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Biomedical subjects

W Schaftenaar

Publications and source records attributed to W Schaftenaar.

15 recordsLinked to original sources

Endotheliotropic elephant herpes virus (EEHV) infection. The first PCR-confirmed fatal case in Asia.

Since 1995, 4 suspected cases of Endotheliotropic Elephant Herpes Virus (EEHV) infection, i.e. based on clinical presentation, have occurred in Asia without resulting in epidemic outbreaks as expected. In order to confirm the presence of EEHV on the continent of Asia, viral DNA particles from liver samples of a wild-caught 3-year-old elephant found dead at a Cambodian elephant sanctuary and clinically diagnosed with EEHV, were PCR processed using known EEHV strain primers. The presence of EEHV viral nucleic acids was confirmed and the nucleic acids had a 99% sequence similarity to the U.S.A strain (gene bank locus: AF117265) and 97% sequence similarity to the European strain (gene bank locus: AF354746) assigning this case to the EEHV-1 cluster. More than the confirmation of EEHV on the continent of Asia, is the phylogenic relationship to the USA and European strains with no corresponding contact or transport of USA or European elephants to Asia. Thus, this brings many of the traditional theories into question. Although almost forgotten, this disease is still ramped in captive elephant populations worldwide and continues to devastate particularly the neonatal and weaning-age population. Special attention and continued research are needed specifically in the area of basic virology and epidemiology.

Animals↗

Cataract surgery with foldable intraocular lens implants in captive lowland gorillas (Gorilla gorilla gorilla).

Two juvenile, male, captive-born lowland gorillas (Gorilla gorilla gorilla) with the same father but different mothers developed bilateral cataracts. The cataracts were surgically removed within 6 yr and 3 mo, respectively, of diagnosis, and foldable intraocular lenses were implanted. Although vision was not restored in one eye with a mature, 6-yr-old cataract in gorilla A, surgical intervention on the other eye was performed before a complete cataract developed, and vision was fully restored. Gorilla B was treated at the age of 17 mo, and normal visual development proceeded in both eyes. This animal developed bilateral after-cataract and therefore needed a second intervention in both eyes using Nd:YAG laser treatment. The genetic component of juvenile cataracts should be considered in breeding management programs.

Animals↗

Use of vaccination against foot and mouth disease in zoo animals, endangered species and exceptionally valuable animals.

A historical review of foot and mouth disease (FMD) in non-domestic species is given and the use of FMD vaccines to protect those species is described. Several non-domestic species are susceptible to FMD. Legislation in many countries, based on the definition of FMD-free status as determined by the Office International des Epizooties (OIE: World organisation for animal health), forms an important barrier against the use of vaccines. National authorities may even feel obliged to slaughter animals of threatened species protected by international agreements during an outbreak of FMD to preserve their FMD-free status. The importance of international breeding programmes for endangered species is forcing the international community to reconsider the role that vaccination against FMD should play in animal health prevention programmes of captive populations. Much research is still required in regard to vaccine types and diagnostic procedures. Species-specific differences in susceptibility to FMD make this a challenging research topic for zoological institutions.

Animals↗

A variant of the endotheliotropic herpesvirus in Asian elephants (Elephas maximus) in European zoos.

Newly discovered, lethal elephant endotheliotropic herpesviruses (EEHV) have been identified in both Asian (Elephas maximus) and African (Loxodonta africana) elephants. Carried by otherwise healthy African elephants they can be fatal mainly for young Asian elephants. Since zoos often harbour both elephant species, we conducted a survey on the presence of EEHV in Asian elephants from 12 European zoos, 3 circuses and 1 Israeli zoo. Here, we demonstrate that all EEHV that have affected Asian elephants so far belong to the EEHV1 group. We also describe the detection and the partial sequencing of an endotheliotropic herpesvirus variant (named EEHV1b) in Asian elephants, being either an EEHV endogenous to Asian elephants or indicating different sources (African elephants) of infection.

2-Aminopurine↗

Fecal progesterone, estrogen, and androgen metabolites for noninvasive monitoring of reproductive function in the female Indian rhinoceros, Rhinoceros unicornis.

This investigation aimed to establish noninvasive methods for endocrine monitoring of estrous cycles and pregnancy in the Indian rhinoceros. Fecal samples were collected 1-3 times per week from nonpregnant and pregnant captive females (n = 7). Enzyme immunoassays for fecal progesterone, androgen, and estrogen metabolites, respectively, were tested for their ability to determine follicular and luteal phases and to characterize endocrine profiles during pregnancy. Antibodies used were raised against pregnanediol (20 alpha-OH-pregnanes), 20-oxo-pregnanes, epiandrosterone (17-oxo-androstanes), and total estrogens. Androgens and estrogens were found to be reliable indicators of the follicular phase, whereas 20 alpha-OH- and 20-oxo-pregnanes were reliable indicators of luteal function. Progesterone metabolites were also reliable indicators of pregnancy, whereas 17-oxo-androstanes and estrogens were basal throughout gestation. Estrous cycles were regular throughout the year, with an average cycle length of 43.4 +/- 1.5 (n = 27) days; the length of the follicular phase, as indicated by elevated estrogen levels, was 15.9 +/- 1.0 days, whereas the luteal phase, as indicated by elevated 20-oxo-pregnane levels, was 19.1 +/- 0.4 days. Fecal pregnane values were already increasing while follicular estrogen values were still decreasing. The length of the diestrus, indicated by basal steroid levels between declining 20-oxo-pregnanes and subsequently increasing estrogens, was 11.4 +/- 1.2 days. Pregnane levels increased from the 3rd month of gestation onward and levels exceeded luteal phase concentrations approximately 10 times by the 7th month of gestation onward. HPLC separation of immunoreactive fecal metabolites indicated the presence of estrone, estradiol-17beta, and several 17-oxo-androstanes, 20 alpha-OH-pregnanes, and 20-oxo-pregnanes. Concentrations of a peak with an elution profile similar to that of pregnanediol increased as pregnancy progressed. Postpartum fecal estrogen and 17-oxo-androstane concentrations in one animal indicated follicular development comparable to the follicular phase of the estrous cycle, but this was not followed by a subsequent luteal phase. In conclusion, estrous cycle and pregnancy in Indian rhinoceroses can be monitored using fecal steroid analysis. Pregnane metabolites were reliable indicators of the corpus luteum and pregnancy, whereas fecal 17-oxo-androstanes and estrogens were indicators of the follicular phase.

