Further studies on the diagnostic value of gamma-glutamyl transpeptidase and 5'-nucleotidase in cattle, sheep and horses

The distribution of 5'-nucleotidase (5'-NT) and gamma-glutamyl transpeptidase (gamma-GT) is similar in the tissues of the sheep, calf and horse, except that there is relatively less gamma-GT in calf liver than in the liver of the other two species. The liver lesion produced by the oral administration of chloroform is similar in the three species and is accompanied by the release of 5'-NT into the plasma of the sheep and calf but not of the horse. Conversely, gamma-GT is released into plasma of the horse but not of the sheep or calf. This difference is not related to the tissue distribution of the two enzymes. The kidney lesion in sheep produced by the intravenous administration of mercuric chloride is accompanied by a reduction in the rate of excretion of an injected dose of inulin and by an increase in the concentration of urea in plasma and in the activity of gamma-GT in plasma and urine. There was no increase in 5'-NT activity in plasma or urine.     

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.     

Efficiency of phenoxyethanol at removing formaldehyde from immersion fixed muscle tissue

The propensities of several fluids for extracting formaldehyde from fixed muscle tissue were compared. Following formalin fixation, similar samples of muscle tissue were immersed in solutions of 0.5%, 1%, 2%, 4% phenoxyethanol, 40% ethanol, 25% ethylene glycol or water. Following storage periods of 4, 25, 50 or 100 days, the formaldehyde content of the fluids was determined by sodium sulfite titration. The solution containing 40% ethanol was clearly superior to the others. Solutions containing 2% or 4% phenoxyethanol were least effective and there was a significant inverse linear relationship between the concentration of phenoxyethanol and amount of formaldehyde extracted. This suggests that phenoxyethanol decreases the ability of water to extract formaldehyde from fixed tissues.     

Bovine leukosis virus transmission with mouthparts from Tabanus abactor after interrupted feeding

A successful attempt was made to mechanically transmit bovine leukosis virus (BLV) from a BLV-infected cow with a normal lymphocyte count to sheep by inoculation with horse fly (Tabanus abactor) mouthparts. After interrupted natural feeding, horse flies were anesthetized with CO2. Mouthparts were severed and pooled into a tissue grinder containing medium. Five inocula containing the mouthparts of 10 flies each, and 5 inocula containing the mouthparts of 20 flies each, were prepared and inoculated SC in the right axilla of 10 BLV antibody-negative sheep. Five additional sheep served as controls. Serum samples were collected at 2-week intervals and tested by agar gel immunodiffusion for BLV antibodies. One sheep injected with 20 mouthparts developed antibodies to BLV at 10 weeks after inoculation. Six months after inoculation with fly mouthparts, 1 BLV antibody-negative sheep was randomly selected from each treatment group and injected, in the left axilla, with 3 ml of blood from the donor cow to confirm susceptibility of the sheep. All 3 sheep developed antibodies to BLV within 4 weeks.     

Transendoscopic Chemical Ablation of Progressive Ethmoidal Hematomas in Standing Horses

Objective —To examine the response of horses with progressive ethmoidal hematoma (PEH) to intralesional injection of 4% formaldehyde solution.
Study Design —Nasal passages of horses affected with PEH were examined endoscopically at different intervals to determine the effects of intralesional injection of formaldehyde solution.
Animals —21 horses with PEH.
Methods —PEHs were injected transendoscopically with 4% formaldehyde solution. Horses were examined endoscopically and retreated at different intervals until the PEH was eliminated or was so small that reinjection was not possible.
Results —Lesions diminished significantly in size or were eliminated after 1 to 18 injections (median, 5; mean, 7.0 ± 5.62). Seventeen lesions (60.7%) resolved completely after 1 to 18 injections (median, 5; mean, 7.2 ± 5.71). Five lesions decreased markedly in size but did not resolve after receiving 1 to 18 injections (median, 5; mean, 7.6 ± 6.66). Injection of these lesions was discontinued 4.0 to 25.1 months (median, 9.5; mean, 11.02 ± 8.446) after the first injection. The PEH of one horse was removed surgically after one injection. Three horses, one with bilateral PEH, were lost to follow-up. One horse developed signs of laminitis. No other complications were observed.
Conclusions —Horses with a PEH can be treated effectively by transendoscopic, intralesional injection of 4% formaldehyde solution.     

