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Results for “Dictyocaulus Infections”

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At least 19 recordsLinked to original sources
PubMed1975

[Fluorescent microscopy in the diagnosis of Dictyocaulus infection in sheep].

Fluorescence microscopy was employed to study Dictyocaulus infection in 15 experimentally infected lambs each given 2000 D. filaria larvae. Studied were also the sera of 10 control lambs and of 20 sheep and goats infected with other helminths. Antibodies were established after the 14th day in 53 per cent of the lambs, the 20th day in 86.6 per cent, and the 27th day in all animals infected with the parasite. Antigens were found mainly in the wall of the digestive and reproductive organs, and in the cuticle of the larvae. As a method of early diagnosis fluorescence microscopy is simple, precise, and readily applicable in establishing Dictyocaulus infections.

Animals↗
PubMed1976

Lungworm infection (Dictyocaulus arnfieldi) of horses and donkeys.

Dictyocaulus arnfieldi (Cobbold 1884) infects the respiratory tract of horses, donkeys, mules, hinnies and zebra. A review of the literature has been given by Round (1972). In the western hemisphere it is popularly believed that donkeys are the natural host and that horses become infected by association with infected donkeys. There is scant documentary evidence for this and, in the Soviet Union, patent infections may reach 70 per cent without mention of donkey association (Koulikov 1935, Borovkova 1948, Akramovskii 1952a). Poynter (1963) considered the infection to be rare in the United Kingdom although cases had been reported by Fletcher (1960) and Holmes (1960). The lack of precise data on this parasite has led to the assumption that it behaves like D filaria and D viviparaus of ruminants. Studies made in the United Kingdom have shown that there are some important differences (Round, 1972).

Animals↗
PubMed1982

Spread of infective Dictyocaulus viviparus larvae in pasture and to grazing cattle: experimental evidence of the role of Pilobolus fungi.

Four calves experimentally infected with Dictyocaulus viviparus were made Pilobolus-free by hygienic measures and by feeding them irradiation sterilized feed. Two of the calves were only administered laboratory cultured Pilobous sporangia daily. As a result, the faeces from one pair contained D. viviparus larvae and Pilobolus sores, and the faeces from the other one pair contained D. viviparus larvae, but no Pilobolus spores. Two identical plots were used for deposition of the two kinds of faeces, and one of them remained free of Pilobolus fructification. Herbage sampling and the use of tracer calves revealed that on this plot the larval contamination and the infectivity of the pasture were greatly reduced. A mean larval count of 1321 near the faecal pats (0-5 cm) in the plot where Pilobolus was observed was reduced to 69 per kg of herbage on the Pilobolus-free plot. At a distance of 100 cm from the pats, a reduction from 99 to 3 larvae per kg herbage was found. Each plot was grazed by four parasite-free tracer calves for 3 days. During the subsequent stabling period of these calves, the lungworm larval excretion of those from the Pilobolus-free plot was reduced by 90% and the clinical symptoms were milder than those which grazed the plot which contained the fungus. The mean post mortem worm counts after 4 weeks of stabling showed a reduction from 167 to 25 worms. A more marked effect of Pilobolus fungi on the transmission of D. viviparus infection is to be expected under field conditions where calves are grazing more selectively than in the present study.

Animal Feed↗
PubMed1993

Dose-dependent pathophysiological changes in cattle experimentally infected Dictyocaulus viviparus.

In two trials five calves were each experimentally infected on three consecutive days with a total number of either 30 Dictyocaulus viviparus larvae per kg body weight (trial A) or 3 larvae/kg body weight (trial B). Five calves served as non-infected controls. Infected cattle in trial A developed severe clinical signs of dictyocaulosis and one calf died 37 days post infection (p.i.), whereas all cattle in trial B remained clinically healthy. Weight gains in both trials were not statistically different. Haemoglobin concentrations, packed cell volume (PCV), number of erythrocytes and leucocytes, blood pH and albumin concentrations were in the physiological range in all groups. Infected cattle in trial A showed increases in respiratory rates, body temperature, serum protein concentrations, and blood eosinophil counts and decreases in oxygen partial pressure. Infected cattle in trial B showed increased blood eosinophil counts. Antibody formation in infected cattle of both trials showed a similar pattern. Excretion of larvae from infected cattle reflected the different infection doses. Microbiological examinations showed an increase of facultatively pathogenic bacteria in the lung fluid.

Animals↗
PubMed1980

Dictyocaulus infection in farmed red deer (Cervus elaphus).

Post mortem examination of red deer calves on a deer farm situated on hill ground in north-east Scotland revealed infection by a lungworm morphologically similar to Dictyocaulus viviparus. Trials were conducted to monitor the natural development of D viviparus infection in red deer, to investigate the value of a commercial lungworm vaccine and to evaluate methods of treating clinical cases. The findings indicate that the syndrome may be less apparent in red deer than it is in cattle, protection might be gained by vaccination and that housing and medication provide useful therapy. The extent of clinical disease is likely to depend on the general health, bodily condition and nutritional status of the animals versus the weight of infection acquired from the pasture. However, various factors can affect both sides in this confrontation.

Animals↗
PubMed1978

The response of Suffolk lambs to an escalating experimental infection with Dictyocaulus filaria.

Infection of Suffolk lambs with Dictyocaulus filaria larvae beginning at two months of age with one larva per day, six days per week, and doubling every four weeks to reach a final infection rate of 64 larvae per day gave rise to a pattern of larval excretion in the faeces which approximated to that seen in naturally infected Suffolk lambs in Midlothian in 1974. Several of the lambs were still infected with adult D filaria and were excreting larvae in their faeces 28 weeks after the infection began. However, when some of the lambs were challenged at this time, those which had received the previous escalating infection were resistant to the challenge infection.

