Protozoan and Helminth Infections of Aviary-Reared Alectoris rufa (Galliformes: Phasianidae) before Releasing for Hunting in the Czech Republic: Infection Dynamics and Potential Risks

Age-related dynamics of protozoan and helminth infections in the red-legged partridge, Alectoris rufa, were studied in an intensive breeding aviary in the Czech Republic before releasing birds for hunting purposes. Pooled fecal samples (n = 900) were examined over 3 rearing seasons (2012-2014). A total of 4 protozoan species, Cryptosporidium baileyi, Cryptosporidium meleagridis, Eimeria kofoidi, and Eimeria legionensis, and 4 helminths, Capillaria phasianina, Eucoleus perforans, Heterakis gallinarum, and Syngamus trachea, was found. The most common parasite was S. trachea (prevalence 20-26%) in dead birds (n = 99), which represents a high risk for breeders. Co-occurrence of protozoans and helminths indicated similarities in infection dynamics throughout the 3 breeding seasons. Mixed infections of Cryptosporidium baileyi and C. meleagridis with other parasitic species are reported for the first time. Our findings provide new insights into breeding of A. rufa and may help to improve the efficacy of disease control strategies and prevention, especially with the potential for spreading of parasitic infections to wildlife through released birds into open areas.

Comparison of digestive microflora between feedlot cattle with and without infection byCryptosporidium andersoni

The influence of cryptosporidial abomasitis on digestive anaerobic microflora in feedlot cattle with spontaneous Cryptosporidium andersoni colonization of abomasum was shown. Significant differences were found after the cultivation of abomasal content. Scopulariopsis brevicaulis was detected in damaged areas of infected abomasum. PCR analysis of ruminal fluid showed no differences between the two animal groups regarding qualitative composition of anaerobic and facultative anaerobic rumen microflora. The concentration of volatile fatty acids (acetate, propionate, butyrate) and ammonia in the rumen content showed that examined metabolic parameters were within normal limits except for ammonia content, which was higher in infected (291 mg/kg) than in healthy animals (203 mg/kg).

Performance and oocyst shedding in broiler chickens orally infected with Cryptosporidium baileyi and Cryptosporidium meleagridis

To study effects of experimental cryptosporidiosis, broiler chickens were infected per os with 5 x 10(5) oocysts of Cryptosporidium baileyi and Cryptosporidium meleagridis. In the first experiment, chickens were infected with oocysts of C. baileyi at the age of 7, 14, and 21 days. In the second experiment, chickens were infected with oocysts of C. baileyi, C. meleagridis, or both cryptosporidial species at the age of 7 days. Although clinical signs of infection were apparent, neither final live weight nor mortality was significanty influenced in chickens infected with a single Cryptosporidium species. In chickens infected with C. meleagridis, the growth retardation was observed in the 2-wk period after infection. The compensatory growth, however, started when the oocyst shedding had ceased. The number of oocysts in excreta specimens of chickens infected with C. meleagridis was two to three times lower than in excreta of chickens infected with C. baileyi. Chickens infected with both C. baileyi and C. meleagridis (5 x 10(5) oocysts of each) had significantly lower final live weight and worse feed efficiency than chickens of other groups. Concurrent infection did not influence individual C. baileyi or C. meleagridis oocyst shedding.

Susceptibility of common voles to experimental toxoplasmosis

Common voles (Microtus arvalis) in groups of nine to 10 animals were inoculated per os with a dose of 1, 10, 1x10(2), 1x10(3), and of the K1 strain of Toxoplasma gondii. All the common voles inoculated with 1 to 1 x 10(3) oocysts remained subclinical and survived. Three of the 10 voles inoculated with 1 x 10(4) oocysts died between days 7 and 12 post inoculation (p.i.). Antibodies were demonstrated in all the infected voles killed on day 60 p.i. The highest antibody titres in voles detected by the dye test (DT) and latex agglutination test (LAT) were 1,024 and 1,280, respectively.

