Malignant catarrhal fever (gangrenous coryza of the wildebeest)

What is it?

Gangrenous coryza, or malignant bluetongue, is a serious viral disease caused by herpesviruses of the Macavirus group. The wildebeest is the natural reservoir host of one of these viruses, Alcelaphine herpesvirus 1, which it carries without developing the disease itself. On the other hand, this virus is formidable for other species such as cattle, African buffalo or certain deer, in whom it often causes fatal illness. In the wildebeest, the infection is therefore most often asymptomatic, but certain stressed or immunocompromised young animals may occasionally present mild clinical signs.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Causes and risk factors

The disease is caused by herpesviruses of the Macavirus genus, notably Alcelaphine herpesvirus type 1 (AlHV-1), of which the wildebeest is the natural asymptomatic carrier. The virus is mainly transmitted during the birthing period of wildebeests, via nasal and ocular secretions, and can contaminate other susceptible species such as cattle, buffalo or certain deer, in which the disease is often fatal. In the wildebeest itself, the infection generally remains silent and without serious clinical consequences.

Newborn young wildebeest shed more viruses, especially during the birthing season. Stress, overcrowding in an enclosure or immunosuppression can promote clinical expression in the wildebeest, although this remains rare. Close cohabitation with susceptible species greatly increases the risk of cross-transmission.

Transmission

The virus is transmitted mainly by direct or indirect contact with the nasal and ocular secretions of wildebeests, especially around the calving period. Transmission typically occurs from wildebeest to other susceptible species such as cattle or buffalo, with transmission between individuals of the susceptible species itself generally being rare or even exceptional.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

Treatment

There is no specific antiviral treatment for this disease. In susceptible species presenting clinical signs, treatment remains only symptomatic and supportive: anti-inflammatories, treatment of dehydration, and pain management, with no guarantee of cure. In healthy carrier wildebeest, no treatment is necessary since it does not develop the disease.

Prevention

Possible complications

In susceptible species other than wildebeest, complications include irreversible eye damage which can lead to blindness, severe digestive damage, multi-organ failure and death. In the carrier wildebeest, there are generally no observable clinical complications, the animal remaining a silent reservoir of the virus.

When to see a veterinarian

Prognosis

In the wildebeest itself, the prognosis is excellent since the animal remains carrier without developing significant clinical disease. On the other hand, the prognosis is very poor in susceptible infected species, such as cattle or buffalo, where the outcome is most often fatal despite supportive care.

Frequently asked questions

References

WOAH — Organisation mondiale de la santé animale (ex-OIE)

MSD Veterinary Manual

Content reviewed by the TunisieVet editorial team · Updated 16 September 2026