Final report for LNC14-363
Project Information
Footrot in small ruminants is an extremely contagious disease, and there is no effective vaccine available in the US. This program has developed an early detection, diagnosis, and monitoring scheme that has integrated with footrot preventive education, demonstration, and training in an effort to reduce seasonal outbreaks among small ruminants. Over the project period, 320 animal footrot swabs or hoof lesion specimens were collected for culture and bacterial identification. Footrot lesion swabs were collected in transportation broth culture tubes and subsequently inoculated on sheep blood agar culture plates in duplicate for both aerobic (incubators) and anaerobic (anaerobe chamber) bacterial isolates. Identification of about one thousand isolates resulted in significantly more aerobic species and subspecies (n = 74) than anaerobic bacterial species (n = 21). Most footrot and hoof infections in these inspections were caused by mixed species (both anaerobes and opportunistic aerobes). The bacterial species more frequently isolated from these lesion swabs were Staphylococcus Spp., Prevotella spp., Actinomyces spp., Fusobacterium spp., Spirochaeta spp., and Corynebacterium spp. Whereas, more virulent bacteria species, such as Dichelobacter nodosus was identified for less than 6% of inspected farms. Selected species, including Dichelobacter nodosus, Fusobacterium necrophorum, Prevotella spp., Porphyromonas spp., Bacteroides spp., and Spirochaeta spp. were also examined for antibiotic resistant assays. Field demonstrations and hands-on training activities (e.g., hoof trimming and foot-bathing) were conducted at Crowder College Farm (Neosho, MO) and Lincoln University’s Alan T. Busby Farm (Jefferson City, MO). The regular footrot outbreaks were effectively prevented using a frequent, preventive foot-bathing schedule, and no footrot outbreak was observed in treated animals throughout the seasons. Farmers’ participated in the project through hands-on learning, attending training workshop and field day demonstrations, and adopting good practices at their own farms. Following the developed project protocols, workshop participants performed animal foot inspections, foot health scoring, hoof trimming, and foot-bathing. Eighty percent of producer-participants stated they were confident and felt proficient to conduct these preventive operations and treatments on their own farms after attending the training workshops and lectures. The technical information and research progress results were provided to the general public, goat and sheep farmers, veterinarians, agriculture students, and other researchers via website, workshop, field day presentation, producers’ society newsletters, report, and conference. The milestones achieved over the project’s duration have enhanced small ruminant producers’ skills and knowledge significantly for the on-farm detection, prevention, and diagnosis of footrot disease outbreaks. The accomplishment of project has improved small ruminant farming sustainability and profitability and decreased footrot outbreak frequency, labor cost, and animal loss.
The main purpose of this project is to organize farmers’ and producers’ training workshops for topics of small ruminant animal production, welfare, foot and hoof care, and demonstrate footrot prevention, treatment, and on-farm biosecurity protocol. Therefore, objectives of this project were (1) to develop early detection, diagnosis, and monitoring techniques for footrot outbreaks in small ruminants (goats and sheep); (2) to organize farmers’ and producers’ training workshops for small ruminant animal welfare, foot and hoof care, and on-farm biosecurity; and (3) to demonstrate footrot prevention, treatments, and management practices.
Small ruminant farming has become one of the popular diversifications for sustainable small farm operations in the North Central Region (NCR). Specifically, meat goat and sheep numbers have significantly increased in the last decade due to their suitability to graze on low-quality pastures, to control invasive plant species, to meet ethnic consumption demands, and as tools for forest-range management schemes. The frequent footrot outbreaks have reduced the profitability and sustainability of the small ruminant enterprise in Missouri and the North Central Region. Although footrot outbreaks in ruminant livestock have been reported more frequently throughout the US and footrot disease is becoming endemic in goat and sheep flocks in humid, seasonally warm regions with high rainfall. Footrot disease begins as an interdigital dermatitis that can extend into the adjacent hard horn tissue of animal hooves and cause debilitating pain, discomfort, and lameness as well as economic losses. Understanding the cause of footrot outbreaks and its prevalence is essential for developing a sustainable management, control, and prevention program. Although footrot disease is contagious and treatments are costly, an early detection, prevention, and management program should help producers to avoid frequent, large-scale outbreaks and livestock loss.
