Kansas State University College of Veterinary Medicine Mississippi State University College of Veterinary Medicine Virginia-Maryland Regional College of Veterinary Medicine Texas A & M University College of Veterinary Medicine.

This site demonstrates our approach to evidence based antimicrobial dosing. As such, you should expect that features may change and content will increase with time. Although we believe the current information to be accurate, it is NOT complete and should NOT be used as a guide to therapy at this time .
We encourage you to contact us with questions or comments.

Supportive Therapy for Calf Diarrhea

In many cases of calf diarrhea, antimicrobial therapy is either insufficient by itself or unnecessary. Calves with diarrhea, particularly those with moderate to severe illness including recumbency and/or a loss of the suck reflex, have physiologic issues such as dehydration, acidosis, and electrolyte imbalances, which must be addressed therapeutically. Depending on the pathogen causing the diarrhea, resolution of the imbalances in hydration and electrolytes may be sufficient to resolve the disease, without administration of antimicrobial drugs.

Physical Examination is critical to deciding the course of therapy. Factors such as presence of other disease processes (e.g. omphalitis, arthritis or pneumonia), degree of depression, presence or absence of suckle reflex, rectal temperature, heart rate and degree of dehydration must be assessed before appropriate treatment decisions can be made.

Fluid Therapy is the cornerstone of treatment for calves with diarrhea. In addition to returning the dehydrated calf to normal hydration status, orally or intravenously administered fluids may also be used to correct acid-base or electrolyte imbalances. One must consider a number of factors when deciding how to administer fluid therapy.

Intravenous Fluids are the best choice for calves that are recumbent or lack a suckle reflex.. Factors to be considered in designing an intravenous fluid therapy regimen include:

Acid-Base and Electrolyte Disturbances

1) Acidosis

It would be difficult to overstate the importance of correcting acidosis when treating the diarrheic calf. Fluid solutions containing bicarbonate or acetate are effective alkalinizing agents when administered to acidotic calves. Practitioners with access to a blood gas machine may quickly estimate the base deficit in an acidotic calf with diarrhea using the following formula (note that mmol/L and mEq/L are the same):

Base deficit to be replaced as bicarbonate, in mmol or mEq=

Body weight in kg x (30mmol/L-TCO2mmol/L) x 0.6

Of course, many or most practitioners either do not have access to a blood gas analyzer, or cannot receive results quickly enough for them to be used in making initial therapeutic decisions. Schemes have been devised to correlate severity of clinical signs with severity of base deficit, but these have had mixed reliability. In general, a reasonable rule of thumb is that a severely diarrheic calf less than one week of age will have a base deficit of 10 to 15 mmol/L and a calf greater than one week of age with severe diarrhea will have a base deficit of 15 to 20 mmol/L. These estimated deficits can be used in place of “30 mmol/L-TCO2 mmol/L” in the formula given above. The base deficit and the fluid deficit should be replaced over a period of about four hours.

Bicarbonate should not be added to solutions containing calcium, such as Lactated Ringer's Solution, as a precipitate may form. Bicarbonate may be added to saline solutions. An isotonic bicarbonate solution may be made by dissolving 13 grams of sodium bicarbonate (baking soda) in one liter of water.

2) Hyperkalemia

Blood electrolyte analyses on diarrheic calves may indicate hyperkalemia. This finding is usually due to increased extracellular presence of potassium due to acidosis, and once acidosis is corrected, it may be found that the calf actually has an absolute potassium deficit due to ongoing losses in the feces and reduced intake. After correction of acid-base balance, 10 to 20 mEq/L of potassium may be added to fluids to replace losses. One gram of Potassium Chloride contains 14 mEq potassium.

Sodium and Chloride levels are also frequently low in diarrheic calves. An isotonic solution if sodium chloride may be used to maintain plasma sodium and chloride concentrations.

3) Hypoglycemia

Maldigestion and malabsorption in diarrheic disease, especially when combined with the practice of withholding milk from such calves, may result in hypoglycemia. A 1 to 2 percent dextrose solution may help temporarily alleviate hypoglycemia and its attendant signs of weakness, lethargy, coma or convulsions until proper nutrition can be provided to the calf.

