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Abstract Background The parasitic fauna of beavers (Castor fiber and C. canadensis) has been well studied in many parts of their respective areas of distribution. In Scandinavia there have, however, been limited investigations conducted on the parasites of beavers in recent times. The present study is the first quantitative survey of parasites on beavers living in Sweden and elsewhere in Scandinavia. We investigated the parasitic fauna of the Eurasian beaver (C. fiber) in a North–South gradient in Sweden. The aim of the study was to investigate parasite distribution and prevalence in particular, related to average yearly air temperature and different age groups of beavers. A total of 30 beavers were sampled at eight localities, spanning a 720 km North–South gradient during the springs of 1997 and 1998. Results Five parasite taxa were identified. Four of these were present in all of the examined beavers, Stichorchis subtriquetrus (trematode), Travassosius rufus (nematode), Platypsyllus castoris (coleopteran), and Schizocarpus spp. (arachnid). A higher number of new infections of S. subtriquetrus, and more adults of T. rufus, were seen in beavers in southern Sweden where temperatures are higher. One-year old beavers had a higher infestation of S. subtriquetrus, but not of T. rufus, than older individuals. Conclusions The parasite fauna of Swedish beavers mirrored the impoverished parasite fauna of the original Norwegian population, and the high prevalence of parasites could be due to low major histocompatibility complex (MHC) polymorphism. Young beavers had a higher load of trematodes, probably depending on behavioural and ecological factors. Warmer temperatures in southern localities likely contributed to increased endoparasite loads.

Sweden is often seen as a leading country in animal welfare and legislation, but some recent amendments to the legislation are perceived as relaxing animal welfare requirements in order to improve the competitiveness of the relevant industry and of farmers. In this study, we analysed the suggested and actual changes in the Swedish national animal welfare regulations relating to horses, cattle and pigs between 1988 and 2019 and the consequences for the intended animal welfare level. The regulations and amendments, including the proposals, the written motivations, the stakeholders’ written responses to the proposed amendments and the final amendments, were scrutinised in detail. A sample of 77 requirements was then selected to assess whether and how the animal welfare level was affected by these legislative changes. The results indicated that the animal welfare protection level for cattle, pigs and horses increased overall during the 30-year period, but that a number of specific requirements had been relaxed to meet objectives other than animal welfare. It was more difficult to determine whether animal welfare improved in practice during the same period, due to the lack of systematic evaluations of the consequences of amending the regulations. Future evaluations are needed to evaluate the outcome of new legislative requirements and to monitor whether they serve their purpose in practice.

Wild animals are used for research and management purposes in Sweden and throughout the world. Animals are often subjected to similar procedures and risks of compromised welfare from capture, anesthesia, handling, sampling, marking, and sometimes selective removal. The interpretation of the protection of animals used for scientific purposes in Sweden is based on the EU Directive 2010/63/EU. The purpose of animal use, irrespective if the animal is suffering or not, decides the classification as a research animal, according to Swedish legislation. In Sweden, like in several other European countries, the legislation differs between research and management. Whereas, animal research is generally well-defined and covered in the legislation, wildlife management is not. The protection of wild animals differs depending on the procedure they are subjected to, and how they are classified. In contrast to wildlife management activities, research projects have to implement the 3Rs and must undergo ethical reviews and official animal welfare controls. It is often difficult to define the dividing line between the two categories, e.g., when marking for identification purposes. This gray area creates uncertainty and problems beyond animal welfare, e.g., in Sweden, information that has been collected during management without ethical approval should not be published. The legislation therefore needs to be harmonized. To ensure consistent ethical and welfare assessments for wild animals at the hands of humans, and for the benefit of science and management, we suggest that both research and management procedures are assessed by one single Animal Ethics Committee with expertise in the 3Rs, animal welfare, wildlife population health and One Health. We emphasize the need for increased and improved official animal welfare control, facilitated by compatible legislation and a similar ethical authorization process for all wild animal procedures.

A total of 961 harvested and 241 unharvested moose (Alces alces) carcasses and parts from throughout Sweden were examined for Elaphostrongylus alces from 1985 to 1989. When available, the central nervous system and skeletal muscles were searched for adult nematodes, and lungs and feces were examined for first-stage larvae. The parasite was distributed throughout Sweden with highest prevalence (56%) in the central region and lowest in the south (13%). Prevalence was highest in calves and old moose (>9 years) and lowest in middle-aged animals (5–9 years), with no statistical difference between sexes, although prevalence trended higher in young males. Body condition and abundance of Elaphostrongylus alces were negatively correlated, and condition was poorer in unharvested than harvested moose. A short (39–73 days) prepatent period was documented, and calves as young as 1.5 months were infected. These results indicate the importance of continued surveillance of Elaphostrongylus alces, particularly because a warming climate will likely increase abundance of intermediate mollusk hosts and possibly cause increased infection of moose.

