Strongyloides papillosus: prenatal and transmammary infection in ewes

The absence of larvae in lambs of six infected and controlled ewes immediately killed at birth without suckling may indicate the absence of prenatal infection. The ewes had larvae in their milk immediately prior to lambing and several hours afterwards. The persistence of infection, even after intestinal infection was removed with thiabendazole at 50 mg/kg body weigh, may be due to the pool of inhibited larvae. All the suckling lambs had patent infections within 4 to 5 days. Infection of suckling lambs with Strongyloides papillosus via milk from their ewes demonstrates the transmammary route of infection of this nematode.     

Sudden death in calves associated with Strongyloides papillosus infection

In recent years, a total of 152 calves have died suddenly on three farms in the southern part of Japan which used sawdust as litter. Calves often died within a few minutes of a violent fall without showing previous clinical signs. On necropsy of these cases, only a slight lesion was observed, although all showed heavy infection with Strongyloides papillosus (SPL). They appeared to have not only a large number of SPL eggs in the faeces, together with many adult SPL worms in the intestine, but also many migratory SPL larvae in tissues such as the lung and muscle. These outbreaks ceased following medication with thiabendazole or ivermectin. It is concluded that 'sudden death' is associated with heavy infection with SPL.     

Gastrointestinal motor disturbance in rabbits experimentally infected with Strongyloides papillosus

Strongyloides papillosus is a common nematode in ruminants, and the rabbit is the only susceptible experimental animal that has been identified to date. It is known that heavy infection with S. papillosus causes death in a number of animals. However, even though a number of fatal cases have been reported, the mechanism by which S. papillosus infection leads to death remains unknown. In this study, the pathogenic effect of S. papillosus infection on gastrointestinal motility in infected rabbits was investigated by radiographic means. Gastrointestinal motility in rabbits experimentally infected with S. papillosus was assessed by contrast radiography after oral administration of barium sulfate on days 11 (group A) and 13 (group B) of infection. Body weight, food intake, fecal weight and egg count per gram of feces (EPG) were examined in order to investigate the effect of infection on gastrointestinal motility. Seven rabbits from each S. papillosus-infected and uninfected group were examined. Significant declines in body weight, daily food intake, and fecal weight, as well as gastrointestinal motor disturbances, were observed in association with elevated EPG counts in infected rabbits. This was only observed during the intestinal phase of S. papillosus infection. These results suggest that gastrointestinal motor disturbances underlie the anorexia, weight loss and subsequent death observed in rabbits infected with adult stage S. papillosus.     

Observations on dry season strongyle infestations of permanent swamps grazed by cattle in Vom area, Plateau State, Nigeria

Herbage samples were taken from 4 permanent swamps (2 heavily and 2 lightly pastured) located in Vom area every fortnight from November 1985-April 1986 and November 1986-April 1987. Larvae were extracted by washing and sedimentation and counts expressed as number of larvae per kg dry herbage. Worm larvae seen in faecal cultures were differentiated as Haemonchus, Cooperia and Oesophagostomum and these formed the bulk. Trichostrongylus, Bunostomum and Strongyloides were also seen but these were generally few. Lightly pastured permanent swamps were lightly infested and heavily pastured were contaminated with corresponding high infectivity. Heavily contaminated pastures are with risk from mild dry to late dry season. Dry season routine treatment is therefore necessary for cattle with access to swamps during the dry season especially heavily contaminated ones.     

Dynamics of faecal egg counts in rabbits experimentally infected with Strongyloides papillosus

An experiment using rabbits was carried out to determine basic data to maintain the calf strain of Strongyloides papillosus (SPL). Rabbits treated with four different numbers of doses of dexamethasone were exposed to 50,000 or about 100,000 infective larvae of SPL (Himeji strain, 1988). As a result, faecal egg output was valid in individual rabbits, regardless of dexamethasone administration. Eggs appeared in the faeces 9 or 10 days after exposure, and increased to as much as 20,000-573,000 eggs per gram (EPG). Thirteen of 18 rabbits died (72%) 12-29 days after infection. Five surviving rabbits discharged eggs in their faeces for more than 1 month; however, the EPG value of these cases on the last day was comparatively low.     

Sudden cardiac death in calves with experimental heavy infection of Strongyloides papillosus.

