Diagnosis of Giardia infection in 14 calves.

Fourteen calves, 12 days to 12 weeks old, were treated for diarrhea. Fecal examination for parasitologic, bacteriologic, or viral infection revealed Giardia in all calves; rotavirus and coronavirus were found in some calves. Thirteen affected calves were treated orally with dimetridazole (50 mg/kg of body weight, daily, for 5 days), with complete resolution of the diarrhea and elimination of the Giardia. Giardiasis should be considered as an etiologic agent of diarrhea in calves.

A new approach in the prevention of gastrointestinal parasitic infections in cattle.

The efficacy of a morantel long-acting device in preventing parasitic gastroenteric infections throughout a whole year was evaluated in heifers and steer calves in south central Québec. Thirty-two calves, comprising nine Hereford steers, one Hereford heifer, fourteen Holstein crossbred steers and eight Holstein crossbred heifers, were allotted into two treatment groups and maintained throughout the grazing season on adjacent pastures resulting from equivalently dividing one original pasture. One morantel long-acting device was administered to each animal in one group at the time of turnout onto the pasture in the spring while the calves in the other group remained as nonmedicated controls. The parasitic infections incurred during the pasture season were primarily Ostertagia, Trichostrongylus, Cooperia and Nematodirus.The following fall, after twelve calves were necropsied for worm counts, the twenty remaining ones were brought into the barn where they were kept throughout the winter with access to an outside yard. They received good quality hay and rolled barley (1 kg/head/day) up until the following May, at which time they were weighed and had fecal samples taken for egg counts. In contrast to the results observed among controls, the morantel long-acting device treatment group had an 87% reduction in fecal worm egg excretion and a 67.3 kg per calf increased weight gain after one year.

Control of Sarcoptes scabiei Infestation with Ivermectin in a Large Intensive Breeding Piggery.

Ivermectin given in a single subcutaneous dose of 300 mug/kg was tested for safety and efficacy against swine hyperkeratotic scabies in a large breeding piggery. Approximately 15% of the adult population was showing severe clinical mange. Skin scrapings were taken from 40 affected animals to provide parasite counts. Eight of 40 animals were used as untreated controls; all test animals were injected subcutaneously on day 0 with Ivermectin. General improvement was noted as early as eight days after treatment. Scratching stopped by day 21 in all treated animals. The results are discussed in regard to a control program for Sarcoptes scabiei infestation in pigs.

Conglutinin, immunoconglutinins and heterophile antibodies in the sera of apparently healthy moose (Alces alces) and caribou (Rangifer tarandus) in Quebec.

Serum samples from apparently healthy wild populations of moose and caribou in the province of Quebec, Canada were screened for the presence of conglutinin (K), immunoconglutinins (IKS) and heterophile antibodies. The conglutinating factor in moose and caribou sera was characterized utilizing the necessity of calcium ions for its reaction with sensitized sheep erythrocytes which had been alexinated with horse complement. The conglutinating substance in these animals did not require calcium ions for its activity. The conglutinating activity in both moose and caribou sera was characterized due to IKS as those present in sheep, dog and rabbit sera. Both moose and caribou had non-agglutinating type of heterophile antibodies. Their titres varied from 0 to 80. None of the animals tested had K in their blood. The titre of IKS varied from 0 to 640 with a mean value of 41 in moose, whereas it varied from 0 to 80 with a mean value of 18 in caribou. About 75% of all the animals in both the groups were positive for IKS. The specificity of IKS was demonstrated by the total removal of its activity on absorption with alexinated cells. Presence of IKS in these animals is suggestive of latent infection(s) possibly of bacterial, viral or parasitic origin.

Milk production effect of a morantel tartrate treatment at calving in dairy cows with subclinical parasitism.

A field trial involving 217 dairy cows from 13 herds located in four different areas of Quebec was conducted to determine the level of subclinical parasitism. The effect on milk production was evaluated on 116 cows following a single anthelmintic treatment with morantel tartrate administered at freshening. The results showed that this treatment increased milk production in nine herds, which was statistically significant at P 0.05).

Seasonal changes in the prevalence of ova of Diphyllobothrium ursi and Baylisascaris transfuga in the feces of the black bear (Ursus americanus).

An analysis of 114 samples of feces from black bears (Ursus americanus) from La Verendrye Park, Quebec revealed that the prevalence of eggs of Diphyllobothrium ursi and Baylisascaris transfuga varied seasonally. D. ursi ova were most prevalent during the summer and fall and at their lowest in spring while the converse was true for B. transfuga. This phenomenon possibly is associated with the cessation of feeding during the winter denning of black bears.

Helminths of the black bear in quebec.

Twenty-one complete carcasses of black bears, Ursus americanus , together with 34 intestinal tracts, 86 diaphragms and 168 faecal droppings collected between June, 1971 and November, 1972 in the Province of Quebec were examinel for helminths. Species found and their prevalence were as follows: Dirofilaria ursi in 57%; Uncinaria yukonensis in 6%; Baylisascaris transfuga in 21%; larvae of Trichinella spiralis in less than 1%; Diphyllobothrium ursi in 36%; and Taenia krabbei and Taenia hydatigena in 4%. These findings are discussed in the light of other reports.

Seasonal fluctuation and inhibited development of populations of Dictyocaulus filaria in ewes and lambs.

The fluctuation of populations of Dictyocaulus filaria in sheep was studied under field conditions in which animals are housed during the winter and grazed from late spring to autumn. A comparison was made between residual pasture contamination with overwintered larvae, the fecal larval deposition by ewes from June and both of these factors combined as sources of infection for spring born lambs. Ewes and lambs were killed serially over a year and worms were recovered from the lungs and counted. It was found that during the stabling period most of the ewes were carrying moderate numbers of D. filaria. However, while the vast majority of lungworm populations in the winter was inhibited in development at the early fifth larval stage, virtually all worms in the spring were adults. Any one source of infection studied contributed to the acquisition of important burdens of D. filaria by lambs as well as ewes. Worm counts reached peak in all lambs by November and this pointed to only one important Dictyocaulus generation per grazing season. It would also appear that larvae picked up by ewes and lambs as the grazing season advanced had become inhibited in development with the inhibition rate being most marked in autumn.

Gastrointestinal nematode populations in stabled ewes of Rimouski region.

Nematode populations is stabled ewes of the Rimouski region were studied by means of fecal worm egg counts, fecal culture of larvae, and worm counts at necropsy. It was found that during the winter strongyle egg counts were low, Trichostrongylus eggs being most numerous, The stronglye egg counts increased following lambing and reached peak in June. Ostertagia spp was the principal contributor to this "spring-rise", with substantial contribution from Trichostrongylus and Haemonchus contortus. The bulk of adult worm populations in winter, however, was made up of Trichostrongylus, whereas the great majority of the populations of Ostertagia spp, H. contortus and Nematodirus spp were inhibited in development at the fourth larval stage. All the worms recovered at necropsy in spring were adults, coinciding with the "spring-rise".