidemiología , Animales , California , Oído Externo/parasitología , Oído Externo/patología , Zorros/parasitología , Hiperplasia/epidemiología , Islas , Ácaros/patogenicidadRESUMEN
Ear mites (Otodectes cynotis) and ear canal tumors are highly prevalent among federally endangered Island foxes (Urocyon littoralis catalinae) living on Santa Catalina Island off the coast of Southern California. Since studies began in the 1990s, nearly all foxes examined were found to be infected with ear mites, and ceruminous gland tumors (carcinomas and adenomas) were detected in approximately half of all foxes ≥ 4 years of age. We hypothesized that reduction of ear mite infection would reduce otitis externa and ceruminous gland hyperplasia, a risk factor for tumor development. In this study, we conducted a randomized field trial to assess the impact of acaricide treatment on ear mite prevalence and intensity of infection, otitis externa, ceruminous gland hyperplasia, and mite-specific IgG and IgE antibody levels. Treatment was highly effective at eliminating mites and reducing otitis externa and ceruminous gland hyperplasia, and mite-specific IgG antibody levels were significantly lower among uninfected foxes. Ceruminous gland hyperplasia increased in the chronically infected, untreated foxes during the six month study. Our results provide compelling evidence that acaricide treatment is an effective means of reducing ear mites, and that mite removal in turn reduces ear lesions and mite-specific IgG antibody levels in Santa Catalina Island foxes. This study has advanced our understanding of the underlying pathogenesis which results in ceruminous gland tumors, and has helped inform management decisions that impact species conservation.
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Acaricidas/farmacología , Enfermedades del Oído/veterinaria , Neoplasias del Oído/veterinaria , Zorros , Ácaros/patogenicidad , Enfermedades de los Animales , Animales , California/epidemiología , Enfermedades del Oído/parasitología , Enfermedades del Oído/prevención & control , Neoplasias del Oído/prevención & control , Femenino , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Masculino , Infestaciones por Ácaros/tratamiento farmacológico , Infestaciones por Ácaros/epidemiología , Ácaros/efectos de los fármacos , Ácaros/inmunología , Otitis Externa/etiología , Otitis Externa/parasitología , Factores de Riesgo , Resultado del TratamientoRESUMEN
Wildlife populations of conservation concern are limited in distribution, population size and persistence by various factors, including mortality. The fisher (Pekania pennanti), a North American mid-sized carnivore whose range in the western Pacific United States has retracted considerably in the past century, was proposed for threatened status protection in late 2014 under the United States Endangered Species Act by the United States Fish and Wildlife Service in its West Coast Distinct Population Segment. We investigated mortality in 167 fishers from two genetically and geographically distinct sub-populations in California within this West Coast Distinct Population Segment using a combination of gross necropsy, histology, toxicology and molecular methods. Overall, predation (70%), natural disease (16%), toxicant poisoning (10%) and, less commonly, vehicular strike (2%) and other anthropogenic causes (2%) were causes of mortality observed. We documented both an increase in mortality to (57% increase) and exposure (6%) from pesticides in fishers in just the past three years, highlighting further that toxicants from marijuana cultivation still pose a threat. Additionally, exposure to multiple rodenticides significantly increased the likelihood of mortality from rodenticide poisoning. Poisoning was significantly more common in male than female fishers and was 7 times more likely than disease to kill males. Based on necropsy findings, suspected causes of mortality based on field evidence alone tended to underestimate the frequency of disease-related mortalities. This study is the first comprehensive investigation of mortality causes of fishers and provides essential information to assist in the conservation of this species.
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Conservación de los Recursos Naturales , Contaminantes Ambientales/envenenamiento , Contaminación Ambiental/efectos adversos , Mustelidae , Animales , California , Femenino , Cadena Alimentaria , Humanos , Masculino , Densidad de PoblaciónRESUMEN
Seven of 28 passerine birds that died in captivity were positive for malarial parasites by polymerase chain reaction targeting the mitochondrial cytochrome b (cytB) and apicoplast ribosomal RNA (rRNA) genes. Each bird was infected with a single parasite lineage having a unique genotype. Apicoplast rRNA sequences were present both in Haemoproteus spp. and Plasmodium spp. and had typically high adenosine + thymidine content. Phylogenies for cytB and apicoplast rRNA sequences were largely congruent and supported previous studies that suggest that Plasmodium-Haemoproteus spp. underwent synchronous speciation with their avian hosts, interrupted by sporadic episodes of host switching. Apicoplast phylogeny further indicated that Haemoproteus spp. are ancestral to Plasmodium spp. All the 7 infected passerine birds had histologic lesions of malaria, and malarial parasites may have contributed to the death of at least 4 animals. These findings provide new genetic data on passerine hematozoa, including initial sequences of apicoplast DNA, and emphasize the relevance of parasite prevalence, evolutionary relationships, and host switching to modern management and husbandry practices of captive birds.