EFFICACY OF A BOLUS IN OSTERTAGIA AND INFECTIONS Taylor Sm, Mallon T, Carrol B

To cite this version:

Taylor Sm, Mallon T, Carrol B. EFFICACY OF A LEVAMISOLE BOLUS IN OSTERTAGIA AND COOPERIA INFECTIONS. Annales de Recherches Vétérinaires, INRA Editions, 1988, 19 (2), pp.107- 110. ￿hal-00901812￿

HAL Id: hal-00901812 https://hal.archives-ouvertes.fr/hal-00901812 Submitted on 1 Jan 1988

HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. EFFICACY OF A LEVAMISOLE BOLUS IN OSTERTAGIA AND COOPERIA INFECTIONS

TAYLOR SM MALLON T CARROLB

Veterinary Research Laboratory, The Farm, Stormont, Belfast, BT4 3SD Northern Ireland

received 04/04/87, accepted 15/07/87

Résumé

RECHERCHE DE L’EFFICACITÉ D’UN DIFFUSEUR DE LEVAMISOLE INTRA-RUMINAL AU COURS D’INFES- TATIONS EXPÉRIMENTALES PAR ET COOPERIA ONCOPHORA. - Dix veaux indemnes de parasites ont été répartis en deux groupes de cinq. Un groupe a reçu dans le rumen un diffuseur destiné à produire un relargage lent de levamisole. Les deux groupes de veaux ont été alors infestés par 30000 larves infestantes d’O osiertagi et de Concophora pendant six semaines. Huit semaines après le début de l’infestation, tous les veaux sont abattus et le nombre total de vers estimé. La concentration plasmatique moyenne en levamisole chez les veaux traités vingt-quatre heures après l’introduction du diffuseur était de 0,37 ¡Ag/ml, mais elle décroît rapidement et deux semaines après, elle était de 0,054 ¡Ag/ml. Ce taux s’est maintenu pendant les trois semaines suivantes puis il est tombé à 0,02 ¡Ag/ml. La moyenne géométrique du nombre d’O ostertagi a été réduite de 27,7 % et celle de C oncophora de 100 % chez les veaux traités. Il est apparu que la concentration en levamisole circulant était suffisante pour inhiber 0 ostertagi pendant seulement deux semaines mais était efficace contre C oncophora pendant au moins six semaines.

