RECOGNIZING SICKNESS IN CATTLE CAN BE CHALLENGING

by: Lee Jones
MS, DVM, University of Georgia


If you deal with livestock, at some point you will also have to decide to treat a sick one or call a veterinarian to make a diagnosis and treatment recommendation. Knowing what to look for and how to decide whether an animal needs treating and what kind of treatment is sometimes easier said than done.

First Observation

Sometimes, animals don't appear sick because they are hiding their illness. Most cattle are more comfortable in their pasture, and will show signs such as lameness or depression in that safe environment; but they might not show it when they get in the pen. The stress of attention can cause them to mask their symptoms. When stress hormones kick in, animals may not always show that something is wrong with them. It is important to remember that they are still prey animals and they regard us as predators. Prey have always hidden vulnerabilities from predators because the vulnerable prey are usually the first to get eaten. Livestock have to trust their handlers and their environment before they 'show' us they are sick. These animals may get better without treatment; but if not, they continue to get worse until they are in such severe shape that treatment might be too late.

Most farmers rely on physical appearance to tell whether an animal is sick. Clinical signs vary, but the most common signs include: depressed attitude and lying around, referred to as lethargy; shade seeking; separation from others in the pasture or pen; drooping ears; standing posture; rapid shallow or open-mouthed breathing; coughing; not eating or poor appetite (anorexia) and subsequent hollow gut behind ribs on left side (same side as the rumen); purulent nasal discharge (may or may not be present); excessive drooling; or other signs. More specific signs might include obvious lameness, bloated appearance, diarrhea, pinkeye, or other signs.

Some signs listed above may be obvious, but it takes time and training to recognize sick livestock. Any animals not eating (may be easier to determine in a pen rather than a grazing situation) or away from other cattle may be inspected more closely to see whether they are simply sleeping or resting or are in fact ill. It is important for a caregiver to approach a resting animal slowly and allow the animal to rise calmly. Healthy animals stretch after rising, swish their tails and walk off calmly when approached. Sick animals typically do not stretch. Some diseases also cause pain, and sick animals may stand hunched because of pain of infection. Severely diseased animals may not rise; or if they do, they may not walk very far. These animals require immediate aggressive treatment. Not all animals that cough are sick. Healthy animals may cough during rumination if a small amount of rumen fluid drips into the trachea. This is nothing more than clearing the airway. Coughing with a nasal discharge may be a sign of a more serious problem.

Animals with any of the above signs should be moved to a chute to be restrained for a hands-on, physical examination. It is important to determine what disease is affecting the animal and what is causing it. If it is a disease caused by an infectious bacteria, then choosing an appropriate AM is the correct course of treatment. If the disease is something like bloat or other gastric disorder, then it will need to be treated differently or held in a small pen for supervision.

Clinical Symptoms

The first symptom most often noted is respiratory rate and character. Calm cattle will typically breathe (15-40, breaths per minute) with minimal effort. Often the only sign is rise and fall of the skin behind the ribs. Breathing of cattle with pneumonia will often be shallow and rapid. However, this isn't specific to pneumonia, as animals with abdominal pain will also have rapid, shallow breaths. So it is important to determine why the affected animal is breathing abnormally.

Another important symptom is body temperature. Normal resting body temperature varies (98.5-102 F). Infections cause an increase in body temperature (fever). However, other things can also cause an increase in body temperature - physical exertion and environmental temperature; and some increases in body temperature have also been noted three to four days following vaccination with a modified live virus vaccine. Typically, a body temperature of 103.5 F or higher, in combination with other clinical signs, is considered a fever and indicates a disease requiring treatment. It may be necessary for some excited animals to calm down and rest to determine their actual body temperature, as excitement and activity can increase body temperature. Cattle grazing endophyte-infected fescue may also have an elevated body temperature and respiratory rate.