Cooperators
Research
- Casual infections of aerobic and anaerobic bacteria cause footrot disease in small ruminants.
- Hoof care and frequent foot-bathing during the prevalent seasons can prevent footrot outbreaks.
The objective of this field research experiment was to detect and monitor footrot outbreaks in goats and sheep, conduct bacterial culture and identification, provide training for foot and hoof care, and demonstrate an effective footrot management practice.
Farmers’ participation and training: Forty-eight sheep or goat farmers participated in the footrot detection and monitoring activity annually for three years, which involved reporting footrot outbreaks; engaging in diagnostic inspection, lesion swabbing, and pathogenic identification; providing periodic, preventive foot-bathing; and developing a footrot control protocol. A workshop that taught footrot detection, diagnosis, preventive foot-bathing, and animal health and care was conducted each spring (April) prior to the footrot-prevalent seasons. The footrot scoring system was standardized by using a 5-point scale (0-4), where a score or 0 is normal, while scores of 3 and 4 are severe footrot and treatable grades, in addition, 4C was classed as a chronic footrot grade (Figure 1). Producers were trained to provide hoof trimming, foot-bathing, footrot diagnosis, lesion swabbing, and to develop a footrot control protocol at Crowder College Farm, Lincoln University’s Busby Farm, and their own farms.
Footrot monitoring and pathogen identification: Hoof lesion swabs were collected from 36 flocks (10 goat and 26 sheep flocks) that had reported current or chronic footrot infections during the footrot-prevalent seasons. From each flock, 5-7 animals that showed either a sign of limping or a footrot score of 3 or 4 in their inspection records, were sampled. Over the period, 320 animal footrot swabs or hoof lesion specimens were collected for culture and bacterial identification. Footrot lesion swabs were collected in transportation broth culture tubes and subsequently inoculated on sheep blood agar culture plates in duplicate for both aerobic (incubators) and anaerobic (anaerobe chamber) bacterial isolates. Bacterial colonies were segregated and sub-cultured three or more times, until confirmation of a single species. The isolates were identified and verified for species identify by comparative tests using Biolog® and Biotyper® or Biotyper® and Sherlock™ Microbial Identification systems. Selected species, including Dichelobacter nodosus, Fusobacterium necrophorum, Prevotella spp., Porphyromonas spp., Bacteroides spp., and Spirochaeta spp. were also examined using antibiotic resistant assays with commonly used drugs (penicillin, oxytetracycline, and ZACTRAN®) at Crowder College Farm and Busby Farm. Over the project’s duration, 25 animals’ hoof trimmings were collected from those with a footrot score of 4 or 4C lesions for histological examinations by light, fluorescent, and/or scanning electron microscope, respectively.
Hoof care and frequent foot-bathing: Hoof care and periodic preventive foot-bathing demonstrations were conducted for a goat flock (n = 75) at Crowder College Farm (Neosho, MO) and for a sheep flock (n = 110) at Lincoln University’s Busby Farm (Jefferson City, MO). A selected number of animals (15 goats and 20 sheep) from these flocks were used by the training workshop’s participants for operational skill practice, including footrot inspection, hoof lesion swabbing, footrot scoring, body condition scoring, footbath solution formulation, FAMACHA© scoring, and fecal egg counting exercises. The goat flock was under an experimental biweekly (every 14 days) foot-bathing schedule (10 times) during the spring/summer months. The footbath solution was made with zinc sulfate at 12% (ZnSO4/water) concentration in ground built or portable troughs, where animals could stand and soak for 30 mins. The sheep flock at Busby Farm was managed as a control, without a preventive foot-bathing schedule in spring and summer. Animals were evaluated for footrot score and had their hooves trimmed prior to the start and end of the schedule (April and September).
The control and preventive footbath flocks were compared to determine the number of animals infected and treated for footrot during spring and summer. Data were analyzed using chi-square statistical procedures (SAS). Footrot lesions and infected wounds were treated with topical sprays of long-acting antibiotics in an alcohol (70%) formulation or Kopertox®. Animals with severe footrot were isolated and treated with antibiotics (penicillin, oxytetracycline or ZACTRAN®) prescribed by a local veterinary service.
