Black quarter (langri / BQ)
It picks the best animals in the herd — the well-grown 6-month-to-2-year cattle on good grazing — and kills them so fast that treatment is rarely in time.
- Cause
- Clostridium chauvoei (spores)
- Age hit hardest
- 6 months – 2 years
- Tell-tale sign
- Swelling that crackles
- Control
- Annual vaccine pre-monsoon
Overview
Black quarter is caused by Clostridium chauvoei, a spore-forming bacterium that survives in soil for years. Spores are swallowed with grass, cross the gut wall and lie dormant in the muscles. A trigger — a bruise, hard exercise, a sudden growth spurt on lush feed — lets them germinate, and the bacteria release toxins that rapidly destroy muscle and poison the whole animal.
It typically strikes cattle between 6 months and 2 years in good body condition; very young and old animals are usually spared. The first sign is often severe lameness, then a hot, painful swelling in the heavy muscles of a hind leg, shoulder, hindquarter or, sometimes, the neck or brisket. Press it and it crackles like tissue paper — gas in the tissue. The skin over it soon goes cold, dark and leathery.
Fever is high early and then may drop as the animal collapses. Death usually comes within 12–36 hours of the first sign. Because it is so fast, prevention is everything: an annual vaccine before the rains in areas with a history of the disease, given to all cattle from 6 months of age.
This is a general guide, not a substitute for a veterinarian. Always call a vet for diagnosis, dosage and treatment of a sick animal.
Signs to look for
- Sudden severe lameness in a young, well-grown animal, often the first thing noticed.
- A hot, painful swelling in the thick muscle of the thigh, hip, shoulder or brisket that enlarges quickly.
- The swelling crackles or crepitates when pressed — gas under the skin — and later becomes cold, dark and hard.
- High fever (41–42 °C) at first, dullness, off feed, stopped rumination.
- Rapid weakness, laboured breathing, the animal goes down and dies, often within a day.
- Sometimes an animal is simply found dead, bloated, with blood-stained froth at the nose and anus.
How animals get it
- Grazing pasture whose soil carries the spores — often low-lying land, or fields flooded and then dried.
- Spores enter through the gut; muscle bruising from butting, transport or rough handling can trigger dormant spores already in the tissue.
- Outbreaks cluster after the first monsoon showers and after floodwater recedes, exposing spores.
- The disease is not spread animal-to-animal directly — each case comes from the soil — but one pasture can produce several cases in days.
Vaccination
- In areas with a history of BQ, vaccinate all cattle and buffalo from 6 months of age once a year, before the monsoon.
- Use the black quarter vaccine, or a combined clostridial / HS-BQ vaccine where supplied by the state.
- Calves vaccinated before 6 months should get a repeat dose at 6 months because maternal antibody blunts the early response.
- In an active outbreak, vaccinate all healthy animals in the herd at once and move them off the affected pasture.
- Keep to the same date every year — protection lasts about 12 months.
If a case occurs
- Call a vet immediately — high-dose penicillin very early, with surgical lancing of the swelling to let gas and toxins out, occasionally saves an animal caught in the first hours.
- Report it — BQ is a notifiable disease and a cluster needs the veterinary department’s attention.
- Do not open the carcass in the field. Burn it, or bury it very deep with plenty of lime, at the spot it died — dragging it across the pasture spreads spores.
- Fence off or stop grazing the affected field for the rest of the season if you can.
- Vaccinate the rest of the herd the same day and watch them closely for a week.
Animals affected
Open an enterprise page for its full feeding, breed and vaccination-calendar guide.
Frequently asked questions
Why do my healthiest calves die of black quarter and not the weak ones?
The toxin damages muscle, so the animals with the most muscle — well-fed, fast-growing young cattle on good pasture — have the most tissue for the bacteria to work on and go down hardest. It feels backwards, but losing a thriving calf is the typical picture. That is exactly why those are the animals the vaccine must cover.
Can I treat black quarter myself with an antibiotic injection?
By the time you see the swelling, the muscle is already dying and toxins are in the blood; farm treatment almost never works. Penicillin helps only in the first hours and usually alongside a vet lancing the swelling. Put your effort into the annual vaccine — this is a disease you prevent, not one you treat.
One animal died in the field. Is the meat or hide usable?
No. Do not skin, cut or eat an animal that died of black quarter. Opening the carcass releases billions of spores that will contaminate that ground for years. Burn or deep-bury it with lime where it lies.
Is black quarter the same as haemorrhagic septicaemia?
Both are fast monsoon killers of cattle, but they are different diseases. HS causes a throat swelling and breathing distress; black quarter causes a crackling swelling in a leg or hindquarter muscle with lameness. Many states supply a combined HS-BQ vaccine so one pre-monsoon round covers both.
Signs, prevention and treatment follow ICAR, DAHD and state veterinary-university practice; vaccine schedules are the commonly notified ones and may vary by region or outbreak status. Always confirm with a veterinarian before treating an animal. editorial policy.