For obtaining the preliminary data on the pathogenesis of sudden death in calves naturally heavily infected with Strongyloides papillosus, we monitored 8 Holstein calves experimentally infected with the larvae on electrocardiographic and pneumographic changes. Six calves died suddenly on days 11 to 17 after infection. Sinus tachycardia had been recorded continuously since 1 to 6 days before death. Heart rates increased gradually until death. Since 1 or 2 days before death, various patterns of tachyarrhythmia and bradyarrhythmia had been observed among patterns of sinus tachycardia. Arrhythmias included serious ventricular premature beat, paroxysmal ventricular tachycardia, complete atrioventricular block and so on. The terminal pattern observed suddenly in all of the cases was ventricular arrhythmias consisting of serial ventricular tachycardia, flutter and fibrillation, which were followed by respiratory arrest. Abnormal pneumograms were not obtained before the terminal ventricular fibrillation. Two of 8 calves recovered from the infection, only one of which showed sinus arrest and the second degree of atrioventricular block transiently. We concluded that calves heavily infected with the larvae died due to sudden cardiac arrest.     

Hypolipemia associated with the wasting condition of rabbits infected with Strongyloides papillosus

Rabbits develop a wasting condition in the intestinal stage of Strongyloides papillosus infection. Serum inflammatory cytokine and lipid profiles were investigated in five rabbits infected with S. papillosus and five uninfected pair-fed controls to ascertain whether the disease is inflammatory cytokine-mediated cachexia. Tumor necrosis factor alpha (TNF alpha) was detected in one infected animal at Day 7 after infection. Interleukin (IL)-1 was detected in three infected, and one control, animals at Day 28. IL-6 remained unchanged in both the groups. Infected animals developed hypolipemia, including hypotriglyceridemia in the intestinal stage of infection. Control animals lost body weight in the same manner as the infected animals, but had elevated cholesterols and phospholipids with normal triglyceride concentrations. The results suggested that the wasting condition has no association with cachexia induced by TNF alpha. IL-1 or IL-6, and that hepatic function for lipid synthesis is affected during the intestinal stage of S. papillosus infection.     

Serological prevalence of bovine leptospirosis in Plateau State, Nigeria

Serum samples obtained from 1.537 cattle in the 14 local government areas (LGAs) of Plateau State of Nigeria were screened for the presence of leptospiral antibodies using 13 serovars in a modified microscopic agglutination test (MAT). Two hundred and twenty-two (14.4 p.100) of the cattle tested had leptospiral antibody titres of 1:100 or higher to one or more of the test antigens. The prevalence rates of antibodies to individual serovars were: hardjo (35.6 p.100), pomona (11.7 p.100), pyrogenes (11.7 p.100), canicola (9.5 p.100), grippotyphosa (7.7 p.100), bratislava (5.9 p.100), icterohaemorrhagiae (5.9 p.100), ballum (4.5 p.100), autumnalis (3.6 p.100), bataviae (2.3 p.100) and tarassovi (1.8 p.100). The serological prevalence of bovine leptospirosis in the various local government areas of Plateau State of Nigeria differed significantly (P less than 0.05; X2).     

A survey of the ectoparasitic infestations of dogs in Nigeria

Between January and December 1973, a survey of ectoparasitic infections of domestic dogs was carried out at Ibadan. The ectoparasites were detached from dogs brought for treatment at the two veterinary clinics in Ibadan and from those living in the less developed areas of Ibadan. A similar but briefer survey was made during a trip to the northern states in August.
Ticks were the most common ectoparasite found on the dogs. Among these, Rhipicephalus sanguineus predominated throughout the year. Another species, R. longus was strongly represented in some of the northern towns. The only myiasis producing larvae obtained were those of Cordylobia anthro-pophaga and they were most common during the wet season. Very few lice and fleas were obtained.     

Sudden death of calves by experimental infection with Strongyloides papillosus. I. Parasitological observations.

Recently, an unknown disease, 'sudden death', in calves has been found in Japanese beef production farms. A previous study conducted by Taira and Ura indicated that sudden death can be effected in calves by hyperinfection of Strongyloides papillosus (SPL) and that the disease is possibly caused by SPL infection. In the present work, an experimental infection of SPL in calves was conducted to confirm the field occurrence. Fifteen Holstein Friesian calves, ranging from 45.5 to 85.6 kg in body weight, were divided into six groups. Calves of Groups A, B, C, D, E and F were infected once at the rate of 100,000, 320,000, 1,000,000, 3,200,000, 10,000,000 and 32,000,000 SPL larvae per 100 kg of body weight, respectively. Five calves were assigned to Group B, while two calves were assigned to the other groups. After showing no premonitory signs, sudden death of ten calves took place. The survival time of these calves was 27.4 and 16.8 days (Group B), 14.8 and 14.8 days (Group C), 13.3 and 14.2 days (Group D), 11.0 and 11.1 days (Group E) and 11.6 and 10.8 days (Group F). Three calves of Group B did not exhibit sudden death. The results of this study demonstrate that strongyloidiasis was the cause of sudden death.     

