P‐87 Alopecia in two guinea pigs due to hypopodes of Acarus farris

Mites are frequent agents of skin diseases in veterinary dermatology, particularly in rodents. The authors report an original case of infestation in two guinea pigs of the same household. Two adult guinea pigs were presented with a 3‐month history of alopecia, matted hair, erythema, scales and mild pruritus. The first guinea pig showed almost complete truncal alopecia with mild scaling, whereas the other one had only recently developed mild alopecia of the abdomen and mild pruritus. Numerous live, long‐legged mites were present both in adhesive tape and skin scrapings. Mycology (Wood's lamp and DTM agar culture) was negative. Histopathological examination of a skin biopsy did not reveal any significant inflammatory disease and morphological changes were limited to hair follicles in the telogen phase. Mites were identified as hypopodes of Acarus farris (Acaridae), but no adult stages were present. Hypopodes were also found in the hay. Control was obtained with acaricidal treatment with Phoxim 0.05% once weekly for 4 weeks, and the elimination of contaminated hay. The lesions and the alopecia resolved rapidly. Hypopodes are additional nymphal stages of some mites of the suborder Astigmata. They develop for dispersing or dormancy under disadvantageous conditions. They can be active or inert, and some can be phoretic on the skin surface or intrafollicular. Although nonparasitic, they may cause dermatitis. Acarus farris have been rarely mentioned in the literature as a cause of dermatitis. This condition could be underdiagnosed or misdiagnosed in veterinary dermatology. Funding: Self‐funded.     

Feline demodicosis: a consideration in the itchy or overgrooming cat

PRACTICAL RELEVANCE: In cats, three species of demodex mites have been identified as causes of demodicosis, which may manifest as pruritus, miliary dermatitis and/or self-induced alopecia. The condition has been recognized in various countries but does seem to show regional preferences. CLINICAL CHALLENGES: Diagnosis of feline demodicosis can be a challenge as mites are not always readily found within scrapings of the skin examined microscopically. One or more species of demodex mite may be involved in an infestation. Furthermore, the condition can be difficult to treat effectively. AUDIENCE: This review is intended as a clinical update for veterinary surgeons in practice who rarely encounter demodicosis.     

P-32 Giant cell dermatosis in a FeLV-infected cat: detection of the virus in infected skin by immunohistology and PCR

The aim of this study was to report 20 cases of Lynxacarus radovskyi infestation in 20 cats . Lynxacarus radovskyi was diagnosed by physical examination and microscopic examination of plucked hair where countless adult mites and immature stages were identified. Microscopic examination was repeated every 7 days. The animals were observed daily for the first 7 days, and again on day 15 and day 30 for mites, pruritus and clinical signs. Clinical signs included salt-and-pepper appearance to a dull and opaque hair coat, alopecia of the dorsal and lateral areas of the hind limbs, and evidence of self-mutilation. One case had papules and crusts of the hind limbs. The pruritus was mild in animals with low infestation, but very intense in those with a heavy infestation. Most mites occurred in the lateral area of the hind limbs and sacral area. Twenty of 100 animals had confirmed L. radovskyi infestation. Therefore, we suggest that the transmission occurs through fomites. Treatment consisted of 0.5 mL application of Fipronil^® (Frontline TopSpot) per cat, with resolution in 100% of cases by day 15.
Funding: Merial.     

Trombiculosis in a cat.

Trombiculosis (dermatitis caused by trombiculid mites) in a Domestic Shorthair cat was characterized by diffuse thickening and crusting of the skin of the abdomen and limbs and by multiple papules on the face, ears, and sides of the trunk. Skin biopsy revealed acanthosis and hyperkeratosis involving the epidermis and hair follicles, mites in epidermal tunnels, and edema of the dermis, with infiltration of eosinophils and mast cells. Mites from skin scrapings were identified as Walchia americana. The cat was treated systemically with a broad-spectrum antibiotic and topically with a carbaryl and pyrethrin powder preparation. The lesions were resolved within 2 months.     