There was no difference in the bacterial species that were isolated and identified from the goat and sheep footrot lesion swabs. Most of the swab cultures resulted in the isolation of three to nine species, which were a mixture of anaerobe and aerobes (Figure 2A), mostly commensal microbes. However, Gram-negative, rod-shaped bacteria (Figure 2B) dominated in the infected wound swab cultures. Identification of about one thousand isolates resulted in significantly (P < 0.01) more aerobic species and subspecies (n = 74) than anaerobic bacterial species (n = 21). The bacterial species more frequently isolated from these lesion swabs were Staphylococcus Spp., Prevotella spp., Actinomyces spp., Fusobacterium spp., Spirochaeta spp., and Corynebacterium spp. However, Dichelobacter nodosus (Figure 2C) and Fusobacterium necrophorum (Figure 2D), which are known to cause more virulent footrot in goats and sheep, were identified for six of the 36 farms. Whereas, it is critical to detect and monitor any presence of a more virulent bacterial species, such as Dichelobacter nodosus, involved in foot and hoof disease outbreaks in small ruminants. Selected species antibiotic resistance test assays indicated there was no resistance to these antibiotics in the footrot-infected animals.
The severe footrot and chronic foot or hoof lesions in goats and sheep prevented animals from standing, walking, and grazing (Figure 4A), and caused low live weights and/or production performance, which sometimes resulted in culling of valuable breeding stock. Especially during the hot and wet summer months, footrot infected animals were very prone to fly strikes, and subsequently developed secondary infections or external parasites (Figure 4B).
The footrot diagnosis and treatment or intervention frequency (%) was significantly higher in the control flock (Busby Farm) than in the preventive foot-bathing flock (Crowder Farm), based on the monthly evaluation summary (Table 1).
Table 1. Footrot diagnosis and treatment or intervention frequency (%) in control and footbath flocks
|
Infection rate (%) |
May |
June |
July |
August |
September |
|
Control flock |
10.9ns |
10.9** |
68.0** |
39.5** |
27.7** |
|
Footbath flock |
8.3 |
1.6 |
0.0 |
0.0 |
0.0 |
ns: no statistical difference; **: P < 0.01
Most footrot and hoof infections in these investigations were caused by mixed species (both anaerobes and opportunistic aerobes). Hoof trimming and footbaths for small ruminants prior to and during footrot-prevalent seasons were highly effective in preventing frequent outbreaks and flock-scale infections. The project benefitted producers through their collaboration and hands-on experience in footrot detection, prevention, and management practices for their farms, which decreases the disease control cost and breeding stock loss. Therefore, the project enhanced producers’ knowledge and skills for the detection and prevention of footrot outbreaks, and improved small ruminant livestock farming sustainability and profitability.
Education
The outreach education approach used for producers was primarily to train-the-trainers. As such, producers who participated in workshops, field days, and Crowder College Farm or Lincoln University’s Busby Farm demonstrations would be able to organize their local on-farm workshop/demonstration and/or adopt the biosecurity protocols and footrot preventive practice on their farms. The project enhanced producers’ knowledge and skills for the detection and prevention of footrot outbreaks in goat and sheep flock.
Accomplishments
- Facilitated footrot prevention, control, and management practice. Footrot preventive education, control, and management workshops were organized for producers, Extension professionals, researchers, and students during the spring of 2016 and 2017, respectively. The Project Coordinator, local veterinarian, and participant farmer-speaker presented a series of lectures and workshops. Field demonstrations and hands-on training activities (e.g., hoof trimming and foot-bathing) were conducted at Crowder College Farm (Neosho, MO) and Lincoln University’s Alan T. Busby Farm (Jefferson City, MO). At Crowder College Farm and Busby Farm, footrot preventive foot-bathing was conducted once weekly for six weeks in the summer and six weeks in the fall. The footrot outbreaks were effectively prevented using a frequent, preventive foot-bathing schedule, and no footrot outbreak was observed in the treated flock throughout the seasons. Following the developed project protocols, workshop participants performed animal foot inspections, foot health scoring, hoof trimming, and foot-bathing.
