Parsnips may have caused foot and mouth scare

Press, 31 January 1986, Page 13

Parsnips may have caused foot and mouth scare

The cause of foot-and-mouth scares at Temuka in 1981 and Warkworth in 1968 appears to have been an innocuous and non-contagious condition familiar to market gardeners.

Water blisters form on the arms of market gardeners who harvest parsnips in sunshine, and M.A.F. veterinarians believe that condition affected the suspect pigs. “The new discovery will be taken into account at future suspect exotic disease investigations,” a veterinary officer at Levin, Mr John Montgomery, has said. Foot-and-mouth disease is the single most dangerous threat to New Zealand’s agricultural exports. Overseas markets do not accept agricultural produce from countries affected by foot-and-mouth disease without it first being quarantined for a lengthy period. With agriculture earning the bulk of New Zea-

land’s export receipts, an outbreak would shatter the economy. Imports from European countries affected by the disease are held in Great Britain for six months before being allowed Into

New Zealand. Despite knowing foot-and-mouth was not the cause of the two scares the Ministry had not been able to identify the cause of the blisters on the pigs’ snouts and feet. Experiments at the central veterinary laboratory in Upper Hutt involved pigs snouts and feet being rubbed with parsnip leaves and irradiated with ultraviolet light. Blisters similar to those caused by foot-and-mouth then developed, confirming the theory, Mr Montgomery said. Parsnip and related plant leaves contain furocoumarins, which cause skin cell damage when activated by ultraviolet light. The foot and. mouth scares at Temuka in 1981

and Warkworth in 1968 were very probably caused by phytophotodermatitis, he said, although it could not be proved because the exact diets of the pigs are unknown. "Household scraps, which possibly contained parships or celery were fed at Warkworth and substantial amounts of green vegetable waste were fed at Temuka,” Mr Montgomery said.

On each occasion the pigs had been exposed to several days sunshine before the disease was noted.

The condition has been noted several times recently in New Zealand and each time has been fully investigated by the M.A.F.’s Animal Health Division.

Mr Montgomery said blisters or vesicular lesions on pigs must still be notified immediately to the nearest animal health division office to allow a full investigation to be made.