[Occurrence of Echinococcus multilocularis Leuckart, 1863, in foxes (Vulpes vulpes) in the Czech Republic]

During the period between December 1994 and December 1996 the authors examined, using the method of helminthological dissection of the intestinal tract in 15 districts of four regions in the Czech Republic a total of 824 foxes from 350 land registers. Echinococcus multilocularis was found in the following regions: South Bohemian (districts Jindrichův Hradec, Ceský Krumlov, Prachatice and Strakonice), Central Bohemian (Benesov district) and North Bohemian (district Teplice and Chomutov). There were 87 positive (10.6%) foxes in 56 places (16%). In some areas of the South Bohemian region examinations of foxes were repeated. It was found that there are places where the prevalence of E. multilocularis varied between 28.6 and 75% (mean 53.7%) but also areas which were repeatedly negative. In 1996 after one-week intervals foxes from the Prachatice district (South Bohemian region) were sent for parasitological examination. During different months of the year the prevalence of E. multilocularis varied between 2.6 and 33.3%. A similar investigation was made during May to October 1996 (except September) also in the district of Ceský Krumlov (South Bohemian region). Tapeworms were found in 7.14 to 66.7% of foxes.

[Spontaneous Cryptosporidium infection in weaned rabbits]

The first occurrence of Cryptosporidium parvum Tyzzer, 1912 in broiler rabbits in the Czech Republic is reported. The protozoon was determined on the basis of morphometrical parameters of oocysts and of localization of endogenous developmental stages. The dynamics of natural Cryptosporidium infection was studied in a group of 72 young rabbits after weaning (their age ranging from 23-33 to 82-92 days) obtained from six large flocks and used in a feeding experiment. C. parvum was found in rabbits from four farms (Tab. I). Animals under observation were divided into 9 subgroups according to the genotype (Hyla 2000, California White, crosses of New Zealand x California, New Zealand White, Cunistar and Zika) as well as according to the farm of origin. The animals were housed in 28 cages under the conditions of two-floor cage technology. The upper floor consisted of cages housing three head, the lower floor two head each. The animals were fed ad libitum with commercial feed mixture (till the average age of 64.days supplemented with Robenidin as coccidiostat). During the first 10 days of observation pooled samples of droppings from each cage were examinated by flotation-centrifugation method according to Breza (1957) and Pavlásek (1991) in the intervals of three to four days, later one-week intervals. Post mortem scrapings from mucous epithelium taken from young rabbits were examinated (to reveal endogenous developmental stages of C. parvum) together with digesta (to detect oocysts of the protozoon) taken from the full length of the small intestine using method of native preparations and Giemsa stain. In one 37-day dead animal the small and large intestines were examined histologically. The maximum number of young rabbits infected with C. parvum were 30-40 and 33-43 days old (Fig. 1). In animals of this age category the oocysts of the protozoon were found in pooled samples in 11 and 12 cages (39.3 and 42.9%) from totally 28 cages under study. In rabbits of more than 50 days of age the occurrence of infection was significantly decreased (3.7%). During the experiment seven rabbits (9.7%) died; six of them (8.3%) at the age of 30-40 days. All these naturally infected and dead animals represented cases of monoinfection with C. parvum. The major clinical signs were typical diarrhoea lasting 3-5 days, inappetency, apathia, lethargy, prominent signs of exhaustion followed by dehydration of the organism. Atrophy of villi of the ileum in one of young rabbits was found histologically. Table II presents concrete data on significantly lower body weights (the decrease being 7-61.5%) as compared with rabbits of the same age not infected with cryptosporidia. It was not possible to evaluate objectively the differences in susceptibility to C. parvum infection between the individual genotypes of rabbits. As was found in the course of our further studies (unpublished data) a possible source of infection of young rabbits can be represented by their mothers in which oocysts are excreted sporadically shortly before parturition and during several days after it. Cryptosporidium infection (cryptosporidiosis) in flocks of broiler rabbits is taken as a new protozoal disease in the Czech Republic and C. parvum as one of possible agents in cases of disorders of digestive tract, namely in rabbits after weaning.