Pruritus in rabbits, rodents, and ferrets

This article attempts to cover the more specific pruritic problems encountered in rabbits, rodents, and ferrets. There are certainly other causes of pruritus in these animals. Dermatophytes in guinea pigs are not reported to be pruritic, but because they are pruritic in other species, they should be considered in a differential diagnosis. A cryptococcal dermatitis in a guinea pig that was pruritic has been reported. Although mites were not seen on scraping, the animal was treated for sarcoptid mites and apparently the pruritus lessened. Because the cryptococcis was still present, it is questionable whether it was causing the pruritus. Pruritic ulcerative dermatitis over the back and shoulders has been seen in some lines of rats. Staphylococcus aureus was cultured from many of the lesions. Clipping the toenails on the feet helped lessen the severity of the lesions. Syphacia spp. have been reported in rats, gerbils, and hamsters and should be considered if there is perineal pruritus. MOBS, or "move over buddy syndrome," is seen especially in mice and may be seen in hamsters, gerbils, and rats that are overcrowded or stressed. The lesions are actually bite wounds that have been inflicted around the tail base and the perineum and on the tail, but these wounds can be mistaken for self-inflicted trauma from pruritus. All of the recommended treatments are extralabel, and clients should be informed of this. I have observed a guinea pig become lethargic and anorexic after only one application of a flea powder approved for use in cats. Brushing most of the powder off and offering dandelion greens to stimulate appetite helped. The second dusting was done with the same flea powder diluted with baby powder. Whenever these animals are dipped, it is important to let them dry in a warm, draft-free area. Again, it is important to be aware that the ratio of surface area to body weight is much higher in these small animals than in the species routinely seen in veterinary practice especially to prevent toxicoses from topically applied medications and iatrogenic hypothermia or hyperthermia.     

Cutaneous xanthomas with concurrent demodicosis and dermatophytosis in a cat

Multiple cutaneous xanthomas, associated with fasting hyperlipidaemia, are described in a 9-month-old domestic long-haired cat. A severely pruritic, papular, and crusting dermatitis affecting the head and neck, initially diagnosed as lesions of the eosinophilic granuloma complex, progressively developed on the head and pinnae. Pruritus was controlled with administration of prednisolone and chlorambucil. Repeat histological examination confirmed the diagnosis of cutaneous xanthoma and concurrent mild demodicosis. Marked fasting hypercholesterolaemia, hypertriglyceridaemia and transient hyperglycaemia were subsequently confirmed. Treatment for hyperlipidaemia and xanthomas with a low-fat diet (Hill's Feline r/d) and the previously unreported treatment for feline demodicosis of daily oral milbemycin were commenced. Multiple pink, alopecic plaques and papules gradually regressed, however pruritus recurred if immunosuppressive treatment was reduced, and well-demarcated areas of alopecia developed on the head, limbs and trunk, despite negative skin scrapings for demodex mites. Fungal culture of hair samples yielded Microsporum canis. All cutaneous lesions resolved with the addition of griseofulvin to the treatment regimen. Concurrent corneal ulceration and keratoconjunctivitis sicca ultimately resolved with treatment, including topical cyclosporin. Diabetes mellitus developed 6 months after resolution of skin lesions. No cutaneous or ocular abnormalities were present 6 months later with continued low-fat diet and insulin administration, although transient recurrence of papules and pruritus occurred after inadvertent access to a fatty meal. An underlying primary hyperlipidaemia was suspected, causing pruritic xanthomas. This may represent the first report of concurrent cutaneous xanthomas, demodicosis and dermatophytosis in a cat.     

Epidermal dysplasia and Malassezia infection in two West Highland White Terrier siblings: an inherited skin disorder or reaction to severe Malassezia infection?