Since Pott et al 1974 (Proc. 3rd Int. Cong Parasi- being investigated for such purposes. This paper tol., 2: 747) reported that suppression of the multi- reports on the effectiveness of experimental bolus plication of gastro-intestinal of cattle designed to release levamisole for approximately by repeated doses of in the early part ninety days on artificial infections of the common of the summer grazing season had an effect which pathogenic gastro-intestinal nematodes of cattle, lasted until late autumn, pharmaceutical compa- Ostertagia ostertagi and Cooperia oncophora. nies have attempted to facilitate the means of achieving the same effect with a single administra- tion of anthelmintic contained in various forms of Materials and Methods slow or delayed release devices. The methods of release have been continuous slow release with either gradual reduction (Armour eta/1981, Jacobs Experimental Design et a/ 1981) or abrupt cut off (Laby 1978 Australian Ten calves of Friesian type were purchased shortly after Patent No. 35908/78, Proc. l4th World Cong. Disea- birth and reared indoors on milk, milk substitute, concentra- ses of Cattle, 1: 160) of anthelmintic release, or by tes hay and silage until approximately 12 weeks of age. At periodic pulsed doses of anthelmintic triggered by that time the calves were divided randomly into two groups of five. One groupe had the slow release bolus which the rate of corrosion of a central alloy core Morgan contained 22.2 levamisole hydrochloride (Chronomintic and Rowlands 1986 (Proc. 14th World Disea- g Cong. MK III, Laboratoires Virbac) administered to them, the other ses of 1: The used so far Cattle, 1361. remained as controls. The bolus consisted of levamisole, have been morantel, and oxfendazole iron filings and a copolymer homogenised plastic material. respectively. The method of prolonged administra- It was cylindrical and measured 105 x 27 mm. tion depends on the chemical characteristics, phar- macokinetics, potential toxicity, and the possibility Artificial infections of undesirable tissue residues as well as anthelmin- On the day after administration of the boluses all calves tic efficacy of the used. To date there compound were infected with 2 500 infective larvae of both Ostertagia have been no of the use of imidothiazoles reports ostertagi and Cooperia oncophora. This procedure was such as levamisole in such devices, but since it is a repeated twice weekly until all had received 30 000 larvae common anthelmintic it is not surprising that it is of both species ie 6 weeks after the start of the experiment. Experimental observations respectively 169.1, 167.6, 169.4, 160.5, and 166.6 g. The mean pre-infection bolus were 158.8 Faeces and plasma samples were taken on the day after weights + The mean bolus increase insertion and then weekly to follow changes in worm egg 1.2 g. weight during output (Dunn 1978) and to estimate plasma levamisole the eight weeks of the experiment was ie 7.8 g, (Graziani and De Martin 1977) and pepsinogen concentra- presumably due to absorption of water. Abomasa tions (Mylrea and Hotson 1969). Eight weeks after adminis- from both groups showed evidence of Ostertagia tration of the boluses all the calves were euthanised using type infection. intravenous sodium pentobarbitone, the abomasa and intestines carefully removed and the number of worms in Faecal egg counts (table 1) each organ estimated using standard parasitological techni- ques. The number of worms was estimated by counting Infections were observed to become patent in those observed in a five per cent aliquot of the total organ the control calves on the 21st day after the start of contents. the trickle infections, and on the 28th day in treated . There were large and statistically highly Female fecundity significant differences between the egg output of One hundred female Ostertagia from both groups were the groups, with treated cattle having much lower laid out on glass slides, cleared with lactophenol solution numbers of eggs per g of faeces than the untreated and the number of eggs present in their uteri counted after controls. microscopic observation. Total worm counts Statistical techniques Abomasal burdens (table 2) The mean worm and faecal egg counts for each group The worms recovered from the abomasa were were obtained using the logarithm of (count + 1) and counted and adult males from each compared by Student’s T test adjusted for small groups twenty-five using the logarithmic values. were collected, laid out in rows on glass micros- cope slides cleared by the addition of lactophenol and their genera identified. All were Ostertagia ostertagi. The geometric mean numbers of worms Results in the control and treatment groups were 5 344 and 3 868 respectively. The difference between Observations at autopsy them was not statistically significant. Small intestinal burdens (table 2) All boluses were found to be in the reticulum ; There were no worms recovered from the intesti- none were missing from treated animals. The wall nes of the bolus treated calves. In contrast all of the reticulum in each was washed, examined controls were moderately infected, the geometric and compared with the same organ from control mean burden being 5 465. All the worms identified animals. No abnormalities were observed and it were Cooperia oncophora. appeared that bolus had caused no adverse local reactions. Plasma pepsinogen The recovered boluses were rinsed, lightly dried The group mean pepsinogen concentrations of with paper towels and weighed. The weights were neither group reached levels such as would be expected in clinical ostertagiasis. Those of the Levamisole administered in a single dose of control increased eight days earlier than those in 8 mg/kg bodyweight to cattle is known to be an the treated group. Both peaked in the samples effective anthelmintic for adult 0 ostertagi and C taken on day 43, at which time the mean value of oncophora, at which dose the plasma concentra- the controls was significantly greater (P < 0.05) tion ranged from a mean of 2.34 ¡Ag/ml than that of calves with the bolus. one hour after treatment to 0.239 wg/ml seven hours later (Graziani and De Martin 1977). At the Female Ostertagia ostertagi fecundity reduced dose of 1.5 mg/kg (Hart et al 19691, it was however found to be only moderately effective for In an effort to ascertain whether the difference in Ostertagia spp whilst still highly efficient for Coo- faecal egg output between the groups was due peria spp. This result was further verified in field entirely to the presence of Cooperia oncophora in infections, where even at 8 mg/kg bodyweight untreated cattle and whether the Ostertagia fema- there was evidence of differential susceptibility of les in treated calves had a reduced egg output. The these species to levamisole (Presidente et al 1971, mean number of eggs present in female Ostertagia Dorn and Federmann 19761. ostertagi from treated calves was 24.85 ± 12.71, and from untreated control calves 23.84 + 9.75. It is evident that a similar reaction took place in The difference was not statistically significant, and this experiment. The total worm count of O oster- it was concluded (a) that the egg laying capacity of tagi was reduced only by 27.7 % in treated cattle Ostertagia spp females in bolus treated calves was from that found in the controls, whereas the popu- unaffected by the presence of the bolus and (b) lation of C oncophora was reduced by 100 %. that the differences in faecal egg output were due Since 0 ostertagi were administered for six weeks both to the presence of Cooperia oncophora and to it is evident that the circulating concentration of the slightly larger numbers of Ostertagia ostertagi levamisole was high enough to be effective fort present in control calves. that species for a maximum of two weeks, but was sufficient to affect C oncophora for the whole Plasma levamisole concentrations period of infection. The differences in faecal The highest observed concentrations were those egg output between in plasma samples taken one day after administra- treated and control groups can be examined in tion of the intraruminal boluses. At the time the relation to the populations present. In the controls there was a of C group mean concentration was 0.368 !g/mi. By population oncophora not present week 1 the mean concentration had decreased to in treated cattle in addition to a slightly but insigni- burden C 0.106 Erg ml and to 0.054 lig/ml by week 2. Thereaf- ficantly larger of O ostertagi. Oncophora to a more than ter up to week 5 it remained at approximately the is known be prolific egg producer 0 in in same level, and then reduced to approximately ostertagi primary infections calves (Smith 0.02 I!g/ml during the remainder of the observation 1970). The disproportionate differences in mean period. faecal egg counts from each group therefore arose mainly from C oncophora, since the fecundity of female 0 ostertagi was essentially similar in both Discussion populations, the difference being statistically insi- gnificant. The plasma pepsinogen concentrations After consideration of the results it is possible to reflected the numbers of 0 ostertagi recovered from the abomasa and the faecal counts. rationalise a working hypothesis on release rate egg and efficacy of this stage of development of a slow In conclusion, it would appear that the release of release levamisole bolus. levamisole from this particular prototype bolus exerted a satisfactory level of suppression of C with the latter species alteration of the rate of oncophora for at least six weeks after insertion. release to enable a higher concentration of levami- The period of control of 0 ostertagi was in the sole to be maintained for a longer period is requi- region of two weeks and would be insufficient for red. practical purposes. For more satisfactory results

