Fur animal epidemic necrotic pyoderma : pathology, etiology, and epidemiology

In 2007 Finnish fur farmers detected new kind of signs in farmed mink, foxes and raccoon dogs (Finnraccoon). Mink had severe pyoderma in the head around eyes, mouth or ears or in the feet around the nailbeds. Finnraccoons developed painful abscesses in the paws between the toes. Foxes had severe keratoconjunctivitis that occasionally spread to the eyelids and to facial dermatitis. The disease caused severe symptoms and even increased mortality on the farms. The spread of the disease was typical to an infectious disease. Similar signs have been detected in fur animals in other pelt producing countries as well. Similar signs in mink have been reported for the first time in U.S.A at 1970´s and in Canada 1996. North-American farmers and later researchers linked the onset of the symptoms to the start of feeding mink with feed containing seal byproducts. The University of Helsinki (UH), the Finnish Fur Breeders´ Association (FFBA), and the Finnish Food Safety Authority Evira initiated a collaborative project in 2009 to describe the pathology of the disease, identify the causative organism(s), describe the occurrence of the disease in Finland and to find out possible sources and risk factors for the disease. This thesis includes these studies. Ninety nine fur animals underwent necropsies with complete microbiological examinations, including both diseased and healthy control animals. Due to the common lesions, in diseased animals of all fur animal species, the disease was named Fur animal epidemic necrotic pyoderma (FENP). The bacterium Arcanobacterium phocae was isolated from all diseased animals, but not from healthy controls. The finding of A. phocae is particularly interesting, because this bacterium causes skin inflammations and abscesses in marine mammals such as seals, and there had been found a temporally connection between the onset of the symptoms in mink and the use of seals as feed source in North America. However, the disease occurs also in the countries where seal meat is not used as a feed raw material. Thus, it is probable that there has been a species shift of the bacteria A. phocae from seals to fur animals via feed, and the disease is currently spreading by diseased/carrier animals. The results indicate that the presence of the bacteria A. phocae alone is not enough to cause the disease, as predisposing factors, such as skin or mucosal trauma is needed to evoke the disease. In addition, new Streptococcal species, closely related to Streptococcal species of seals, was detected in these investigations. Furthermore, the infection trial proved that A. phocae caused FENP-like symptoms when mink were experimentally infected. The mail survey study showed that FENP had spread to all areas where fur farming is practiced in Finland and signs of FENP was detected on 40% of responding farms. The results indicated that the disease was introduced to Finland by imported carrier animals and it spread further in the country via domestic purchases. The disease seems to spread on the farms by bird and other wild life contacts. The study revealed also other possible risk factors, such as the farm type; FENP was seen more on larger size farms and on mixed farms (farms farming more than one fur animal species). Also some other predisposing factors were relieved. The results provide a basis for developing preventive methods and treatment of FENP diseased animals to improve animal welfare.Vuonna 2007 suomalaiset turkiseläinkasvattajat huomasivat tarhatuissa minkeissä, ketuissa sekä supikoirassa (Suomensupi) uudenlaisia, vakavia silmä- ja iho-oireita. Minkeillä tauti aiheutti märkäisen kuolioivan ihotulehduksen päässä suun, silmien tai korvien ympärillä ja jaloissa kynsivallien ympärillä. Suomensupeilla tavattiin kipeitä paisemaisia muutoksia tassuissa varpaiden välissä. Ketuilla oireet alkoivat voimakkaana silmätulehduksena, joka saattoi levitä myös silmäluomien sekä pään ihoon. Tauti aiheutti eläimille vakavia oireita ja jopa kuolleisuutta. Tauti levisi tarttuvan taudin tavoin sairastuneilla tiloilla eläimestä eläimeen sekä tilojen välillä. Vastaavanlaisia oireita turkiseläimillä tavataan tällä hetkellä myös muissa turkistuotantoa harjoittavissa maissa. Ensimmäiset havainnot sairaudesta minkeillä on tehty Yhdysvalloissa 1970 ja Kanadassa 1996. Pohjois-Amerikkalaiset tuottajat, sekä myöhemmin tutkijat, yhdistivät oireiden puhkeamisen hylkeiden sivutuotteiden käytön aloittamiseen minkin rehussa. Taudinsyy jäi silloin tutkimuksista huolimatta selvittämättä. Suomen turkiskasvattajain liitto (STKL), Elintarviketurvallisuusvirasto Evira sekä Helsingin yliopisto käynnistivät vuonna 2009 hankkeen taudin selvittämiseksi. Hankkeen tavoitteena oli selvittää taudinaiheuttaja, taudinkulku, taudin levinneisyys Suomessa sekä mahdolliset taudin tartuntalähteet ja sairastumiselle altistavat tekijät. Tämä väitöskirjatyö sisältää hankkeessa suoritetut tutkimukset. Taudinsyynselvitys suoritettiin 99 turkiseläimelle, sekä tautiin sairastuneille eläimille että terveille kontrollieläimille. Tauti nimettiin tyypillisten taudinoireiden mukaisesti; turkiseläinten tarttuva kuolioinen märkäinen ihotulehdus, fur animal epidemic necrotic pyoderma, FENP. Tutkimuksissa sairaista eläimistä, mutta ei terveistä kontrolleista, eristettiin bakteeri Arcanobacterium phocae. Löydös on hyvin mielenkiintoinen, sillä A. phocae- bakteeri aiheuttaa hylkeille märkäisiä tulehduksia, ja Pohjois- Amerikassa oli havaittu yhteys sairauden oireiden puhkeamisen ja hylkeiden sivutuotteita sisältävän rehun käytön aloittamisen välillä. Koska tautia esiintyy nykyään maissa, joissa ei käytä hylkeitä rehuraaka-aineena, on todennäköistä, että alun perin hylkeissä esiintyneet bakteerit ovat siirtyneet rehun välityksellä turkiseläimiin ja sairaus leviää nykyään sairaiden/bakteeria kantavien turkiseläinten välityksellä. Taudin puhkeamiseen vaaditaan kuitenkin A. phocae bakteerin läsnäolon lisäksi altistavia tekijöitä, kuten iho- tai limakalvovaurio. Tutkimuksissa todettiin myös uusi Streptokokkeihin kuuluva bakteeri, joka on läheistä sukua hylkeissä esiintyvälle Streptokokille. A. phocaen osuus taudin synnyssä varmistettiin infektiokokeessa, jossa minkeille syntyi FENP sairaudelle tyypilliset oireet, kun ne tartutettiin A. phocae- bakteereilla. Turkistuottajille suunnatussa kysely osoitti että tautia esiintyi kaikkialla Suomen turkistuotantoalueella, ja oireita oli havaittu peräti 40 %: lla vastanneista tiloista. Tutkimuksen tulokset viittaavat siihen, että tauti tuli Suomeen tuontieläinten mukana ja levisi Suomessa edelleen eläinostojen välityksellä. Tauti näyttää leviävän tiloilla edelleen lintujen sekä muiden luonnon eläinten mukana. Tutkimus toi esille myös muita mahdollisesti taudin puhkeamiseen vaikuttavia tekijöitä. Tutkimuksen tuloksia hyödynnetään taudin vastustamisessa sekä sairastuneiden eläinten hoidon suunnittelussa eläinten yleisen hyvinvoinnin lisäämiseksi

