New research from the Royal Veterinary College (RVC), has shown that repeated needle use which could lead to increased pain experienced by piglets as it increases the necessary puncture force.
The reuse of needles between animals is common in livestock farming. However, without regular needle changes, the RVC study found significant blunting of needles after multiple uses, meaning the force needed to administer the injection increases and may cause pain and distress for the piglet.
As the majority of indoor born piglets require an iron injection in the first few days following birth to prevent iron deficiency – a condition that can reduce growth rates and increase disease susceptibility and mortality – the research provides critical data supporting the recommendations of changing needles between litters (12 piglets), crucial for protecting piglet welfare.
In conducting this study, the research team – led by undergraduate veterinary student, Kathryn Owen, supported by Dr Nicola Blackie, senior lecturer in production animal science; and Dr Troy Gibson, associate professor in animal welfare science – examined the force required to puncture the skin of a piglet cadaver for the first time, 12th time, 36th time and 100th time, mimicking real-life reuse of needles.
The RVC researchers viewed the needles under scanning electron microscopy to assess the damage caused to needles over repeat usage, founding that the puncture forces increased after 36 uses and the electron microscopy imaging showed visible damage to the needle tip after only 12 uses.
The team also surveyed a sample of UK pig farmers asking about their iron injection practices. From the 31 respondents, 81% of farms reported needle reuse. Of these, only 39% changed the needle between litters or earlier if damaged, and 23% changed the needle when it felt blunt or damaged, after each injection session or when changing the bottle of iron solution.
Kathryn Owen, the lead researcher on this paper and undergraduate veterinary student at RVC, said: “Needle reuse increases the force required to puncture the skin, this indicates blunting which could cause pain and distress of piglets”
“Electron microscopy shows that after 12 injections the needle tip is visibly blunted.”