Antigenic Characterization of Rabies Virus Isolates from Vaccinated Dogs in Plateau State,Nigeria

Rabies isolates (genotype 1 lyssaviruses) from vaccinated dogs that died of rabies infection in the Plateau area of Nigeria were characterized using monoclonal antibodies (MAbs). The isolates were examined for rabies (genotype 1) and rabies-related (genotypes 2, 3 and 4) viruses by the indirect fluorescent antibody test carried out with MAb 502-2, which recognizes the nucleocapsid protein of all known lyssaviruses, and with MAb 422-5, which identifies only rabies-related viruses. All three isolates showed positive immunofluorescence with MAb 502-2 and were negative with MAb 422-5, indicating that they were all rabies (genotype 1) viruses.Characterization with a panel of 36 anti-nucleocapsid monoclonal antibodies showed that all three isolates reacted positively with 35 of the anti-nucleocapsid MAbs, including MAb 102-27 and MAb 377-7. Characterization using a panel of 44 anti-glycoprotein MAbs differentiated the isolates sharply from LEP Flury and PM vaccine viruses. The pattern of anti-glycoprotein reactivity of the isolates showed them to belong to one distinct viral subtype, except for a minor variation in one isolate that was not neutralized by MAb 1101-3. None of the three isolates was identified as the Flury low egg passage (LEP) vaccine strain used for vaccinating dogs in Nigeria. In fact, all the three isolates had the typical pattern of reactivity of isolates from unvaccinated dogs, including MASS 83, a rabies virus isolated in Nigeria and characterized at the Wister Institute before this study.     

Effects of infection intensity with Strongyloides papillosus and albendazole treatment on development of oxidative/nitrosative stress in sheep

The objective of this study was to estimate and evaluate oxidative/nitrosative stress parameters in sheep infected with Strongyloides papillosus and after antihelminthic treatment with albendazole (ABZ). This parasite, especially during development stages can seriously damage parenchaematous organs during migration within the host. The presence of parasites leads to increased productions of reactive oxygen species (ROS) and reactive nitrogen species (RNS). It is also well known that certain drugs can be very harmful for the delicate oxidant-antioxidant equilibrium, provoking oxidative stress during their biotransformation. ABZ is a broad spectrum antihelminthic drug, frequently used in veterinary medicine for therapy of parasitic infections. The current research was performed on female Württemberg sheep (n=48). The distribution of parasites in sheep was evaluated using the native smear coprological technique, by sedimentation and flotation methods, revealing the presence of S. papillosus. The degree of infection intensity per sheep was quantitatively established by the method of McMaster, the animals having been divided into three groups according to the intensity of infection; mild, moderate and high. The control group consisted of sheep negative to the parasites. After determining the type of parasite infection, the sheep were treated with ABZ, per orally, in single doses of 5mg/kg per body weight. Sampling of feces for parasitological and blood for biochemical assaying was performed on the 0 and 21st day after treatment with ABZ. The oxidative stress parameters were measured for catalase activity (CAT), the red cell membrane damage by level of malondialdehyde (MDA), while carbonyl and thiol plasma protein group concentrations were used as indicators of the degree of protein oxidative modification. The activity of Cu,Zn-superoxide dismutase (SOD) and relative distribution of lactate dehydrogenase (LDH(1)-LDH(5)) activity were determined electrophoretically. The distribution of LDH isoenzymes in sheep moderately and highly infected with S. papillosus revealed that the parasite induced damage to the myocardial (LDH(2)), lung (LDH(3)) and liver cells (LDH(5)) in infected animals, while ABZ treatment only damaged liver cells (LDH(5)). The MDA concentration revealed that lipid peroxidation increased both in the presence of parasites and the antihelminthic formulation tested (p<0.001) when compared to the control sheep, while the increase of carbonyl concentration (p<0.001), as well as the observed decrease of thiol concentration (p<0.001) indicated significant oxidative damage of plasma proteins in experimental sheep, when compared to the control animals. Our results indicate that S. papillosus induces oxidative/nitrosative stress in sheep. The antihelminthic treatment with ABZ further promotes the disbalance of oxidative-antioxidative equilibrium in all tested sheep.     