Comparisons of mammalian Giardia duodenalis assemblages based on the β-giardin, glutamate dehydrogenase and triose phosphate isomerase genes

The objective of this study was to determine and compare the assemblages of Giardia duodenalis isolated from mammalian fecal samples using the β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. A total of 202 samples, either submitted to the Veterinary Diagnostic Laboratory (Parasitology) at Colorado State University or part of ongoing research studies, were typed. A subset of 50 dog samples were also assessed by the tpi-D-specific primers. Of these, 183 were from dogs, 13 were from cats, two were from llamas, and one each was from a calf, an alpaca, a sheep, and a horse. The majority of the dogs (171 of 183 isolates) in this study were infected with only dog-adapted Assemblage C or D. The tpi-D-specific primers confirmed that 28 of the samples that typed as Assemblage D by the bg and gdh genes were also Assemblage D by the tpi-D-specific primers. Only 12 isolates were Assemblage A alone or Assemblage A and Assemblage C or D. Of the 13 cat isolates, seven were Assemblage F, two were Assemblage D, three were Assemblage A and 1 contained both Assemblages C and D. The calf isolate was Assemblage E (gdh, tpi) and the alpaca (bg, gdh), llamas (gdh), sheep (bg, gdh, tpi) and horse (tpi) isolates were all Assemblage A. When the assemblage could be determined for more than one gene, 91 of 117 dog isolates gave consistent results and 8 of 9 cat isolates gave consistent results.     

Fatal Pasteurella haemolytica pneumonia in bighorn sheep after direct contact with clinically normal domestic sheep

Six Rocky Mountain bighorn sheep were raised in captivity from birth (n = 5) or taken from the wild as a lamb (n = 1). After the bighorn sheep were in captivity for over a year, 6 clinically normal domestic sheep were placed on the 2 ha of pasture on which the bighorn sheep were kept. Nasal swab specimens were obtained from all sheep at the time the domestic sheep were introduced. Pasteurella haemolytica was isolated from swab specimens obtained from 4 of 6 domestic sheep, but not from specimens obtained from the bighorn sheep. All 6 bighorn sheep died of acute hemorrhagic pneumonia after exposure to domestic sheep. Death in the bighorn sheep occurred on days 4, 27, 27, 29, 36, or 71 after initial exposure to domestic sheep. Pasteurella haemolytica was isolated from respiratory tract tissue specimens of all bighorn sheep at the time of death. None of the domestic sheep were clinically ill during the study. At the end of the study, 3 of 6 domestic sheep were euthanatized, and at necropsy, P haemolytica was isolated from 2 of them. The most common serotypes in bighorn and domestic sheep were P haemolytica T-3 and A-2. Other serotypes isolated included P haemolytica A-1, A-9, and A-11 in bighorn sheep and A-1 in domestic sheep. On the basis of results of this study and of other reports, domestic sheep and bighorn sheep should not be managed in proximity to each other because of the potential fatal consequences in bighorn sheep.     

Sirius red is able to selectively stain eosinophil granulocytes in bovine, ovine and equine cervical tissue

The aim of the present study was to examine the suitability of sirius red staining for selective light microscopic demonstration of eosinophil granulocytes in cervical tissue of mares, cows and sheep. For this purpose, tissue was fixed in 4% neutral buffered formol or in Bouin's solution. Paraffin sections of 5-microm thickness were stained with sirius red. In cows, mares and sheep a selective distinction of eosinophilic infiltration is successful after both fixation methods.     

Isolation of Legionella pneumophila from calves and the prevalence of antibodies in cattle, sheep, horses, antelopes, buffaloes and rabbits

The lungs of 139 calves presented for autopsy and 29 healthy slaughtered calves were examined for Legionella by culture and by direct immunofluorescence (DIF) with fluorescein-conjugated antisera. About 17% of the cadaver lungs and 4% of lungs from slaughtered animals were positive by DIF. Legionella organisms were only isolated from the lungs of two cadavers (L. pneumophila, serogroup 1). In a prevalence study of antibodies to Legionella in domestic and wild animals of various species, titers of greater than or equal to 64 were demonstrated by indirect immunofluorescence in sera of 10% of dairy cattle, 5% of beef cattle, 4% of sheep, 22% of antelopes, 35% of horses, 36% of buffaloes and 0% of laboratory rabbits. The isolation of Legionella from lung tissue is evidence for a possible etiologic role of Legionella spp. in natural pathology of animals.     

