www.nina.no Case I Case IV: Case III: Case II

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Case IV: This wolverine was filmed in. Kuhmo in Eastern Finland in ... thank Terje Bø, Norwegian Environmental Agency, that first saw the link between the three.
Idiopathic Facial Lesions in Wolverines (Gulo gulo) from Norway and Finland Bjørnar Ytrehus1, Oddmund Kleven1, Øystein Flagstad1 & Jon M. Arnemo2 1 Norwegian Institute for Nature Research (NINA) 2 Hedmark University of Applied Sciences Three Norwegian and one Finnish wolverine (Gulo gulo) has been found with strikingly similar lesions. They all seem to have lost the soft part of their nose and lips, exposing their teeth and nasal conchae and giving them a grotesque appearance. The lesions are healed and it is hence difficult to determine the etiology of the lesions. As wolverines live a rough life, often fight each other and are exposed both to other predators, animals of prey that may defend themselves and a harsh environment, it may seem plausible that these lesions are traumatic. However, their bilateral symmetrical appearance and the degree of similarity between individuals is confusing. Is there another explanation?

Photo : Jon Martin Arnemo, Hedmark University of Applied Sciences

Photo : Thomas Rødstøl, The Norwegian Nature Inspectorate

Photo : Rein-Arne Golf, The Norwegian Nature Inspectorate (top)/ Bjørnar Ytrehus, NINA (bottom)

Photo : Yle/Kimmo Ohtonen

Case I

Case II

Case III:

Case IV:

Could this be something analogous to bullous pemphigoid or discoid lupus erythematosus? There were however no histological changes consistent with such disorders.

Cold injury?

10 year old female, 8,2 kg. Shot during hunting in January 2016 in Sogn, Western Norway, about 100 km from Case I and 90 km from Case II. The hunter observed that the animal made a wheezing sound when breathing. This animal was necropsied. It was below average body condition and had no content in its GI tract. Apart from the facial lesions, it had severe dental wear and several severe, relatively fresh bite wounds in its head and hindfeet. It was the soft tissues of the nose and lips that were absent and replaced by smooth, hairless and partly pigmented skin. The swollen, partly collapsed rostral parts of the conchae obstructed air flow. The histological changes of the skin and nasal mucosa were unspecific and chronic. Type I PS?

In severe cases, the ischemic necrosis typical of cold injury may result in dry gangrene and sloughing of the affected part. But isn’t this unlikely in an animal so well adapted to cold climate?

Occurs when photodynamic or fluorescent pigments are deposited in sunlight exposed skin. The distribution and character of the lesions may be consistent with this, but where should the agent come from?

Genetic disorder?

Cutaneous filaroidosis? Could filaroid nematodes deposited in the blood vessels of the nose cause ischemic necrosis? We do not know any such parasites of wolverines in Europe, but….

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Photosensitization (PS) dermatitis?

Could this be an inherited disorder? If so -should we not see lesions in other parts of the skin and appendages? Anything else? Do you have an idea? Or have you seen anything similar in any species? Please tell us!

Acknowledgements: We would like to thank Terje Bø, Norwegian Environmental Agency, that first saw the link between the three Norwegian cases and led our attention to them! We would also like to thank the rangers in the Norwegian Nature Inspectorate that conscientiously have inspected the wolverines and taken photographs; Rein-Arne Golf, Thomas Rødstøl and Lars Olav Lund. Great thanks are also due to Timo Heikkinen, Kimmo Ohtonen and their TV-team from YLE, Finland; and to our skilled and trusted lab technichians at NINA; Merethe Spets, Line B. Eriksen, Torveig Balstad, Aniko Hildebrand and Frode Holmstrøm.

This wolverine was filmed in Kuhmo in Eastern Finland in october 2014 by a TV-team from Yle. The animal was reobserved in the summer of 2015. It did not show any obvious signs of disease.

Caused by exogenous substances, typically plant pigments or drugs? But wolverines normally do not eat much plants, and Type I PS is not common in other species in Norway.

Type II PS? Congenital enzyme deficiencies in the heme synthesis may cause accumulation of photodynamic porphyrins and different types of porphyria

Bog Asphodel (Narthecium ossifragum)

Autoimmune disease?

10 year old female, 8 kg. Killed in trap during hunting in December 2011 in Romsdal, Western Norway, about 50 km from case I. The right outer ear was not present, while the left partially lacked. Its upper left, lower left and upper right canine teeth were absent, and its left foreleg was amputated in the carpal joint. Not examined further.

Photo : Bjørnar Ytrehus, NINA

7 year old male, 13 kg. Culled in March 2008 in Sunnmøre, Western Norway to prevent loss of livestock. Had also lost a toe on a hindfoot. Genotyping based on 11 microsatelites showed that this individual was closely related (parent/offspring or sibling) to Case II, but not closely related to Case III. Not examined further.

Type III PS? Hepatogenous PS is due to disturbance of the excretion of phylloerythrin, a metabolite of clorophyll. This is common in sheep in Western Norway after ingestion of Bog Asphodel. Could the wolverines have been exposed to high levels of phylloerythrin after eating tissues from affected sheep cadavers? But – Bog Asphodel is not common in Finland…. Could this individual originate from Norway?

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