Histomoniasis in turkeys and : prevention and treatment

urkeys are by far the most mortality and a drop in egg susceptible species for the production. Tdisease histomoniasis Organic flocks as well as (blackhead). The caused by conventional farms may be affected the parasite and clinical signs vary from may lead to outbreaks characterised forms with rapidly increasing by high losses with mortality that mortality to lingering elevated may increase up to 100%. mortality for several weeks. Typical caecal cores and necrotic lesions in the are the by Monita Vereecken, predominant lesions reported. In Technical Team of chickens, co- with other Huvepharma NV, Belgium. might increase mortality. www.huvepharma.com Histomoniasis has been described as a complicating factor in chronic . Histomoniasis causes very typical Often, histomoniasis is diagnosed lesions in caeca and , therefore after antimicrobial treatment against the diagnosis can be easily made Escherichia coli infections fails. when doing necropsy on dead or In these cases where co-infection Turkeys affected with histomoniasis will be sick, sitting down silently diseased turkeys. Laboratory occurs, typically after diagnosis of (hunching) with closed eyes and drooped wings. diagnosis by microscopy, histology, Escherichia coli septicaemia (by PCR or cultivation can be used for necropsy and bacteriological diagnosis confirmation. investigation), there is limited or no histomoniasis have been registered turkeys for the treatment of improvement of treatment with for food producing animals on the histomoniasis when the disease has antimicrobials, even though their use European market for several been diagnosed in the flock. Emerging disease for is based upon sensitivity testing. decades. It is currently the only registered breeders and layers In these cases, Histomonas product in Europe for this meleagridis can be a possible reason indication. Recently, histomoniasis has been for the lingering mortality. Diagnosis New veterinary premix It has been demonstrated that reported as an emerging disease for for Histomonas is then most paromomycin is an effective breeders and layers. Where, in the frequently made based upon PCR The only exception is the product molecule for the reduction of past, chickens were believed to be testing of the typical caecal cores ‘Paromomicina Huvepharma’, a mortality and lesions due to mainly asymptomatic carriers for that are often observed in these veterinary premix containing the histomoniasis when it is applied in Histomonas meleagridis, nowadays cases. active paromomycin sulphate, which an early stage of the infection. more outbreaks in chickens have Due to ever increasing regulatory is registered in Italy with the Paromomycin is an antibiotic, been reported with increased restrictions, no against indication that it can be used in Continued on page 28

Typical lesions caused by Histomonas meleagridis in caeca and liver after experimental infection in chickens. Administration of paromomycin sulphate was able to decrease the occurrence of severe lesions in the caeca and prevented the occurrence of specific Histomonas lesions in the livers (Vereecken et al, 2015).

International Production • Volume 28 Number 5 27 Continued from page 27 paying special attention to caeca birds and an increased level of disease to the next or other flocks) is belonging to the aminoglycosides and the livers. biosecurity in the farm will avoided as much as possible. group. Besides the antibacterial In breeder or layer flocks,with contribute to the decrease of This is especially important in activity, paromomycin also exerts an elevated mortality special attention spreading of the parasite. breeders and layers as they are activity against certain parasites. should be paid to the caeca when The importance of Heterakis better hosts for Heterakis and they This is also shown for the parasite doing necropsies. The presence of gallinarum for the transmission of usually live for longer periods, causing histomoniasis, where the caecal plugs are an indication that the disease is often questioned. It allowing an infection pressure to binding site of paromomycin on the Histomonas might be involved. can be assumed that Heterakis build up. parasite has been demonstrated. Another possibility is to use the gallinarum is of importance as an Therefore, deworming should be The need for early application is sensitive PCR testing to detect intermediate for the considered an important strategy in linked to the fact that paromomycin histomoniasis at a very early stage. introduction of the disease into the the management of histomoniasis is poorly absorbed from the gastro- Dust is a sensitive substrate to farms. outbreaks. intestinal tract. detect Histomonas and can help to The flagellated form of The parasite will only be present in identify farms where the parasite is Histomonas is only able to survive the gut (caeca) at an early stage of present and where special attention for several hours outside the host, Summary infection, where it is sensitive for the should be paid when doing necropsy. whilst the form in Heterakis eggs can activity of the product. Once the disease is present in the survive for years. In summary, histomoniasis remains a In a later stage of infection, the flock, paromomycin should be Horizontal transmission by cloacal severe problem in turkeys and is an parasite will move to the inner applied as quickly as possible. drinking is probably of more emerging problem in breeders and organs (especially the liver) where it Besides treatment with importance for the spreading of layers. is difficult for the product to reach paromomycin, attention must be Histomonas within the flock. Currently, only paromomycin it. paid to the management of the farm. Even though chickens are better (Paromomicina Huvepharma) is Sick turkeys will spread the disease hosts for than registered in Europe (Italy) with the and must be culled or isolated as turkeys, the presence of Histomonas indication of treatment of Early diagnosis is crucial quickly as possible. will compromise the survival of the histomoniasis in turkeys. worm and the production of eggs. The product needs to be applied in Early diagnosis of histomoniasis is This aspect, in combination with the very early stages of infection and crucial to avoid disaster in the flock. Good hygiene and litter the low sensitivity of the classic should be accompanied by increased Turkeys affected with histomoniasis management worm count investigation, may management of the affected flocks. will be sick, sitting down silently underestimate the actual role of In breeders and layers, it is (hunching) with closed eyes and Good hygiene and litter Heterakis gallinarum in turkeys and in recommended to regularly deworm drooped wings. management in affected farms is chickens. in order to avoid infection of Typical sulphur-coloured diarrhoea crucial to try to stop the spread of It is therefore advisable to Heterakis eggs with Histomonas. n can be found in the flock. Increased the disease. regularly deworm flocks where mortality should be checked as Bringing fresh, new litter into the Histomonas outbreaks occur so that quickly as possible by performing house, dividing the house into infection of Heterakis eggs with References are available necropsy on the dead animals; compartments, removing affected Histomonas (and spread of the from the author on request

28 International Poultry Production • Volume 28 Number 5