Abstract

Ten parasite free calves were divided into two groups of five. One group was given a prototype intraruminal bolus designed to give a slow release of levamisole. Both groups of calves were then infected with five thousand infective larvae of 0 ostertagi and C oncophora for six weeks. Eight weeks after the start of infection all the calves were slaughtered and total worm counts carried out. The mean plasma levamisole concentration of treated calves twenty four hours after insertion of the bolus was 0.37 pglml, but rapidly decreased and by two weeks was 0.054 [tg/ml. It remained close to that level for a further three weeks then reduced to 0.02 ¡Ag/ml. The geometric mean worm counts of 0 osiertagi was reduced by 27.7 % and of C oncophora by 100 % in treated calves. It was concluded that the circulating concentration of levamisole was sufficient to inhibit 0 ostertagi for only two weeks but was effective against C oncophora for at least six weeKS.

References

Armour J, Bairden K, Duncan JL, Jones RN, Bliss DH, 1981. Studies on the control of bovine ostertagiasis using a morantel sustained release bolus. Vet Rec 108:532-535

Dorn H, Federmann M, 1976. Citarin-L spon-on - a new form of administration of an est iblished anthelmintic. Vet Med Rev 1:5-17 Dunn A, 1978. Veterinary Helminthology, Heinemann Medical Books, London. Graziani ci. De Martin GL, 1977. Pharmacoki- netic studies on levamisole. Drugs Exp Res 2:221-233 Hart JA, James PS, Curr C, 1969. The anthelmintic efficiency of laevo-tetramisole hydrocsloride against parasites of sheet and cattle. Aust Vet J 45:73-77

Jacobs DE, Fox MT, Walker NJ, Jones RM, Bliss DH, 1981. Field evaluation of a new metnod for the prophylaxis of parasitic gastro-enteritis in calves. Vet Rec 108:274-276 Mylrea PJ, Hotson IK, 1969. Serum pepsinogen activity and the diagnosis of bovine ostertagiasis. Br Vet J 125:379-387 Presidente PJA, Schlegel MW, Knapp S, 1971. Efficacy of levamisole in alfa pellets against naturally occurring gastrointesti- nal nematode infections in calves. Am J Vet Res 32:1359-1364 Smith HJ, 1970. On the development of gastrointestinal parasitision in bovine yearlings. Can J Comp Med 34:303-308