Auscultation

Listening to lung and gut signs with a stethoscope, called auscultation, is another tool some livestock health technicians or veterinarians use to diagnose and treat animals. Learning to listen to lung sounds and understand their significance can be a bit of an art. Cows have a limited lung area that is accessible to listening. Bacterial pneumonia often affects the cranioventral (lower lungs immediately behind elbow) parts of the lungs. Sometimes crackles and wheezes may be heard during exhalation. If no breath sounds are heard, then it may indicate consolidated lungs with no airflow. Sounds higher up the rib cage indicate serious lung disease also.

Body weight change is an important indicator of animal health. Animals that have lost weight are more likely to get sick than animals that gain weight. Animals brought in for further evaluation that have gained weight may not require treatment if they don't have a fever. If an animal has gained weight since its initial arrival, and doesn't have a fever and lungs sound normal, it might be prudent to delay treatment and keep the animal in a close up pen for further supervision. Many of these animals do fine without treatment.

Pasture evaluation is subjective; animals may appear lethargic or painful, but after a trip to the chute may in fact be normal. While some people may consider "over-pulling" animals from the pen or pasture a waste of time, it is actually a sign of astute observation. In one research study at Kansas State, veterinarians and experienced feedlot pen crews had as many as 20 percent of the animals they pulled for signs of disease called normal at the chute, and these animals did not receive treatment.

If more than one person is responsible for animal health observation in several groups of animals, a scoring system may be useful to help communicate to others that some animals need to be re-evaluated. A system such as this helps caregivers compare notes on animals with each other:

Normal animals would have a score of 0;

1 = mild depression and lethargy, and poor appetite;

2 = moderate depression and lethargy, inattentiveness to surroundings, no appetite, hollow gut fill, and unwillingness to move when aroused;

3 = severe depression, lethargy and/or weakness, marked hollow gut fill, severe inattentiveness, lack of willingness to move despite attempts at arousal;

4 = moribund or down and out.

Recording clinical score and body temperature at the time of first treatment will help if an animal needs repeat retreatments. Animals that have a low clinical score and normal body temperature may not need to be treated, but watched for changes in clinical signs and re-evaluated later. This can save a lot of money on drugs by reducing unnecessary treatments.

Deciding to Treat

Just as in a good rain dance, timing is everything. That is also true with treating sick cattle. Wait too long, and treatment may be more complicated and expensive; worse yet, treatment might be too late to do any good. Many times, deciding to treat is easy; but deciding how to treat may be complicated. Most people think of treating with a shot. Many times, that is sufficient; but it leaves out a lot of good options, and not every disease is best treated with just a shot. Also, make sure it is the right shot. Not all drugs work the same way, and not all drugs are equally effective in every situation.

Whether to use antimicrobials (AM) to treat disease in animals depends on the diagnosis. Antimicrobials (AM) work only against bacterial infections, and not all AM work the same or are equally effective against different infections. It is also important to understand that AM do not heal animals; they only combat the infection. Infections can return if the animal's immune system isn't effective in clearing the infection. Animals must be on a good nutrition program to get well. This requires a good appetite and access to a balanced ration or adequate feed and plenty of clean, fresh water. It is important to use antimicrobials according to their label. AM are not the same; some are approved for pneumonia but not for pinkeye. The FDA does allow for limited extra-label use of some drugs, but only by the order of a veterinarian.

When to re-treat depends on the drug used. Some drugs, such as penicillin or ampicillin, require daily treatment. This can add a lot of stress on the animal. Other drugs concentrate in the lungs and can provide therapeutic levels for days. While some animals may be better in 24 hours, most drugs take at least 48 hours to reduce infections. For that reason, it is best to wait 48-72 hours to give the drug time to work. If an animal is obviously getting worse, it needs to be re-evaluated and possibly treated differently.

Learning to recognize sickness behavior in animals takes time. With experience, caregivers can learn effective ways to observe cattle; working with their veterinarian, they can design effective and cost-effective treatment plans. We have heard it said, "If it's worth doing, it's worth doing right." That is especially true for treating animals.







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