New vaccine give cattle farmers hope against roundworm

 

 

A breakthrough in roundworm control could see worm burdens lowered by up to 90%.

 

Recent trials at the Moredun Research Institute in Edinburgh found it was possible to successfully immunise sheep against the roundworm Haemonchus contortus, a blood sucking worm most common in the tropics and sub-tropics.

 

"Although this worm is commonplace in warm, humid environments, thanks to climate change, it has also recently been described as an emerging UK disease by the Vet Lab Agency," explained researcher, David Smith.

 

The barber pole worm, as it is otherwise known, causes huge problems in sheep, cows and goats with many drug resistant strains of Haemonchus commonplace in countries like Australia.

 

The highly effective vaccine developed at Moredun won't kill 100% of the parasite but it will reduce the worm burden by 80-90%, said Dr Smith.

 

Crucially, the most recent experiment found the dose of vaccine needed to reduce worm burdens was low. "This breakthrough means it should be possible to make the vaccine commercially, simply by extracting it from adult worms.

 

Incorrect use of wormers in cattle means resistance to a wide range of drugs is becoming increasingly common, according to Moredun's Jacqui Matthews.

 

"Compared to sheep, wormer resistance in roundworms of cattle and horses has received far less attention and it is emerging multi drug resistance occurs in these species too," she said.

 

"The problem is, people are overusing wormers, treating too frequently, using the same wormer for the same period and sometimes not even using the right wormer. In horses we predict 80-90% to be infected with a specific roundworm cyathostomin, not because they aren't being treated, but because of drug resistance."

 

Work is currently being conducted at Moredun to establish how widespread resistance is in the important roundworms of cattle.

 

"It's important we find out whether a lack of efficacy to a product is because of drug resistance or whether the product isn't working properly because it is being washed off before it has chance to absorb in to the skin," said Prof Matthews.