Interdigital phlegmon in Finnish dairy herds

Interdigital phlegmon (IP) is an infectious hoof disease of cattle. Typically, it causes severe clinical signs, such as lameness, and hence impacts cattle welfare. IP has been a well-known disease of both dairy and beef cattle all over the world for decades. In general, IP occurs as sporadic infections. Lately however, outbreaks of IP have been detected in dairy herds in Finland. Most of these outbreaks have occurred in recently built or renovated free stall barns. In these outbreaks morbidity in IP has been substantial, which has led to the extensive use of antimicrobials and heavy financial losses associated with affected herds. The aim of this thesis was to investigate the characteristics of the IP outbreaks in Finnish dairy herds and to explore the morbidity, clinical manifestation and degree of inflammation of the affected animals in these outbreaks. Moreover, we aimed to investigate the bacteriology in IP, i.e. to investigate several bacteria detected earlier from hoof diseases. An additional objective was to identify herd level risk factors behind these outbreaks. This thesis is based on three studies. The first two were observational, cross-sectional studies, which were performed on commercial free stall dairy herds. The majority of the herds suffered from an outbreak of IP and three herds were unaffected control herds. Altogether 100 cows with IP were clinically checked, diagnosed, and sampled for the bacteriological culture and PCR, and analysis of acute phase proteins; serum amyloid A, haptoglobin and albumin. Cows with other hoof diseases and control cows were sampled similarly for comparison. The third study was a survey of free stall dairy herds of ≥50 cows. We sought general herd data, barn characteristics, herd management details, and asked questions about leg and claw health of the herd. Based on the replies, the risk factors for an outbreak of IP to occur were investigated among farms that had experienced an outbreak and farms that had not. Fusobacterium necrophorum ssp. necrophorum is the main IP pathogen. The most common finding in IP samples in the early, acute stage was a combination of F. necrophorum and Dichelobacter nodosus. Trueperella pyogenes was frequently associated with IP at the later, healing stage. However, various bacterial combinations existed in IP samples. In outbreak herds, the morbidity was either high (≥50%), or moderate (9 – 33%), and no herd had intermediate morbidity. Strong acute phase response was detected among IP cows in the early stage of the disease; the values for serum amyloid A and haptoglobin were clearly elevated, and albumin decreased in comparison with the case for other hoof diseases or control cows in our study. The acute phase response was even greater in herds of high morbidity and with a bacterial combination of F. necrophorum and D. nodosus. The possible herd level risk factors for an outbreak of IP to occur were animal movement between herds, i.e. animal purchase or contract heifer rearing, enlargement of the barn within three years, and fields under organic farming. Mechanical ventilation in the barn seemed to lower the risk. Moreover, herds that had experienced an IP outbreak more often had other infectious hoof diseases. Based on our study results, the same cow may have several hoof diseases and a thorough clinical inspection is essential in diagnosing IP, also during an IP outbreak. Furthermore, IP causes severe clinical signs and a very strong APR. Thus, an anti-inflammatory should be included in the treatment of affected animals. Even though F. necrophorum is the key pathogen in IP, in the disease process several other bacteria play a role, such as D. nodosus, which may affect the severity of IP. To lower the risk of an IP outbreak, new cattle should be purchased very cautiously, if at all, and enlargement of the barn should be constructed without undue restrictions being placed on time and labour inputs.Sorkkavälin ajotulehdusta on esiintynyt naudoilla ympäri maailmaa jo vuosikymmeniä. Yleensä vain yksittäiset eläimet sairastuvat, mutta viime vuosina Suomessa on todettu taudinpurkauksia etenkin uusissa lypsykarjapihatoissa. Ajotulehdus aiheuttaa voimakkaita oireita, kuten ontumista ja heikentää siten eläinten hyvinvointia. Koska sairastuneet hoidetaan antibiooteilla, aiheutuu epidemiasta isoja taloudellisia tappioita tiloille. Tutkimuksen tavoitteena oli tutkia ajotulehdusepidemioita, kuten eläinten sairastuvuutta, taudin kliinistä kuvaa, sairastuneiden tulehdusvastetta ja ajotulehduksen bakteriologiaa. Lisäksi tavoitteena oli löytää epidemioiden riskitekijöitä. Tämä väitöskirjaa koostuu 3 osatyöstä. Kaksi osatyötä toteutettiin lypsykarjatiloilla, joilla oli äskettäin puhjennut ajotulehdusepidemia. Lehmät tutkittiin ja niiden sorkkavälistä otettiin bakteriologisia näytteitä. Lisäksi verinäytteistä analysoitiin tulehdusta ilmentäviä akuutin vaiheen proteiineja. Ajotulehduslehmien lisäksi näytteitä otettiin terveiltä verrokkilehmiltä ja muita sorkkasairauksia sairastavilta lehmiltä. Kolmas osatyö oli kaikille lypsykarjatuottajille (lehmämäärä ≥50) lähetetty kyselytutkimus. Kysyimme tietoja karjasta, navetan ominaisuuksista, tilan toimintatavoista ja karjan sorkka- ja jalkaterveydestä. Epidemiatiloilla sairastuvuus oli korkea (≥50 %) tai keskinkertainen (9–33 %). Ajotulehduksen pääaiheuttaja on Fusobacterium necrophorum ssp. necrophorum –bakteeri, mutta näytteistä todettiin myös muita bakteereita ja bakteeriyhdistelmiä. Tyypillisin yhdistelmä ajotulehduksen alkuvaiheessa oli F. necrophorum ja Dichelobacter nodosus. Trueperella pyogenes todettiin usein ajotulehduksen myöhemmässä vaiheessa. Ajotulehduksen alkuvaiheessa havaittiin verinäytteiden perusteella voimakas akuutin vaiheen tulehdusvaste, joka oli voimakkaampi korkean sairastuvuuden tiloilla ja eläimillä, joilla todettiin bakteeriyhdistelmä F. necrophorum ja D. nodosus. Karjatason riskitekijöinä havaittiin tilojen välinen eläinliikenne, äskettäin tehty navettalaajennus ja peltojen luomuviljely. Toisaalta koneellinen ilmanvaihto navetassa vähensi riskiä epidemialle. Lisäksi havaittiin, että ajotulehdustiloilla oli useammin muita tarttuvia sorkkasairauksia. Tulosten perusteella voidaan todeta, että ajotulehdus aiheuttaa vakavat oireet ja voimakkaan akuutin vaiheen vasteen, joten sairastuneille tulee antaa myös kipulääkitys. F. necrophorum on ajotulehduksen pääpatogeeni, mutta myös muilla bakteereilla on rooli taudinkuvassa. Uusia eläimiä tulisi ostaa harkitusti ja mieluummin miettiä vaihtoehtoisia menetelmiä karjan laajentamiseksi

