Synonyms: Bovine malignant catarrh, Malignant head catarrh, Catarrhal fever, Epitheliosis
- Malignant catarrhal fever (MCF) is a fatal disease of cattle characterized by catarrhal inflammation of the nasal and oral mucosa, keratoconjunctivitis, encephalitis, rapid dehydration, and generalized enlargement of lymph nodes.
- The disease is usually sporadic.
- The disease is worldwide in distribution and prevalent in both temperate and tropical zones.
- This disease is caused by ovine herpes virus -1 and alcelaphine herpesvirus- 2 which are belonging to the family Herpesviridae.
- The disease is primarily a disease of cattle and buffalo. The inapparent infection in sheep and goats is also prevalent.
- This disease is transmitted through wild beasts.
- The wild beast develops viremia which may persist up to 3 months and during that time they remain highly infective for cattle of all ages.
- Cattle acquire the infection through subclinically affected sheep.
- The sheep are the indicator host and wild rabbits are the reservoir host for MCF.
- The incubation period of the disease ranges from 2-8 weeks.
1. Peracute form:
The high rise of temperature, dyspnoea, and diarrhea but without any head and eye lesions
2. Head and eye form:
The clinical course of around 9 days characterized by nervous syndrome-like paralysis and convulsion before death
3. Intestinal form
4. Inapparent (mild) form
The disease shows following symptoms;
- Dullness, depression, anorexia, and high rise of temperature ranging from 105-108ºF.
- Oocular and nasal discharge.
- Discharges are initially mucoid which soon become mucopurulent, stingy, and contain blood flecks.
- There is an acceleration of pulse and respiratory rate.
- Signs of dyspnea may be evident.
- Edema of the eyelids leading to panopthalmitis
- Changes in the epithelium of the mouth cavity comprising of congestive changes, precisely on the gum, beneath the tongue, hard palate, and oral papillae.
- Erosive and ultimate necrotic changes may follow in the oral mucosa giving rise to offensive odor from the mouth.
- Ocular lesions– Photophobia and meiosis, corneal opacity, blindness
- Cutaneous lesions (congestion, petechiation, bluish discoloration, and thickening) localized or generalized prominent on the muzzle, skin of the hoof, scrotum, base of the horn, and teat.
- Based on clinical signs
- No reliable serological or immunological tests
- Mucosal disease
- Infectious bovine rhinotracheitis
Prevention and control
- Inactivated or live vaccines with suitable adjuvants induce antibodies against MCFV.
- In the absence of a vaccine, the only effective strategy is to limit contact between MCF susceptible species and the natural hosts of the virus.
- Sheep is a spreader of field outbreaks. Therefore, a rigid separation of cattle from sheep is must.
- The feed used by ewes and lambs should not be provided to cattle.
- Avoid contact between reservoir host (wildebeest and wild rabbits) and cattle