Questionnaire survey of detrimental fur animal epidemic necrotic pyoderma in Finland

Background: In 2007, a previously unrecorded disease, fur animal epidemic necrotic pyoderma (FENP), was detected in farmed mink (Neovision vision), foxes (Vulpes lagopus) and Finnraccoons (Nyctereutes procyonoides) in Finland. Symptoms included severe pyoderma with increased mortality, causing both animal welfare problems and economic losses. In 2011, an epidemiologic questionnaire was mailed to all members of the Finnish Fur Breeders' Association to assess the occurrence of FENP from 2009 through the first 6 months of 2011. The aim was to describe the geographical distribution and detailed clinical signs of FENP, as well as sources of infection and potential risk factors for the disease. Results: A total of 239 farmers (25%) returned the questionnaire. Clinical signs of FENP were observed in 40% (95% CI 34-46%) of the study farms. In addition, the survey clarified the specific clinical signs for different animal species. The presence of disease was associated with the importation of mink, especially from Denmark (OR 9.3, 95% CI 2.6-33.0). The transmission route between Finnish farms was associated with fur animal purchases. Some risk factors such as the farm type were also indicated. As such, FENP was detected more commonly on farms with more than one species of fur animal in comparison to farms with, for example, only foxes (OR 4.6, 95% CI 2.4-8.6), and the incidence was higher on farms with over 750 breeder mink compared to smaller farms (OR 3.8, 95% CI 1.6-9.0). Contact between fur animals and birds and other wildlife increased the risk of FENP on farms. Responses also indicated that blocking the entry of wildlife to the animal premises protected against FENP. Conclusions: FENP was most likely introduced to Finland by imported mink and spread further within the country via domestically purchased fur animals. Some potential risk factors, such as the type and size of the farm and contact with wildlife, contributed to the spread of FENP. Escape-proof shelter buildings block the entry of wildlife, thus protecting fur animals against FENP.Peer reviewe

Intact tails as a welfare indicator in finishing pigs? Scoring of tail lesions and defining intact tails in undocked pigs at the abattoir