[Cryptosporidia and other endoparasites in heifers imported into the Czech Republic]

Totally 887 heifers of Holstein-Friesian breed mostly in late pregnancy imported to the Czech Republic from France (597), Germany (89), Denmark (181) and Holland (20) were examined coprologically from September 1993 to March 1995 in the parasitological laboratory of the National Veterinary Institute (NVI). Prague. Feces were sampled individually, rectally, always on days 1-3 following importation from heifers housed in particular quarantine sheds. In compliance with presently valid veterinary regulations, all animals were examined for liver fluke disease (fascioliasis) and lungworm. Moreover, 634 heifers were submitted to qualitative coprological examination aimed at revealing the presence of cysts and oocysts of protozoa, eggs of taenias and nematodes of gastrointestinal tract. The method according to Pavlásek (1991), especially designed for proving oocysts of the genus Cryptosporidium, was applied in all fecal specimens delivered to the SVI from animals in quarantine (N = 887). From trematodes, 12 heifers imported from France were positive for eggs of Fasciola hepatica and in other two animals eggs of the genus Paramphistomum were found. None of the imported heifers showed lungworm disease. Summary of data on occurrence of endoparasites gained during qualitative examination of samples of feces taken from heifers imported from France, Germany and Denmark is presented in Tab. I. Parasitologically, 91.2 to 100% of imported animals were positive. Taeniasis (the genus Moniezia) was detected in 2.8% of heifers imported from France and in 9.8% animals from Denmark. Protozoal parasites were found in 58.8% (Denmark) and 92.8% (Germany) heifers. Coccidial oocysts most frequently observed represented the genus Eimeria (E. bovis, E. auburnensis and E. zuernii). Gastrointestinal nematodes of nine genera were found in 72.5 to 80.8% of heifers. The most frequent findings were genera Ostertagia, Haemonchus and Trichostrongylus. Oocysts, morphologically identical with Cryptosporidium muris Tyzzer (1907), 1910, were detected in 4.5% of heifers imported into the Czech Republic from France and in 7.9% of those from Germany. In view of the fact the imported heifers were sampled always on days 1-3 of their quarantine following their importation it is quite impossible, considering the development of the protozoon, they could become infected just in the territory of the Czech Republic. Therefore, with the highest probability, our findings of C. muris-like oocysts in heifers are of priority importance for France and Germany because in the literature these countries do not report cattle as a host of this protozoon. We have found out 57.9% out of 19 animals positive for C. muris on one farm of a private cattle keeper. On the basis of a long-term monitoring of three dairy cows and one bull, the duration of the patent period is longer than 18 months, while we do not know precise onset of shedding oocysts of the protozoon in these naturally infected animals. Furthermore, the paper discusses the need of future studies of C. muris from the point of view of spread, pathogenicity, specificity and host spectrum. The author proposes and recommends obligatory examinations of imported animals with special attention paid to presence of coccidia of the genus Cryptosporidium in order to maintain, with respect to their zoonotic character, these protozoal infections under proper control. At present the parasitological laboratory of the NVI in Prague has a bank of oocyst isolates of the C. muris type from cattle (Bos taurus), from desert hamsters (Phodopus roborovskii Satunin, 1903) and camels (Camelus bactrianus). Experimental infections is permanently kept in laboratory mice following successful transmission from desert hamsters.

[The first finding of a spontaneous gastric cryptosporidiosis infection in hamsters (Phodopus roborovskii Satunin, 1903)]

The desert hamster (Phodopus roborovskii Satunin, 1903) represents a new host of Cryptosporidium muris Tyzzer (1907), 1910. This very first finding was made in the laboratories of the National Veterinary Institute, Prague, Czech Republic. In September 1994 three 11-month and one 3-month desert hamsters were sent for laboratory examination. Parasitological examination post mortem of a 3-month desert hamster revealed "large" Cryptosporidium oocysts in excrements as well as in the contents of intestines. In all animals in which autopsy was carried out congestion of lungs, spleen and liver, acute catarrhal inflammation and flatulences in portions of gut were observed. Presence of morphologically identical oocysts of cryptosporidia was confirmed in the same group of desert hamsters also during parasitological reexamination carried out in October 1994. Applying the methods according to Breza (1957) and Pavlásek (1991) oocysts of the protozoon under study were detected in pooled samples of excrements of 3, 4, 5, 10 and 11-month animals. Two out of four live 2-3-month desert hamsters were infected naturally, both parents (10-11 months old), sent by the owner to our laboratory to be used for further observation. Both adult animals showed slight tremor, somnolence, rough hair and recumbent position, the male showed paresis of pelvic limbs. For four days in the laboratory conditions excrements of all six live desert hamsters, the interval being 2-12 hours, were examined and in four of them the finding of oocysts of the protozoon was repeatedly positive. Adult animals were euthanasied.(ABSTRACT TRUNCATED AT 250 WORDS)