Survey of interdigital phlegmon outbreaks and their risk factors in free stall dairy herds in Finland

Background: Severe outbreaks of interdigital phlegmon (IP) associated with a high morbidity and major economic losses have occurred in Finland in the past decade. A survey was performed to indicate the current occurrence of infectious hoof diseases and to identify herd level risk factors predisposing to an outbreak of IP. Results: Responses to a questionnaire revealed that an outbreak of IP defined as morbidity >= 5% within the 1st month of the outbreak, had occurred in 18.0% of the respondent study farms. Risk factors for an outbreak included animal transport between herds, i.e. either animal purchase or contract heifer rearing, enlargement or renovation of the barn, and if the fields of the farm had been organically cultivated. Having any kind of mechanical ventilation in comparison to natural ventilation seemed to lower the risk of IP. Additionally, the farms that had experienced an outbreak of IP often had other infectious hoof diseases. However, it was unclear which disease appeared first. Conclusions: More attention is needed before and during enlargement or renovation of the barn and substantial planning is crucial for every part of the enlargement process in dairy farms.Peer reviewe

Acute phase response and clinical manifestation in outbreaks of interdigital phlegmon in dairy herds

Several Finnish dairy herds have suffered from outbreaks of interdigital phlegmon (IP). In these new types of outbreaks, morbidity was high and clinical signs severe, resulting in substantial economic losses for affected farms. In our study, we visited 18 free stall dairy herds experiencing an outbreak of IP and 3 control herds without a similar outbreak. From a total of 203 sampled cows, 60 suffered from acute stage IP. We demonstrated that acute phase response of bovine IP was evident and therefore an appropriate analgesic should be administered in the treatment of affected animals. The response was most apparent in herds with high morbidity in IP and with a bacterial infection comprising Fusobacterium necrophorum and Dichelobacter nodosus, indicating that combination of these two bacterial species affect the severity of the disease

