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There are reports of horses with acute onset acquired cervical scoliosis and cutaneous analgesia. The underlying dorsal gray column myelitis that produces these neurologic signs has been only presumptively attributed to migration of Parelaphostrongylus tenuis within the spinal cord. Despite previous confirmation brain by polymerase chain reaction testing, of P. tenuis within the brain of horses by polymerase chain reaction testing, genetic testing has failed to definitively identify the presence of this parasite in cases of equine myelitis. This case report provides molecular confirmation via polymerase chain reaction of P. tenuis within the cervical spinal cord of a horse with scoliosis and cutaneous analgesia. [ABSTRACT FROM AUTHOR]

A total of 961 harvested and 241 unharvested moose (Alces alces) carcasses and parts from throughout Sweden were examined for Elaphostrongylus alces from 1985 to 1989. When available, the central nervous system and skeletal muscles were searched for adult nematodes, and lungs and feces were examined for first-stage larvae. The parasite was distributed throughout Sweden with highest prevalence (56%) in the central region and lowest in the south (13%). Prevalence was highest in calves and old moose (>9 years) and lowest in middle-aged animals (5–9 years), with no statistical difference between sexes, although prevalence trended higher in young males. Body condition and abundance of Elaphostrongylus alces were negatively correlated, and condition was poorer in unharvested than harvested moose. A short (39–73 days) prepatent period was documented, and calves as young as 1.5 months were infected. These results indicate the importance of continued surveillance of Elaphostrongylus alces, particularly because a warming climate will likely increase abundance of intermediate mollusk hosts and possibly cause increased infection of moose. [ABSTRACT FROM AUTHOR]

The article discusses research on the use of genetic sequencing in analyzing undefined protostrongylid nematode larvae discovered from the endangered pampas deer in Argentina. It describes experimental procedures done including fecal collection, DNA extraction and cloning of polymerase chain reaction (PCR) products. The phylogenetic relationships determined among protostrongylid nematodes are outlined. The need for further studies to fully characterize protostrongylid in deer is emphasized.

Case Description—2 juvenile (17 and 19 months of age) male American bison (Bison bison) were examined because of acute bilateral hind limb weakness and ataxia; 1 animal also had urinary incontinence. Treatment and Outcome—Given the clinical signs and rapid deterioration in the condition of these 2 animals, obtaining a definitive diagnosis was considered essential to minimizing the risk of disease in the remaining bison herd and among other animals at the facility. Therefore, both affected animals were euthanized. At necropsy, no gross abnormalities were seen. Histologic examination of sections of the brains from both animals revealed mild to moderate multifocal aggregates of eosinophils and mononuclear cells in perivascular regions of the meninges and gray matter of the cerebrum, cerebellum, and brainstem. Systematic examination of multiple sections of brain and spinal cord revealed evidence of nematode sections and aberrant parasite migration. Clinical Relevance—Findings suggested that CNS migration of Pare/aphostrongylus tenuis in American bison may cause clinical signs. These findings have implications for the management of captive bison and free-ranging bison sharing ranges with white-tailed deer (Odocoileus virginianus), the definitive host, and elk (Cervus elaphus canadensis). [ABSTRACT FROM AUTHOR]