Fluid Volume to be Administered

Along with acidosis, dehydration is one of the major reasons for death in diarrheic calves. The goal of fluid therapy should be to correct dehydration within the first four hours of therapy. The degree of dehydration can be estimated by physical examination of the calf, using the skin tent test on the neck, degree of sunkeness of the eye in the orbit, and moisture of oral mucous membranes to gauge the severity of dehydration. Mildly dehydrated calves will generally be between 1 and 5% dehydrated, whereas the most severely affected calves may have dehydration levels of 10 to 12%. By multiplying the estimated percentage dehydration by the weight of the calf in kg, the number of liters of fluid deficit can be estimated, for replacement over the first four hours of treatment.

After initial deficits have been replaced, calves should be given maintenance levels of fluids until suck reflex and apetite have returned and the calf can be maintained on oral feeding and fluids only. The maintenance fluid requirement for the calf will be 50 ml/kg/day plus amounts lost to diarrhea, which may be as much as 4 liters per day.

Rate of Fluid Administration

Fluids should be administered at a rate that will restore fluid deficit over a period of about 4 hours. If the calf is in hypovolemic shock, the first liter of fluid may be administered at the maximum safe rate (one reference suggests a maximum rate of 50 mL per kg per hour). Once the shock state has been reversed, diuresis will be minimized if the remaining fluid deficit is replaced over a period of hours. After 24 hours of appropriate therapy, the calf should stand and have a suckling reflex. If this is not the case, it is likely that the calf remains acidotic or is septicemic.

Oral Fluids may be used as a maintenance therapy following intravenous fluid administration, or as a first-line treatment for mild to moderate cases of diarrhea in calves. In either case, a calf that is able to stand and suckle is a good candidate for oral fluid therapy. If the calf has some suckle reflex but will not drink an oral electrolyte solution, the solution may be administered using a tube feeder. Most any solution containing water and electrolytes will help maintain hydration status of the calf, but it is very important that the solution also be alkalinizing, especially in older calves. Alkalinizing ability can vary greatly between products. For calves that are still being fed milk, solutions that contain acetate as an alkalinizing agent are a good choice, as acetate is effective and does not inhibit milk clot formation in the gut of the calf. Bicarbonate and citrate are also effective alkalinizing agents orally, but they may interfere with digestion of milk in the gut. Oral electrolyte solutions should contain 50 to 80 mmol of alkalinizing agent per Liter. No oral solution for the treatment of diarhheic calves contains enough energy to sustain a calf's body weight, but high-energy products are available that may help minimize weight loss in calves that are in poor condition.

Milk feeding to calves with diarrhea is still debated, but evidence is accumulating that feeding milk to a calf with diarrhea is unlikely to negatively affect outcome. On the other hand, withholding milk from calves with coronavirus, cryptosporidiosis or salmonella over the long period it takes for the diarrhea to resolve may result in the calf starving to death. Digestion and absorption of milk or milk replacer may be maximized in diarrheic calves by feeding smaller but more frequent milk meals. If bicarbonate-containing oral electrolyte solutions are also being used, they should be given at least 30 to 60 minutes after a milk meal to minimize their disruption of milk clot formation in the gut of the calf.

Gut protectants or adsorbents such as Koalin-Pectin or Bismuth salts are sometimes used as adjunct therapy for diarrhea. Kaolin-pectin, while it may improve the character of the stool, has not been shown to improve fluid and electrolyte imbalances or shorten the course of calf diarrheal disease. Bismuth subsalicylate may be useful, however, as it has been shown to have anti-secretory, antimicrobial and anti-prostaglandin activity, and it is considered anti-endotoxic.

Hypothermia can be a significant problem in diarrheic calves. Oral and intravenous fluids should be warmed to target body temperature before administration. Calves with severe hypothermia may be most effectively warmed by submersion in a warm water bath.

NSAID drugs have a high potential for toxicity in calves with diarrhea, because dehydration potentiates their nephrotoxic effects. Therapy with NSAID drugs may be beneficial for calves with endotoxemia, but hydration status and renal function must be closely monitored in these calves.

Antibiotics have limited usefulness in the treatment of uncomplicated calf diarrhea. Viruses and cryptosporidia are unaffected by antibiotics, and the course of Salmonellosis may be extended by their use. Calves greater than 3 days of age no longer have K99 antigen binding sites in their gut, so use of antibiotics against Enterotoxigenic E. coli in this class of cattle will be of little benefit. Antibiotic use is only likley to be beneficial where there is a risk of bacteremia or concurrent infection of another organ system.

Copyrighted - all rights reserved (VADS)