Dourine

Dourine is a disease of equids caused by Trypanosoma equiperdum of the subgenus Trypanozoon mainly transmitted directly from animal to animal during coitus.

Etiology

• Dourine is caused by T. Equiperdum.
• Horse and donkeys are highly susceptible.
• Natural transmission occurs through coitus (Veneral transmission).
• Predilection site: genital organs, subcutaneous tissue, peripheral and central nervous system.

Pathogenesis

• Trypanosomes are deposited during coitus, penetrate the genital mucosa, and multiply locally in the extracellular space, and produce an edematous swelling.
• Subsequent systemic invasion in subcutaneous tissue and nervous system causes vascular injury, leads to subcutaneous edema, incoordination.

Clinical manifestation

Incubation period is 1-4 weeks for Dourine.

• First stage:
  • Stallion -Swelling and edema of penis, scrotum, prepuce and surrounding skin extending as forward upto chest, swollen inguvinal lymph node, paraphymosis and mucopurulent urethral discharge.
  • Mare- edematous swelling in the vulva, perineum, udder and abdominal floor, profuse vaginal discharge, hyperaemia and ulceration of vaginal mucosae.
• Second stage:
  • Urticaria like plaques (2-5 cm) develop on the neck and body is called as silver dollar spots.
• Tertiary stage:
  • It is characterized by progressive anemia, emaciation, stiffness and weakness of limbs, ataxia, paralysis and atrophy of the hindquarters.

Diagnosis

• Demonstration of trypanosomes, edema fluid, cutaneous plaque and vaginal or urethra washing and blood.
• Serological tests like CFT, IFAT, ELISA and capillary agglutination test.

Differential diagnosis

• Coital exanthema
• Equine infectious anemia
• Purulent endometritis

Treatment

• Diminacine aceturate (Berenil) at 7.0 mg/kg body weight I/M, second injection after 24 hours with half of the dose.
• Suramin at 10 mg/kg body weight I/V for two to three treatment.
• Quinapyramine sulphate at 3-5 mg/ kg body weight S/C.
• For CNS involvement: Melarsoprol is to be used.

Control

• Control of breeding.
• Restriction of animal movement.
• Testing and  disposal of infected animals.