Thirty-six moose (Alces alces) reported as acting abnormally were examined in north- western Ontario and adjacent northeastern Minnesota in 1986 - 2000. Thirty-four typically had little fear of humans, remained in an area for some time, and showed clinical signs of neuromotor incoordination including walking in circles, showing weakness and difficulty in rising, head tilted to one side, or standing with legs positioned wide apart. A definitive diagnosis of parelaphostrongylosis was confirmed in 15 (44%) of these by finding small numbers (2.5 ± 0.6; 1-9) of adult meningeal worms, Parelaphostrongylus tenuis, within the cranium; the meninges of 12, (excluding 3 unsuitable for examination), were cloudy in appearance. An additional 5 clinically abnormal animals had no visible P tenuis but presented with cloudy inflammation of the meninges. No evidence of infection other than typical neurological signs was found in 14 more, but examination was impossible or incomplete for 9 of these. One, however, had P tenuis-like, dorsal-spined larvae in its feces and another tested positive for P tenuis using the newly developed serological test (ELISA). Female animals predominated in the sample (21/34) and 10 were judged underweight. The remaining 2 moose in the sample, although aggressive toward humans, had no worms visible in the cranium and neither showed neuromotor signs or cloudy meninges; I tested using the ELISA was negative for P tenuis. Moose with adult P tenuis in the cranium were younger (1.8 ± 0.5 yr) than those abnormal animals without worms (5.2 ± 1.2 yr) (U = 20, .P = 0.006). Five of 15 moose with adult worms in the cranium were passing small numbers of dorsal-spined larvae in their feces (0.1 - 2.8 larvae/gm). Sixty-five percent of animals exhibiting typical neuromotor clinical signs of moose sickness showed post-mortem evidence of parelaphostrongylosis. The diagnostic reliability of clinical signs would have been further increased by wider use of the P tenuis ELISA. This is a convenient, commercially available test and potentially a valuable tool for investigating the level of P tenuis exposure experienced by moose populations sharing range with infected white-tailed deer. [ABSTRACT FROM AUTHOR]

The article cites studies on the bionomics of larvae of Parelaphostrongylus odocoilei in experimentally infected gastropod intermediate hosts. The study investigates factors that may determine the distribution of P. odocoilei. The significance of larval emergence and the effects of temperature on the development of larvae were determined. It shows that the larvae emerged from all slugs and only 60 percent of snails.

The article demonstrates the polymorphism in the structure of the tail among first-stage larvae of Parelaphostrongylus odocoilei (Protostrongylidae). It examines the hypothesis that the distinct forms do not represent separate species, but are representative of dimorphic phenotypes. The article provides new information for structural characteristics of protostrongylid based on scanning electron microscopy.

Studies the geographic distribution of the muscle-dwelling nematode Parelaphostrongylus Odocoilei among animals in North America. Characteristics of dorsal-spined larvae; Use of molecular techniques to the identification of prevalent nematodes in animals; Extent of nematode distribution.

Investigates the effect of different exposures of white-tailed deer and red deer to the parasite Parelaphostrongylus tenuis. Acquired immunity after experimental infection; Life history of P. tenuis; Anatomical location; Prepatent period and output of first-stage larvae in feces; Persistence of P. tenuis; Daily output.

