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.     

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.     

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.     

Molecular analysis of aspermic Fasciola flukes from Korea on the basis of the nuclear ITS1 region and mitochondrial DNA markers and comparison with Japanese aspermic Fasciola flukes

It has been speculated that populations of aspermic Fasciola flukes in Korea and Japan have a close phylogenetic relationship. To evaluate this, we analyzed 33 Korean aspermic Fasciola flukes on the basis of nuclear ribosomal internal transcribed spacer 1 (ITS1) and mitochondrial NADH dehydrogenase subunit 1 (nad1) and cytochrome c oxidase 1 (cox1) sequences. Fh, Fg, and Fh/Fg types were detected in the ITS1 region and displayed the fragment patterns of F. hepatica, F. gigantica, and both species, respectively by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Additionally, three concatenated haplotypes of nad1 and cox1(nad1/cox1) were detected, and 2 of these, Kor1/Kor1 (Fsp1/Fsp1) haplotype and Kor2a/Kor2 (Fsp2/Fsp2) haplotype, were shared by Korean and Japanese aspermic flukes. The Fst value (0.019), calculated using the concatenated sequences, indicated that Korean and Japanese aspermic Fasciola populations were genetically undifferentiated. Interestingly, a combination of the Fh/Fg type and Kor1/Kor1 haplotype was found at the highest frequency in Korean aspermic flukes, whereas the Fg type and Fsp2/Fsp2 haplotype combination was found at a conspicuously high frequency in Japanese aspermic flukes. This indicates that a founder effect caused by the introduction of infected hosts may have played a key role in the introduction of aspermic Fasciola flukes from Korea into Japan.     

Within-flock transmission of sheep scab in naive sheep housed with single infested sheep.

The within flock transmission of sheep scab was studied in two trials, which lasted 14 and 12 weeks, respectively. A total of 40 non-infested, scab-naive sheep were divided into six groups of between 6 and 20 individuals. Each group was subsequently housed with a single infested index case, carrying scab lesions of different ages. The groups of sheep in both trials were video recorded continuously and all the sheep were individually examined on a weekly basis. The occurrence of transmission was measured in two ways: first, by the detection of early scab lesions during clinical examination and, second, by an increase in the rubbing of individual sheep as noted from the analysis of the video recordings. These two methods complemented each other in predicting the week on which transmission occurred. Overall, transmission was detected in 34 of the 40 scab-naive sheep. Transmission was shown to occur at about the time when the population of adult mites in lesions on index cases reached their peak numbers. The highest number of mites at this time, however, differed markedly between index sheep. There was no obvious relationship between the incidence of transmission and the time index sheep spent rubbing each day or other index sheep variables, including the age of the lesion or the time since the introduction to the scab free sheep.     

Globule leukocyte and mast cell in bile ducts of cattle naturally infected with liver flukes

In n previous report dealing with the pathology of bovine fascio-liasis the author described an unknown cell type in the epithelium of bile ducts. The histological and histochemical investigations published in this paper suggest that the cell may be considered a globule leukocyte. Globule leukocytes are rare in uninfected livers but are occurring in abundance in main bile ducts of cattle with spontaneous fascioliasis and also in small perilobular ducts in dicrocoeliasis. Liver fluke infection causes an increase in the population of subepithelial mast cells. Mast cell and globule leukocyte present similarities In their cytochemical properties. However, at low pH toluldinc blue shows a stronger but Alcian blue a weaker affinity for mast cells than for globule leukocytes.     

Fasciola hepatica: Histological demonstration of apoptosis in the reproductive organs of flukes of triclabendazole-sensitive and triclabendazole-resistant isolates,and in field-derived flukes from triclabendazole-treated hosts,using in situ hybridisation to visualise endonuclease-generated DNA strand breaks

Investigation of the triclabendazole (TCBZ) resistance status of populations of Fasciola hepatica in field cases of fasciolosis, where treatment failure has been reported, can be supported by histological examination of flukes collected from recently treated hosts. In TCBZ-sensitive flukes (TCBZ-S) exposed to TCBZ metabolites for 1–4 days in vivo, but not in TCBZ-resistant flukes (TCBZ-R), morphological changes suggestive of apoptosis occur in cells undergoing meiosis or mitosis in the testis, ovary and vitelline follicles. In order to verify or refute the contention that efficacy of TCBZ treatment is associated with apoptosis in the reproductive organs of flukes, histological sections of TCBZ-S (Cullompton isolate) flukes and TCBZ-R (Sligo isolate) flukes were subjected to the TdT-mediated dUDP nick end labelling (TUNEL) in situ hybridisation method, a commercially available test specifically designed to label endonuclease-induced DNA strand breaks associated with apoptosis. Additionally, sections of in vivo-treated and untreated flukes originating from field outbreaks of suspected TCBZ-S and TCBZ-R fasciolosis were labelled by the TUNEL method. It was found that in treated TCBZ-S flukes, strong positive labelling indicating apoptosis was associated with morphologically abnormal cells undergoing mitosis or meiosis in the testis, ovary and vitelline follicles. Background labelling in the positive testis sections was attributed to heterophagy of cell debris by the sustentacular tissue. The triggering of apoptosis was probably related to failure of spindle formation at cell division, supporting the contention that TCBZ inhibits microtubule formation. In treated TCBZ-R (Sligo Type 1) flukes, and in treated flukes from field outbreaks of suspected TCBZ-R fasciolosis, no significant labelling was observed, while sections of fluke derived from a field case of fasciolosis where TCBZ resistance was not suspected were heavily labelled. Light labelling was associated with the testis of untreated Cullompton (TCBZ-S) and Sligo Type 2 (TCBZ-R) flukes, which exhibit abnormal spermatogenesis and spermiogenesis, respectively. This was attributed to apoptosis and to heterophagy of effete germ line cells by the sustentacular tissue. It is concluded that demonstration of apoptosis by in situ hybridisation using the TUNEL method on sections of 1–4 days in vivo TCBZ-treated F. hepatica can contribute to the diagnosis of TCBZ resistance in field outbreaks of fasciolosis.     

Catarrh in sheep

Catarrh or influenza in sheep occupies a unique position in livestock diseases in Australia. The condition, recognised in 1834, was the subject of government enquiries and the passing of special legislation for its control. Within 30 years it had disappeared. The identity of the condition was not determined then nor has it been identified in subsequent years. The purpose of the article is to review what was recorded about the disorder and to speculate on its nature.