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Biomedical subjects

E M Abbott

Publications and source records attributed to E M Abbott.

16 recordsLinked to original sources
PubMed1998

Elimination of mucosal cyathostome larvae by five daily treatments with fenbendazole.

The efficacy of five daily treatments with 7.5 mg fenbendazole/kg bodyweight against mucosal cyathostome larvae was evaluated in 20 12- and 24-month-old ponies with naturally acquired cyathostome infections. After three weeks communal grazing on infected pasture and six weeks indoors, one group of 10 ponies were treated. Six weeks later, both groups of ponies were humanely destroyed and their burdens of large intestinal cyathostome worms, including luminal parasites and mucosal larvae, were assessed. In the control animals approximately 7 per cent of the total worm burden was present in the gut lumen and 93 per cent was present as larvae in the large intestinal mucosa. The efficacy of fenbendazole against the luminal cyathostomes was 90.7 per cent (P < 0.01). The total numbers of mucosal larvae, recovered after digestion, were reduced by 95.3 per cent (P < 0.0005); mucosal late third and fourth stage larvae were reduced by 99.4 per cent (P < 0.0001), and early inhibited third stage larvae by 91.5 per cent (P < 0.005).

Animals↗
PubMed1996

Evaluation of the effect of the fenbendazole sustained-release intraruminal device on the immunity of calves to lungworm.

Each of 10 set-stocked calves was given a fenbendazole sustained-release intraruminal bolus at turnout for the control of parasitic bronchitis while a group of 10 similar calves was left untreated. The respiratory rates of the control calves were not greatly increased during the grazing season, but persistent coughing was evident from early July when they all had patent lungworm infections. Only occasional coughing was reported from the bolus-treated calves except for a transient increase in its frequency in late September. In mid-August, one of the treated calves was passing lungworm larvae and when they were housed six of the 10 had patent infections. In August tracer calves picked up an average of 23.5 lungworms per day from the control paddock but only 2.1 from the paddock grazed by the treated calves. In September the corresponding figures were 7.6 and 19.2 lungworms per day, respectively, from the control and 'treated' paddocks. After housing, the post mortem worm counts after an experimental challenge with Dictyocaulus viviparus larvae were reduced by 99.2 and 98.7 per cent (P < 0.0001), respectively, for the control and bolus-treated calves in comparison with weight-matched parasite-naive calves. Thus, despite a relatively low level of challenge during the grazing season, the treated animals had developed a considerable degree of protective immunity.

Animals↗
PubMed1993

Efficacy of fenbendazole and piperazine against developing stages of toxocara and toxascaris in dogs.

In a series of controlled trials involving 59 naturally infected greyhounds, fenbendazole at a dose rate of 50 mg/kg/day for three consecutive days reduced the overall numbers of third and fourth stage Toxocara canis by 94.0 per cent and third stage, fourth stage and immature adult stages of Toxascaris leonina by 92.4 per cent. In contrast, piperazine at 100 mg/kg had little or no useful effect against the larval stages of T canis and T leonina and variable efficacy against immature adult T leonina. Fenbendazole was also 100 per cent effective against immature Trichuris vulpis. In a separate controlled experiment, puppies in three litters exposed to reinfection with T canis were treated with fenbendazole at two weeks old and again only after their mean faecal egg counts exceeded 200 epg. Between one and three doses were required to suppress the output of eggs during the puppies' first 12 weeks of life.

Animals↗
PubMed1991

Worming bitches.

Explore the source record for details and available documents.

Animals↗
PubMed1990

Influence of dietary protein on the immune responsiveness of sheep to Haemonchus contortus.

Twenty helminth-free lambs were fed diets containing either 169 g crude protein (CP) kg-1 dry matter (DM) or 88 g CP kg-1 DM from the age of seven months. One month later five lambs from each dietary group were vaccinated against Haemonchus contortus by the oral administration of 10,000 irradiated larvae on two occasions, four weeks apart. Four weeks following the administration of the second dose of irradiated larvae both the vaccinated and unvaccinated lambs were exposed to an experimental infection of 10,000 non-irradiated H contortus larvae Faecal egg output and haematological changes were monitored throughout the study. The lambs were slaughtered 28 days after challenge when worm burdens were assessed. Vaccination was equally successful in inducing a strong resistance to the challenge infection regardless of dietary status. It was concluded that dietary protein does not influence the response to vaccination with irradiated H contortus larvae of lambs more than seven months old.

