Does tail docking prevent Cochliomyia hominivorax myiasis in sheep? A six-year retrospective cohort study.

Tail docking is a husbandry practice widely incorporated in sheep farms around the world. It is an irreversible mutilation that impairs animal welfare, both immediately and in the longer term. The defence of tail docking as a practice is centred around the perception that doing so contributes to the promotion of local hygiene, allowing the use of the wool, facilitating reproductive management and reducing the chances of myiasis, a disease caused by the invasion of blowfly larvae in the tissues of warm-blooded animals. However, current understanding of farm animal welfare questions the need to maintain practices such as tail docking. Thus, the aim of this study was to evaluate the effect of tail docking on the incidence of Cochliomyia hominivorax myiasis in sheep in an experimental flock in Brazil during a six-year retrospective cohort study. Relative risk, odds ratio and incidence rate ratio were the association measures adopted. A total of 4,318 data-points were collected and supplied the analytical model. Tail docking did not decrease the risk and, on the contrary, was found to increase the chances of sheep being affected by myiasis. The results support the hypothesis that tail docking is not a protective factor against the occurrence of myiasis and further fuel calls for a rethink of tail docking being deployed as a blanket measure in the prevention of myiasis in sheep.

Homeopathic Sulphur Ointment as Adjuvant in the Treatment of Sheep with Myiasis by Cochliomyia hominivorax (Diptera: Calliphoridae): A Case Series.

BACKGROUND: Myiasis by Cochliomyia hominivorax (Diptera: Calliphoridae) is a serious problem in animal health. Homeopathic Sulphur presents similarity with the clinical presentation verified in these cases and has already shown in vitro efficacy on the blowfly that causes this pathology. This article presents the report of a series of clinical cases of myiasis by C. hominivorax in sheep that underwent adjuvant treatment with homeopathic Sulphur and presents a theoretical-scientific discussion of biological events related to the clinical treatment of the condition. PATIENTS: Seven naturally occurring myiases affecting sheep from an experimental farm were treated by an ointment impregnated with the homeopathic medicine Sulph 12cH, used as adjuvant after the manual removal of accessible larvae from the wound during wound cleaning. The animals were treated daily and evaluated clinically until complete healing of the lesions. Clinical information on the evolution of the inflammatory and scarring process was collected. Blood counts and bacteriological examinations were performed before and after topical homeopathic treatment. RESULTS: The homeopathic ointment Sulph 12cH was able to inhibit the development of parasitic C. hominivorax larvae and promote tissue repair and healing in naturally occurring myiasis in the sheep of this study. CONCLUSION: The homeopathic medicine Sulphur, formulated as an ointment, may be a useful new and adjuvant therapeutic option for treating myiasis in animals.

Effect of Ointments of Sulphur or Pyrogenium on Larvae of Cochliomyia hominivorax (Diptera: Calliphoridae).

BACKGROUND: Myiasis by Cochliomyia hominivorax (Diptera: Calliphoridae) is a serious problem in animal health in tropical and sub-tropical regions. Ointment-type preparations are a good option of formulation in cases of myiasis in farm and pet animals. Sulphur and Pyrogenium have already shown in-vitro efficacy on C. hominivorax. This article describes an in-vitro experiment to test the inhibition of development from exposing larvae of C. hominivorax to two homeopathic ointments (prepared individually with Sulphur or Pyrogenium). METHODS: The homeopathic ointments were produced by mixing sterile lanolin, tocopherol and homeopathic medicine on a hydroalcoholic basis according to the Brazilian Homeopathic Pharmacopoeia. Larvae were obtained from naturally occurring myiases in sheep (wild larvae) or from a laboratory colony. The test consisted of exposing a group of 10 third-stage C. hominivorax wild larvae in contact with Sulphur or Pyrogenium ointment, or a group of 15 laboratory-propagated larvae in contact with the alcoholic vehicle of the ointment or homeopathic medicines prepared in sterile water (Sulphur or Pyrogenium), and observing the effect on the development, longevity and fertility of the blow-fly specimens. RESULTS: The C. hominivorax larval inhibition rate was 90.0% for the Sulphur ointment group and was 86.0% for the Pyrogenium ointment group. The non-alcoholic vehicle and the alcoholic vehicle inhibited the development of 24.0% and 22.08% of the larvae respectively. Sulphur prepared in sterile water inhibited the development of 74.67% and Pyrogenium in sterile water inhibited 73.33% of larvae. Specimens that survived contact with homeopathic ointments had their longevity decreased and did not reproduce. CONCLUSION: Ointments of Sulphur or Pyrogenium were able to inhibit the development of C. hominivorax larvae. The ointment vehicle was harmless.