Therapeutic Options in Management of a Clinical Case of Chorioptic Mange in a Goat

An adult male Jamnapari goat was presented with the history of skin itching and apparent loss of hair around the hind limbs and ears. The vaccination and deworming status of the patient were up-to-date.

Figure 1: A) Animal rubbing body against pen; B) Alopecia on the hind limb

Upon examination, the goat was observed frequently rubbing its body against the wall of the pen (Figure 1A). Examination of the limbs revealed bilateral crusty lesions on the hind limbs (Figure 1B) and there were also hard crusty patches on both ears (Figure 2A).

Figure 2: A) Hard brown crusty lesion on the ear; B) Scrapings from the affected ear

Skin scraping samples were collected from the affected regions (Figure 2B) and the samples were prepared and then examined under a light microscope at 40x and 100x magnification. Clusters of mite eggs were observed (Figure 3A), Active mites and a few female mites with an egg inside the body were also identified (Figure 3B). Examination of the mite pedicles revealed short pedicles and the presence of cup-shaped suckers on the legs (Figure 4A). Based on these findings, a definitive diagnosis of Chorioptic mange was made.

Figure 3: A) Clusters of mite eggs; B) Gravid female mite

Initial treatment was instituted with three weekly doses of ivermectin (0.2 mg/kg), subcutaneously as an ectoparasiticide. Unfortunately, one week after the treatment regime, the lesions of mange still persisted. Further treatment was thereafter instituted with Amitraz (0.05%) bath as topical ectoparasiticide (Figure 4B), weekly for 3 weeks. Examination of the goat after a week post-treatment revealed resolution of the lesions, hence a good prognosis.

Figure 4: A) Mite with rounded head and cup-shaped suckers; B) Bathing procedure with Amitraz (0.05%) starting from the head and ending at the tail region

Based on the clinical examination and laboratory findings, this case report was a definitive case of Chorioptic mange infestation. There was no evidence of pyrexia reported, which rules out the possibility of a systemic secondary bacterial infection, even though skin abrasions were apparent. The animal was stable but the frequent rubbing of the body on the wall of the pen might lead to exhaustion due to an expected drop in appetite and subsequent emaciation as reported by (Lughano and Dominic, 2006). Ivermectin, a broad spectrum non hygroscopic, semisynthetic, anthehelmintic, antiparasitic drug has been proven to be effective against endo and ectoparasites (Chanie et al., 2010; Cornall and Wall, 2015). In this case, ivermectin was used as ectoparasiticide at one dose weekly for three weeks (Marimuthu et al., 2015). The weekly interval of administration was simply to halt the parasite’s life cycle by inactivating the viable stages of the parasite on the animal (Lughano and Dominic, 2006), hence, avoiding the growth of the parasite to maturity.

Selective administration of ivermectin has been reported to be successful in treating mange infestation in goats (Leon-Vizcaino et al., 2001; Marimuthu et al., 2015). However, the treatment of Chorioptic mange with ivermectin has proved to be less effective in this study as lesions persisted even after the completion of the recommended treatment regime. This may be due to low systemic levels of the drug or due to re-infestation of the goat by mites from the environment (Demite et al., 2015). Mites can survive in the environment such as the wall of the pen, the bedding and floor for up to 12 weeks (Demite et al., 2015). Hence, spraying of the pens with acaricides after such treatments is of paramount importance in order to halt the reoccurrence of the parasitic infestation (Seid et al., 2016).

Scabs provide a safe haven for mites where they get protection and escape drug therapy. Subsequently they mature into adult and result in more infestation. In such kind of situation, topical treatment is strictly recommended (Tabassam et al., 2008). In this case, the use of Amitraz bath was able to successfully resolve the mange infestation in the goat(Brugger and Braun, 2000). The success achieved with the bath is because it was applied topically and Chorioptes mites are non-burrowing and surface living mites (Vieira et al., 2014). Amitraz generally has the ability to wash off scabs when applied topically as in this case, it washed off the layers of crusts and scabs which gave protection to the mites, thereby exposing the mites to the effects of Amitraz and their subsequent eradication.

In conclusion, ivermectin is an effective antiparasitic drug used to treat mange in goats, but in cases of re-infestation from the environment and/or presence of thick crusts and scabs, the use of topical bath with Amitraz proved more effective as it was able to wash off the scabs and resolve the condition as was observed in this case report.. Therefore, combination of ectoparasiticide drugs and compounds that can digest the layers of crusts and scabs is highly suggested in order to achieve an effective treatment regimen.

The authors wish to appreciate the management and staff of the University Veterinary Hospital (UVH) and Taman Pertanianuniversiti (TPU) of the Universiti Putra Malaysia (UPM) for their cooperation throughout the course of this case.

None to declare.

All authors contributed equally and approved the final manuscript.