Salmonellan leviäminen suomalaisille sika- ja nautatiloille

Hankkeen tavoitteina oli tunnistaa nauta- ja sikatilojen salmonellatartuntojen lähteitä sekä toimintatapoja, joilla saneeraus ja tartuntojen ehkäisy tiloilla parhaiten onnistuu. Lukuisista tartuntalähteistä tärkeimmiksi arvioimme yhdyskuntalinnut ja muut haittaeläimet sekä turkistuotanto mahdollisena alkulähteenä haittaeläinten välittämille tartunnoille. Viime vuosina nauta- ja sikatiloille tehtyjen saneerausten aineistosta arvioimme seikkoja, jotka johtivat saneerauksen onnistumiseen tai pitkittymiseen tai tartunnan uusimiseen. Saneeraus pitkittyi, jos tartunta oli alkutilanteessa levinnyt laajalle, tartuntalähdettä ei saatu heti selville, salmonellapositiivisia eläimiä ei poistettu ajoissa, puhdistus-, pesu- ja desinfiointitoimet eivät olleet riittäviä tai käytettävissä oleva työpanos ei riittänyt. Saneerauksen onnistumista edistivät hyvä työnjohto, systemaattisuus, saneeraussuunnitelma sekä suunnitelman ja muiden ohjeiden noudattaminen. Tarkastelimme tilan salmonellatartunnan ja sen saneerauksen vaatimuksia myös työturvallisuuden suhteen. Salmonellatartunnan ehkäisy edellyttää tilatason tautisuojausta, jonka on oltava jokapäiväistä ja kohdistuttava tilan koko toimintaan ottaen huomioon haittaeläimistä aiheutuva tartuntavaara. Hankkeessa syntyi tietopääomaa salmonellan epidemiologiseen seurantaan, saneerausneuvontaan ja suosituksia tukemaan salmonellatorjuntaa.Tämä julkaisu on toteutettu osana valtioneuvoston selvitys- ja tutkimussuunnitelman toimeenpanoa. (tietokayttoon.fi) Julkaisun sisällöstä vastaavat tiedon tuottajat, eikä tekstisisältö välttämättä edusta valtioneuvoston näkemystä

Prevalence of digital dermatitis using mirror scoring in Finnish freestall dairy herds

(in herds where at least 1 cow had a M2 lesion) was 5.7% and varied between 0.4% and 18.8%. Herds with active DD lesions also had more any DD lesions than herds without active DD lesions. The herd-level prevalence was higher than previously thought, with only 1 herd without any DD lesions. However, the animallevel prevalence of active DD lesions was relatively low. Farmers and veterinarians need to be informed of the disease and possible control measures. Because of the low within-herd prevalence, the control of the disease might be easier than in countries where DD is widespread. Further studies are needed to identify factors associated with DD prevalence in Finnish dairy herds. Key words: digital dermatitis, prevalence, mirror Digital dermatitis (DD) is a severe bacterial hoof disease found worldwide. The disease can be classified into 5 different stages, denoted as M1 to M4 and M4.1, by clinical examination. The main objective of this study was to estimate prevalence of DD lesions in Finnish freestall dairy cattle population through hind feet inspection of standing cows with a mirror. Another aim was to estimate the sensitivity and specificity of mirror scoring on standing cows in a pen or in a milking parlor without washing the feet. Three veterinarians visited 81 randomly selected herds across the country. During the herd visits, hind feet of standing cows (n = 7,010) were scored with a mirror without washing the feet, either when the cows were standing in a pen (n = 4,992) or in the milking parlor (n = 2018). In total, 128 cows (111 from pen and 17 from milking parlor) including 256 feet were chosen with cross-sectional sampling and scored in a trimming chute. Animal-level sensitivity for scoring M2 lesions with a mirror was 55% and specificity was 97%; for all active DD lesions (M1, M2, or M4.1), sensitivity was 36% and specificity was 96%. Sensitivity for scoring any DD lesions was 90% and specificity was 82%. The bias-corrected sensitivity and specificity for scoring any DD lesions were 79% and 92%, respectively. The bias-corrected sensitivity and specificity for scoring M2 DD lesions were 10% and 100%. We found M2 lesions in 12.1% of the study herds, and true herd-level prevalence was the same. Altogether, 33.3% (true prevalence 28.4%) of the herds had either M1, M2, or M4.1 DD lesions. However, only 0.7% (true prevalence 5.4%) of cows in total had active M2 lesions. The within-herd prevalence of M2 lesions (in herds where at least 1 cow had a M2 lesion) was 5.7% and varied between 0.4% and 18.8%. Herds with active DD lesions also had more any DD lesions than herds without active DD lesions. The herd-level prevalence was higher than previously thought, with only 1 herd without any DD lesions. However, the animal level prevalence of active DD lesions was relatively low. Farmers and veterinarians need to be informed of the disease and possible control measures. Because of the low within-herd prevalence, the control of the disease might be easier than in countries where DD is widespread. Further studies are needed to identify factors associated with DD prevalence in Finnish dairy herds.Peer reviewe