Most Common Infectious Cattle Diseases: Symptoms and Prevention

Cattle health is vital for the success of dairy and beef operations. Infectious diseases can drastically reduce milk production, impair fertility, cause calf mortality, and even result in the death of adult cattle, which in turn hurts farm profitability. According to the USDA, infectious diseases account for over half of all calf mortality, generating significant veterinary costs for producers.

This article will explore the most common infectious cattle diseases, their symptoms, transmission, and essential prevention strategies to help safeguard your herd.

1. Bovine Viral Diarrhea (BVD)

Bovine viral diarrhea (BVD) is a widespread viral infection that affects the gastrointestinal, respiratory, and reproductive systems of cattle. There are two strains of the BVD virus: BVDV 1 and BVDV 2.

• Transmission: Spread through direct contact with infected cattle, contaminated equipment, or facilities. The virus can also be transmitted from cow to calf during pregnancy, resulting in persistently infected calves.
• Symptoms: Diarrhea, fever, nasal discharge, coughing, reproductive issues like infertility and calving problems, and the birth of persistently infected calves.
• Prevention: Regular testing and culling of persistently infected animals, quarantining new arrivals, vaccination, and strong biosecurity measures. Avoid contact with outside cattle to prevent introduction of the virus.

2. Bovine Respiratory Disease (BRD)

Bovine respiratory disease (BRD) is the most common and costly illness affecting cattle, particularly in the U.S. It often occurs when stress and viral infections weaken the immune system, allowing bacterial infection to invade the lungs.

• Transmission: Spread through aerosolized droplets from infected cattle, with risk factors like transport stress, poor ventilation, and crowding increasing susceptibility.
• Symptoms: Breathing difficulties, fever, coughing, nasal discharge, lethargy, and loss of appetite. Calves may exhibit signs such as drooling, stretching their necks, or open-mouth breathing.
• Prevention: Reduce stress, improve ventilation, vaccinate cattle, and administer antibiotics when necessary. Good colostrum intake in calves helps boost immunity against BRD.

3. Bovine Tuberculosis (TB)

Bovine tuberculosis (TB) is a chronic bacterial disease caused by Mycobacterium bovis that primarily affects the lymph nodes and respiratory system.

• Transmission: Spread through the air via coughing and sneezing from infected cattle. It can also spread through contaminated milk or feed.
• Symptoms: Weight loss, fever, weakness, coughing, and enlarged lymph nodes. Lesions may be observed in the lymph nodes, lungs, intestines, and other organs.
• Prevention: Regular testing and culling of infected cattle. Pasteurizing milk helps kill TB bacteria, and restricting contact with wildlife reservoirs (like deer) helps reduce transmission risks.

4. Brucellosis

Brucellosis is a contagious zoonotic bacterial disease that affects the reproductive systems of cattle, caused by Brucella species.

• Transmission: Spread through contact with aborted fetuses, placentas, calving fluids, milk, urine, and reproductive discharges from infected cows. Indirect spread through contaminated feed and water can also occur.
• Symptoms: Abortions, stillbirths, infertility, fever, reduced milk yield. In bulls, inflammation of the testicles (orchitis) and epididymis may occur.
• Prevention: Vaccination of calves between 4-12 months, regular testing, culling seropositive cattle, and ensuring proper disposal of aborted materials. Pregnant cattle should be kept separate from infected herds.

5. Johne’s Disease

Johne’s disease is a chronic bacterial infection caused by Mycobacterium avium subspecies paratuberculosis, affecting the intestines of cattle.

• Transmission: Spread through the fecal-oral route, with young calves under 6 months most susceptible. Infection typically occurs through contact with manure from infected cows.
• Symptoms: Diarrhea, rapid weight loss, and poor nutrient absorption, even though the cattle maintain a normal appetite. Damage to the intestines leads to severe malabsorption.
• Prevention: Effective manure management, clean calving areas, reducing cow density, and pasteurizing colostrum. Vaccination may help reduce clinical signs in infected herds.

6. Bovine Leukosis Virus (BLV)

Bovine leukosis virus (BLV) is a retroviral disease that weakens the immune system and can lead to the development of tumors (lymphosarcoma) in infected cattle.

• Transmission: Spread through blood containing infected lymphocytes, often via contaminated needles or dehorning equipment. BLV can also spread through colostrum or milk.
• Symptoms: Persistent increase in lymphocyte counts, enlarged lymph nodes, weight loss, and the development of tumors.
• Prevention: Test and cull infected cattle, avoid using shared needles, pasteurize milk from infected cows, and consider vaccination. Quarantining and preventing the introduction of infected cattle into the herd can limit spread.

7. Foot and Mouth Disease (FMD)

Foot and mouth disease (FMD) is one of the most contagious viral diseases affecting cloven-hoofed animals like cattle, pigs, and sheep.

• Transmission: Spread through direct contact, contaminated equipment, aerosolized droplets, and airborne transmission. Recovered animals can continue to carry and spread the virus.
• Symptoms: Fever, blisters on the mouth, feet, and teats, leading to salivation, lameness, and reduced milk production.
• Prevention: Strict biosecurity measures, as FMD is not currently found in the U.S. Vaccination is used in regions experiencing outbreaks. Quarantine, culling infected animals, and movement restrictions help control the spread.

Conclusion

Infectious diseases can severely impact cattle health, productivity, and farm economics. Understanding the transmission routes, clinical signs, and prevention strategies for common diseases is key to protecting your herd.

Implementing measures such as biosecurity, vaccination, testing, isolation of sick animals, and stress reduction can help prevent disease outbreaks. Work closely with your veterinarian to establish a proactive, science-based herd health program that supports cattle well-being and farm profitability.