Liver flukes in dogs and treatment with praziquantel

Opisthorchiid eggs were found in 6 out of 27 (22%) huskies while an ELISA detected antibodies against Opisthorchis felineus and Metorchis bilis in 24 (89%) and 25 (93%) sera taken from these dogs, respectively. All dogs showed an increased activity of glutamate dehydrogenase while aspartate aminotransferase was normal in all samples. Ten weeks after treatment with praziquantel no fluke eggs were found in the faeces from any animal and antibody titres dropped in all animals.     

Fasciola hepatica: Histology of the testis in egg-producing adults of several laboratory-maintained isolates of flukes grown to maturity in cattle and sheep and in flukes from naturally infected hosts

A total of 8 calves approximately 6 months old and 22 lambs of similar age were infected with metacercariae of Fasciola hepatica of various laboratory-maintained isolates including: Cullompton (sensitive to triclabendazole) and Sligo, Oberon and Leon (reported as resistant to triclabendazole). Ten to 16 weeks after infection, flukes were harvested from these experimental animals and the histology of the testis tissue was examined in a representative sample of flukes from each population. Adult wild-type flukes were also collected from 5 chronically infected cattle and 7 chronically infected sheep identified at post-mortem inspection. The testis tissue of these flukes was compared with that of the various laboratory-maintained isolates. Whilst the testes of the wild-type, Oberon and Leon flukes displayed all the usual cell types associated with spermatogenesis in Fasciola hepatica (spermatogonia, spermatocytes, spermatids and mature sperm), the Cullompton flukes from both cattle and sheep showed arrested spermatogenesis, with no stages later than primary spermatocytes represented in the testis profiles. The presence of numerous eosinophilic apoptotic bodies and nuclear fragments suggested that meiotic division was anomalous and incomplete. In contrast to the wild-type flukes, no mature spermatozoa were present in the testes or amongst the shelled eggs in the uterus. A high proportion of the eggs collected from these flukes hatched to release normal-appearing miracidia after an appropriate incubation period, as indeed was the case with all isolates examined and the wild-type flukes. It is concluded that the eggs of Cullompton flukes are capable of development without fertilization, i.e. are parthenogenetic. The implications of this for rapid evolution of resistant clones following an anthelmintic selection event are discussed. Amongst the Sligo flukes examined, two subtypes were recognised, namely, those flukes with all stages of spermatogenesis and mature spermatozoa present in the testes (type 1), and those flukes with all stages of spermatogenesis up to spermatids present, but no maturing spermatozoa in the testes (type 2). Each sheep infected with the Sligo isolate had both type 1 (approximately 60%) and type 2 (approximately 40%) flukes present in the population. Spermatozoa were found amongst the eggs in the uterus in 64% of flukes and this did not necessarily reflect the occurrence of spermatozoa in the testis profiles of particular flukes, suggesting that cross-fertilization had occurred. The apparent disruption of meiosis in the spermatocytes of the Cullompton flukes is consistent with reports that Cullompton flukes are triploid (3n=30), whereas the Sligo and wild-type flukes are diploid (2n=20). In the Sligo flukes the populations are apparently genetically heterogenous, with a proportion of the flukes unable to produce fully formed spermatozoa perhaps because of a failure in spermiogenesis involving elongation of the nucleus during morphogenesis.     

A cross-sectional coprological survey of liver flukes in cattle and sheep from an area of the southern Italian Apennines

A cross-sectional coprological survey of liver flukes (Fasciola hepatica and Dicrocoelium dendriticum) was conducted on 81 bovine farms and 197 ovine farms with animals pasturing in an area (3971 km(2)) of the southern Italian Apennines. The farms were selected to be uniformly distributed throughout the study area using geographical information system (GIS) software. Between June 1999 and March 2000, faecal samples were collected from 975 cattle and 3940 sheep and examined using a modified McMaster technique. The results were subjected to statistical analysis and point distribution maps (PDMs) were drawn by GIS.Cattle of 9 of the 81 (11.1%) farms were positive for F. hepatica and of 43 (53.1%) for D. dendriticum. Sheep of 8 of the 197 (4.1%) farms were positive for F. hepatica and of 133 (67.5%) for D. dendriticum. Co-infection was found in cattle of 2 (2.5%) farms, and in sheep of 8 (4.1%) farms.The findings of the present survey show that D. dendriticum was the predominant liver fluke found in cattle and sheep with respect to egg count numbers for both farms and animals. In addition, the general trends of the PDMs show that D. dendriticum was widely and homogeneously spread throughout the study area, whereas F. hepatica was present only in a few concentrated zones of the study area that had both positive bovine and positive ovine farms.     

