Metabolic Diseases In Cattle

These are diseases of livestock caused by productivity practices when the body's reserves of calcium, magnesium or energy cannot meet the metabolic needs. They are very important in places where high producing animals are required, e.g. in the dairy industry. In cattle, metabolic diseases include ketosis, milk fever, fat cow syndrome, and hypomagnesaemia. All these can produce an acute, temporary, but potentially fatal deficiency. Correcting the diet for cows during the period from late pregnancy to peak lactation is crucial in preventing these diseases.

Prevention

All the above diseases result from nutritional deficiencies during the crucial period from late pregnancy to peak lactation when the body's reserves of calcium, magnesium or energy cannot meet the metabolic needs. Correcting the diet of cows during this crucial period is the key to the prevention of these diseases. If metabolic diseases occur frequently, it is essential to seek professional veterinary and nutritional advice

Ketosis

Ketosis usually occurs within a few days to a few weeks after calving. It is characterised by a sudden drop in appetite and milk yield, constipation, mucus-covered faeces, depression, a staring expression, loss of weight, and a humped back suggesting mild abdominal pain. Some animals may develop nervous signs such as salivation, chewing, incoordination, blindness and aggression.

Effective treatment can be achieved if it is administered in time. Ketosis can be treated by intravenously injecting 500 ml of 40% glucose, plus twice-daily oral dosing of 150 ml of propylene glycol (a glucose precursor) for 4 days.

Milk Fever

Milk fever usually occurs one or two days before or after calving. Loss of appetite and a slight drop in temperature is the first signs of milk fever. Later, the animals may exhibit some unsteadiness as they walk. More frequently, a sick animal may be found lying on her sternum with her head resting on the shoulder. The eyes are dull and staring and the pupils are dilated. If untreated, the cow becomes comatose and dies within a day of the appearance of the first signs.

Effective treatment can be achieved if it is administered in time. Milk fever can be treated with a slow intravenous infusion of 600-800 ml of 20% calcium borogluconate.

Fat Cow Syndrome

Fat cow syndrome most commonly occurs in fat cows which were heavily fed in early pregnancy, but suffer severe nutritional stress during the 2 months before calving. After calving, the affected cows lose their appetite and become weak. The pulse is small and fast, and droppings are small and firm. Sternal recumbence follows. There is a greater than normal clear nasal discharge. The respiration is rapid and grunting. About a week after the first signs appear, the cows become comatose and die quietly.

Effective treatment can be achieved if it is administered in time. Fat cow syndrome, treatment is generally ineffective, especially if the cows are already recumbent. Anabolic steroids and supportive therapy with glucose, fluids and electrolytes IV, and propylene glycol, fluids and electrolytes orally are recommended.

Hypomagnesaemia

Hypomagnesaemia occurs most commonly in adult cows that are lactating heavily and are grazing on lush grass pastures, and in calves reared predominantly on a diet of milk. In the peracute form of the disease, affected animals may be grazing normally, but suddenly develop staggers, fall and undergo severe paddling convulsions. These convulsion periods may be repeated at short intervals and death quickly follows. In many cases, animals at pastures may be found dead without illness having been observed. Acute cases are similar apart from the animals surviving a few hours during which periods of convulsion are followed by quiet periods. In subacute cases, affected animals may progress to the acute or peracute, convulsive stage after a period as long as 2 to 3 days. All cases of hypomagnesaemia are characterised by loud heart sounds and rapid heart rate.

Effective treatment can be achieved if it is administered in time. For cases of hypomagnesaemia, use the same treatment as for milk fever, plus a subcutaneous injection of 200 ml of 50% magnesium sulphate.

Grass Staggers

Characterised by convulsive seizures where the animal lies down and paddles wildly. Caused by magnesium deficiency. Can be reversed by intravenous administration of magnesium compounds.