Anatomical variations and pathological changes in the hearts of free-ranging Eurasian lynx (Lynx lynx) in Finland

Abstract

The Eurasian lynx (Lynx lynx) despite the wide distribution has fragmented populations with possibly decreased genetic variability. Reports from Central Europe have raised cardiac health as possible risk factor for lynx populations. The knowledge on normal anatomic variations of lynx heart is crucial to assess emerging pathological or hereditary disorders. The aim of this study was to give a detailed description of the cardiac anatomy and circulation of the Eurasian lynx and to report the cardiac health of the lynx in Finland. The cardiac anatomy and pathology were studied post mortem from 63 legally hunted lynx. In general, the cardiac anatomy of Eurasian lynx corresponded with that described for other felids. In the ventricles, varying number of thin ventricular bands was a common feature and their histological appearance was characterized by a fibromuscular pattern. The size of the heart varied between males and females, but the relative size was similar to that described for most domesticated carnivores. No marked pathologic lesions were observed in the lynx hearts. Fibrosis was observed in 56% of the hearts, but it was focal and mild in degree and unlikely to affect cardiac function or to have clinical significance. In conclusion, the cardiac health of the Finnish Eurasian lynx population is good with no signs of heritable cardiac disorders. Furthermore, we were able to give a detailed anatomic description of the lynx heart, which can serve as a reference for further epidemiological investigations on cardiac diseases in lynx populations.

Genetic analysis indicates spatial-dependent patterns of sex-biased dispersal in Eurasian lynx in Finland

“…Our study area was characterized by different land uses and levels of urbanization but lacks dispersal barriers for lynx [ 25 ]. This finding is also supported by good population health [ 69 ], and active gene transfer [ 31 ]. Hence, anthropogenic and environmental changes that may trigger changes in sex-biased dispersal in this large Eurasian lynx population may be low compared to other studies.…”

Cardiomyopathy Associated With Coronary Arteriosclerosis in Free-Ranging Eurasian Lynx (Lynx lynx carpathicus)

“…The ratio obtained for two cachectic adult males without evidence of clinical cardiac disease was 0.64 and 0.69, respectively. The HW:BW ratio in healthy Northern lynx was within the same range as for domestic cats ( 42 ), i.e., 0.58 ± 0.28–0.88 ( 13 ) . b Thickness of the right ventricle free wall (RV), interventricular septum (S) and left ventricle free wall (LV) measured in millimeters.…”

“…The ratio obtained for two cachectic adult males without evidence of clinical cardiac disease was 0.64 and 0.69, respectively. The HW:BW ratio in healthy Northern lynx was within the same range as for domestic cats ( 42 ), i.e., 0.58 ± 0.28–0.88 ( 13 ) .…”

“…Furthermore, the differences with the first phase of our study demonstrated the importance of harmonized methods to conduct proper comparisons ( 67 ). Interestingly, a subsequent study in lynx from Finland underlined the existence of population-related differences even more, as minimal to mild fibrosis was detected in 56% of 63 Northern lynx heart but arteriosclerosis was never observed ( 42 ).…”

“…Since there are no published reference values for the morphology of the Carpathian lynx heart, and those generated for Northern lynx do not include the ratios necessary to overcome body size and weight differences ( 28 , 42 ), a healthy individual from Switzerland, originally taken into a rehabilitation station as an orphan and roadkilled after its release, was used as a “control” animal for comparison ( Table 1 , Figure 1 ). Repeated auscultation performed under anesthesia with medetomidine and ketamin ( 39 ) did not reveal any anomaly.…”