During the years 1985 to 1987, 689 moose (Alces alces L.) collected throughout Sweden were necrop-sied at the National Veterinary Institute in Uppsala, Sweden. Sixty-eight of those investigated had catarrhal to hemorrhagic enteritis, atrophied lymphoid organs, and/or numerous erosive, uclerative, necrotizing lesions of the digestive mucosa. Histopathology of the mucous membranes revealed marked inter- and intracellular oedema, erosions, ulcers and intracytoplasmic inclusion bodies. Neither Bovine Virus Diarrhoea/Mucosal Disease (BVD/MD) or Infectious Bovine Rhinotracheitis (IBR) virus could be isolated from the diseased animals. It is suggested that the syndrome resembling BVD/MD complex, may have been caused by an yet unidentified virus.

Nematodes of the genus Elaphostrongylus collected from moose (Alces alces L.), reindeer (Rangifer tarandus tarandus L.), and red deer (Cervus elaphus L.), respectively, were studied by means of scanning electron microscopy. Morphological differences in the ribs of the genital bursa were demonstrated. The Elaphostrongylus species from reindeer and red deer differed from each other in four ribs of the genital bursa. These results agree with the morphological characters of E. cervi and E. rangiferi described by Cameron (1931) and Mitskevitch (1960). The genital bursa of Elaphostrongylus sp. from moose, in accordance with the description of E. alces by Steen et al. (1989) showed characteristics differing from those found in Elaphostrongylus spp. from reindeer and red deer respectively. These results support the hypothesis that there are three separate species of Elaphostrongylus present in Scandinavian Cervidae. S vep-elektroniska studier på Elaphostrongylus spp. hos skandinaviska hjortdjur. Abstract in Swedish / Sammandrag: Rundmaskar inom slaktet Elaphostrongylus funna hos alg (Alces alces L.), ren (Rangifer tarandus tarandus L.) och kronhjort(Cervus elaphus L.) studerades med hjalp av svepelelektronmikroskop. De hanliga bursorna med sin a stodjeribbor uppvisade variationer i utseende, langd och placering mellan dessa rundmaskar. De arter av Elaphostrongylus funna hos ren och kronhjort skilde sig åt avseende fyra stodjeribbor på de hanliga bursorna. Dessa resultat stammer val overens med de karaktarer som tidigare ar beskrivna av Cameron(1931) och av Mitskevich (1960). Den hanliga bursan hos arten Elaphostrongylus funnen hos alg, vilken tidigare ar beskriven av Steen et al. (1989), visade upp ett utseende som skilde sig från bursorna hos de Elaphostrongylus-arter funna hos ren och kronhjort. Dessa resultat stoder hypotesen om tre skilda arter av Elaphostrongylus hos skandinaviska hjortdjur.

It has been suggested that grazing horses could be used as a credible tool for landscape conservation which would, at the same time, improve horse welfare as opposed to conventional housing. A study was conducted between May 2014 and April 2015 on 12 one year old Gotland ponies managed extensively without supplementary feed. Monthly animal welfare assessments (n = 13) revealed welfare issues in most of the horses, i.e. low body condition score (BCS 0) in the human approach test and BCS < 3 and ocular discharge. Avoidance Distance test values were correlated with faecal parasite counts (> 350 eggs per gram [EPG]). These results indicate that the horses had acceptable welfare during late spring/summer (May–September) and that some horses required additional feed during winter. The animal welfare protocol proved to be an efficient tool for monitoring welfare. The results showed that factors important for extensive management are: daily monitoring; enclosures that provide sufficient feed; access to recovery enclosure; and habituation of horses to human approach.

Two months old moose calves exhibiting neurological signs were videotaped, killed and necropsied. The parasite Elaphostrongylus alces (Steen et al 1989) was found epidurally along the meninges of the spinal cord, and in the muscle faciae of the thoracic and lumbar regions. Progressive inflammatory processes were present in the epineurium, perineurium and endoneurium. Accumulations of inflammatory cells, eosinophils, lymfocytes and macrophages, were found around eggs and larvae and frequently, around regional blood wessels. The neurological disturbances in the moose calves were pronounced, with locomotive abnormalities and ataxia. They showed weakness in the hindquarters, with uncoordinated and swaying movements of the hind legs. In addition, one of the calves was lame on the left forelimb. The muscles of the leg were visibly atrophic. The lesions produced by E. alces at the lumbar nerve roots and in the cauda equina are suggested to be the cause of the clinical signs observed.

Malignant catarrhal fever (MCF) was diagnosed in two moose (Alces alces L) from the county of Uppland, Sweden. The animals showed an abnormal behaviour e.g. nervous signs as circling movements, nodding of the head and lack of awareness. One of these two animals was shot. The other was found dead on the day after being observed. Gross and histologic findings revealed characteristic lesions of MCF. Serological investigation and viral isolation for BVD and IBR/IPV viruses were negative.