Tail biting lesions are a potential measure of on-farm animal welfare, as a large range of stressors increase the risk for tail biting outbreaks. Further, tail biting is a major challenge, as lesions due to tail biting decrease animal welfare and health, as well as production efficiency and carcass quality. The aim of this study was to suggest a tail scoring system for use at slaughterhouses processing undocked pigs, and to link tail lesion scores to meat inspection data. A further aim was to suggest a definition for an intact enough tail. To validate the suggested scoring system we assessed tails before and after scalding and compared results to pathological examinations. In total, 14,433 tails were scored, and 117 tails were collected for pathological examination. After scalding, 49.2% of all tails were scored as fully intact. Of tails with lesions 2.5% were scored as having major acute wounds (>2 cm), while 11.6% had minor acute wounds (<2 cm), and 36.7% healed lesions. Intact tails were on average 31.5 cm (SD 2.5 cm) long. Lesion scored at the slaughter-line agreed well with the pathological assessment. Tail lesions were associated with several meat inspection findings: tails with more severe lesions and of shorter length increased the risk for meat inspection findings to a higher degree. A detailed lesion scoring method helps to identify carcasses at risk for condemnations, as well as being a potential method for on-farm welfare estimation. We suggest that a system for scoring tail lesions in undocked pigs should utilize a combination of scoring of the lesion and measuring the tail length. As bite marks or bruises on an otherwise intact tail were not a concern for meat hygiene, we suggest the definition of an intact enough tail could allow the inclusion of tails with these mild changes. Meat inspection findings in carcasses with tails scored as healed, but with no fresh lesions, and with more than 75% of the average intact length remaining were rather similar to those of fully intact tails. Based on these findings we suggest that a tail of this length, and with no visible fresh lesions could also be considered intact enough.info:eu-repo/semantics/publishedVersio

Intact Tails as a Welfare Indicator in Finishing Pigs? Scoring of Tail Lesions and Defining Intact Tails in Undocked Pigs at the Abattoir

Tail biting lesions are a potential measure of on-farm animal welfare, as a large range of stressors increase the risk for tail biting outbreaks. Further, tail biting is a major challenge, as lesions due to tail biting decrease animal welfare and health, as well as production efficiency and carcass quality. The aim of this study was to suggest a tail scoring system for use at slaughterhouses processing undocked pigs, and to link tail lesion scores to meat inspection data. A further aim was to suggest a definition for an intact enough tail. To validate the suggested scoring system we assessed tails before and after scalding and compared results to pathological examinations. In total, 14,433 tails were scored, and 117 tails were collected for pathological examination. After scalding, 49.2% of all tails were scored as fully intact. Of tails with lesions 2.5% were scored as having major acute wounds (>2 cm), while 11.6% had minor acute wounds (Peer reviewe

Comparison of Streptococcus halichoeri isolates from canine and fur animal infections : biochemical patterns, molecular characteristics and genetic relatedness

Background Streptococcus halichoeri infections have been reported in grey seals, a European badger, a Stellar sea lion and humans, but its presence in companion and fur animals is unknown. Since 2010, S. halichoeri-like bacteria (SHL) have been isolated from fur animals and dogs in Finland. Our aim was to retrospectively investigate laboratory records for SHL from canine and fur animal infections, characterize the isolates and compare their genetic relatedness in relation to three reference strains: CCUG 48324(T), originating from a grey seal, and strains 67100 and 61265, originally isolated from humans. Results A total of 138 and 36 SHLs from canine and fur animal infections, respectively, were identified in the laboratory records. SHL was commonly associated with skin infections, but rarely as the only species. A set of 49 canine and 23 fur animal SHLs were further characterized. MALDI-TOF confirmed them as being S. halichoeri. The growth characteristics were consistent with the original findings, but isolates were catalase positive. In total, 17 distinct API 20 Strep patterns were recorded among all 75 isolates tested, of which pattern 5563100 was the most common (n = 30). Antimicrobial resistance to erythromycin and clindamycin was common in canine isolates, but rare in fur animal isolates. Three clusters were observed by PFGE, and 16S rRNA sequencing revealed 98.1-100% similarities with the human strains and 98.1-99.5% with the seal strain. A phylogenetic tree of concatenated 16S rRNA and rpoB revealed closely related isolates with two clades. Fifteen canine isolates were identical to the human strains based on concatenated 16S rRNA and rpoB sequencing. Conclusions Streptococcus halichoeri appears to be quite a common bacterial species in the skin of dogs and fur animals. The clinical significance of S. halichoeri is uncertain, as it was rarely isolated as a monoculture. No apparent temporal or spatial clustering was detected, but isolates from different sources were genetically very similar. Because many canine isolates were genetically similar to the human reference strains, transmission between dogs and humans may be possible. WGS sequencing of strains from different sources is needed to further investigate the epidemiology and virulence of S. halichoeri.Peer reviewe