Prevalence of Sarcocystis cysts in pigs and sheep in Spain

Samples of serum and diaphragm muscle were collected from 100 pigs, and serum samples and oesophagi were collected from 100 sheep. The diaphragm muscle and oesophageal tissues were examined for the presence of macroscopic and microscopic Sarcocystis cysts by compression between trichinoscope plates as well as by tissue digestion with pepsin solution. The sera were examined by the indirect haemagglutination test (IHA), using antigens from Sarcocystis gigantea. With these methods, 95% of the sheep and 43% of the pigs were found to be infected with Sarcocystis sp.     

Continuous in vitro cultivation of a recently identified Babesia that infects small ruminants in China

Babesia sp. Xinjiang was isolated from a splenectomised sheep infested by Rhipicephalus sanguineus and Hylomma anatolicum anatolicum, collected from sheep and cattle in Xinjiang province. It was considered to be a novel ovine Babesia species on the basis of its morphology, pathogenicity, vector tick species and alignments of 18S ribosomal RNA (18S rRNA) and internal transcribed spacers (ITS) gene sequences. Continuous in vitro cultures of the ovine parasite were established using infected sheep blood. In RPMI 1640 medium with 7.5% sheep red blood cells (RBCs) maintained in an incubator at 37 °C and 5% CO(2), the percentage of parasitized erythrocytes (PPE) peaked at 10% in 24- and 6-well plates. It increased to 20-50% with the same culture medium but with 2.5% RBC in 75 cm(2) flasks. Two clonal lines of Babesia sp. Xinjiang were screened using the limiting dilution method. Growth characteristics of these lines in vitro were measured by a microtiter-based spectrophotometric method and from the PPE. The generation time in sheep erythrocytes was between 15.20 h and 16.27 h. Furthermore, the host range of parasite was identified with in vitro culture and in vivo infection. Erythrocytes of sheep, cattle, sika deer and humans could be invaded into by lines in vitro, but the parasites could not propagate in human erythrocytes. The parasites could not enter erythrocytes from goats in vitro. However, in vivo, only sheep could be infected by lines. Finally, a Babesia sp. Xinjiang-like parasite (which shared 99.5% identity with the original strain of Babesia sp. Xinjiang) was isolated using this in vitro culture system from 1 of 19 sheep blood samples collected from western Gansu province, China.     

绵羊肠道寄生虫感染情况调查

为了解河南省绵羊肠道寄生虫感染情况,应用寄生虫常规检测方法对5个规模化养羊场共1265份粪样进行了寄生虫感染情况调查。结果显示,共检出虫卵和卵囊5类,其中原虫2类(球虫、隐孢子虫)、线虫2类（类圆线虫、鞭虫）、绦虫1类。本次调查中共发现1178份粪便样品为寄生虫阳性,寄生虫总感染率为93.12％(1178／1265),5个绵羊场的隐孢子虫平均感染率为3.10％,球虫平均感染率为88.94％,鞭虫平均感染率为10.83％,类圆线虫平均感染率为59.11％,绦虫平均感染率为43.96%。本次调查发现绵羊寄生虫混合感染现象比较严重,其中球虫、绦虫和类圆线虫混合感染的比例达到60.10％;绵羊寄生虫感染率呈现随着年龄的增长而减少的趋势。     

Determination of sheep prion gene polymorphisms from paraffin-embedded tissue.