Animals↗
PubMed1982

Experimental infections with Dictyocaulus viviparus in vaccinated and unvaccinated red deer.

Four of eight red deer calves which had been artificially reared and were lungworm free were vaccinated with bovine lungworm oral vaccine when eight weeks old; the other four were not vaccinated. Three of each category were challenged daily with 500 Dictyocaulus viviparus infective stage larvae per kg liveweight for 17 days when six months old while one in each category was left as an unchallenged control. The effects of challenge were monitored and all challenged deer and one control were killed for post mortem assessment. Challenge with D viviparus was associated with reduced food intakes and weight gains but vaccinated calves were less affected than unvaccinated ones. The reaction of the alveolar tissue of red deer lung to D viviparus was mild in vaccinated and unvaccinated animals and differed from that of bovine lung in that alveolar epithelialisation was limited and hyaline membrane formation and interstitial emphysema were not seen. The disease was most evident in and around airways and was less in vaccinated calves. It was concluded that young red deer are tolerant to D viviparus but will readily acquire infection.

Animals↗
PubMed1987

Serum lactate dehydrogenase: clinical significance of alterations in its activity in lambs infected with Dictyocaulus filaria.

Alterations in the serum lactate dehydrogenase activity of Dictyocaulus filaria infected lambs were studied. The significant increase in its activity during patency correlated well with the progress of the disease and lung damage caused by the parasite. The enzyme may be of use in assessing the potency of D filaria vaccine and the chemotherapeutic value of an anthelmintic. Its use as a non-invasive method for earlier diagnosis and prognosis of the disease under experimental conditions is suggested.

Animals↗
PubMed1980

Effect of treatment with levamisole or fenbendazole on primary experimental Dictyocaulus viviparus infection and on resistance in calves.

Based on faecal larval counts, respiratory rates and live-weight gains, the anthelmintics levamisole and fenbendazole were equally efficacious against primary infection with Dictyocaulus viviparus in calves. Calves that were treated with levamisole or fenbendazole resisted the live-weight depressing impact of reinfection. Treatment somewhat impaired resistance to establishment of the secondary challenge as determined at necropsy. However, compared with previously uninfected controls, the treated animals harboured significantly fewer D viviparus, showing that they still strongly resisted reinfecting worms becoming established. The animal responses measured did not demonstrate any difference between levamisole and fenbendazole in relation to efficacy or to effect on resistance.

Animals↗
PubMed2005

Mononuclear cell subsets in bronchoalveolar lavage fluid during Dictyocaulus viviparus infection of calves: a potential role for gamma/delta TCR-expressing cells in airway immune responses?

Mononuclear cell populations in the lungs of calves infected with Dictyocaulus viviparus were studied during primary infection and reinfection in order to identify cells involved in development of protective immunity to parasitic bronchitis. Three groups of calves were either inoculated with 500 third-stage larvae at both weeks 0 and 10 (n = 6), inoculated only at week 10 (n = 6), or remained uninfected (n = 3). The animals were monitored weekly by collection of bronchoalveolar lavage fluid (BALF), blood and faeces. Among mononuclear BALF-cell populations, the gamma/delta TCR-expressing cells showed a pronounced transient increase in proportion as well as in relative cell size 2 weeks post primary infection, whereas CD4-, CD8-, Ig- and CD14-expressing cells showed no significant differences related to the infection. The increase in gamma/delta TCR-expressing cells coincided with significantly increased proportions of eosinophils and recovery of adult worms in BALF. After reinfection, gamma/delta TCR-expressing cells increased again, but not until week 3 post inoculation, whereas eosinophils were increased by week 2 and reached higher levels than after primary infection. After reinfection, establishment of D. viviparus was less successful than after primary infection. In conclusion, these results indicate a role for gamma/delta TCR-expressing lymphocytes in the pathogenesis of D. viviparus infection.

Animals↗
PubMed1989

Effect of Dictyocaulus filaria infection on the osmotic fragility of sheep erythrocytes.

The osmotic fragility of erythrocytes in lambs experimentally infected with Dictyocaulus filaria was studied weekly for 71 weeks. In acute infection, the erythrocytic fragility increased from the third week of infection onwards, reached its peak by the eleventh week and declined thereafter. However, in the chronic immune-carrier stage, this increase in the fragility did not return to normal until the end of the experiment. This enhanced fragility showed a positive correlation with the faecal larval count, worm burden and the extent of lung damage in lambs.

Acute Disease↗
PubMed1991

Morphological investigations on the pathology of Dictyocaulus viviparus infections in cattle.

Morphological investigations of lungs obtained from cattle that had been experimentally infected with Dictyocaulus viviparus were carried out using a new fixation technique that excludes post-mortem changes in the samples. Light and electron microscopical investigation showed a substantial loss of ciliated epithelial cells in the bronchi, severely affecting the mucociliary clearance. Bronchiolitis, peribronchiolitis and cell-rich mucus caused bronchial atelectasis and consolidation of the related alveoli. Interlobular septa completely separated diseased from normal tissue. Clara cells contained abundant intraplasmatic glycogen. Alveolary walls were thickened and showed cellular infiltration, loss of functional epithelial cells and hyperplasia of alveolar type II cells. Increased connective tissue indicated an irreversible chronic decline in lung performance. Lung eosinophilia and the cytotoxic abilities of eosinophils are discussed as a cause of the changes in lung tissue after infection with D. viviparus.

Animals↗