In India, plant-based compounds have been used as a source of remedies since ancient times. They are more environment friendly, safer and effective against a range of animal parasites and pathogens (Jamil et al., 2022). Among such plants, neem is a widely distributed tropical plant that originated from India. Almost all parts of the neem tree reported to have varied insecticidal, larvicidal and acaricidal effects, mediated by groups of phytochemical compounds such as cardenolide, triterpene, azadirachtins, salannin, nimbin, and 6-desacetylnimbin (Gopinath et al., 2018; Pasipanodya et al., 2021). In the present study, camels treated with neem herbal formulation showed significant improvement of skin condition during the study. The camphor oil and mustard oil used in this neem formulation also reported to have acaricidal effect and they help in reliving itching, skin dryness/ roughness and alopecia (Morsy et al., 2003; Fang et al., 2016). It is speculated that the different compounds used in this formulation may have synergistic effect in treating the mange lesions and improving skin condition. The mustard oil can cause mechanical blockage and penetrate the integument. This would affect the ability of the arthropods to breathe by blocking their spiracles which are the external openings that allow oxygen to enter the body of the arthropods (Suraj et al., 2019). Mustard oil is rich in Vitamin E content and help to optimize hair growth, relieve dryness and itchiness of the skin and have cleansing effect making the skin more soft (Sharma and Joshi, 2004). The overall improvement in skin smoothness and fur growth of camels treated with neem herbal formulation may be attributed to these properties of mustard oil. The freshly prepared camphor oil also found effective in treating human facial demodicosis (Morsy et al., 2003). Curcuma longa powder used in the present herbal formulation has been used in previous studies for successful treatment of sarcoptic mange in buffalo calves (Sharma and Joshi, 2004; Naresh et al., 2005). In another study, daily topical application of neem leaves and turmeric paste along with ivermectin injection showed significant clinical improvement by the third week of therapy in mange affected camels (Periasamy et al., 2018). The synergistic effect of all the herbal components used in the present formulation may be thought to be responsible for drastic recovery of the camels within short span compared to previous studies using herbal preparations.
In histopathology of skin treated with neem formulation, absence of hyperkeratosis, acanthosis, inflammatory cells and mites or their remnants were recorded. This improvement may be related to the death of the mites and stoppage of the irritation, inflammation, pruritus, and consequently stoppage of skin destruction and hyperkeratosis in camels of both treatment groups. The neem formulation was also found to be safe for the camels, as there were no observed signs of skin irritation and inflammation or restlessness during the time of application and afterwards. As ascertained in previous studies, the neem has found to have high safety index and do not display any adverse effects when applied on skin or ingested by the animals (Seddiek et al. 2013, Pasipanodya et al., 2021).
Although ivermectin treated camels also showed improvement of clinical signs after the end of experiment, however the skin appearance was not found completely improved. In earlier studies it was reported that the ivermectin may have low efficacy against mange mites in chronically infected camels and may take upto 21 days for complete cure of mange lesions (Darwish et al., 2020). Moreover there could be possible resistance of mites against Ivermectin since indiscriminate use of Ivermectin is very common in India. Camel farmers in India usually self treat the animals which may lead to underdosing or overdosing and may initiate the resistance among mites.
Overall the neem herbal formulation of the present study was found to have comparable therapeutic modality with ivermectin, with superiority of healing of lesions and overall improvement of skin condition with short duration of treatment. The results of the present study also revealed that camels treated with neem formulation showed slight increase in feed intake, weight gain and improvement of body condition due to reduction in itching, irritation and restlessness. The preparation of this formulation does not require any sophisticated technique and farmers can easily prepare this formulation with locally available cheap ingredients. Hence, this can prove to be a farmer friendly and environment friendly solution for treating mange in camels. In conclusion, the results of the present study indicated that neem herbal formulation can provide a cheaper, safer, easily available and more eco-friendly alternative for the control of sarcoptic mange in camels.