A. Lactation Tetany

The lactation tetany is known to be a highly fatal disease of all classes of ruminants. It reaches its highest incidence in lactating cows. To fight it we have to know that this disease occurs not only at pasture but we can observe it in housed cattle too.

The morbidity rate is highly variable, some researchers observed it to reach as high as 12 per cent in individual herds, and up to 2 per cent in particular areas. They believed the lactation tetany to affect cattle and sheep turned out to pastures in the early spring after wintering indoors, and in late autumn. Most cases are known to occur during the first 2 weeks after the animals leave the barn.

Pasture which has been heavily fertilized with nitrogen and potashes is potentially most dangerous. When animals begin to graze on the pasture heavy losses may occur in all classes of sheep and cattle, particularly when the pasture is in early stages of growth.

Although the disease is not specifically related to parturition we know it to occur most commonly in the first 2 months after calving, hence the name "lactation tetany". The disease is most common in lactating dairy cattle; it may reach a moderate incidence in beef cattle and calves and has affected dry cows and bulls.

The disease affects cattle in the 4- to 7-year age group that are most susceptible. Ewes which have lambed during the preceding month are the most susceptible group.