- Conducted on-farm visitations, field inspections, and footrot diagnostic trainings. Dr. Wuliji and his project team conducted frequent footrot prevalence surveys at small ruminant production workshops, field days, and livestock sales. In addition, the Project Coordinator engaged in online communication and also visited new participant producers’ farms and provided training for footrot inspection, diagnosis, and prevention practice. As lameness is a typical sign of footrot infection in goats and sheep, for a preliminary diagnosis, farmers were advised to inspect any animals that lagged behind the rest of the flock, limped, carried or lifted a sore foot, and/or knelt and crawled when grazing. Meantime, Dr. Wuliji established a standard diagnostic footrot score chart for producers to grade their animals using five score groups: 0 = normal foot and hoof; 1 = mild interdigital dermatitis; 2 = moderate interdigital dermatitis; 3 = extensive dermatitis and under-run horn; and 4 = severe dermatitis, under-run horn, and hoof wall; and in addition, 4C was classed as a chronic footrot grade. Producers were advised to use the chart to grade the severity of the footrot in their flocks and communicate with the project team by sending a short video clip or cell phone photos, and subsequently, to take action by either swabbing the lesions for bacterial culture or engaging in hoof trimming, foot-bathing, isolation, other treatments, or culling animals.
- Conducted footrot lesion swabs sampling, culturing, and pathogen identification. Footrot pathogens are anaerobes that inhabit animals or their environment. These pathogens spread from infected goats or sheep to soil, manure, and pasture, where footrot can be picked up by noninfected animals or taken by carrier animals to a new environment. Dr. Wuliji, Dr. Pennington, and Mr. Wilkins conducted footrot inspections, footrot lesion swabbing, and hoof trimming demonstrations on more than 60 goat and sheep farms during footrot-prevalent seasons from 2014 to 2016, including farms in North, Central and Southwest Missouri, where they worked for three years, repeatedly. At each farm site inspection, five to 10 animals suspected of having footrot infection were swabbed for foot/hoof lesions or interdigital necrosis for pathogenic culture and identification analysis conducted at the Small Animal Research Facility labs (Lincoln University). The producers were informed of the test results, infectious bacterial species and any antibiotic resistance information, biosecurity protocol, and treatment options. In addition, two flocks were inspected and monitored for footrot prevention or infection occurrence, one at Crowder College (Neosho, MO) (n = 75) and the other at Busby Farm (n = 110) during footrot outbreak seasons from 2015 to 2017. Mr. Wilkins, Dr. Pennington, and Dr. Wuliji inspected and monitored the Crowder College flock periodically. Whereas, Dr. Wuliji, Dr. Borigihan Hasibagan, Amy Bax, and Liga Wuri, a graduate research assistant, inspected and monitored the sheep flock (n = 110) at Busby Farm (Jefferson City, MO) during footrot outbreak seasons (2016/2017).
- Presented papers at meetings and conferences. Dr. Wuliji presented two poster displays (“An Out-of-season Breeding System for Organic Fall Lamb Production” and “Footrot Prevention in Sheep and Goats”) for the Lincoln University Field Day at the Missouri State Capitol (2017). He and his coauthors (L. Wuri, W. Lamberson, J. Hickford, S. Azarpajouh, and A. Bax) presented and published a research paper titled “Survey Screening for Footrot-resistant Gene Markers in US Hair Sheep and Their Crossbreds” in the Proceedings of the 19th International Symposium and 11th International Conference on Lameness in Ruminants (September 7-9, 2017, Munich, Germany). Dr. Wuliji, Dr. Pennington, and Jay Wilkins presented a poster titled “Detection and Prevention of Footrot Outbreaks in Goat and Sheep Flocks” at the 3rd National Goat Conference (September 16-18, 2018, Montgomery, AL). Dr. Wuliji, Dr. Pennington, Jay Wilkins, and Amy Bax presented a poster titled “Detection, Preventive and Management of Footrot in Sheep and Goats” at the 20th International Symposium and 12th International Conference on Lameness in Ruminants (March 10-13, 2019, Tokyo, Japan).
Project Activities
Educational & Outreach Activities
Participation Summary:
Learning Outcomes
- Footrot bacteriology, animal health and welfare, gastrointetinal parasilogy, footrot inspection and diagnosis, footrot bath formulation, hoof trimming etc
Project Outcomes
Periodic inspection, infected animal's isolation, hoof trimming and foot-bathing, and farm biosecurity protocol