NADIS disease forecast – pigs (February)
NADIS is a network of 40 veterinary practices and six veterinary colleges monitoring diseases in cattle sheep and pigs in the UK. NADIS data can highlight potential livestock disease and parasite incidence before they peak, providing a valuable early warning for the month ahead. |
NADIS disease forecasts are written specifically for farmers, to increase awareness of prevalent conditions and promote disease prevention and control, in order to benefit animal health and welfare. The forecasts are based on national trends and farmers are advised to discuss their individual farm circumstances with their veterinary surgeon.
February 2005
By Mark White BVSc DPM MRCVS
NADIS Pig Disease Forecast
Many herds continue to struggle to cope with major health issues associated with PMWS/PDNS and it is very concerning that we appear to be no closer to finding the real answers to this disease syndrome than we were when it first appeared in the UK in the late 1990’s.
However, N.A.D.I.S. veterinary reports over the last year indicate that many herds continue to suffer the effects of a wide range of other more “traditional” diseases, for which science has provided us with clear understanding and for which control programmes are well established.
Is this a result of producers and advisers concentrating on the obvious and serious problems and ignoring other underlying issues which have a role to play in the overall herd picture?
For instance, PRRS activity in weaner pigs undoubtedly exacerbates PMWS problems and its control can dramatically improve the overall picture.
One disease that was consistently reported throughout the year was Erysipelas. It is interesting to note that clinicians in mainland Europe – particularly southern Europe where the warmer climate would be expected to favour the disease – do not regard Erysipelas as either a common or serious problem.
So why is it such a common finding in the UK? The bacteria that causes Erysipelas – Erysipelothrix rhusiopathiae – is a widespread gut based organism that is not restricted to pigs. Whilst disease tends only to be seen in turkeys and sheep, the organism is a common commensal (harmless) finding in the gut of wild birds and rodents.
It seems likely that at least part of the story in the UK is related to pig keeping systems that encourage contamination from these pests. Moreover, the bacteria survives well in warm, moist conditions such as are found in straw yard finishing systems – common in the UK. Erysipelas is rarely seen in growing pigs on fully slatted accommodation.
Vaccination policies for sows are effective if applied correctly. Care must be taken to ensure:
a) That a correct 2 dose primary course is applied with the appropriate interval – different vaccines have different protocols and confusion, particularly where vaccines are chopped and changed in the interests of cost saving, frequently leads to errors.
b) Regular booster doses are applied every 6 months (or every breeding cycle).
Control of such “basic” disease problems is simple and cost effective but N.A.D.I.S. reports suggest many producers are failing to get it right.
Health Reports
Adults
As is normally the case, production and fertility issues tend to dominate the breeding herd. NADIS reports a mixture of managemental failure and health problems.
The importance of staff ability was highlighted in one herd where a dramatic decline in fertility of gilts was ascribed to incompetent relief staff having been left to serve them. In another case, delayed weaning to service and subsequent infertility were corrected by improving boar contact but also re-organising working practices to ensure that weaning occurred first thing in the morning.
Disease in sows was seen to have delayed effects on farrowing houses. Thus, a period of sow inappetance for unknown reasons produced variable litter size and high return rates in affected sows. More specifically, an outbreak of Swine Influenza in the autumn led to similar problems in December farrowings with litter size declining to 7-8 pigs born alive compared to the usual 11.
PRRS continues to circulate on many farms and was associated with poor piglet quality and high mortality in the farrowing house.
Lameness continues to be commonly reported with one outbreak of severe hind limb lameness – possibly associated with spinal lesions – producing dog sitting sows.
The mild weather early in the month may have been to blame for flare ups in Erysipelas in sows. Skin lesions associated with Staphyloccal infection (Greasy Pig Disease) was also reported in adults.
Growers
Respiratory and enteric disease continue to dominate the growing herd with grower scours still common and the complication of prolapse and torsion frequently reported. In one episode involving an organic farm, Salmonella caused enteritis and death in weaners (up to 6% mortality).
The current ZAP monitoring programme shows that Salmonellae are commonly found on farms – albeit at variable levels – but disease is not common and is often associated with poor hygiene. PMWS continues to feature prominently in reports.
Respiratory infections include Enzootic Pneumonia (is vaccination being scaled down?), Actinobacillus pleuropneumoniae and Glassers Disease.
Erysipelas was commonly reported – on one unit, not just as a clinical disease in the growing pigs but as a cause of high levels of condemnation at slaughter.
Piglets
High mortality was seen in several herds associated with poor piglet quality. In some, weak pigs were the result of disease (e.g. PRRS) whilst in one, inadequate early pregnancy feeding led to poor placental growth and hence very low birthweight in gilts litters.
Scouring continues to be common with most undiagnosed. Where a diagnosis is achieved, E coli and Coccidiosis predominate.
There was, unusually, one report of Vitamin E/Selenium deficiency in piglets, although the trigger factors were not established.
While every effort is made to ensure that the content of this forecast is accurate at the time of publication, NADIS cannot accept responsibility for errors or omissions. All information is general and will need to be adapted in the light of individual farm circumstances in consultation with your veterinary surgeon
Copyright © NADIS 2002
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