[The fist detection of Giardia spp. in horses in the Czech Republic]

The first occurrence of Giardia spp. in horses in the Czech Republic is reported. During preventive examination of 360 five-month up to 14-year horses from various parts of the region of Central Bohemia carried out from January 1993 to June 1994 in the parasitological laboratory of the State Veterinary Institute in Prague, the Giardia cysts were detected in the excrements of 18 (5%) horses, mostly 2-4 years of age, and in two foals 3 and 6 weeks old. During the period between March 1993 and June 1994, systematic and repeated observation was aimed at a group of 38 racing horses two up to four years of age from two studs in the surroundings of Prague. In one of these studs Giardia spp. cysts were found in 7 horses (35%) out of a total of 20 animals. During bacteriological examination of horses infected with Giardia carried out parallely, only in one animal pathogenic bacteria Rhodococcus equi and Streptococcus equi subsp. zooepidemicus were detected in the excrements. After the application of Entizole (following discontinuation of the preparation on days 4 and 50), however, the result of bacteriological examination was negative. The size of cysts (n = 100) was 12.8-16.0 x 9.6-11.2 microns (with the mean of 14.6 x 9.9 microns) there was no finding of free trophozoites of Giardia in the horse excrements examined. On the basis of morphological characteristics of the protozoon cysts and of the structure of median bodies (following excystation of the Giardia cysts in vitro), the intestinal flagellate found in horses can be included into the morphological group of G. intestinalis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Methods of isolating pure cultures of invasive intestinal helminth larvae of the genus Strongyloides, suborder Strongylata]

A special diagnostic laboratory aid L-STAR has been made and new methodics has been worked out of isolating pure cultures of invader larvae of Strongyloides papillosus and nematodes of ruminant gastrointestinal tract of the Strongylata suborder from various substrates. L-STAR competes successfully with a currently used device and with potential modifications of Baermann's method (1917). Invader larvae of strongyloids and strongylata are easy to recover in a short time if L-STAR is used. When the material is treated and examined in veterinary and human parasitological laboratories, or when the material is recovered directly in field conditions (on pastures, in runs, etc.), safe and hygienic conditions are secured with respect to labour safety in an infectious environment. This aid can be used not only for diagnostics, but also for effective isolation of pure cultures of invader larvae for further studies and experimental purposes.

[The most important parasitic intestinal infections in calves and their role in diarrheal diseases]

Various stock breeding herds in the USSR were examined for the presence of endoparasites. Coccidia of Cryptosporidium genus occurred in calves at the age of 3 to 4 days to one month, individually in older calves, too. Coccidia C. parvum infected the animals aged 14-15 days most frequently. Coccidia of Eimeria genus and intestinal round worm Strongyloides papilosus were registered sporadically in calves aged 13-15 days; most frequently they occurred in calves aged 1-2 months and older. Of the total number of the examined calves (aged 20 days), which were infected by Cryptosporidium, 77.7 resp. 89.8% were diarrhoeic. In cases of polyinfections with various species of coccidia of the Eimeria genus and S. papillosus, diarrhoea was recorded in 31.2% of one- to two-month-old calves. In cases of monoinfection with coccidia of the Eimeria genus diarrhoea was recorded in 15.8% of the calves, and in cases of infection with the intestinal worm S. Papillosus in 9.1% of the calves.

Subclinical cryptosporidiosis of turkeys in Iowa

Cryptosporidium oocysts were found in the feces of 16 of 20 (80%) 17-day-old and 38 of 100 (38%) 24-day-old turkeys in a healthy commercial flock in central Iowa. Mean dimensions of 50 oocysts were 4.5 x 5.3 micron. In experimentally inoculated turkeys and chickens, the parasites frequently infected the ceca, colon, and cloaca, but rarely infected the small intestine or bursa of Fabricius. These data differ from published descriptions of Cryptosporidium baileyi in chickens and turkeys. The results indicate that the cryptosporidia of poultry are not a homogeneous group and demonstrate that Cryptosporidium infections can occur in apparently healthy poultry flocks.

