The US turkey industry continues to be hampered by a lack of approved efficacious drugs, according to a 2017 survey. Since 2005, four medications have been withdrawn, leaving the industry without any recourse to treat colibacillosis, blackhead and other diseases.
As he has done annually for over 17 years, Steven Clark, DVM, Devenish Nutrition, conducted the survey, which represents 99.9% of the turkey industry.1
In addition to the lack of medications for important diseases, the 23 turkey veterinarians and professionals surveyed expressed concern about the shortage of veterinarians trained in the field. Clark notes that “most post-DVM poultry-medicine training programs have little to no exposure to the turkey industry.”
Colibacillosis is the disease that most affects the industry, the survey indicates. The withdrawal of a New Animal Drug Application for enrofloxacin in 2005 has left the industry without an adequate treatment for the disease, which continues to grow in importance, he reports.
There’s been no treatment for blackhead (histomoniasis) since nitarsone sales were suspended in 2015. There were 109 reported cases of the disease in 2017, an increase of eight cases compared to the year before. Three-quarters of the respondents reported at least one case of blackhead, and 5% of affected flocks were destroyed to alleviate animal suffering.
Ornithobacterium rhinotracheale, the highly contagious respiratory disease of turkeys, ranked No. 3 in importance in 2017. In 2015, it was No. 7 on the list. Strong biosecurity procedures and good management systems are a must. Recently, controlled exposure of individual flocks seems to help control the disease, Clark says.
Interestingly, coccidiosis has moved to the No. 6 spot on the list, compared to No. 13 last year, a change that reflects the increase in turkeys raised without antibiotics and no antibiotics ever. These production systems do not permit the use of ionophore anticoccidials, and many programs prohibit the use of non-ionophore anticoccidials. Therefore, control programs consist of vaccination or antibiotic alternatives, such as nutritional supplementation with phytonutrients, he says.
Although clostridial dermatitis (CD), or cellulitis, has dropped from No. 2 in 2016 to No. 4 in 2017, it remains a major issue across the industry. CD is most commonly seen in market-age male turkeys. Clostridium septicum, C. perfringens type A, or C. sordelli are commonly isolated in birds with this condition. Keys to CD control include early recognition, removal of dead birds two to three times per day and medicating affected flocks with appropriate antimicrobials. Additional measures include managing water spills and wet litter, avoiding feed outages and keeping composted litter at least 200 feet away from the poultry barn, Clark continues.
Turkey arthritis reovirus (TARV) has become an industry-wide concern with 182 cases reported in the 2016-2017 production year, compared to only 31 cases the year before. This disease, also known as turkey reovirus digital flexor tendon rupture, emerged in 2011. A unique reovirus has been identified as the cause.
Clinical signs of TARV in young flocks are mild or nonexistent but can develop into lameness and/or abnormal gait starting at 12 weeks of age. Affected flocks also have poor flock performance. The combined efforts of breeder vaccination, commercial farm biosecurity and flock management previously controlled this disease to some extent. The increase in the disease despite greater awareness could indicate the reovirus has mutated, Clark says.
1. Clark SR, Ahlmeyer V. Current Health and Industry Issues Facing the US Turkey Industry. Proceedings 121st Annual Meeting of the USAHA, San Diego, CA; Committee on Poultry and Other Avian Species. Pending Publication. Oct 17, 2017.