Cattle can show the same warning signs for very different diseases. A cough, fever, weight loss, diarrhoea or reduced milk production does not identify the cause by itself.
The farmer’s job is to notice the pattern early, isolate risk where necessary and get the right diagnosis before treatment spreads across the whole herd.
Do not treat a disease name. Treat a confirmed or strongly supported cause.
This guide covers five important cattle health problems farmers should recognise: bovine respiratory disease, mastitis, bovine tuberculosis, bovine viral diarrhoea and foot and mouth disease.
1. Bovine respiratory disease is a complex, not one infection
Bovine respiratory disease, often called BRD or shipping fever, is not caused by one bacterium.
The Merck Veterinary Manual describes BRD as a multifactorial disease involving the animal, the environment and several possible viruses and bacteria.
Risk increases with:
- weaning;
- transport;
- mixing unfamiliar cattle;
- crowding;
- dust;
- poor ventilation;
- bad weather;
- dehydration; and
- other stressful procedures.
Signs that should make you suspicious
- coughing;
- nasal discharge;
- rapid or difficult breathing;
- fever;
- depression;
- reduced feed intake;
- drooping ears; and
- animals falling behind the group.
One cough does not confirm pneumonia.
Check whether several animals are affected, whether the problem followed transport or mixing and whether fever and breathing changes are present.
What farmers should do
Reduce stress, improve ventilation, provide clean water and separate obviously sick animals where practical.
Because bacterial pneumonia may develop after viral damage, veterinary treatment can include antimicrobials when bacterial BRD is diagnosed or strongly suspected. Choice of drug and withdrawal period should follow veterinary and label guidance.
2. Mastitis in dairy cattle
Mastitis is inflammation of the udder, commonly associated with bacterial infection.
It may be obvious or subclinical.
Visible signs
- swollen or painful quarter;
- heat in the udder;
- clots, flakes or watery milk;
- reduced milk yield;
- fever or depression in severe cases; and
- changes in milk colour or consistency.
Subclinical mastitis may show no obvious udder change but still reduce production and milk quality.
Prevention
- keep milking hands and equipment clean;
- keep bedding and resting areas dry;
- avoid teat injury;
- use a consistent milking routine;
- identify chronic problem cows; and
- investigate repeated cases instead of repeatedly treating by guesswork.
Milk from treated cows must not enter the food chain until the stated withdrawal period has passed.
3. Bovine tuberculosis
Bovine tuberculosis is caused mainly by Mycobacterium bovis.
It can affect cattle, other animals and people.
This makes it both an animal health and public health concern.
Possible signs
Many infected cattle may show no obvious signs for a long time.
Advanced disease may cause:
- progressive weight loss;
- weakness;
- chronic cough;
- enlarged lymph nodes;
- reduced production; and
- poor condition despite feeding.
These signs are not specific enough for farm diagnosis.
Testing and official disease control procedures are important.
Why raw milk matters
M. bovis can infect people, including through unpasteurised milk and close contact with infected animals.
Do not use chronic cough and weight loss alone to label an animal as having TB. Report suspicious cases through veterinary channels and follow local testing and movement control requirements.
4. Bovine viral diarrhoea is more than diarrhoea
The name can mislead farmers.
Bovine viral diarrhoea virus, BVDV, can affect the immune system, reproduction, the respiratory tract and the digestive tract.
The World Organisation for Animal Health explains that infection of a pregnant cow can produce abortion, stillbirth, fetal abnormalities or a calf that becomes persistently infected.
For routine pregnancy planning, use the cow gestation calculator and calving guide. Disease-related abortion or reproductive failure still needs veterinary investigation.
Persistently infected cattle are especially important because they can shed large amounts of virus and maintain infection in a herd.
Possible signs
- fever;
- depression;
- reduced appetite;
- diarrhoea;
- nasal discharge;
- reduced milk production;
- reproductive failure;
- weak calves; and
- poor resistance to other infections.
Many infections can also be mild or unnoticed.
Control
Control may include:
- biosecurity;
- testing for persistently infected animals;
- removing confirmed PI animals from the breeding herd;
- careful introduction of replacement stock; and
- a herd specific vaccination programme where appropriate.
The Merck Veterinary Manual stresses that testing and elimination of persistently infected cattle are important parts of control.
5. Foot and mouth disease is an emergency disease
Foot and mouth disease, FMD, is a highly contagious viral disease of cattle and other cloven hoofed animals.
It can spread quickly between farms and has major trade and production consequences.
The World Organisation for Animal Health lists FMD as a reportable disease and emphasises early detection and surveillance.
Signs that should raise suspicion
- fever;
- drooling;
- blisters or erosions in the mouth or on the tongue;
- blisters around the feet or between the claws;
- lameness;
- reluctance to move;
- reduced feed intake;
- teat lesions; and
- sudden production losses.
Young animals can die from heart damage even when adults mainly show mouth and foot lesions.
What to do if FMD is suspected
Do not move the animal, sell it, slaughter it for market or move other cattle off the farm while you wait to see what happens.
Restrict movement and contact a veterinarian or appropriate animal health authority immediately.
Laboratory confirmation is required because other diseases can also cause mouth or foot lesions.
One symptom can fit several diseases
For example:
- coughing can occur with BRD, TB or other respiratory disease;
- diarrhoea can occur with BVD, parasites, feed problems or bacterial disease;
- weight loss can occur with TB, parasites, poor nutrition or chronic disease;
- reduced milk can occur with mastitis, fever, poor feeding, heat stress or BVD; and
- lameness can come from FMD, injury, foot rot or other hoof problems.
That is why symptom lists are useful for suspicion, not final diagnosis.
What the farmer should check before treatment
- How many animals are affected?
- What ages are affected?
- When did the signs start?
- Were new cattle recently introduced?
- Was there recent transport or mixing?
- Has feed or water changed?
- Are there abortions or reproductive problems?
- Is milk production dropping?
- Are there mouth or foot lesions?
- Are deaths occurring?
Biosecurity measures that reduce cattle disease risk
- quarantine new arrivals;
- avoid unnecessary mixing of cattle from different sources;
- clean shared equipment;
- provide enough feeder and water space;
- reduce transport and handling stress;
- control visitors and vehicles where practical;
- keep good treatment and vaccination records;
- isolate visibly sick animals; and
- report suspected notifiable diseases promptly.
Do not copy vaccination schedules blindly
Vaccination can be important for several cattle diseases, but the useful programme depends on:
- the disease risk in your area;
- age and production class;
- pregnancy status;
- previous vaccination;
- vaccine type; and
- official control programmes.
Use current veterinary and local animal health guidance rather than a generic internet calendar.
Do not ignore withdrawal periods
When cattle receive medicines, record:
- animal identification;
- drug used;
- dose and route as prescribed;
- date treated;
- meat withdrawal; and
- milk withdrawal.
Do not sell milk or send treated animals for slaughter before the required withdrawal period ends.
Bottom line
The five conditions in this guide are important, but they do not cover every cattle disease. Farmers starting or expanding a herd should also review this beginner’s guide to cattle farming in Nigeria.
Farmers should use signs to recognise danger early, then combine herd history, examination and testing before deciding on treatment.
Notice the pattern early, isolate risk, and get the diagnosis right before treating the whole herd.
Farmer friendly disclaimer: This guide provides general cattle health information. Suspected foot and mouth disease, bovine tuberculosis, rapidly spreading respiratory disease, severe diarrhoea, abortion outbreaks or unexplained deaths require prompt veterinary and, where applicable, official animal health attention.