[Efficacy of levimasole and nilverm on gastrointestinal nematodes in cattle and their effect on milk yield]

Effect of Levamisole and Nilverm on gastrointestinal nematodes in cattle and on the milk yield. The effect of Levamisole--pure substance and the preparation Nilverm on the milk yield of cattle was experimentally tested, however, significant positive results were not recorded. Following Nilverm application and after the experiments had been terminated, t-test showed significant daily decrease (2.5 l) in milk yield in the treated animals when compared to the controls. This decrease was directly proportional to the resumed increase in the extensity of invasion with gastrointestinal nematodes recorded after the treatment had been terminated. Regarding that the possibility of reinvasion of animals in cow sheds could be excluded and that the extensity of invasion with gastrointestinal nematodes was higher in the treated cows than in the controls at the end of the experiments, we assume that following the eradication of adult nematodes with anthelmintics activation of hypobiotic worm larvae occurred in the mucosa.

The effect of intermittent treatment with sulphadimidine on coccidiosis in preruminant calves

Preruminant calves excreted coccidia oocysts in their faeces after 3 weeks of group housing. Two weeks of oral sulphadimidine (SDM) administration, 50 mg/kg on the first day of treatment followed by daily administration of 37.5 mg/kg, under the same housing conditions kept the faeces free of oocysts. Three weeks later, these calves excreted oocysts again. Repetition of the same treatment for 2 weeks controlled the infection again, but a second treatment for 5 days did not suffice. The repeated long treatment affected immunoglobulin levels adversely. SDM given repeatedly at a lower dose rate (30 mg/kg) for 1-week periods with medication-free intervals of 1 week controlled the infection and no adverse effects were noted. In comparison with controls, weight gains were greater in treated calves.

Coccidiosis in preruminating calves the effect of management and short-term treatment on the spread of infection and reinfection

In farms with large numbers of individually-housed calves, the spread of coccidia is slow. In group pens, however, all the calves became infected within 3-4 weeks of being housed together. At the beginning of group housing no oocysts were found in the faeces of any of the calves. Sulphadimidine (SDM) was administered for 3 or 12 days at different doses and different times. Administration of the drug on Days 3-5 of group housing had no effect. Given between Days 11 and 13 or 17-19, the drug lowered (for a short period) the number of animals found to be excreting oocysts. SDM given between Days 6 and 17 kept the animals oocyst-free during that period. Within 2-3 weeks after the treatment all animals were excreting oocysts.

[The effect of a single disinfection of a farm on cryptosporidiosis infection in calves]

The disinfection of a farm with Dikonit (active substance: sodium dichlorocyanuran) exerted no significant influence on the course of the spreading of cryptosporidiosis infections in newborn calves. The oocysts of Cryptosporidium sp., isolated from the faeces of a spontaneously infected calf and left in a 2.5% disinfecting solution of Dikonit under laboratory conditions for four hours, did not lose their viability. Laboratory mice experimentally infected with these "disinfected" oocysts, began to produce oocysts of Cryptosporidium sp. the sixth day from infection. The findings of different developmental stages of this protozoan obtained during the histological examination of the intestinal tissue of test mice are also considered as evidence of successful experimental infection. The cryptosporidium-free period which lasted only 14 days from disinfection was mainly due to thorough mechanical cleaning of the area where the calves were kept after birth. This is also proved by the results of the examination of old residues of calf faeces scraped from the floors: only individual individual oocysts of Cryptosporidium sp. were found in these samples.

[The effect of different methods of housing calves after birth on the incidence of Cryptosporidium sp]

On the Hrdĕjovice farm belonging to the Agricultural Co-operative Farm Dukla Hosín, district Ceské Budĕjovice, three groups of new-born calves housed in different ways were compared as to the occurrence of the Cryptosporidium coccidia, scours and as to the overall health condition. Cryptosporidium infections and scours were observed in all 19 calves, independently of the fact whether they were housed for 10 to 16 days after birth at the stalls together with the dams, on the litter in a special area of the farm or in individual cages. The earliest occurrence of Cryptosporidium sp. coccidia and of scours was observed in the calves housed on litter (third day). In the calves housed at the stalls with the dams, cryptosporidia occurred beginning the fourth day, scours beginning the sixth day of age. As the last were infected the calves housed in individual cages, i. e. on the sixth day when the scours onset was observed. The application of Chronicin, Duon, Axetonal and Rehyvet resulted in a certain improvement of the health conditions of calves, however, the occurrence of scours continued. The application of Sulfakombin had no effect. Under production conditions of this farm cryptosporidiosis is to be considered enteric infection of the new-born calves.