Androgens↗

Characterisation of a recently isolated lyssavirus in frugivorous zoo bats.

In July 1997 a lyssavirus was isolated in Denmark from a colony of Egyptian flying foxes (Rousettus aegyptiacus) originating from a Dutch zoo. Sequencing of a 400 nucleotides coding region of the nucleoprotein and of a major part of the G-protein ectodomain encoding region of the newly isolated virus, revealed a very high similarity with European Bat Lyssavirus subtype 1a (EBL-1a). For characterisation of the recently isolated lyssavirus in frugivorous zoo bats, 16 frugivorous bats (Rousettus aegyptiacus) of the same colony and 80 mice were experimentally infected with the Rousettus isolate or with a well defined EBL-1a strain isolated from a Dutch insectivorous bat (Eptesicus serotinus). Inoculation viruses were titrated in mice to determine LD50's of both isolates. Clinical signs of inoculated bats were recorded during 6 weeks. After showing neurological signs or at the end of the experimental infection all animals were euthanized. During the experimental infection sera and various tissues of inoculated bats were collected. Immunoassays, mouse inoculation tests (MIT) and polymerase chain reaction (PCR) were employed for detection of lyssavirus specific antibodies, antigen or RNA. Five bats inoculated with the Rousettus isolate and 2 bats inoculated with the Eptesicus isolate showed neurological signs. The remaining 9 bats survived and cleared the virus; at least under the detection limit of the used assays. Despite a much higher pathogenicity of the Rousettus isolate observed in mice, LD25's in bats were quite the same for the 2 isolates. The pathogenicity of both isolates suggested that like many other mammals, Rousettus aegyptiacus bats could be victims of lyssavirus infection besides reservoir hosts of infectious EBL1a. There was no significant difference in detecting the different lyssavirus isolates in Rousettus aegyptiacus bats. An employed immunoperoxidase staining (IP) method was very useful for sensitive detection and localization of lyssavirus antigen in histologic preparates.

Animals↗

Noninvasive reproductive monitoring in the okapi (Okapia johnstoni).

Fecal progestagen analysis in okapis (Okapia johnstoni) was used for diagnosis of pregnancy and reproductive disorders, including a comparison of urinary and fecal progestagen analysis and endocrine data on the postpartum period. Data were generated on reliability of fecal progestagen analysis in early pregnancy diagnosis, and case reports were compiled involving single animals with missing luteal activity, abortion after twin pregnancy, and abortions due to deficient placental progestagen production. There was approximately 100-200-fold higher progestagen concentration in feces than in urine, thus explaining the high reliability of fecal progestagen evaluations in diagnosing luteal function and pregnancy. The postpartum period was characterized by lactational anestrus of several months duration, and a postpartum estrous cycle about 2-3 wk after parturition was observed in two of eight animals. An animal with five abortions due to deficient placental progestagen production was treated with altrenogest in a subsequent pregnancy and carried the fetus to term.

Abortion, Veterinary↗

[Oxytetracycline and oral herd treatment: a literature review].

Pharmacotherapeutic, pharmacodynamic and pharmacokinetic aspects of oral mass medication with oxytetracycline (OTC) in pigs, calves and poultry are discussed in this review. Clinical studies with successful therapeutic results are scarce in literature; however, OTC is still frequently used for mass medication. Some practical advice to improve the bioavailability of OTC is given. This mainly concerns the reduction of the interaction between calcium ions and OTC. OTC may be useful for oral mass medication when applied as a prophylactic drug. Pharmacological studies are required in order to provide more knowledge about the efficacy of OTC-mass medication. Additional information can be acquired from the field by improving and extending the reciprocal co-operation between field veterinarians and diagnostic laboratories. This may lead to a more justified choice from the various possibilities of antimicrobial use in livestock.

Animals↗

[Studies on intersucking in dairy cattle (author's transl)].

Intersucking occurred on nearly 50 per cent of the farms in the Province of Utrecht. The incidence was not affected by housing systems, the size of the herd and the surface area available to each cow in cubicle stalls. It is unlikely that the animals imitate intersucking by others. Intersucking often occurs prior to evening milking, the sucking animal usually forming a steady pair with the suckled cow. Of four A.I. bulls studied, one had a significantly higher proportion of intersucking heifers among his offspring than the others. Some other factors possibly affecting the incidence of intersucking, such as the rearing system, composition of the ration and the space allotted to each cow for feeding were not studied because of insufficient information or inadequate variation of the material.

Animal Feed↗