Amino acid polymorphisms of the prion protein (PrP) greatly influence the susceptibility of sheep to scrapie. Selective breeding to increase the prevalence of PrP gene alleles associated with scrapie resistance is a flock management practice that is important for scrapie control programs. Determination of sheep PrP alleles typically has required extraction of DNA from host tissues that are freshly derived or stored frozen. We describe application of a DNA extraction procedure for formalin-fixed, paraffin-embedded tissues (PET) for the purpose of PCR amplification and nucleotide sequencing of relevant codons (136-171) of the sheep PrP gene. Tissues derived from 96 sheep were studied. The DNA sequence identity was confirmed in 87 of 94 matched samples of PET and frozen tissue specimens. DNA from brainstem PET of 2 sheep, from which fresh tissue was not available, was amplified and sequenced after formalin fixation for 7-70 days. This method will allow retrospective analysis of PrP genetics of sheep subsequent to postmortem diagnosis of scrapie when nonfixed tissue is unavailable for DNA extraction; however, it is not recommended that submission of fixed tissue supplant collection of fresh tissues for the purpose of determining PrP gene polymorphisms.     

Incidence and prevalence of tick-borne haemoparasites in domestic ruminants in Ghana

Giemsa-stained thin blood smears prepared monthly from cattle, sheep and goats in the Greater Accra region of Ghana between May 1994 and December 1996 were examined for presence of tick-borne haemoparasites. The majority of animals were less than 2 months old at the start of the survey. Monthly and cumulative incidences are presented of Anaplasma sp., Babesia bigemina, Borrelia sp., Eperythrozoon sp., Theileria mutans and Theileria velifera in cattle, Anaplasma sp., Borrelia sp., and Theileria sp. in sheep, and Anaplasma sp. in goats. T. mutans was the commonest parasite in cattle, with 100% incidence in calves by 10 months of age, and Anaplasma was commonest in small ruminants. The relative prevalence of these haemoparasites in blood smears from cattle, sheep and goats sampled on a single occasion at sites in all 10 regions of Ghana was found to be similar, though actual infection rates were lower. Packed cell volume (PCV) measurements from the sampled animals are also presented; no seasonal trends were evident in the PCV of the cattle, sheep and goats sampled monthly. In animals sampled on a single occasion, mean PCV was significantly higher in cattle and sheep without detectable haemoparasite infection, and in cattle was lowest in animals positive for both Babesia and Anaplasma, while there was no difference in mean PCV levels between parasitised and non-parasitised goats.     

Suppression of sheep and goat lymphocyte proliferation by sheep, goat, and sheep x goat hybrid trophoblast tissue cultures.

Immunosuppressive activity of conditioned medium from cultured ovine, caprine, and hybrid trophoblast tissue was examined. Conceptuses were obtained from naturally mated donor ewes and does at d 20 of gestation and trophoblast tissue was cultured for 24 h in medium supplemented with 15% calf serum and 1% antibiotic/antimycotic. Conditioned medium was added to pokeweed mitogen-stimulated sheep and goat lymphocyte cultures. Quantification of [3H]thymidine uptake by cells was used to measure lymphocyte proliferation. Ovine, caprine, and hybrid conditioned medium effectively suppressed sheep and goat lymphocyte proliferation (P less than .01). There were no differences (P greater than .05) between the immunosuppressive activity of the three tissue types on either sheep or goat lymphocytes. For all treatment groups, sheep lymphocytes were suppressed more than goat lymphocytes (P less than .05). These results indicate that, at d 20 of gestation, sheep x goat hybrid trophoblast tissue is capable of suppressing pokeweed mitogen-stimulated lymphocyte proliferation.     

Isolation of reoviruses from mink]

In this first report of the isolation of reovirus from mink, isolates were obtained from 18 to 26 young mink with viral enteritis, by using cultures of cat kidney cells. The isolated also produced cytopathic changes in cell cultures of mink kidney, dog kidney, piglet kidney, calf kidney, bovine embryonic kidney and calf testis. A characteristic feature was the formation of eosinophilic inclusion bodies in the cytoplasma of culture cells. Haemagglutination tests were negative with erythrocytes from cat, rabbit, pig, horse and cattle. Attempts to infect old and young mink, kittens and ferrets with tissue culture material failed. It was not known to what extent this second infection with reovirus influenced the course of mink viral enteritis.     

