Bovine ostertagiosis, a review. Analysis of types and syndromes found in France by post mortem examinations and total worm counts.

We have completed an analysis of the total worm counts (including digests) performed on 74 weaned cattle of various ages and sacrified in our laboratory. We identified 21 cases of animals suffering from Ostertagiosis (harbouring over 40,000 adults + immatures in the lumen and the mucosa) or moribund animals showing symptoms and lesions of Ostertagiosis. The results are presented with the Parasite profiles (percentage of G.I. genera) and Parasite levels ("Very low, Low and Average" for carrier animals and "High" and "Very High" for animals suffering from parasitism). We have observed typical cases of Type I on weaned calves but not on calves grazing when suckling their own dams (Charollais, Limousin type), Pretype II and typical Type II on 2 year old or older animals. Variants of Type II were found : Fasciologis/Ostertagiosis complex and Parturient Ostertagiosis which seems to be well-known by practitioners. Complexes of a clinical Type II + stage of Pretype II with 1 to 2 million hypobiotic L4 larvae could explain the difficulty to control very severe diseases. Oedematous ostertagiosis is also described as an original type or syndrome in 2 to 3 year old cattle : the typical lesion is a dramatic oedema of the abomasum which is found enlarged up to X 2 or X 3 times its normal size/weight. The abomasal folds and the edges are filled with a watery oedema and have an appearance of "foetal membranes". As only few parasites are present the disease is considered to be an allergic over reaction in adult animals. It is recommended that the peptic digestion of the abomasal mucosa and differential counts of the various developmental stages of the parasites be added to the routine technique used in diagnosis laboratories.