Despite improvements in management practices and prevention and treatment strategies, diarrhea is still the most common and costly disease affecting neonatal small ruminants. A study at the U.S. Sheep Experiment Station (Dubois, ID) showed that diarrhea accounted for 46 percent of lamb mortality. Diarrhea in lambs and goats is a complex, multi-factorial disease involving the animal, the environment, nutrition, and infectious agents. The four major causes of diarrhea in lambs and kids during the first month of life are E. Coli, rotavirus, Cryposporidum sp. and Salmonella sp. E. coli scours are most common.
E. Coli
E. coli scours is an opportunistic disease associated with sloppy environmental conditions and poor sanitation. It is seen in lambs and kids less than 10 days of age, but is most common at 1 to 4 days of age. It usually presents itself as an outbreak in lambs and kids between 12 and 48 hours of age. It is also called “watery mouth,” because affected lambs salivate and have a cold mouth. Fluid therapy is the mainstay of therapy.
Antibiotics are used for both treatment and prevention of E. coli scours in lambs. Spectinomycin oral pig scours medicine is commonly used, though it is not approved for sheep and goats. Ewes and does can be vaccinated with bovine E. coli vaccine before they give birth to increase passive immunity. The use of neomycin in lambs that appear normal may stop the progression of the outbreak. Adequate ingestion of colostrum by newborns decreases the incidence of the disease.
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Infectious causes of diarrhea in sheep and lambs |
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| Bacterial | E. coli Salmonella sp. Clostridium perfringins |
| Viral | Rotavirus Coronavirus |
| Protozoa | Cryptosporidia Coccidia (Eimera sp.) Giardia sp. |
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Non-infectious causes (or contributing factors) |
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| Parasitic | Gastro-intestinal worms (not Haemonchus) |
| Nutritional | Dietary changes Overfeeding Simple indigestion Poor qualtiy milk replacers Inadequate intake of colostrum Poor quality colostrum Poor quality or stagnant water Lush or wet pasture Inadequate dry matter intake Plant and fungal toxins Allergies |
| Management (Poor environment) |
Overstocking/Overcrowding Poor sanitation |
| Stress | Weaning Handling Weather extremes Shipping/Transportation |
Rotavirus
Lambs and kids are infected with a group of B rotaviruses, whereas most other animals and humans are infected with group A rotoviruses. Rotavirus generally causes diarrhea in lambs and kids at 2 to 14 days of age. Young animals become very depressed and dehydrated.
Rotavirus is treated with supportive care. Vaccinating ewes and does with bovine rotavirus vaccines before they give birth will increase passive immunity. Viruses tend to be less a cause of diarrhea in lambs and kids than calves.
Cryptosporidium
Cryptosporidium parvum is a protozoa that can cause diarrhea similar to that of rotavirus infection. Cryptosporidia can cause diarrhea in lambs and kids 5 to 10 days of age. Affected animals are often active, alert, and nursing. The diarrhea is usually very liquid and yellow.
No consistently effective treatment for cryptosporidiosis in ruminants has been identified. Anectodotal reports suggest that decoquinte (Deccox®) and monensin sodium (Bovatec®) may be useful in the control of Cryptosporosis. Ammonia and formalin seem to be most effective at removing Cryptosporidium from the environment. The best control of cryptosporidiosis comes from lambs and kids getting adequate immunity through colostrum soon after birth.
Salmonella
The bacteria Salmonella has thousands of serotypes and all can potentially cause diarrhea in animals. Salmonella can cause diarrhea in lambs and kids of any age. Animals less than 1 week of age are more likely to die without clinical signs, whereas animals older than 1 week are more likely to have diarrhea. Salmonella also causes outbreaks of diarrhea in late gestation and is frequently associated with abortion. Bleach is an effective disinfectant to use during an outbreak. Vaccine efficacy is questionable, and to date vaccination has not been thoroughly evaluated in sheep and goats.
Giardia
Giardia-induced diarrhea is more commonly, but not limited to 2 to 4 week old lambs and kids. The diarrhea is usually transient, but infected animals can continue to shed cysts for many weeks, providing a source of infection for other animals and possibly humans. Infected animals can be treated effectively with fenbendazole (SafeGuard®, Vabazen®).
Nutritional
Infectious agents are not the only cause of diarrhea in neonates. Nutritional problems can result in diarrhea. Nutritional diarrhea is most common in orphaned animals as a result of poor quality milk replacers, mixing errors, and overfeeding. Consumption of lush pasture or high-energy diets can also result in diarrhea in young lambs and kids.
A scouring lamb or kid loses large amounts of fluids and electrolytes, such as sodium and chlorine. Usually the cause of death in scouring lambs and kids is dehydration and acidosis, or increased body acidity. Whatever the microbial cause of scours, the most effective treatment for a scouring lamb or kid is rehydration by administering fluids.