Abomasum↗
PubMed1988

Influence of dietary protein on the pathophysiology of haemonchosis in lambs given continuous infections.

Mixed-sex groups of three-month-old Finn Dorset and Dorset Horn lambs were given complete diets containing either high or low protein. A trickle infection with Haemonchus contortus of 200 larvae, given three times a week, began one month later for a 17 week period. Erythrokinetic, metabolic, digestibility and balance studies were conducted with the male lambs during weeks 12 to 14 of the infection. Clinical signs of haemonchosis became evident only in the low protein diet group. The infection was characterised by severe macrocytic anaemia, hypoproteinaemia, hypoalbuminaemia, reduced survival, high egg counts and a significantly greater worm burden. In the high protein diet group many lambs developed resistance to further infection in contrast to the low protein group in which no resistance developed. Live-weight gain was not affected by infection in the high protein diet group but decreased in the lambs given the low protein diet compared with uninfected controls. However, infection did not appear adversely to affect the digestive efficiency, nitrogen retention or iron absorption in either dietary group although loss of appetite occurred in the low protein group. Examination of a sample joint from the carcases showed infection was associated with a marked reduction in muscle mass in lambs given the low protein diet relative to the control animals.

Animals↗
PubMed1986

The effect of dietary protein on the pathogenesis of acute ovine haemonchosis.

Two experiments were conducted to examine the influence of dietary protein on parasite establishment and pathogenesis in Finn Dorset/Dorset Horn lambs infected with Haemonchus contortus. The lambs were introduced to high (169 g) or low (88 g crude protein (CP) kg-1 dry matter (DM)) protein diets at 3 months of age and infected 1 month later with 350 larvae kg-1 body weight (BW). Blood and faecal samples were collected for analysis and body weights recorded weekly. In the first experiment some of the infected lambs were killed 6 weeks after infection and the remainder 5 weeks later. In the second experiment all the infected lambs were killed 4 weeks after infection. The results showed that lambs on a low protein diet were less able to withstand the pathogenic effects of infection with 350 H. contortus larvae kg-1 BW than lambs given the higher protein diet. Thus mortality was greater in the low protein group and adverse clinical signs, such as inappetence, weight loss and oedema were observed more frequently. This group also had a more severe anaemia, hypoproteinaemia and hypoalbuminaemia than the high protein group. In contrast, faecal egg counts, total daily faecal egg output and worm burdens were similar in all groups of infected lambs, indicating that the diets did not influence parasite establishment.

Acute Disease↗
PubMed1986

The effect of dietary protein on the pathophysiology of acute ovine haemonchosis.

An experiment was conducted to examine the effect of dietary protein on the pathophysiology of acute haemonchosis in Finn Dorset/Dorset Horn lambs. Erythrokinetic and metabolic studies using 51Cr-red cells, 59Fe-transferrin and 125I-albumin and digestive efficiency and nitrogen balance measurements were conducted between 19 and 39 days after infection. Identical radioisotopic and nutritional studies were conducted later on pair-fed control lambs. The results demonstrated that lambs on a low protein diet (88 g crude protein (CP) kg-1 dry matter (DM)) were less able to withstand the pathophysiological consequences of infection with 350 Haemonchus contortus larvae kg-1 body weight than lambs given a high protein (170 g CP kg-1 DM) diet, despite similar worm burdens. Erythrokinetic studies indicated that abomasal blood loss was similar in both groups of infected lambs, and circulating red cell volumes were reduced and plasma volumes were expanded to a similar degree in both groups. The majority of infected lambs in both dietary groups responded equally well to the gastric haemorrhage by increasing the rate of red cell production and their absorption of dietary iron was greater than in the control lambs. Albumin catabolism was increased in both groups of infected lambs, particularly in those given the low protein diet. Within each dietary group there were no differences in the digestibilities of the various proximate fractions of the experimental diets and no differences in the urinary or faecal nitrogen losses between infected lambs and their pair-fed controls. However, loss of appetite was a major feature of the disease, particularly in the lambs given the low protein diet and this feature appeared to be crucial in determining the ability of the infected sheep to withstand the pathophysiological effects of the parasite.

Acute Disease↗
PubMed1985

Influence of dietary protein on the pathophysiology of ovine haemonchosis in Finn Dorset and Scottish Blackface lambs given a single moderate infection.

