(Equine Metabolic disease)

1. (Equine Metabolic disease) LACTATION TETANY OF MARES Transit tetany of mares, Eclampsia of mares

2. Definition: • It is a metabolic neurotic disease of lactating mares characterized clinically by stiffness in gait and tetany and biochemically by hypocalcaemia. (Tetany:a condition marked by intermittent muscular spasms, caused by malfunction of the parathyroid glands and a consequent deficiency of calcium)

3. Incidence, occurrence and predisposing factor: 1- Most cases occur in lactating mares, either at about the l0th day after foaling or 1-2 days after weaning. 2-Mares have a heavy flow of milk. 3-Pregnant mares subjected to hard physical work or exercise (stress of work). 4-Pregnant mares during or after prolonged transport (stress of transport).

4. Etiology and pathogenesis • 1- The basic constant biochemical finding is lowserum calcium level (hypocalcemia) in which serum calcium level ranges between 4-8 mg% • 2- Hypo- or Hypermagnesemia have been observed in some cases.

5. Clinical signs Clinical signs are related to the degree of hypocalcaemia, because: 1- When serum calcium level is higher than 8 mg%, the only clinical sign is increased excitability. 2- At levels of 4-8 mg %, there are tetanic spasms. 3- At levels less than 4 mg%, there are recumbency and stupor (state of unconsciousness).

6. The clinical signs proceed as follow: 1-Profuse sweating 2-Muscular fibrillation particularly of the masseter and shoulder region 3-Trismus (spasmodic contraction of Muscles of mastication) 4-Normal pulse in early stages, but later becomes rapid and irregular.

7. 5-Rapid, violent respiration accompanied with wide dilation of nostrils. 6-Normal temp. or slightly elevated. 7-Dysphagia (unable to swallow) 8- OLiguria or even anuria and constipation.

8. 9- Difficulty in moving, stiffness in gait and incoordination. 10-Within 24 hours, the animal goes down then tetanic convulsions develop and death may occur about 48hrs. after onset of illness due to respiratory failure.

9. Profuse sweating

10. Tetanic spasm

11. Stiffness

12. Diagnosis • I- History • II- Clinical signs. • III- Laboratory diagnosis: • Estimation serum calcium level usually between 4-8 mg% (normal around 10 mg%) • IV-Therapeutic diagnosis • Response to treatment with calcium preparations • Differential diagnosis: Tetanus and Laminitis

13. Laminitis & Tetanus Tetanus

14. Treatment and prevention • I/V administration of calcium solutions, such as20 % C.B.G (calcium borogluconate) usually results in full recovery. Administered slowly (over 20 min) at 250- 500 mL/500 kg, diluted at least 1: 4 in saline or dextrose, and the cardiovascular response should be closely monitored. If arrhythmias or brady-cardia develop, I/V treatment should be discontinued immediately.

15. Once the heart rate has returned to normal, the infusion may be resumed at a slower rate. • If the horse does not improve within 1-2 hours of the initial infusion, a second dose may be given. • Some horses require repeated treatments over several days to recover from hypocalcemic tetany. N.B: • One of the earliest signs of recovery is the usually followed by of large volume of urine.

16. Prevention: • Single IV or S/C. 10 millions I.U. crystalline vit. D immediately after foaling and repeated at weaning time for lactating mares. • A balanced feed ration should be provided to supply adequate amounts and rations of calcium and phosphorus throughout gestation • In times of increased calcium demand such as lactating, fasting should be avoided and high quality forage as Alfa Alfa or calcium –containing mineral mixes should be provided. • Stress and fasting during transport should be minimized.

17. In endurance horses water and electrolyte deficits associated with porolonged exercise and sweating may be prevented by provision of a sufficient water supply and electrolyte supplementation