Neonatal Diarrhea: Giardia, Cryptosporidium and Eimeria in Crias
Shannon Bowen DVM student, Class of 2005
David E Anderson, DVM, MS, DACVS
Ohio State University
Columbus, Ohio 43210
March 29, 2003
The neonatal period of an animal's life is often the most vulnerable stage for disease. The most common diseases in crias are diarrhea and infectious diseases. Diarrhea may be caused by bacterial, viral or nutritional means, although most commonly it is caused by the protozoal parasites Giardia, Cryptosporidium, and Eimeria. Neonatal diarrhea is a disease of hygiene and is most often a problem on larger farms. Diarrhea in crias can often be treated successfully and outbreaks can be reduced using preventative methods.
Giardia lamblia is a water borne protozoal parasite responsible for mammalian infection. Infection is induced via fecal-oral transmission. G. lamblia cysts are commonly shed in the feces of both symptomatic and asymptomatic mammals. These cysts are then ingested by drinking contaminated water, milk or food. Once ingested, the trophozoite form of the G. lamblia is released from the cyst and attaches to the epithelial cell lining of the small intestine. The trophozoites reproduce and form infective cysts that are then released out into the feces. Clinical signs in effected crias infected with G. lamblia most often occur at two to three months of age, although it may be seen as early as 14 days or as late as one year. These signs include chronic low-grade diarrhea, weight loss, and poor growth.
Cryptosporidium parvum is a protozoal parasite that is also spread thru fecal-oral transmission. Infection does not usually cause the clinical signs of diarrhea unless the host's immune system is compromised. C. parvum in the form of oocysts are ingested from the feces and release their four sporozoites that invade the cells of the lower small intestine. It is here that C. parvum undergoes sexual reproduction and produces new oocysts most of which are expelled in the feces. Crias develop clinical signs between one week and ten days, however, signs can occur upwards of three months old. Clinical signs range from mild, transient diarrhea, to protracted diarrhea with poor growth, to acute, severe diarrhea with dehydration, weakness, and possibly death.
Eimeria bovis is also a coccidian protozoan parasite that is transmitted via the fecal-oral route. Once again a host shedding the parasite in its feces does not have to be symptomatic. After the oocyst is ingested it undergoes two asexual reproductive cycles. The first cycle takes place in the ileum and the second cycle occurs in the cecum and colon prior to shedding the mature oocysts in the host's feces. A cria may show symptoms as early as three weeks and up to one year in age. Clinical coccidiosis can be seen in adults, but rarely causes a problem unless the host's immune system is compromised.
When Should I Call My Vet?
In addition to diarrhea, crias will exhibit lethargy, weakness, loss of appetite, dehydration, and dullness. If a cria develops diarrhea make sure to weigh it daily as well as monitor systemic parameters such as heart rate (normal is 80-120 bpm), respiratory rate (normal is 20-40), and rectal temperature (normal is 99-102 F). If there are abnormal systemic signs, blood in the diarrhea and/or consistent weight loss over several days or a total of 10% loss of body weight at any time, consult your veterinarian immediately.
Owners can begin to give calf electrolyte replacers or other glucose enriched electrolyte solutions to crias when symptoms develop. The cria should be isolated as soon as possible to prevent further spread of infection. Clean, dry bedding should be provided for the cria and appropriate heat lamps and blankets should be used in winter to prevent hypothermia. In summer, crias should be moved to shade to avoid hyperthermia.
In a clinical setting, the cria can be started on IV fluids and parenteral nutrition. Biolyte and Resorb are common calf electrolyte replacers that are used by the OSU veterinary hospital to restore electrolyte balances as well as provide nutritional support.
Supportive therapy, in addition to the appropriate antiparasitic drugs, can help reestablish optimum health to an infected cria with diarrhea. Fenbendazole at 50 mg/kg or Albendazole at a dosage of 10 mg/kg can be used to treat Giardia. No specific treatment is available for Cryptosporidium, but Lasaloid, an ionophore drug, has been used with apparent success in many crias. This drug is potentially toxic and should only be used with the strict supervision of a veterinarian. Eimeria can be treated with Albon at a dosage of 15 mg/kg orally, twice a day for 5 days or Amprolium at a dosage of 10 mg/kg usually given in water over the course of five days.
Prevention of parasitic agents is primarily an issue of hygiene as mentioned before. It is recommended that parturition occurs in a clean, dry area to lessen the likelihood of infection. The cria should receive adequate colostrum within 6 hours after birth. The colostrum will help ensure the health of the cria but it may help to decrease the infectious agent and clinical signs. Providing clean, dry pens for crias and allowing each pen to dry between crias will help prevent parasite infection. It is imperative that a sick cria is removed from the herd or at least separated from other crias as soon as diarrhea begins. This, in addition to the prevention of overcrowding will prevent the ground and water sources from overwhelming parasite infection.
If a farm becomes infected with one of the parasites and neonatal diarrhea becomes a problem, certain measures should be taken in an attempt to reduce the parasite load of the herd and environment. Pens should be cleaned regularly. Feeding and watering areas should be cleansed with an appropriate disinfectant. All animals with diarrhea should be isolated from the rest of the herd while undergoing treatment. Shedding of the parasite can be an ongoing problem from both asymptomatic and treated animals. Hygiene as well as common sense are the best precautionary measures.
Anderson, David E. Conversational. November 2002.
Anderson, David E. Neonatology in Llamas and Alpacas. May 15, 2002.
Bowman, Dwight D. Georgi's Parasitology for Veterinarians. W.B. Saunders Co. New York, 1999.
University of California Davis. Cryptosporidiosis and Diarrhea in Calves. Medical Ecology and Environmental Health. July 1997.www.vetmed.ucdavis.edu