Coccidiosis in Small Ruminants
What are the primary costs that factor into raising small ruminant animals?
What is coccidiosis?
Coccidiosis or intestinal coccidiosis in small ruminants is the clinical disease and accompanying array of symptoms caused by the infection of coccidian protozoa in the genus Eimeria. Depending on the level of infection and type of coccidia species, coccidiosis can be characterized by varying levels of morbidity, mortality, enteritis and a decrease in performance parameters.
How does coccidiosis impact the global sheep, goat and deer industries?
Coccidiosis is a major concern in small ruminant species worldwide due to its effects on enteric health and overall herd performance. In the U.S., coccidiosis is responsible for an estimated $341 million in economic losses. Additionally, interactions of coccidiosis with other disease pathogens and nutritional imbalances can lead to further stress in animals — and, as a result, an increase in the severity of other clinical disease symptoms. Considering the costs of prevention and/or treatment, as well as the production losses it can incur, coccidiosis is widely recognized as a disease with a great economic impact on small-ruminant operations.
What causes coccidiosis in small ruminants?
Coccidiosis is caused by the apicomplexan protozoan parasite in the genus Eimeria. Eimeria are host-specific, meaning that various distinct forms of intestinal coccidiosis can manifest in different species. Young kids and lambs are the most vulnerable to this disease and can become infected by ingesting oocytes when grazing or through poorly sanitized supplies that have been contaminated with feces from infected animals. When an animal is infected, the oocytes subsequently make their way to the intestine, where they ultimately multiply further.
Coccidial infections are self-limiting, and their severity is correlated to the number of oocysts ingested, as well as the type of Eimeria species. Eimeria oocysts are ubiquitous in small-ruminant environments and can be introduced to new farms via paratenic hosts, infected equipment, litter, vermin, personnel, equipment and other means.
Signs to watch for:
Coccidiosis symptoms can vary from mild to severe, but most infections are considered mild. However, due to the disease’s invasion and subsequent destruction of host cells, even mild infections can negatively impact the conversion of feed nutrients into meat. The clinical signs associated with coccidiosis are species-distinctive, and the severity of the infection is determined by analyzing the gross lesions, as well as any microscopic intestinal lesions.
Signs to watch for:
- Watery diarrhea with or without mucus or blood
- Constipation
- Lack of appetite accompanied by fever
- Dehydration because of diarrhea
- Weakness in the animal
- Emaciation caused by weight loss
Management tips to help prevent coccidiosis
The prevention of coccidiosis in small ruminants is key to avoiding damage from infections and to mitigating any associated production losses and welfare issues.
The recommended integrated approach includes a combination of:
- Antimicrobials
- Antiprotozoal agents (coccidiocidal vs. coccidiostatic)
- Vaccines
- Improved animal husbandry practices
Additionally, as many in the industry decrease their use of antibiotics for management and prevention, naturally derived feed additives have become more popular — especially those derived from:
- Essential oils
- Prebiotics
- Probiotics
- Postbiotics
- Saponins
- Tannins
These additives are most successful when used in conjunction with good facility-management practices.
Here are a few additional tips and recommendations to help reduce the risk of coccidiosis:
1. Maintaining good sanitation practices in pastures, pens, and food and water sources is crucial, regardless of the type of production system. Additionally, cleaning and disinfecting must be done between groups and a quarantine period should be observed to prevent other diseases from being introduced into the current group of animals.
2. Minimize weaning stress when possible and introduce a creep feed to young, newly weaned or soon-to-be weaned animals.
3. Immune status plays a significant role in the recovery from — and subsequent tolerance for — diseases. Help ensure a healthy start by mitigating any immunosuppressive causative agents, such as viruses and mycotoxin challenges.
4. Providing high-quality feed ingredients and ensuring the availability of feed will contribute to the delivery of feed additives that help mitigate coccidia infections while also diminishing any secondary infections associated with coccidia cycling and helping the animal maintain positive gut health overall.
Coccidia control programs should be tailored to each operation’s unique circumstances. That being said, every plan for controlling coccidia long-term should include routine monitoring and testing to evaluate the effectiveness of the program. Implementing sustainable practices when possible is also recommended.