When One Animal Gets Sick: How to Protect the Rest of Your Herd

When you own livestock, finding one animal that suddenly looks sick raises an immediate question: Is this an individual problem, or could the rest of the herd be at risk?

Whether you keep a few goats or sheep on a small property or manage a larger cattle or mixed-livestock operation, recognizing illness early can make a significant difference. Some health problems affect only one animal, while infectious diseases, parasites, environmental problems, or feed-related issues can affect multiple animals.

Knowing what to do when you first notice a problem can help protect both the sick animal and the rest of your herd.

Know What Is Normal for Your Animals

One of the best ways to recognize illness early is simply knowing how your animals normally behave.

Livestock owners see their animals every day, which gives them an advantage when something begins to change. An animal may not initially show dramatic symptoms. Instead, the first indication of a problem might be standing away from the herd or showing less interest in feed.

Changes worth paying attention to can include:

• Reduced appetite or water consumption
• Separating from the herd
• Unusual posture or reluctance to move
• Coughing or nasal discharge
• Diarrhea
• Rapid or difficult breathing
• Sudden weight loss
• Lameness
• Abnormal swelling
• Reduced milk production
• Changes in behavior or energy level

Not every change means an animal has a serious illness. However, noticing these changes early gives you an opportunity to investigate before the problem becomes more severe.

Separate Sick Animals When Appropriate

When you do not know why an animal is sick, limiting its contact with healthy animals can be a sensible precaution.

Ideally, an isolation area should prevent direct contact with the rest of the herd while still providing appropriate shelter, feed, water, and enough space to monitor the animal comfortably.

Separate buckets, feeders, halters, and other equipment can also help reduce the possibility of carrying infectious material from one group to another.

If possible, take care of healthy animals before working with animals that are sick or isolated. Boots, clothing, hands, buckets, tools, and other equipment can potentially move infectious material around a farm or ranch.

Don’t Assume Similar Symptoms Have the Same Cause

A symptom is not the same thing as a diagnosis.

Diarrhea, for example, can have many potential causes. Coughing can also result from different conditions, and an animal that stops eating could be experiencing anything from a digestive problem to pain or systemic illness.

This is particularly important when more than one animal begins showing similar symptoms.

Treating every animal based only on what worked previously can delay identifying the actual problem. A veterinarian may recommend a physical examination, diagnostic testing, fecal testing, bloodwork, or evaluation of feed and management practices depending on the animals involved and the symptoms being seen.

Be Careful When Introducing New Animals

New animals are one of the ways disease can enter an otherwise healthy herd or flock.

An animal does not necessarily need to look sick to carry a pathogen. Transportation and the stress associated with moving to a new environment can further complicate the situation.

The University of Connecticut Extension recommends quarantining new livestock for at least three to four weeks and keeping new animals from interacting with the existing herd during that period. It also recommends separating animals that become ill and having them evaluated by a veterinary professional before returning them to the herd. (source)

A quarantine period provides time to observe a new animal for symptoms and gives you an opportunity to review vaccination history, parasite management, previous health records, and any testing that may be appropriate.

Remember That Disease Can Travel Without an Animal

Biosecurity involves more than keeping sick animals separated.

People, trailers, equipment, feed containers, boots, clothing, and shared tools can all potentially move infectious material between groups of animals or between properties.

Livestock shows, breeding visits, shared trailers, newly purchased animals, and visitors who have recently been around other livestock can create additional opportunities for exposure.

Practical biosecurity does not necessarily mean turning a small farm into a highly controlled facility. It means recognizing where the most likely risks exist and taking reasonable steps to reduce them.

Something as simple as cleaning equipment, limiting unnecessary contact with isolated animals, and avoiding shared feed and water containers can become part of a useful routine.

Keep Basic Herd Health Records

Good records become particularly valuable when a health problem affects more than one animal.

At minimum, consider recording vaccinations, medications, illnesses, births, reproductive information, new animal arrivals, deaths, and significant changes in feed or management.

If several animals become sick over the course of a few weeks, those records can help identify a pattern.

For example, you may discover that symptoms began shortly after new animals arrived, after a feed change, or after animals returned from an event.

Records also give your veterinarian more information to work with when investigating a herd health problem.

Know When a Herd Problem Needs Veterinary Attention

One sick animal may require an individual examination. Multiple animals developing similar symptoms can indicate a larger herd-level problem.

Contacting a veterinarian becomes especially important if symptoms are severe, spreading quickly, affecting several animals, or accompanied by unexpected deaths.

Before the veterinarian arrives, gather as much useful information as possible.

Know approximately when the symptoms began, how many animals are affected, their ages, recent vaccination history, whether any new animals were introduced, and whether there have been recent changes in feed, pasture, housing, or management.

Photos or videos of unusual behavior can also be helpful, particularly when symptoms are intermittent.

Prevention Is Easier Than Managing an Outbreak

Veterinary care for livestock does not have to begin when something goes wrong.

Routine herd health evaluations provide an opportunity to review vaccinations, parasite control, nutrition, reproduction, hoof health, biosecurity, and other management concerns before they develop into larger problems.

The appropriate preventive program will look different for a small backyard goat herd than it will for a cattle operation or a property with several livestock species.

Having a veterinarian who understands your animals and your operation also means there is already a foundation of information available when an unexpected health problem occurs.

Arizona Mobile Veterinary Practice provides mobile livestock veterinary services throughout Arizona, including routine and preventive care, sick-animal evaluations, herd health services, and veterinary care for cattle, goats, sheep, pigs, llamas, alpacas, horses, and donkeys.