We have previously discussed the importance of hydration in treating calves with diarrhea (scours). Rehydrating calves with an oral electrolyte solution (or intravenous fluids) is an example of a non-specific treatment—one that applies to (and is important to) treatment of calves regardless of the specific cause of the diarrhea.
While all calves with scours will benefit from fluids and electrolytes, there are certain specific causes of scours in which specific treatments may be necessary. Infections due to bacteria such as K99 (F5) E. coli, Salmonella, or Clostridium perfringens Types A or C may require specific antibiotic therapy against those agents. Treatment of specific bacterial causes of calf scours with antibiotics should be performed only with the guidance of a veterinarian, as these bacteria are often resistant to many commonly-used antibiotics.
Specific antitoxin products are available to treat clinical signs of illness due to Clostridium perfringens. These products counteract the toxin that is the cause for the damage induced by infection due to these bacteria. In the face of outbreaks of clostridial disease in young calves, these products can be used as aids in treatment as well as for prevention.
Coccidiosis is another cause of diarrhea in calves that usually necessitates treatment with specific antimicrobials. Coccidiosis normally does not affect calves less than 3-4 weeks of age and often is characterized by bloody diarrhea. Treatment of coccidiosis in calves is usually accomplished by using antimicrobials such as amprolium and sulfonamides.
There are many other causes of calf diarrhea that are not directly affected by treatment with antibiotics, such as viral causes of diarrhea (e.g. rotavirus and coronavirus) and the protozoal disease cryptosporidiosis. However, recent research suggests that use of the right antibiotics in ill scouring calves regardless of cause has merit.
Calves suffering from diarrhea due to any cause are more likely to have overgrowth of coliform bacteria in the intestinal tract. This contributes to a malfunction of the gut, as well as an increased likelihood of bloodborne infection (bacteremia). In one study, 30-40% of calves with diarrhea had evidence of bacteremia. This has led to a recommendation that scouring calves with signs of sickness (fever, decreased appetite or activity) be treated with an antibiotic regardless of the cause of that diarrhea. Not any antibiotic will do, however: the antibiotic chosen should be effective against coliform bacteria and effective in the intestine. Therefore, a discussion with a veterinarian about proper treatment options is critical.
Research also indicates that therapies such as non-steroidal anti-inflammatories and continued provision of nutrients through milk are effective in helping calves survive scours. On the other hand, research also indicates that certain other popular treatments such as probiotics and “intestinal protectants” may do more harm than good.
Cow-calf producers have available an enormous variety of treatments touted as helpful in “curing” scours. Sorting out these treatments beyond fluids and electrolytes is best accomplished with consultation from a veterinarian.