Trypan Blue

Trypan Blue Kyron is a stable, blue-violet solution containing 10mg/ml of Trypan Blue. The active ingredient, Trypan Blue, is an azo dye and is therefore distantly related to the sulphonamides. The preparation is used in the treatment of canine babesiosis.

Discussion
Canine babesiosis is one of the most prevalent canine diseases in South Africa. At most veterinary practices, babesiosis cases make up 10 – 20% of the total number of sick dogs treated. Trypan Blue is one of the treatments most preferred by veterinarians. Studies have shown that it is a safe and effective treatment for babesiosis – whether mild, moderate or severe.¹²³

As stated in the Canine Babesiosis Survey in 1993 of Mark G. Collett in 90% of practices Trypan Blue is used for severely shocked cases, and Trypan Blue is preferred where there is a high parasitaemia in the absence of shock ^2• Many practitioners prefer to use Trypan Blue in patients with a high parasitaemia, because there is a widespread belief that diminazene aceturate will cause haemolysis if administered to a patient with a high B.canis parasitaemia. This is based on the assumption that diminazene aceturate causes more rapid destruction of B.canis parasites than Trypan Blue, and that this somehow results in accelerated haemolysis’.

In the Compendium of April 1998 it is explained that Trypan Blue blocks the C3b receptor on both the erythrocyte membrane and parasite itself and probably prevents the parasite from entering the erythrocyte. Trypan Blue suppresses parasitemia and alleviates clinical signs but does not eliminate infection. Parasites can reappear within 9 to 12 days, and recurrence of clinical signs is common. Therefore, administration of diminazene or imidocarb often follows the dose of Trypan Blue in an attempt to sterilize the infection. Because it has no side effects but does have an extremely high therapeutic index, Trypan Blue is most frequently used in the initial treatment of severe cases. It is also used in repeated relapses after treatment with either diminazene or imidocarb. Trypan Blue is a tissue irritant and thus is administered strictly as a 1% intravenous solution ( 10mg/kg). If necessary, treatment can be repeated ^4*

Dosage
By slow IV injection, I ml (IO mg) per kg bodymass.

Side-Effects
Trypan blue stains tissues and secretions a blue-green colour which may persist for some weeks.

Packaging
30 ml amber injection vials

Registration Number
G 1747 Act 36/ 1947