A 5-year-old female alpaca (Bonnie) was brought to our attention by the animal care worker who noticed some dermatological problems. The alpaca was part of a three-animal group (two females and one male) from the public zoo in Galaţi, south-eastern Romania. The animals were housed together in an outside paddock with free access to an inside shelter. The animal was donated to the zoo, together with another alpaca by its former private owner who kept it as a pet. Both donated alpacas were kept in quarantine for 14 days before introducing them in the paddock with the other alpaca from the zoo. As part of the routine parasite control program, all alpacas were given an annual subcutaneous shot of ivermectin (1 mL/50 kg), with the last dose was given in September 2019. In August 2020, the zoo veterinarian performed a clinical examination of the herd and skin lesions on the ears accompanied by restlessness were observed in one of the animals. No other clinical signs were noted, and no other animals were clinically affected. The patient was restrained and a skin sample containing crusts, scabs and plucked hair was collected and sent to the Department of Parasitology and Parasitic Diseases at USAMV Cluj-Napoca. The skin sample underwent a direct examination under a stereo zoom microscope. In addition, artificial digestion of the crusts, using 10% KOH was performed. The collected crusts were mixed with 200 mL of 10% potassium hydroxide solution and heated until boiling. The digestion was interrupted after 3 min, when the skin particles were dissolved. The material was transferred to 50 mL corning tubes and centrifuged for 2 min at 1,000 rpm. The supernatant was discharged, and the sediment was poured into a Petri dish. Mites were cleared from the skin crusts and analyzed under an optical microscope (Olympus BX61). Part of the mites was mounted on slides with lactophenol and morphologically identified. Treatment with doramectin (Dectomax, Zoetis, US) 1 mL/50 kg was injected subcutaneously four times at 2-week intervals. The other two alpacas were also treated even though they did not present any lesions. Every 2 weeks, all the animals from the same group were visually inspected in order to follow the evolution of the disease. Since no improvement was noted, after 2 months, the alpaca with the clinical disease was transferred to the Department of Parasitology and Parasitic Diseases, USAMV Cluj-Napoca. A complete physical examination was performed, followed by hematology and blood biochemistry. Two cutaneous samples were collected using sterile swabs for detection of secondary fungal and bacterial associated infections using specific culture media. A multivitamins and minerals complex (Selevit, Pasteur Institute, Romania, 5 mL/animal) was orally administered daily for 2 weeks in order to help the recovery and acclimatization to the new environment. Local treatment with salicylic acid (BingoSpa, Poland) (100%) mixed with glycerol (BingoSpa, Poland) (99.5%) was applied for five consecutive days for removing the hyperkeratotic crusts. The ear pinas were washed weekly with chlorhexidine 3% shampoo (DouxoS3, Ceva Sante Animale, UK) for the whole period of the treatment, followed by local application of amitraz (0.5 mL diluted in 200 mL water, 12.5% Scobatox, Pasteur, Romania) using a clean sponge. Eprinomectin (Eprecis, Ceva Sante Animale, UK) 0.6 mL (1 mL/100 kg) was administered subcutaneously weekly for 8 weeks. Every week, the animal was removed from the shelter for a cleansing protocol and 5 g tetramethrin + 50 g transmix (Neostomosan, Ceva Sante Animale, UK) (1:200 dilution) was sprayed in the room. Skin scrapings were collected every week to evaluate the efficacy of the treatment, until negative for 2 months. After the complete recovery, the animal was sent back to the zoo.

The animal was legally transported from Galaţi to Cluj-Napoca, regarding the national legislation. Approval of the bioethical committee was not necessary since we did not do any experimental procedures on it. During its stay in Cluj-Napoca, the animal was housed accordingly.

The second episode refers to a couple of adult llamas, a 45 kg 4-year-old female (Pacha) and a 40 kg yearling male (Cuzco), owned by the managers of a recreational teaching farm in Caselette, north-western Italy. Like the fore mentioned alpaca, patients were part of a three-animal group including an adult female goat, housed in a paddock with free access to an indoor shelter. Both llamas were purchased from a nearby llama farm on April 3rd, 2019. According to owners, on arrival both animals appeared in excellent body condition and no skin lesions nor pruritus were observed. No quarantine nor any anti-parasitic treatment were applied before putting llamas in contact with the single adult goat already inhabiting the paddock. In mid-May, owners recorded itching in all animals and obvious alopecia and reddening on the distal hindlimbs of the male llama. Based on contagiousness and symptoms, a local large animal practitioner clinically suspected “mange” and applied to all animals a twofold subcutaneous treatment with 2% ivermectin (Ivomec®, Boehringer Ingelheim) at the approximate dose of 200 μg/kg b.w. at 11-days intervals. Since no clinical improvement was observed in llamas, a third dose of ivermectin treatment was administered after 8 days, with poor results. This prompted the request for a second opinion by the Parasitology unit of the Department of Veterinary Sciences, University of Turin. Patients were first visited on site on June 25th. Itching was noticeable in all animals in the paddock. Both, the llamas, and the goat were physically restrained, and, besides recording and documenting skin lesions, deep skin scrapings were obtained from multiple sites at the margins of affected skin. Collected samples were digested in a 10% KOH solution for 2 h at room temperature, and numerous Sarcoptes mites of all stages were microscopically observed in all scrapings from llamas though not from the female goat. A new therapeutic plan was suggested limited to clinically affected llamas, including an initial twofold subcutaneous administration of 2% moxidectin (Cydectin®, Virbac, Italy) at the approximate dose of 600 μg/kg b.w. at approximately 10-days apart, eventually followed by similar additional administrations in the event of persistent mite positive scrapings independently of clinical improvement. It was established that the treatment plan would have not been suspended before a second serial negative skin scraping would have been obtained from both llamas.

