Elaphostrongylus cervi Cameron 1931 (Nematoda: Metastrongyloidea) in caribou (Rangifer tarandus caribou) of Newfoundland

1979 ◽  
Vol 57 (7) ◽  
pp. 1384-1392 ◽  
Author(s):  
Murray W. Lankester ◽  
Tom H. Northcott

Elaphostrongylus cervi Cameron 1931 is identified for the first time in North America from woodland caribou (Rangifer tarandus caribou) in Newfoundland where up to 88% of animals were infected. First-stage nematode larvae identical to those of E. cervi occur in faeces of barren ground caribou (R. t. groenlandicus) of the Kaminuriak herd and of woodland caribou in northern Labrador, Ontario, and Manitoba, suggesting that the parasite is widespread in Rangifer in Canada.In clinically normal caribou, adult E. cervi were found beneath the skin and in fascia of the thoracic musculature. Verminous pneumonia caused by nematode eggs and larvae in the lungs and diffuse lymphocytic leptomeningitis over the brain and spinal cord were consistent aspects of infection. A 10-month-old caribou calf exhibiting neurologic signs had numerous E. cervi among thoracic and cervical muscles but none in the central nervous system. Accumulations of lymphocytes, eosinophils, and histiocytes in the subarachnoid and perineurium of lateral nerves in the posterior region of the spinal cord and destruction of axons in the cauda equina may explain the clinical signs observed.

1988 ◽  
Vol 66 (2) ◽  
pp. 475-479 ◽  
Author(s):  
Murray W. Lankester ◽  
Stu Luttich

Fifty-eight percent of woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador, were infected with up to 110 giant American liver flukes (Fascioloides magna). The prevalence and intensity of infection did not differ between 2 sampling years or between sexes. Prevalence tended to increase with age while intensity did not differ among age groups. Liver weight increased with intensity of infection but condition, as measured by the mean depth of back fat, did not differ between infected and uninfected animals. Caribou must be considered a suitable host of F. magna since the growth and maturation of the parasite and lesions produced in Rangifer resemble those in deer and wapiti.


2016 ◽  
Vol 36 (8) ◽  
pp. 753-760 ◽  
Author(s):  
Fernanda Menezes de Oliveira e Silva ◽  
Dayane Alcantara ◽  
Rafael Cardoso Carvalho ◽  
Phelipe Oliveira Favaron ◽  
Amilton Cesar dos Santos ◽  
...  

Abstract: This study describes the development of the central nervous system in guinea pigs from 12th day post conception (dpc) until birth. Totally, 41 embryos and fetuses were analyzed macroscopically and by means of light and electron microscopy. The neural tube closure was observed at day 14 and the development of the spinal cord and differentiation of the primitive central nervous system vesicles was on 20th dpc. Histologically, undifferentiated brain tissue was observed as a mass of mesenchymal tissue between 18th and 20th dpc, and at 25th dpc the tissue within the medullary canal had higher density. On day 30 the brain tissue was differentiated on day 30 and the spinal cord filling throughout the spinal canal, period from which it was possible to observe cerebral and cerebellar stratums. At day 45 intumescences were visualized and cerebral hemispheres were divided, with a clear division between white and gray matter in brain and cerebellum. Median sulcus of the dorsal spinal cord and the cauda equina were only evident on day 50. There were no significant structural differences in fetuses of 50 and 60 dpc, and animals at term were all lissencephalic. In conclusion, morphological studies of the nervous system in guinea pig can provide important information for clinical studies in humans, due to its high degree of neurological maturity in relation to its short gestation period, what can provide a good tool for neurological studies.


1994 ◽  
Vol 30 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Patricia J. Holman ◽  
Kris Petrini ◽  
Jack Rhyan ◽  
Q. G. Wagner

1970 ◽  
Vol 7 (5) ◽  
pp. 435-447 ◽  
Author(s):  
K. M. Charlton ◽  
K. R. Pierce ◽  
R. W. Storts ◽  
C. H. Bridges

Twenty-two goats were poisoned with daily oral doses of ground coyotillo fruits and were killed at various times after the first day of dosing. The morphologic features and distribution of lesions in the central nervous system were studied by light microscopy. An axonal dystrophy occurred in several of the goats given high daily doses. Swellings occurred along axons of Purkinje cells in the cerebellum and in the white matter of the spinal cord. There was a fairly close correlation between the occurrence of clinical signs suggestive of the neocerebellar syndrome and the occurrence and distribution of lesions in the cerebellum.


