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Biomedical subjects

M J Hoyer

Publications and source records attributed to M J Hoyer.

11 recordsLinked to original sources
PubMed2006

Vertical transmission of bovine viral diarrhoea virus (BVDV) in mousedeer (Tragulus javanicus) and spread to domestic cattle.

This study investigates the transmission of bovine viral diarrhoea virus (BVDV) 1f from a persistently infected (PI) lesser Malayan mousedeer to two bovine calves. Different contact routes to two calves were analysed: 1) aerosol contact between two adjacent pens without physical contact; 2) indirect contact by use of common utensils; 3) direct nose-to-nose contact for 30 seconds. One of the calves was infected either by aerosol or indirect contact. The virus sequence in 247 nucleotides in the 5'-UTR was 100% identical in mousedeer and calf. To elucidate the distribution of BVDV within the affected mousedeer family the captive population in a Zoo was analysed. The maternal line of PI animals was maintained, whereas a PI male was able to reproduce and have a non-PI calf. As a consequence of this, six female PI mousedeer were killed; subsequent autopsies did not reveal any lesions. Sequencing mousedeer BVD virus in the E2 region (420 nucleotides) through 4 generations showed only 7 mutations, which were maintained from mother to offspring.

Aerosols↗
PubMed2005

Persistent BVDV infection in mousedeer infects calves. Do we know the reservoirs for BVDV?

Bovine virus diarrhoea virus (BVDV)-1f was isolated from a Lesser Malayan Mousedeer in Copenhagen Zoo during a routine screening. Analysis of animals related to the Copenhagen mousedeer revealed that its mother and all siblings were virus positive, a pattern also seen for persistently infected (PI) cattle. BVDV could be transmitted from the PI mousedeer to a calf after indirect contact. The host spectrum for BVDV seems to be even wider than expected; the implications for BVDV control are discussed.

Animals↗
PubMed2005

[Immobilization of cattle and bison with a combination of xylazine, zolazepam-tiletamine and ketamine].

The aim of this study was to find a safe and reliable alternative to Immobilon for the immobilization of (feral) cattle. A combination of xylazine, zolazepam-tiletamine and ketamine was tested in Limousin cattle, Scottish Highland cattle, and American bison. Bodyweight, induction time, arterial O2 saturation and the total downtime were measured. Arterial blood was taken for pH and blood gas analysis. The animals were then injected with atipamezole and the recovery time was recorded. A combination of 500 mg zolazepam, 500 mg tiletamine, 500 mg xylazine, and 1000 mg (10 ml) ketamine, administered in a dosage of 1 ml per 100-150 kg bodyweight (depending on the species), proved to be most reliable and effective. The combination resulted in a fast immobilization. In all animals slight respiratory depression was seen, which indicates that oxygen suppletion may be needed for long-lasting immobilization. After reversal of the xylazine component, almost all animals recovered within 4 minutes. No long term adverse effects were reported by the owners.

Adrenergic alpha-Antagonists↗
PubMed2003

[Recurrent skin problems in a manatee: the diagnostic approach].

A 40-year-old manatee was referred with recurrent vesicular and ulcerative dermatosis for the past 15 years. During this period the animal was anorectic and lost weight. Differential diagnoses were formulated on the basis of the history and clinical signs. Skin scrapings, bacterial and fungal culture, cytological examination, blood examination, and histopathological examination of skin biopsies narrowed this list down to autoimmune dermatosis. Despite corticosteroid therapy the symptoms recurred and the animal died. Histopathological examination of post-mortem skin biopsies showed again autoimmune dermatosis, more specifically subepidermal bullous autoimmune dermatosis, as the most probable cause of the skin lesions. Post-mortem examination showed cardiac decompensation and chronic nephritis. It was impossible to estimate the possible contribution of the chronic dermatosis to the cause of death. The purpose of this case report is to show the importance of a systematic work-up of disease in exotic animals.

Adrenal Cortex Hormones↗
PubMed2003

Characterisation of a pestivirus isolated from persistently infected mousedeer ( Tragulus javanicus).

Serum samples from the male Mousedeer A and the mother, father and sister of A were tested for bovine virus diarrhoea viruses (BVDV) by isolation, and for BVDV antibodies by blocking ELISA and homologous neutralisation test. Further, RNA was extracted and tested by RT-PCR protocol analysing the 5'-untranslated region and the E2 gene of pestivirus. The RT-PCR products were subsequently sequenced. Mousedeer A was positive in virus isolation on three occasions (days 1, 19 and 40) and by RT-PCR. The sister and mother of Mousedeer A were also found virus positive by isolation and RT-PCR. Mousedeer A, its sister and its mother, all had an antibody neutralisation titer below 10. The father of A was virus negative but was positive in the blocking antibody ELISA and had a high neutralisation antibody titer. The repeated detection of BVDV in Mousedeer A, the high amount of virus in serum, the lack of antibodies and the virus positive family members documented that the mousedeer were persistently infected with a pestivirus. The father of A probably had an acute infection resulting in antibodies to pestivirus and viral clearance. Sequence analysis and phylogenetic analysis revealed that the mousedeer pestivirus was closely related to BVDV Type 1f. The existences of persistently infected animals in non-domestic species have great implications for BVDV eradication campaigns in cattle.

5' Untranslated Regions↗
PubMed1997

[Remote anaesthesia of animals in veterinary practice in the Netherlands].

In a series of three review articles different aspects of wild animal immobilization under Dutch conditions will be discussed. The first article deals with the available equipment for remote anaesthesia, their indications for use and some basic darting principles. Part two discusses the various anaesthetics used in wild animal immobilization and their clinical pharmacological properties. A table with effective anaesthetic combinations for ten different species is presented. The third article discusses safety measures and complications which can occur when dealing with wild animal anaesthesia.

Anesthesia↗
PubMed1994

Antitumor effect of locally injected low doses of recombinant human interleukin-2 in bovine vulval papilloma and carcinoma.

In many human clinical trials and in various animal tumor models, the antitumor effect of high doses of systemically applied interleukin-2 (IL-2) is tested. Our studies focused on the effects of low doses of locally injected IL-2. In this paper, the effect of local injection of low doses of IL-2, i.e. a total dose of 25,000-50,000 units, into papillomas or carcinomas of the bovine vulva is described. In 19 out of 23 (83%) cows treated with IL-2 an effect on the tumor load was observed; in three of these animals, complete regression was obtained. In the majority of cases, regression was not restricted to the tumors injected with IL-2.

Animals↗
PubMed1991

Hereditary laminitis in Jersey calves in Zimbabwe.

The clinical signs and radiological findings of a rare laminitis-like condition in Jersey calves (n = 6) are described. Regular hoof-trimming proved very beneficial. Pedigree studies of the affected calves strongly suggest a recessive autosomal inheritance.

Animals↗