Elaphostrongylus rangiferi was introduced to caribou (Rangifer tarandus caribou) of Newfoundland by infected reindeer (R. t. tarandus) from Norway and has caused at least two epizootics of cerebrospinal elaphostrongylosis (CSE), a debilitating neurologic disease. In an attempt to understand the conditions necessary for such outbreaks, we examined the effects of herd density and climatic factors on parasite abundance. The abundance of E. rangiferi was represented by counts of first-stage larvae in feces collected from young caribou (calves and yearlings) in 7 distinct caribou herds in Newfoundland. Abundance of E. rangiferi was highest in February and in the Avalon (632 ± 14 (mean ± SE)) and St. Anthony (526 ± 145) herds, the 2 herds in which CSE was most frequently reported. Mean abundance in February samples from young animals correlated positively with mean annual minimum temperature (r[sub S] = 0.829, df = 6, P = 0.04) and the number of days per year above 0°C (r[sub S] = 0.812, df = 6, P = 0.05) and negatively with mean summer temperatures (r[sub S] = –0.830, df = 6, P = 0.04). Results suggest that abundance of E. rangiferi and the likelihood of cases of CSE are increased by moderate summer temperatures suitable for the activity and infection of gastropod intermediate hosts and by mild winters with little snow that extend the transmission period. Abundance of larvae was not correlated with herd density. Animals in all 7 herds also had the muscle worm Parelaphostrongylus andersoni, a related nematode with similar dorsal-spined larvae. In 2 additional herds (Cape Shore and Bay de Verde), P. andersoni occurred alone and larvae were passed only by young caribou. In herds with dual infections, numbers of P. andersoni larvae were depressed, declined more quickly in young animals, and were considered to be present in only low numbers in February samples used for E. rangiferi analysis. Upon initial infection, young caribou develop a resistance to E. rangiferi that prevents or reduces reinfection later in life. This was demonstrated by examining the brains of caribou for recently acquired worms, which must develop there for up to 90 days before continuing their tissue migration into the skeletal muscles. Recent infections were detected in only calves and yearlings in all herds with E. rangiferi except the Avalon herd, where developing worms were also found on the brains of older caribou. The infection of older animals in the Avalon herd may reflect a lower immunocompetence of a naive herd that has only recently been exposed to E. rangiferi.Elaphostrongylus rangiferi a été transmis aux Caribous (Rangifer tarandus caribou) de Terre-Neuve par des Rennes (R. t. tarandus) de Norvège infectés et a causé au moins deux épidémies d'élaphostrongylose cérébrale (CSE), une maladie neurologique débilitante. Pour mieux comprendre les conditions nécessaires à de telles épidémies, nous avons examiné les effets de la densité élevée des caribous dans la horde et des facteurs climatiques sur l'abondance des parasites. L'abondance des parasites a été évaluée par dénombrement des larves de premier stade dans les fèces de jeunes caribous (jeunes de 1 an ou moins) de 7 hordes distinctes de Terre-Neuve. L'abondance moyenne d'E. rangiferi s'est avérée maximale en février chez les hordes d'Avalon 632 ± 14 (moyenne ± écart erreur)) et de St. Anthony (526 ± 145), les deux hordes où la CSE a été le plus fréquente. L'abondance moyenne dans les échantillons de jeunes animaux en février était en corrélation positive avec les températures minimales moyennes annuelles (r[sub S] = 0,829, dl = 6, P = 0,04) et avec le nombre de jours à température supérieure à 0°C dans l'année (r[sub S] = 0,812, dl = 6, P = 0,05) et en corrélation négative avec les températures moyennes d'été (r[sub S] = –0,830, dl = 6, P = 0,04). Les résultats indiquent que l'abondance d'E. rangiferi et la probabilité des élaphostrongyloses sont accrues par des températures estivales modérées propices à l'activité et à l'infection des gastropodes hôtes intermédiaires, de même que par des hivers doux avec peu de neige, qui prolongent la période de transmission. L'abondance des larves n'était pas reliée à la densité du troupeau. Les animaux des 7 hordes étaient également porteurs du parasite musculaire Parelaphostrongylus andersoni, un nématode apparenté, dont les larves ont aussi des épines sur le dos. Chez 2 autres hordes (Cape Shore et baie de Verde), P. andersoni était seul présent et les larves n'étaient transmises que par des jeunes caribous. Chez les hordes hôtes des deux parasites, le nombre de larves de P. andersoni était réduit et il diminuait plus rapidement chez les jeunes animaux; les parasites de cette espèce n'étaient présents qu'en petits nombres dans les échantillons de février utilisés pour l'analyse d'E. rangiferi. Au moment de l'infestation initiale, les jeunes caribous développent une résistance à E. rangiferi qui prévient les réinfections ultérieures ou en diminue la gravité. Nous avons pu le démontrer en examinant des cerveaux de caribous pour y repérer les vers acquis depuis peu et qui doivent rester dans les cerveaux pour au moins 90 jours avant de continuer leur migration tissulaire jusqu'aux muscles squelettiques. Les nouvelles infections n'ont été observées que chez les nouveau-nés et les animaux de 1 an chez toutes les hordes hôtes d'E. rangiferi, sauf chez la horde d'Avalon où des vers en développement ont été trouvés aussi chez des caribous adultes. La présence d'infections chez des caribous plus âgés à Avalon s'explique peut-être par la compétence immunitaire plus faible qui prévaut chez une horde « naïve » qui n'a été exposée que récemment à la présence d'E. rangiferi.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]