[The occurrence of helminths in calves from large capacity barns]

In calves aged one to six months, housed in a large-capacity calf-house, helminths of the genera strongyloides, Chabertia, Bunostomum, Oesophagostomum, Trichostrongylus, Ostertagia, Cooperia, Haemonchus, Nematodirus, Trichuris, Capillaria were detected. The presence of helminths in this calf-house has a seasonal nature, owing to the composition of the feed ration. The helminthofauna of calves, mainly to five- to six-month-old ones, was the same as in adult cattle on the farms from which the calves had been concentrated to the large-capacity calf-house.

[Occurrence of coccidiosis in calves at one to six months of age, which are housed in a large capacity barn]

One- to six-month-old calves, housed in the large-capacity calf house of the Nová Bystrice state farm in the district of Jindrichův Hradec were studied for the occurrence of coccidia in the period from January 1974 to April 1975. The coccidia found in these animals included nine species of the genus Eimeria: E. zuernii, E. bovis, E. ellipsoidalis, E. subspherica, E. auburnensis. The species E. alabamensis, E. cylindrica, E. wyomingensis and E. bukidnonensis occurred just sporadically. Further, the findings included oocysts of Isopora spp. The oocysts of the coccidia E. wyomingensis and Isopora spp. were found for the first time in Czechoslovakia. The overall extensity of invasion (EI) and intensity of invasion (II) grow with age as follows: (chart: see text) The results suggest that even modern large-capacity calf houses are not free from invasion by coccidia; the calves in the house under study were invaded by ten species. Transition to vegetable feeding is accompanied by a marked rise of the EI of all the species of coccidia found in the animals.

[Helminthiases in newly established large-capacity breeding stations for cattle]

Invasions of gastrointestinal nematodes proved to be the most frequent helminthiases in new-established large-capacity herds of cattle according to the results of parasitary examinations of cattle in one locality in the Tachov district. The nematodes, especially Oesophagostomum spp., Haemonchus contortus, Cooperia spp., Trichostrongylus spp., occurred in animals of all age categories. The Ostertagia spp., Chabertia ovina, Nematodirus spp., Bunostomum phlebotomum and Trishuris spp. participated in the invasions to a smaller extent. The first eggs can already be found in three months old calves. Strongyloidosis can be diagnosed in the first month of age in calves [5%], the incidence rate increasing up to the age of five months, then it begins to decrease. Taenasis was found out in six months old calves [4.4% and11.6%]. Reclamations of pastures reduced the incidence of fasciolosis to the minimum rate; its invasions were heavy before establishing the large-capacity herds of cattle. Dictyocaulosis was not found in the large-capacity herds of cattle at all, due to the same reasons. Not only were nematode eggs proved, but also larvae to develop to the stages capable of invasion [Chabertia ovina, Haemonchus contortus, Oesophagostomum spp., Strongyloides papillosus] in dry excrements on railings of pens, on slatted floors and walls of the calf-sheds that were investigated.

[Endoparasites of calves in large herds]

The authors present preliminary results of the coprological examination of calves in large-capacity calf-houses. In a new large-capacity calf-house in the Benesov district in the Central-Bohemian region, 200 samples of faeces were examined according to Breza (1957) and further examinations were performed regularly in a group of 42 calves from the age of 0.5 to 6 months. The tests revealed 13 species of endoparasites, including eight species of coccidia: Eimeria auburnensis, E. alabamensis. E. bovis, E. cylindrica, E. elliposidalis, E. subspherica, E. zuernii, Isospora spp., and five species of helminths: Strongyloides papillosus, Oesophagostomum radiatum, Trichocephalus ovis, Cooperia spp., and Ascaris suum. The following conclusions were derived from these findings: 1. The calves may carry the germs of coccidia and helminths on their hooves already during transportation to the new calf-house; 2. twelve- to twenty-day-old calves, coming to the calf-houses, are often already attacked by several species of coccidia and helminths; 3. the number of parasite species increases and the extensity of invasion rises with age; 4. it has been demonstrated that the invasion process of eight species of coccidia and five species of worms can take place under the conditions of modern calf-house; 5, stronglyloidosis, oesophagostomosis, and trichocephalosis can be treated as typical stable helminthoses; 6. some other speceis of helminths and coccidia occur in calves after transition to green forage with which they are probably carried to the calf-house.