A comparison of the efficiency of water and ethanol at removing formaldehyde from immersion fixed muscle tissues

The efficiency of water, ethanol solutions, isopropanol and ethylene glycol for extracting formaldehyde from fixed muscle tissue were compared. Similar samples of formalin preserved muscle were immersed in the test extraction fluids. After various storage periods the fluids were analyzed for formaldehyde content by sodium sulfite wet chemistry titration. The resulting data were compared by analysis of variance. Ethanol, isopropanol, ethylene glycol and water were found to be effective in extracting formaldehyde from formalin fixed tissue. The concentration of formaldehyde extraction by increasing concentrations of ethanol (20–40%) was linear. While 25 to 40% solutions of ethanol, 20% isopropanol and 25% ethylene glycol were significantly better at extracting formaldehyde, the actual percent formalin difference between water and the best extraction fluid (40% ethanol) was only 0.2% (2.43 versus 2.63%). This slight difference would hardly justify the added expense of using alcoholic or glycolic solutions solely for their extraction qualities. The problem of formaldehyde vapirs arising from embalmed tissue is associated with unbound and loosely bound formaldehyde. which can be removed by washing with various solutions. Precise methods for washing gross anatomical specimens are not discussed.     

Treatment of progressive ethmoidal haematoma using intralesional injections of formalin in three horses

Three Thoroughbred horses with unilateral progressive ethmoid haematomas were treated using intralesional injections of 10% formalin (4% formaldehyde solution). Injections were performed in the standing sedated horse through the nasal passages under endoscopic guidance and, when the ethmoid haematoma involved the paranasal sinuses, through holes trephined into the affected sinus. Regression of the lesions occurred in all cases after repeated injections. This technique appears to be a safe and effective treatment for progressive ethmoid haematomas in the horse.     

Pathogenic bacteria and fungi associated with extraocular disease in the horse

In 123 cases of external ocular disease in the horse, pathogenic microorganisms isolated with greatest frequency were Streptococcus sp (43.9%), Staphylococcus sp (24.2%), and Pseudomonas sp (13.8%). Fungi were isolated in 4.8% of the cases. In vitro testing showed that most of the Streptococcus sp isolants were sensitive to ampicillin, cephalothin, and carbenicillin. Most of the Staphylococcus sp isolants were sensitive to gentamicin, cephalothin, and bacitracin. Most of the Pseudomonas sp isolants were sensitive to polymyxin B and gentamicin.     

Preliminary study of histological comparison on the growth patterns of long-bone cortex in young calf, pig, and sheep

Some young large farm animals show a laminar bone formation in the long-bone cortex. Such a laminar bone is gradually replaced by Haversian bone with osteons during their growth periods. In this preliminary study, we observed the transverse ground samples of tibia cortex in young calves, pigs, and sheep by backscattered electron imaging. The cortex bones of all the newborn (NB) animals were basically formed with laminar bone structures. The NB and 1-month-old (1-M) calves had a typical concentric structure of laminar bone, whereas the NB and 1-M pigs showed a wire-netting bone with laminar-bone units. The NB sheep was similar to the calf rather than the pig. In the growth rate of bone volume, sheep was similar to calf up to 6 months after birth (6-M). Such calf and sheep showed a more rapid ratio of bone volume than pig. A few osteons had initially appeared in the innermost layer of the 6-M calf. A 1-year-old (1-Y) calf showed scattered osteons in the bone cortex, but many laminar-bone units were still retained in the outer layer. A 6-M pig had many osteons in the entire cortex but only a few osteons in the outermost layer. In the 6-M sheep, no osteons were observed, whereas a 1-Y sheep showed a relatively small number of osteons mainly in the middle layer but a higher osteon-volume than the 1-Y calf. In the 1-Y sheep, the more widely absorbed areas by bone-remodeling with osteons were observed as compared with the 1-Y calf, and the bone volume was decreased from the 6-M into the 1-Y sheep because of the remarkable bone-absorption. Thus, calf kept on possessing many laminar-bone units for a longer time in the growth period than sheep, while pig showed the earliest bone-remodeling with osteons. These results may be caused by their different body size and withers height in calf and sheep after growing and the difference of the dependence upon mother's body during juvenile period between pig and calf with sheep. The initial region of osteon formation may be distinguishable among their animals, respectively. However, further detailed investigations of their young animals at successive stages will be necessary.