IUCN / SSC Cat Specialist Group - Digital Cat Library |
|
||||||||||
|
||||||||||
|
|
| Ryser-Degiorgis, M.-P. | |
| Causes of mortality and diseases of Eurasian lynx (_Lynx lynx_) | |
| 2009 Book Chapter | |
Free-ranging Eurasian lynx mostly die of non-infectious causes such as traffic accidents, poaching and hunting. Thus, human-related mortality is of major importance; depending on the country and study period, it varies from 54 to 96.5%. In contrast, diseases represent only 3.5-25% of the causes of death. However, the importance of infectious diseases is probably underestimated since mortality studies mostly rely on data from lynx found dead by chance. A wide range of infectious and non-infectious diseases has been reported in Eurasian lynx. As a felid, the lynx is probably susceptible to most diseases affecting domestic cats. Furthermore, the Eurasian lynx is exposed to infectious agents through its prey. Nevertheless, epidemic outbreaks do not seem to occur in free-ranging populations. Because of its solitary behaviour, the Eurasian lynx has only rare opportunities to transmit pathogens before a fatal outcome or recovery from the disease - although a disease with long duration and/or incubation period might represent an exception. The absence of detection of antibodies or antigens in population surveys indicate that the investigated populations either did not have any recent contact with these agents, and/or possibly, that the species is highly susceptible to infection (i.e., infected individuals do not survive). In contrast, a high prevalence is an indication that the concerned agents do not cause serious health problems in the species, especially if related mortality has not been observed and infected populations are stable. For example, high prevalences have been documented for _Toxoplasma_,_ Trichinella _and_ Cytauxzoon_, which are normally apathogenic to lynx. The disease most commonly diagnosed in free-ranging Eurasian lynx is sarcoptic mange, but neither mange nor other diseases do appear as a threat to free-ranging lynx populations so far. Nevertheless, losses due to diseases might have an impact if added to serious problems such as poaching and/or habitat destruction. Furthermore, apparently emerging problems such as congenital malformations and heart lesions in Swiss lynx underline the need for a long-term, careful health monitoring of free-living and captive populations, together with extensive sample collection for immediate or later studies. In this context, close collaboration between field biologists and veterinarians is essential, both for data collection and interpretation. |
|
 |
PDF files are only accessible to Friends of the Cat Group. Joining Friends of the Cat Group gives you unlimited access and downloads in the Cat SG Library for one year, and allows you to receive our newsletter Cat News (2 regular issues per year plus special issues). More information how to join here |
(c) IUCN/SSC Cat Specialist Group ( IUCN - The World Conservation Union) |