Mortality in lambs due to enterotoxaemia associated with heavy infestations of Moniezia expansa

Abstract

Extract

Throughout the Hawke?s Bay area of the North Island of New Zealand Moniezia expansa, the common tapeworm of sheep, was extremely abundant in lambs at the end of 1955, following a milder and damper winter and earlier spring than is usual. The numbers of tapeworms were such that workers in the meat-freezing works remarked that they had never before seen so many. Examinations of pasture samples from properties where the lambs were severely infested revealed numbers of the oribatid mites, which are the intermediate hosts of Moniezia, far in excess of the numbers usually encountered. Paddocks at the Wallaceville Animal Research Station, from which pasture samples are examined each week throughout the year, were taken as standard.     

Development and survival of Haemonchus contortus larvae on pasture at Vom,Plateau State,Nigeria

The development and survival of the eggs of Haemonchus contortus on pasture at Vom were studied by depositing faecal pellets on grass plots over a period of 12 months. Development and survival to the infective larvae occurred throughout the study except during the dry season months of December to April. More infective larvae were recovered from the herbage in June, July and August than in other months. The survival time of the infective larvae ranged from 2 weeks in October to 10 weeks in June, July and August. Rainfall was the most important epizootiological factor influencing the development and survival of the infective larvae. Temperature was not a limiting factor.     

A case report of Thelazia infection in a 15-month old heifer in Vom, Plateau State, Nigeria

A case of eye infection in a heifer was reported with bilateral blindness, cornea opacity, excessive lachrymation and nasal discharge. Treatment with 6-10 drops of a 10% solution of levamisole resulted in a complete recovery, a total of 127 adult Thelazia rhodesii being recovered from the eyes.     

The development of the free-living stages of Strongyloides papillosus: I. Effect of temperature on the development of the heterogonic and homogenic nematodes in faecal culture

Temperature had a significant effect on the proportion of free-living females and infective larvae of Strongyloides papillosus developing from faecal culture. The number of free-living males recovered from cultures incubated at 20°C was fairly constant. However, females were most numerous at 30°C and infective larvae at 20°C, with the sum of the two approximately the same at both temperatures. This indicates that infective larvae and females are developing from genetically identical eggs. The critical period by which the course of development has been fixed occurs between 4 and 5 h at 30°C, but between 4 and 24 h at 20°C.     

Experimental studies with Stronglyloides papillosus in goats

Unusual clinical and pathological observations in the field in goats and sheep suffering from Strongyloides papillosus infection prompted experimental work on this parasite. Goats were infected percutaneously with either single or multiple, low or high levels of S. papillosus. Young goats up to 12 months of age were found to be the most susceptible. Some animals, however, showed substantial resistance to infective doses. Clinical signs included transient diarrhoea, misshapen, elongated faecal pellets terminally, dehydration, anorexia, cachexia, gnashing of teeth, foaming at the mouth, anaemia and nervous signs such as ataxia, a wide-based stance, stupor and nystagmus. A 'pushing syndrome' was seen in 22% of the animals. The pathological changes are described and included enteritis, status spongiosus in the brain, hepatosis leading to rupture of the liver, nephrosis, pulmonary oedema, interstitial pneumonia and pneumonia. About 6% of the goats died acutely from fatal hepatic rupture. The development of an acquired immunity was determined. The immunity elicited an allergic skin reaction at the application site of larvae or injection sites of larval metabolites. This immunity, however, could be breached by large doses of larvae. The most profound clinicopathological changes induced by the parasites were an anaemia (most pronounced in the young goats) and hypophosphataemia. Trace element analyses provided evidence of Cu, Mn and possibly Se deficiencies in some goats.     

Sudden death of calves by experimental infection with Strongyloides papillosus. II. Clinical observations and analysis of critical moments of the disease recorded on videotape.

Four calves experimentally infected with different doses of Strongyloides papillosus were examined for changes of body temperature and other clinical parameters. Also, the critical moments of death, which were recorded on videotape, were analyzed in detail. The first clinical signs included initial accelerated respiration. In general, body temperature was almost normal; however, one calf showed a slight increase after 2 or 3 days of infection, and two calves a gradual increase 7 days after infection. Vocal noises and general spasms were observed 5-14 times during the course of death. Initial vocal noises were heard between 0:50 and 1:30 (minute:second) after the appearance of the initial clinical signs. The final spasm, preceding death, occurred between 3:05 and 3:40 after the appearance of the initial clinical signs.