IACUC Learning Module - Cattle | Previous Next |
The information in Appendix 2, "Common Disease Problems of Beef Cattle" is especially useful if you will be working with any of the beef animals. Some general comments about health and disease in cattle follow.
Enterotoxemia, or overeating disease may occur in cattle. It is due to an imbalance in the populations of various species of rumen bacteria; imbalances most often occur as a result of overfeeding of grain or due to a sudden switch in feed sources.
Immediately report any animal with a drop in food consumption. Cattle which do not consume enough feed for their energy requirements will quickly break down muscle and fat stores into metabolites which may be life-threatening.
Overfeeding, or a sudden increase in energy or protein may lead to diarrhea or bloat. Abrupt access to lush pasture also causes digestive upsets. ANY CHANGE IN THE FEEDING PROGRAM SHOULD BE GRADUALLY IMPLEMENTED.
Bloat can usually be recognized by a change in shape viewed from the back, the animal's side may bulge out more than normal. Report this condition immediately.
Immediately report any animal with a change in manure quantity or consistency. Cow feces contain more than 80% water and cattle defecate from 12-18 times each day. The dividing line between normal and diarrhea is not always clear, but diarrhea is more liquid and there is no form to the "cow patty".
Cattle urine has a wide range of normal colors but report any change to the unit supervisor. Urine containing pus or having a strong, rotten smell needs to be immediately reported to the Veterinarian and usually indicates infection. Male cattle are prone to urinary blockages which are life-threatening. Report any animal straining during urination or with swelling of the ventral area of the belly which may indicate that the urethra has ruptured and urine is being deposited in the subcuticular space. Because bulls and steers of all ages will ride or hump other cattle, injuries to the penis are quite common.
Young calves may have horn buds removed with a hot iron; older animals need to be dehorned using special tools. For older cattle, there are a variety of methods used to remove horns and the Farm Animal Veterinarian should be consulted.
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Report any animal with signs of injury or lameness-abnormal gait or movement, pain, swelling, or redness. Cattle in lots are subject to many problems of the feet including sole ulcers, infection of the area between the two claws and injuries due to pieces of wire or nails.
Cattle, as well as horses, may develop "laminitis" or "founder", which is a painful, inflammatory process of the hoof wall. Death may result from sudden onset laminitis, although that is not common. Early signs are lameness, redness of the skin in the area of the coronary band and tenderness when the hoof wall has pressure applied. Some common factors which may lead to the development of laminitis include: ingestion of large quantities of grain; ingestion of lush grass, clover or alfalfa; an overheated, exercised animal drinking very cold water or large quantities of water; a cow right after calving, or cattle with severe pneumonia or other bacterial or viral infection. Treatment is most effective when discovered early and aggressively followed.
Temperature is not usually a problem for older cattle so long as they have protection from direct sun and driving rain or snow.
Adequate control of humidity and drafts is of paramount importance for the health of young calves. The dairy cows must be watched for early signs of inflammation of the udder, called "mastitis". Clinical signs include: swelling, pain, redness or other color changes, loss of milk production, and hardness of the udder. Report any changes, no matter how slight and subtle to the unit supervisor and the Farm Animal Veterinarian. In addition, it is easy for a cow to step on a teat when getting up and down so be sure to report any teat injuries.
Young male cattle are born with descended testicles. Unless being kept for breeding purposes, most males are castrated, usually at the time of weaning. No extensive peri-operative care is required, but animals should be examined for signs of infection in the days following the procedure.
Cattle are polyestrous. Estrus cycles in the cow are about 21 days and the length of time the cow stands to be mounted by the bull is about 18 hours. For artificial insemination, cows that come into "standing heat," the time the female will accept mounting by the male, in the morning are bred in the same afternoon, and cows that come into "standing heat" in the afternoon are bred the next morning. Onset of puberty usually occurs about 40-45 weeks of age, but depends on breed and level of nutrition. The general rule is that puberty occurs when the heifer is about two-thirds of her adult body size, as measured by height and length rather than weight. Gestation period is about 280 days, or nine months. The dairy unit tends to wean calves from 6-8 weeks of age and the beef unit will wean around 5 months of age.
Parturition, or labor, is the act of giving birth. The earliest stage lasts between 2-6 hours in the cow. The cow is usually restless, she may lie down and get back up several times, she often will be bawling and she may strain as though trying to urinate. If observed, notify the unit supervisor. From the onset of labor, the cow should calve within a maximum of eight hours. ** Read the section labeled "Dystocia" in Appendix 2. Dystocia means difficult birth and is often due to improper positioning of the calf. Any cow having a difficult labor should be reported to the Farm Animal Veterinarian.
At the dairy, cows in labor are moved into maternity pens on the southwest side of the milking shed. If the cow can still walk easily, move her to these pens. If not, try to move the rest of the cows into another pen so that they will not bother her.
Cows at the beef unit are simply watched in the pasture to be sure no complications with labor occur.
SQ Subcutaneous Injections are usually made in the loose skin where the neck and shoulder join.
IM Intramuscular Injections may be given in the thigh muscle or the large muscles along the side of the neck.
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The tail vein is a convenient site for blood collection and IV injections. The tail vein is not visible. It may be accessed by pulling slightly up on the tail, inserting the needle straight upwards on the dorsal midline of the tail, between the second and third vertebra of the tail (a shallow groove or depression should be first palpated, this is the venipuncture site).
Ruminant anesthesia poses problems. When asleep, ruminants are likely to regurgitate some of the rumen contents into the mouth, which then drain down the trachea into the lungs and cause a deadly, aspiration pneumonia. Endotracheal intubation is recommended to prevent this problem. Another problem is bloat. The rumen continues to ferment and produce gas while the animal is anesthetized, but due to being asleep, the animals is no longer belching (eructation) to reduce the gas buildup. Therefore, gas pressure can increase to the point that the diaphragm can't contract and expand and the animal may have respiratory distress. Not allowing the animal food for 24-48 hours prior to anesthesia helps to reduce these problems; the Farm Animal Veterinarian should be consulted.
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IV Intravenous Injections are usually done in the jugular vein. The vein can be distended by manual occlusion of the vessel below (toward the heart) the intended venipuncture site.
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