Lameness in piglets - should pain killers be included at treatment?

Joint swelling and lameness are the most obvious and persistent clinical signs of infectious arthritis in piglets. For a positive treatment effect of piglets with arthritis, early initiated treatments with antibiotics are desired. Hitherto pain-reducing drugs have rarely been used within veterinary medicine, but the potential of non steroid anti-inflammatory drugs (NSAID) are interesting from an animal welfare perspective. Therefore, the aim of this study was to compare the long term efficiency of treating lameness with and without pain relief. Further, the incidences of affected joints in lame piglets were analysed.

In total 415 of the 6,787 liveborn piglets included in the study were diagnosed with lameness (6.1 %). Around 86 % of these diagnoses took place during the first 3 weeks of life. There was no difference in the incidence of lameness between the sexes, but lameness was most commonly diagnosed in the offspring to old sows (>4 parturitions). Lameness was diagnosed in about every second litter and on average about two pigs were diagnosed in the affected litters. The incidence of affected litters as well as affected piglets increased with ageing of the sows. Treatments with antibiotics solely and in combination with NSAID improved (P < 0.01 to 0.001) the clinical status from day to day, but the clinical response did not differ between the two treatment groups. Piglets that remained healthy were 1.1 and 1.7 kg heavier (P < 0.001) than piglets diagnosed with lameness at 5 and 9 weeks of age, respectively. There were no differences in piglet body weights between the treatment strategies at any time.

The clinical response to penicillin was good. It was neither improved nor reduced by a concurrent administration of NSAIDs. Nevertheless NSAIDs may improve the animal welfare due to pain relief. An important finding of this study was that decreasing pain due to lameness not was negative in a long term perspective, i.e. reducing pain did not lead to overstrain of affected joints and no clinical signs of adverse effects were noted. Therefore the use of NSAIDs ought to be considered to improve the animal welfare, at least in severe cases.