Liver blood flow and metabolic clearance rate of progesterone in sheep

To study the inverse relationship between feed level and concentrations of peripheral plasma progesterone, 36 ovariectomised ewes were fed rations at levels calculated to maintain liveweight (M). On the seventh day, the ewes were given an intravenous infusion of progesterone and the metabolic clearance rate (MCR) was calculated. The ewes were then randomly allotted to receive either , M or 2M rations for seven days at which time the infusion and blood sampling schedules were repeated. The mean (SE) MCR of infused progesterone in ovariectomised ewes fed either , M or 2M rations for seven days was 7·1 (0·59), 9·9 (1·64 and 13·0 (1·19) litre h⁻¹ kg⁻¹ of liveweight, respectively. Differences in MCR of progesterone between ewes fed and 2M rations were significant (P<0·05). The inverse relationship between level of feed intake and plasma progesterone concentration was attributed to differences in clearance rate of progesterone rather than to changes in the entry rate of the hormone into the blood.     

Liver biopsy as a technique for assessing copper status of sheep

A procedure for taking biopsy samples from the ovine liver by a paracostal route is described. Samples were taken from 120 Merino rams on up to 3 occasions over a 3 month period. At the end of the period, the rams were subjected to 2 further biopsies and were then slaughtered, and the liver was removed and homogenised. Copper contents of all samples were determined.
Frequency of biopsy did not affect hepatic copper concentration which was significantly overestimated by the biopsy method by approximately 5%. Variability associated with the biopsy procedure was approximately ± 30 to 40 mg Cu/kg DM (SD) and was small relative to variability between animals. Experimental designs were preferred in which samples are taken before and after treatments are applied; changes in concentration are then analysed. Such analyses eliminate errors associated with variability between animals and the small bias in the sampling procedure. Liver biopsy did not significantly reduce bodyweight or the rate of gain.     

The incidence of flukes of the genus Paramphistomum in Czechoslovakia

An effort was made to evaluate objectively all findings on the variability of fluke of the family Paramphistomatidae and to give a clear survey on the species occurring in this country in order to be able to control it successfully in the case of widespread occurrence of paramphistomatosis or its intermediate hosts. The individual fluke species have specific intermediate hosts and a correct determination can make preventive measurements easier. Three species of rumen fluke live parasitically in the CSSR: Paramphistomum cervi, P. ichikawai and P. daubneyi. Findings indicated as P. scotiae (and/or Liorchis scotiae) from Slovakia should be evaluated as P. cervi. Also P. leydeni is identical with the species P. cervi. All three species live parasitically on game. Domestic ruminants are parasitized by P. cervi and P. ichikawai. P. cervi is the most widespread species in this territory and also in the whole Central Europe. P. daubney is very rare in this territory; it was found only in moufflon.     

Efficacy of two formulations of albendazole against liver flukes in cattle.

Albendazole (10 mg/kg of body weight) was administered as a drench suspension or as a feed additive to 24 cattle with naturally acquired infections of Fasciola hepatica and Fascioloides magna. Cattle were euthanatized 16 to 30 days after treatment, and the number of viable flukes was counted. Viable F hepatica and F magna were decreased by 91.4% and 70.6% for drench administration and by 82.9% and 71.9% for the feed additive treatment, respectively. There was no significant difference between the efficacy of the 2 formulations in decreasing viable fluke numbers, compared with untreated controls.     

Obstructive cholelithiasis and cholecystitis in a keeshond

A 10-year-old, neutered male, keeshond was presented for vomiting, lethargy, icterus, and anorexia. Obstructive cholelithiasis was diagnosed based on analysis of a serum biochemical profile, abdominal radiographs, and ultrasonography. Choleliths were removed from the gall bladder and common bile duct via a cholecystotomy.     

Liver fluke (Fasciola hepatica) in slaughtered sheep and cattle in New Zealand, 1984-85

A total of 17175 lambs livers and 9322 sheep livers randomly selected from animals slaughtered at export meatworks in 1984 were examined for liver fluke infection. Futher sheep livers from some regions were examined in 1985. The origins of the animals examined were recorded and used to estimate regional prevalences of infection. Infection in lambs was first detected in February and the prevalence increased after then; the mean prevalence in July was 2.7% in the North Island and 2.0% in the South Island . In adult sheep in 1984, regional prevalences in the North Island ranged up to 16.9% (>10% in South Auckland, East Coast, Hawkes Bay and Taranaki) and in the South Island up to 29.4% in Westland (18% in Nelson). The overall prevalence in the North Island was 7.5% and in the South Island 1.1%, about double that recorded in 1969. Data for 1985 were incomplete but prevalences tended to be higher than in 1984. From April 1984 to August 1985 the origins of all lines of cattle with fluke-affected livers were recorded in all abattoirs and export meatworks. During 1985, 16 147 infected lines were traced to all countries in the North Island, with over 60% from the Whangarei, Hamilton, Taumarunui, Gisborne and Hastings areas. In the South Island , over 90% of 1585 infected lines originated from Westland, Waimea, Grey, Inangahua and Buller Counties.     

从南方养羊的一些往事谈起

昨天张子仪先生讲到,南方草地相当于2个新西兰.新西兰生产出很多奶、肉、毛产品.我们的南方草地这个新西兰没有生产出什么东西,没有发挥出来很大的作用.