Two experiments were conducted to examine the influence of dietary protein on the pathophysiology of Haemonchus contortus in lambs of two breeds, namely Finn Dorset and Scottish Blackface. Erythrokinetic and metabolic studies using 51Cr-red cells, 59Fe-transferrin and 125I-albumin, and digestive efficiency and nitrogen balance measurements were conducted between four and six weeks after infection. Identical radioisotopic and nutritional studies were also conducted on pair-fed control lambs of both breeds. The results demonstrated that in normal control animals, there were no significant effects of diet or breed on any of the erythrokinetic, metabolic or nutritional parameters, with the possible exception of red cell survival which was considerably longer in the Finn Dorset lambs. However, in the infected animals diet and breed did influence those parameters. The severest effects were seen in the infected Finn Dorset lambs given the low protein diet. These animals had the highest level of abomasal blood loss and this was associated with low red cell volumes and high levels of both albumin catabolism and plasma iron turnover. These animals were also in negative nitrogen balance which was partly accounted for by a significantly greater urinary nitrogen loss compared with their pair-fed controls and partly due to the poorer digestibility of the crude protein fraction of the diet. In contrast, although the infected Scottish Blackface lambs had high levels of blood loss and associated pathophysiological changes, these did not differ between dietary treatments and were similar to the changes in the infected Finn Dorset lambs given the high protein diet.

Animals↗
PubMed1985

Influence of dietary protein on parasite establishment and pathogenesis in Finn Dorset and Scottish Blackface lambs given a single moderate infection of Haemonchus contortus.

An experiment was conducted to examine the influence of dietary protein on parasite establishment and pathogenesis of Haemonchus contortus in lambs of two breeds. Finn Dorset and Scottish Blackface. The lambs were introduced to high protein (170 g crude protein (CP) kg-1 dry matter (DM) or low protein (88 g CP kg-1 DM) diets at three months old and infected one month later with 125 larvae (kg bodyweight)-1. Blood and faecal samples were collected for analysis and bodyweights recorded weekly. The lambs were killed 20 weeks after infection. A second experiment was conducted in Blackface lambs solely to determine the influence on parasite establishment of the high and low protein diets following infection with 125 larvae kg-1. These lambs were killed five or 14 weeks after infection. Results showed that in Scottish Blackface lambs dietary protein did not significantly influence the establishment of H contortus. However, in Finn Dorset lambs dietary protein may have influenced parasite establishment since lambs on the low protein diet had a higher faecal egg output four weeks after infection and more severe clinical signs than infected lambs of the same breed on a high protein diet.

Animals↗
PubMed1984

Studies on the pathophysiology of chronic ovine haemonchosis in Merino and Scottish blackface lambs.

An experiment was conducted to examine, under laboratory conditions, the pathophysiology of chronic ovine haemonchosis. In the present study, groups of Merino and Scottish Blackface lambs were maintained on a low plane of nutrition and infected with 50 Haemonchus contortus larvae/kg live weight. The parasitized lambs along with respective breed controls were examined over a 27-week period. In addition to the body weight, haematological and parasitological parameters, erythrokinetic, metabolic, digestibility and nitrogen balance studies were conducted in the early stages of the infection. The results demonstrated that a low level of infection with H. contortus in lambs on a poor plane of nutrition caused the development of a normochromic normocytic anaemia which was associated with a modest but significant increase in abomasal blood loss and slightly elevated erythropoiesis in both breeds relative to the controls. The level of anaemia, hypoproteinaemia and pathophysiological changes were more marked in the Merino lambs and they also had higher faecal egg counts than the Blackface lambs.

Anemia↗
PubMed1984

Use of coproantibody measurement to assess the influence of diet on local immune responses of sheep vaccinated against Haemonchus contortus.

Local antibody responses to challenge with 10,000 normal Haemonchus contortus larvae were evaluated in vaccinated and control Blackface sheep fed either a high or low protein diet. Anti-parasite antibody activity was found in faecal extracts of both vaccinated and control animals after infection. The coproantibody levels showed some correlation with abomasal mucosa antibody levels and faecal antibody activity was mostly associated with IgA. The low protein diet reduced local antibody responses in vaccinated and control sheep. However despite lower antibody levels the efficacy of vaccination was not diminished in sheep fed a low protein diet.

Abomasum↗