Identify 'at-risk' calves early to improve prognosis

The earlier "at risk" neonates are identified and treated, the better the prognosis for a healthy and productive life.

Christine B. Navarre, DVM

Any calf that is born following a dystocia, even if it appears normal, should be considered at risk. Many of these calves will look normal for a few hours but deteriorate quickly. I advise that immediately following the dystocia, while the cow is still restrained, milking the cow (if possible) and bottle or tube feeding the calf. This ensures colostrum intake and precludes having to restrain the pair later if the calf has not nursed. It also helps prevent hypothermia and hypoglycemia.

Calves born following dystocia can be depressed due to hypoxia, metabolic acidosis and/or hypothermia. Calves with mild depression can be warmed and given intravenous sodium bicarbonate inexpensively, and this can greatly improve the chances of survival of these calves. If only mildly hypothermic (>96 F), heat lamps and hot water bottles may work. However, if severely hypothermic, peripheral perfusion is poor and external warming is not effective. These calves need to be warmed from the inside. Warm oral and intravenous fluids (balanced electrolyte solution with 1.5 percent dextrose) are best, along with external sources of heat.

Correcting for a base deficit of 10 is usually safe. Concentrated sodium bicarbonate (5 percent to 8 percent) can be administered undiluted at a rapid rate through a needle if a catheter for other fluids is not needed. Calves with more severe depression might require oxygen therapy, which will increase the cost of treatment. However, many times a small amount of early supportive care prevents more extensive, prolonged care later.

Up to 15 percent of first-calf heifers and roughly 5 percent of mature cattle show signs of dystocia, medical experts say. Quick medical monitoring in calves can dramatically improve neonate health and survival rates, experts add.

First days of life

Hypoglycemia is less of a problem in the first hours of life and more of a problem later, secondary to inadequate nutritional intake, septicemia, etc. If severe, hypoglycemia can mimic meningitis with signs such as miotic pupils, ophisthotonus and seizures. Glucose levels can be low in both conditions. If other causes of weakness and neurologic signs have been eliminated (hypothermia, acidosis), a slow infusion of 0.5 mls/10 lbs body weight of 50 percent dextrose IV can be administered without the need of a catheter.

If calves have simple hypoglycemia, they usually will respond to the dextrose by improving. If they do not respond, a CSF tap can be easily performed. If the fluid is grossly abnormal and the prognosis is poor, the owner can factor this into treatment decisions. If the fluid looks grossly normal, the calf might still have meningitis, but the prognosis is good with treatment. If treatment is continued, these calves must have an IV 2.5 percent to 5 percent dextrose since the 50 percent dextrose will cause a rebound hypoglycemia if dextrose isn't continued. Calves should be weaned from dextrose slowly.

First weeks of life

Once calves are a week old, their chances of survival increase. However, morbidity due to septicemia, umbilical problems, pneumonia and diarrhea can cause increased veterinary costs and poor weight gains. Failure of passive transfer (FPT) increases the incidence of these diseases.

In an individual calf with FPT, the most important problems are decreased growth rates and septicemia. Diagnosis of FPT can be made at 24 hours up to about 1 week of age. One of the cheapest tests is serum protein, which should be >6.0 g/dl in beef calves. There are now newer whole-blood tests that can be run without the need of a centrifuge. These tests are more expensive, but allow for immediate on-farm diagnosis.

The only specific treatment for FPT is plasma or, more practically, a whole-blood transfusion (since bovine RBCs don't separate from plasma, which necessitates spinning the blood).

Plasma is of questionable benefit in healthy calves for prophylaxis because even with high volumes, immunoglobulin levels don't reach those of calves that received colostrum, and this is further magnified if whole blood is given because of volume limits.

However there are other benefits, especially in sick calves. The increase in protein levels helps prevent hypoproteinemia if IV fluids have to be given, and if fresh, whole blood is given, benefits of cellular immunity, interferon and other circulating non-specific immune factors might benefit the calf. Treatment with antibiotics prophylactically in healthy calves is controversial and should be considered on a case-by-case basis.

Neonatal septicemia

A potential sequela to failure of passive transfer is septicemia. The source of the bacteria can be the umbilicus, the GI tract or the respiratory tract. Any organ system can be secondarily infected, but the neurologic, musculoskeletal and ophthalmic systems are most likely infected.

General clinical signs are depression and reluctance or inability to stand. Anorexia, poor suckle reflex,+/- fever (more often hypothermia) are other general signs.

Hypoglycemia might be present. Neurologic signs due to secondary meningitis are ophisthotonus, seizures, stiff extremities, nystagmus and/or miotic pupils. Hypopyon, uveitis, synechia and conjunctivitis might occur but are not life threatening, only a sign of serious problems.

Single or multiple swollen joints, edema around the joints and osteomyelitis might occur. Musculoskeletal infections carry a poor prognosis unless caught early. Lameness in neonatal calves should be treated as an emergency since infectious arthritis from septicemia is a more likely cause of lameness than injury/trauma. Diarrhea and pneumonia are not a common sequela to septicemia in beef calves, although they are common problems in calves with FPT.

A diagnosis of the causative organism(s) requires blood culture. The most likely organism is E. coli, but Salmonella sp., A. pyogenes and Staphylococcus aureus can be involved. Broad-spectrum antibiotics are needed unless a culture and sensitivity shows otherwise. Ceftiofur (six times the label dose) in combination with penicillin will give broad-spectrum coverage. If meningitis or joint involvement is evident, florfenicol is a good choice. Anti-inflammatory drugs also are important. If caught early, arthritis can be successfully treated with joint flushes and intra-articular antibiotics. Extensive fibrin buildup will be present in chronic cases that will hinder flushing. Fluid therapy might also be needed.

Umbilical diseases

If an umbilicus does become infected, and the calf is systemically ill or has poor growth, the umbilicus usually should be immediately removed surgically. Systemic antibiotics rarely work long term, and the longer the infected umbilicus stays, the higher the risk of infection spreading to the joints and nervous system.