Necropsy findings, meat control pathology and causes of loss in semi-domesticated reindeer (Rangifer tarandus tarandus) in northern Norway

BACKGROUND

Reindeer herding in Norway is based on traditional Sámi pastoralism with the animals free ranging throughout the year. The animals move over large areas in varying terrain and often in challenging weather conditions. Winter crises, such as difficult grazing conditions caused by icing or large amounts of snow, are survival bottlenecks for reindeer. Calves are especially vulnerable, and many may die from starvation during winter crises. Predation and starvation are the predominant narratives to explain losses, however, carcasses are difficult to find and often little remains after scavenging and decay. Documentation of the causes of death is therefore scarce.

RESULTS

In this study, we investigated the cause of reindeer mortality in Troms and Finnmark, Nordland and Trøndelag during 2017-2019. Necropsies (n = 125) and organ investigation (n = 13) were performed to document cause of death. Body condition was evaluated using visual fat score and bone marrow fat index. A wide range of causes of death was detected. The diagnoses were categorized into the following main categories: predation (n = 40), emaciation (n = 35), infectious disease (n = 20), trauma (n = 11), feeding related disease (n = 5), neoplasia (n = 4), others (n = 6) and unknown (n = 17). Co-morbidities were seen in a number of diagnoses (n = 16). Reindeer herders are entitled to economic compensation for reindeer killed by endangered predators, but a lack of documentation leads to a gap between the amount of compensation requested and what is awarded. An important finding of our study was that predators, during winter, killed animals in good as well as poor body condition. Emaciation was also shown to be associated with infectious diseases, and not only attributable to winter grazing conditions.

CONCLUSIONS

This study highlights the importance of examining dead reindeer to gain knowledge about why they die on winter pasture. The work presented herein also shows the feasibility and value of increased documentation of reindeer losses during winter.

Multiple sclerosis and affective disorder. Family history, sex, and HLA-DR antigens

To investigate a possible genetic cause underlying the clinical association between multiple sclerosis (MS) and affective disorder, we studied 56 patients with MS for psychiatric and genetic (family history, sex, and HLA-DR) characteristics. The 2:1 ratio of females to males expected for patients with MS was observed in this sample (40:16), but the excess of females occurred entirely among the 31 MS patients with major affective disorder (27 females and four males). Bipolar probands with MS had significantly more relatives with affective disorder or MS than did unipolar probands with MS. The HLA-DR antigen frequencies in patients with MS categorized by type and family history of affective disorder suggest that it may be possible to validate such clustering of patients. We concluded that sex and other genetic factors are related to the affective symptoms in MS and emphasize the importance of psychiatric evaluation of these patients.

The relationship of HLA to depression and manic depression. I. The Newfoundland follow-up

This report constitutes the Newfoundland component of a large scale replication study to assess the relationship of HLA to affective disorders; the Ontario component will be published subsequently. In a collaborative study between the University of Toronto, Memorial University and the University of Rochester, first degree family members of Probands with major affective disorder in Newfoundland were assessed for the lifetime presence of psychiatric disorder; their blood was also typed for Human Leucocyte Antigens (HLA). Because of the high rate of refusal to participate, only 10 Newfoundland families could be assessed completely. While this number of families is too small to evaluate the role of HLA as a marker of susceptibility to affective disorder, the results will be added to those of the larger Ontario component. Some problems of conducting research in communities similar to those found in Newfoundland are briefly discussed in the context of characteristics of the Probands in the study group as compared with those of subjects who refused entry into the study.

Gm, Km, and HLA in insulin-dependent type I diabetes mellitus. A log-linear analysis of association

Two hundred sixty families, in which at least one family member had insulin-dependent (type I) diabetes mellitus (IDDM), were typed for HLA antigens and the Gm and Km allotypes. Frequencies of Gm and Km allotypes in the diabetic subjects were compared with family controls (oldest nondiabetic sibling within a family). There were no significant differences between patients and controls for either Gm or Km allotype frequencies considered individually. When the log-linear model was used to analyze subjects and sibling controls, three significant findings emerged. First, there was a significant HLA-Gm interaction, indicating nonrandom segregation of HLA antigens with Gm allotypes, regardless of disease status. Second, there was, as expected, a significant HLA-IDDM interaction, indicating that HLA type is nonrandom with respect to IDDM status. Third, there was a significant HLA-sex-Gm-IDDM interaction, indicating that combinations of HLA antigens, Gm allotypes, and sex may play an important role in defining risk for IDDM. Thus, Gm and sex interacting with HLA may reflect the influence of an unlinked modifier previously hypothesized for IDDM pathogenesis.

Tourette syndrome and HLA

Five kindreds with multiple individuals manifesting Tourette syndrome (TS) or related abnormal movements were evaluated for linkage between TS and HLA-A, B, C and DR antigens. Families were selected to have a constellation of affected individuals which gave the appearance of transmission of a major susceptibility gene. All kindreds had at least two clearly affected first or second degree relatives. Although developmental neurobehavioral disorders are candidates for showing a relationship to specific tissue antigens, we found no evidence for a close linkage between a gene locus determining susceptibility to TS and the HLA loci.

Alzheimer disease: evidence for susceptibility loci on chromosomes 6 and 14

We report the transmission of HLA haplotypes and Gm allotypes in 97 members of a single kindred containing 257 individuals, 45 of whom were determined by clinical examination, autopsy, or historical data to have had Alzheimer disease (AD). Extensive inbreeding suggests that more than one gene may contribute to susceptibility to AD in this family, despite the apparent vertical transmission of illness. The distribution of HLA haplotypes and of Gm allotypes to affected and unaffected siblings is consistent with the possibility that genes in the HLA region of chromosome 6 and perhaps also in the Gm region of chromosome 14 are determinants of susceptibility. Further studies are needed to investigate whether susceptibility to AD may result from an interaction between (immune response?) genes on these two chromosomes.

Depressive disorders and HLA: a gene on chromosome 6 that can affect behavior

To determine whether HLA-linked genes on chromosome 6 influence susceptibility to depressive disorders, we tested hypotheses concerning the distribution of HLA haplotypes among specific constellations of affected and unaffected family members. HLA haplotype identity among pairs of affected siblings in families with two affected siblings and among pairs of older unaffected siblings in families with one or two affected siblings was increased over random expectation (P less than 0.005). There was no increase in HLA haplotype identity among affected siblings in sibships with more than two affected members. When parents had a relative difference in estimated load of genes for susceptibility, HLA haplotypes were randomly transmitted to unaffected or affected children from the affected, "high-load" parent, but not from the unaffected, "low-load" parent (P less than 0.001). These results locate a gene contributing to susceptibility to depressive illness on chromosome 6 and provide a second example of the value of the hypotheses in defining the genetic bases of nonmendelian, familial diseases.