Mechanisms behind the varying severity of Aleutian mink disease virus : comparison of three farms with a different disease status

Aleutian mink disease virus (AMDV) is distributed widely among mink farms and wild mustelids despite ongoing attempts to stop the spread. The severity of Aleutian disease (AD) varies from subclinical to fatal but the reasons for its varying severity are complex and unclear. Recently, breeding of tolerant mink has drawn attention as the possible solution to reduce the effects of AD in farms. The aim of this study was to gather information on the effects of breeding based on overall health, production traits, and antibody titer on AD severity by comparing a positive farm (farm 1) that has been breeding for tolerance in mink to an infected farm without tolerance selection, and an AMDV-free farm. During the 2.5-year follow-up, the mink in farm 1 remained mostly free of clinical AD, had normal pelt quality and litter size, and had low virus copy numbers in tissues and low antibody titers in ELISA. In histopathological studies, most of the farm 1 mink had no/mild lesions in their kidneys. 29-43% of the mink were ELISA negative but PCR positive throughout the follow-up and frequent changes in virus strains and coinfections were observed. Several differences in gene expression between animals from different farms were also detected. These results indicate that the disease burden of AMDV can be reduced, with seemingly normal health and production rates, despite continual circulation of ADMV in cases where eradication attempts are unsuccessful.Peer reviewe

Experimental Infection of Mink Enforces the Role of Arcanobacterium phocae as Causative Agent of Fur Animal Epidemic Necrotic Pyoderma (FENP)

Fur Animal Epidemic Necrotic Pyoderma (FENP) is a severe, often lethal infectious disease affecting all three fur animal species: mink (Neovision vision), foxes (Vulpes lagopus) and finnraccoons (Nyctereutes procyonoides). Previous studies showed an association between Arcanobacterium phocae and FENP. An experimental infection was conducted to confirm the ability of A. phocae to infect mink either alone or concurrently with a novel Streptococcus sp. found together with A. phocae in many cases of FENP. Different inoculation methods were tested to study possible routes of transmission. Typical signs, and gross- and histopathological findings for FENP were detected when naïve mink were infected with the tissue extract of mink with FENP, using a subcutaneous/ intradermal infection route. Edema, hemorrhage, necrosis and pus formation were detected in the infection site. A pure culture preparation of A. phocae alone or concurrently with the novel Streptococcus sp. caused severe acute signs of lethargy, apathy and anorexia and even mortality. The histopathological findings were similar to those found in naturally occurring cases of FENP. In contrast, the perorally infected mink presented no clinical signs nor any gross- or histopathological lesions. This study showed that A. phocae is able to cause FENP. The study also indicated that predisposing factors such as the environment, the general condition of the animals, temperature and skin trauma contribute to the development of the disease.Peer reviewe

Gammaherpesvirus Infections in Cattle in Europe

The genus Macavirus, subfamily Gammaherpesvirinae, comprises ungulate viruses that infect domestic and wild ruminants and swine. They cause asymptomatic latent infections in reservoir hosts and malignant catarrhal fever in susceptible species. Lung, spleen, bronchial lymph node, and tongue were collected from 448 cattle (348 necropsied, 100 slaughtered) in Switzerland, United Kingdom, Finland, Belgium, and Germany to determine their infection with bovine herpesvirus-6 (BoHV-6) and gammaherpesviruses of other ruminants, i.e., ovine herpesvirus-1 and -2, caprine herpesvirus-2, and bison lymphotropic herpesvirus, using quantitative PCR. Only BoHV-6 was detected, with an overall frequency of 32%, ranging between 22% and 42% in the different countries. Infection was detected across all ages, from one day after birth, and was positively correlated with age. There was no evidence of an association with specific disease processes. In positive animals, BoHV-6 was detected in all organs with high frequency, consistently in the lungs or spleen. Viral loads varied substantially. In BoHV-6-positive gravid cows, organs of fetuses tested negative for infection, indicating that the virus is not vertically transmitted. Our results confirm previous data indicating that BoHV-6 is a commensal of domestic cattle not associated with disease processes and confirm that infections with other macaviruses are rare and sporadic.Peer reviewe

Experimental Infection of Mink with SARS-COV-2 Omicron Variant and Subsequent Clinical Disease

We report an experimental infection of American mink with SARS-CoV-2 Omicron variant and show that mink remain positive for viral RNA for days, experience clinical signs and histopathologic changes, and transmit the virus to uninfected recipients. Preparedness is crucial to avoid spread among mink and spillover to human populations.Peer reviewe