2014 ◽  
Vol 92 (12) ◽  
pp. 1029-1037 ◽  
Author(s):  
Dave Hervieux ◽  
Mark Hebblewhite ◽  
Dave Stepnisky ◽  
Michelle Bacon ◽  
Stan Boutin

Across Canada, woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) populations are declining because of human-induced changes to food webs that are resulting in apparent competition-induced increases in predator-caused caribou mortality. We tested the hypothesis that wolf (Canis lupus L., 1758) population reduction could reverse declines in a woodland caribou population following a BACI (before-after-control-impact) design conducted over a 12-year period in west-central Alberta, Canada. We monitored annual survival for 172 adult female caribou and calf recruitment from 2000 through 2012 and conducted a provincial government delivered wolf population reduction program annually during the winters of 2005–2006 to 2012 (inclusive) in an area centered on the Little Smoky range. Wolf removal translated to a 4.6% increase in mean population growth rate of the Little Smoky population mostly through improvements in calf recruitment. In contrast, the Red Rock Prairie Creek control population exhibited a 4.7% decline. Although the wolf population reduction program appeared to stabilize the Little Smoky population, it did not lead to population increase, however, with λ remaining approximately equal to 1. Therefore, we recommend, if required, predation management be combined with effective habitat conservation and long-term planning to effect the recovery of species, such as woodland caribou, which are declining as a result of habitat-mediated apparent competition.


2021 ◽  
Author(s):  
Melanie Iverson ◽  
Alexander Leacy ◽  
Phuc H. Pham ◽  
Sunoh Che ◽  
Emily Brouwer ◽  
...  

Abstract Aquatic bird bornavirus (ABBV), a type of avian bornavirus, has been associated with inflammation of the central and peripheral nervous systems and neurological disease in wild waterfowl in North America and Europe. The potential of ABBV to infect and cause lesions in commercial waterfowl species is unknown. The aim of this study was to determine the ability of ABBV to infect and cause disease in day-old Muscovy ducks (n = 174), selected as a representative domestic waterfowl. Ducklings became infected with ABBV through both intracranial and intramuscular infection routes: upon intramuscular infection, the virus spread centripetally to the central nervous system (brain and spinal cord), while intracranial infection led to virus spread to the spinal cord, kidneys, proventriculus, and gonads (centrifugal spread). Infected birds developed both encephalitis and myelitis by 4 weeks post infection (wpi), which progressively subsided by 8 and 12 wpi. Despite development of microscopic lesions, clinical signs were not observed. Only five birds had choanal and/or cloacal swabs positive for ABBV, suggesting a moderate potential of Muscovy ducks to shed the virus. This is the first study to document the pathogenesis of ABBV in poultry species, and confirms the ability of ABBV to infect commercial waterfowl.


2022 ◽  
Vol 13 ◽  
pp. 16
Author(s):  
Coby Cunningham ◽  
Chiara Flores ◽  
Rocco Dabecco ◽  
Palgun Nisarga ◽  
Janice Ahn ◽  
...  

Background: Teratomas are a unique family of tumors derived from two or more of the three embryonic layers: endoderm, mesoderm, and ectoderm. Mature teratomas are comprised the most well-differentiated tissue types and may contain skin, hair, teeth, smooth muscle, respiratory tissues, etc. Infrequently, mature teratomas may be found within the central nervous system and, in exceedingly rare cases, may be occur within the spinal cord itself (i.e., intramedullary/intradural). Case Description: A 78-year-old female presented with a subacute progressive lower extremity paraparesis. The MR revealed a cystic 81 × 30 × 25 mm intradural/intramedullary spinal mass involving the distal conus with exophytic extension into the L1-L4 spinal canal. Following surgical intervention consisting of a L1-L4 laminectomy, the lesion was largely removed. Pathology of the mass confirmed a large mature teratoma containing a multilobulated cyst that intraoperatively compressed the conus and cauda equina. Immediately postoperatively, the patient significantly improved neurologically. However, on postoperative day 2, she acutely developed a change in mental status with the left gaze preference and hemiparesis. CT brain in the acute setting showed no evidence of causative pathology and subsequent MR brain was unremarkable. The patient’s neurologic deficits progressively improved leading to eventual discharge. Conclusion: Intrathecal intramedullary/extramedullary mature teratomas of the conus that results in subacute cauda equina syndromes are rare. The differential diagnosis for such lesions exophytic to the conus must include mature teratomas which, though rare, may be readily resected resulting in generally favorable outcomes.


Sign in / Sign up

Export Citation Format

Share Document