Enzootic posthitis in post-weaning lambs: A case series

Abstract

Enzootic posthitis is a disease that causes ulcerative lesions in the external genitalia of lambs, leading to negative effects on animal welfare, animal health, and profitability. The disease can be observed anywhere in the world where sheep breeding is common. Enzootic posthitis has a multifactorial aetiology but is primarily caused by rations with high protein concentration. Older lambs and adult rams during the mating term are more commonly affected, whereas the occurrence in younger lambs is a rare finding. This report describes the disease detected in 6 Merino male lambs 75-90 days old and compares their clinical and laboratory findings with six healthy lambs. Approximately 100 male lambs in a flock of 300 reportedly had varying degrees of difficulty in urinating, preputial lesions, and bloody urine. Clinical examination of the affected lambs revealed an inflamed prepuce (hot, painful, and swollen) and lesions with slight hyperemia to ulcerative changes. Preputial lesions generally consisted of circular ulcerative lesions and scabs, and the tissue was prone to bleeding when the scabs were removed. Blood and urine samples, as well as preputial swabs, were taken for laboratory analyses. Corynebacterium renale, Staphylococcus intermedius, Streptococcus uberis, and Truperella pyogenes were isolated during the microbiological examination of the preputial samples. A diagnosis of enzootic posthitis was made based upon the clinical and laboratory findings of the affected lambs. For comparison, six healthy lambs were selected and evaluated. Clinical examination and some laboratory analyses performed for all lambs revealed no statistical differences in body temperature (39.78 +/- 0.13 and 39.43 +/- 0.13 degrees C), total leukocyte count (7773.33 +/- 649.13 and 6916.66 +/- 802.25/mm(3)), and hematocrit (PCV%) (47.00% +/- 3.54 and 39.33% +/- 1.45) between the diseased and healthy lambs; however, the mean urine pH values were 8.41 and 7.66, respectively (p <0.05). After the diagnosis, ration was rearranged with addition of ammonium chloride and reduction of protein concentration. Additionally, amoxicillin (15 mg/kg, two doses 48 hours apart, IM), metamizole sodium (20 mg/kg daily for two days, IM), and vitamin C (20 mg/kg for three days, IM) were administered together with local treatment of preputial lesions by using pomade rivanol for three days. With this treatment and management practices, lesions in many animals were healed on the 7th day of treatment and completely healed on the 10th day. Here, for the first time to the best of our knowledge, we document the presence of severe and widespread enzootic posthitis in male lambs aged 75-90 days to emphasize the importance of correct ration planning during the rearing period.