Ethics approval was deemed unnecessary.

Clinical inspection revealed extreme agitation due to pruritus and the presence of scaly, crusty lesions on the external ears accompanied by local alopecia, hyperkeratosis, and thickened skin (Figure 1a). The direct examination of the collected skin sample showed no evidence of a parasitic infestation, but mites were detected after being freed from the galleries by performing the digestion of the skin crusts. The mites were morphologically identified as Sarcoptes scabiei (Figure 2). Different stages of Sarcoptes were detected: eggs, larvae, adult females, and males. No other mites were detected. Blood biochemistry and hematology showed no abnormal values. Secondary infections with bacteria or fungi were not detected.

Two weeks after the first treatment, the lesions failed to improve. However, crusts were almost completely removed after 10 days of topical application of 3% chlorhexidine shampoo and the salicylic acid. After 1 month from the combined antiparasitic treatment in the new location, alive and dead mites were still present in the skin scrapings. After another two weeks, all the detected mites were dead and by the end of the treatment (8 weeks), no mites were detected. The monthly evolution of the skin lesions is presented in Figure 1. None of the people involved in handling the alpaca, nor the zookeepers manifested any pruritus or other dermatological conditions. The animal was followed by phone, by questioning the zoo owner. After 5 months, no relapse was noticed.

At first consultation (Day 0), severe itching was obvious on both llamas though skin lesions were far more extensive in Cuzco, including: severe, diffuse scaling, particularly noticeable after hair clipping; skin reddening on the belly, axillae and, to a lower extent, on forelegs and hind limbs; hair thinning to alopecia on the belly, axillae, forelegs, distal fore and hind limbs, posterior and internal aspects of the proximal hind limbs; skin wrinkling on the last mentioned areas on the hind limbs; soft and relatively thin (≤ 2 mm) exudative crusts on medial cantus of the eye, the ventral aspect of the tail, the perianal zone and the perineum (Figure 3). Skin lesions were more localized in Pacha, in which reddening and hypotrichosis to alopecia, on the axillae, forelimbs, external pinnae and internal aspect of the thighs, and thin, soft (≤1 mm) crusts in the perianal zone were recorded. Trivial dermatological signs were observed in the cohabiting goat, including mild pruritus, a dull coat and small scattered alopecic areas on the neck and shoulders, possibly because of scratching. At second consultation (Day 10 post-treatment–PT), after the treatment, signs had disappeared in the goat though not in the llamas, in which severe itching was persistently noticed by owners in the time interval from the first moxidectin administration. On handling, the only clinical improvement was the attenuation of skin reddening on Cuzco's belly and axillae and the initial drying of the localized crusty lesions in both llamas. Skin scrapings remained positive in both patients, whereas the recovered goat was not sampled. Mites of all stages were observed in Cuzco, though only eggshells, larvae and a few nymphs were present in Pacha. At third consultation (Day 19 PT), after the second dose of moxidectin, mild itching was observed only in Cuzco. In this patient, a general attenuation of scaling and skin reddening was present, together with the disappearance of crusty lesions in the perianal and perineal zone and their further drying in the periocular zone. In Pacha, clinical improvement was evident, including the disappearance of skin reddening, clearance of perianal crusty lesions and the observation of initial hair regrowth on the previously alopecic area. At skin scraping, no mites were detected in Pacha whereas larvae, eggshells and a few larvated eggs and nymphs were still observed in Cuzco. A third dose of moxidectin was administered to both llamas and at fourth consultation (Day 30 PT) no itching was recorded on any animals nor any skin alterations were detectable on Pacha and the goat. In Cuzco, crusts on the periocular zone had cleared and the only persisting alterations were attenuated skin wrinkling on the posterior aspect of the proximal hind limbs and the incomplete hair regrowth in previously alopecic zones. No mites were present in the skin scrapings of both llamas. A fourth dose of moxidectin was administered to them followed by the fifth and final consultation (Day 40 PT), with no clinical signs detected on any of the animals. A lively hair regrowth of previously alopecic areas was present in Cuzco. Skin scrapings blindly obtained from previously affected areas of both llamas yielded negative results. According to protocol, no further treatments were applied. Periodic phone contacts with the llama owners in the 12 months that followed the closure of the case witnessed no relapse and a healthy state in all animals.