Two 9-month-old West Highland White Terrier siblings were referred to our clinic with pruritus, alopecia and lichenification. Cytological examination of Scotch tape strippings revealed Malassezia organisms and cocci. Skin biopsy specimens showed epidermal dysplasia. Treatment included bathing with a 2% miconazole/chlorhexidine-containing shampoo, orally administered ketoconazole (5 mg kg-1, every 12 h) and cloxacillin (25 mg kg-1 every 8 h). Six weeks later, the dermal infection had resolved and there was hair regrowth. However, the dogs were still moderately pruritic. Intradermal allergy testing was positive for house dust mites, storage mites and Malassezia. Immunotherapy was initiated, and treatment with ketoconazole and cloxacillin was stopped. Skin biopsies, which were performed in both dogs 4 months after the first presentation, revealed mild superficial perivascular dermatitis. The remaining mild facial pruritus was easily controlled with topical treatment. These two cases indicate that epidermal dysplasia might be an inflammatory or hypersensitivity reaction to the Malassezia infection or a result of excessive self-trauma, rather than a congenital keratinization disorder.     

Dermatosis associated with Acarusfarris in gerbils

A dermatosis associated with Acarus farris is described in a group of three gerbils. Large numbers of an immature stage (hypopi) of the mite were found on hair pluck samples. Treatment and changes in management led to a resolution of the problem.     

P‐30 Use of fipronil for treatment of Lynxacarus radovskyi in outdoor cats in Rio de Janeiro (Brazil)

The aim of this study was to report 20 cases of Lynxacarus radovskyi infestationin 20 cats. Lynxacarus radovskyi was diagnosed by physical examination and microscopic examination of plucked hair where countless adult mites and immature stages were identified. Microscopic examination was repeated every 7 days. The animals were observed daily for the first 7 days, and again on day 15 and day 30 for mites, pruritus and clinical signs. Clinical signs included salt‐and‐pepper appearance to a dull and opaque hair coat, alopecia of the dorsal and lateral areas of the hind limbs, and evidence of self‐mutilation. One case had papules and crusts of the hind limbs. The pruritus was mild in animals with low infestation, but very intense in those with a heavy infestation. Most mites occurred in the lateral area of the hind limbs and sacral area. Twenty of 100 animals had confirmed L. radovskyi infestation. Therefore, we suggest that the transmission occurs through fomites. Treatment consisted of 0.5 mL application of Fipronil^® (Frontline TopSpot) per cat, with resolution in 100% of cases by day 15. Funding: Merial.     

An undescribed Demodex sp. and demodicosis in a captive koala (Phascolarctos cinereus).

A 12-yr-old male koala (Phascolarctos cinereus) in a zoo collection developed bilateral, noninflammatory, periocular alopecia. Deep periocular skin scrapings yielded multiple adult, nymphal, and larval mites of a previously undescribed Demodex species. Skin biopsies from affected areas revealed multiple mites in superficial keratin and within hair follicles, associated with a mild intramural lymphocytic folliculitis. Treatment with daily oral ivermectin was safe and effective. Although Demodex sp. are previously reported from skin scrapings in another koala with periocular alopecia, this is the first confirmed case of koala demodicosis.     

Severe bilaterally symmetrical alopecia in a horse

A 9-year-old Tennessee Walking Horse gelding was presented for diagnosis of the cause of extensive alopecia. Complete hair loss was noted over the head, neck, shoulder, thigh, and proximal limbs, but the trunk, distal limbs, pelvic area, mane, and tail were unaffected. The alopecic areas were visually noninflammatory with no exudate or crust except on the shoulder and along the back, where multifocal patchy areas of alopecia with scales and crust were evident. The horse was slightly pruritic. Microscopically, the hair bulbs, inner and outer root sheaths of inferior segments, and perifollicular regions were infiltrated by small to moderate numbers of small lymphocytes. Similar inflammation was occasionally evident in isthmus follicular walls as well as some apocrine glands. No sebaceous glands were affected. Immunohistochemistry confirmed that the small lymphocytes were CD3(+) T lymphocytes. The epidermis from the skin with scale and crusts along the horse's back exhibited mild to moderate hyperplasia, mild lymphocytic exocytosis, mild eosinophilic dermatitis, and diffuse parakeratosis with numerous budding yeasts, consistent with Malassezia spp. The final disease diagnosis was made as alopecia areata with Malassezia dermatitis. Alopecia areata could be a contributing underlying factor for Malassezia dermatitis.     

Demodex injai infestation and dorsal greasy skin and hair in eight wirehaired fox terrier dogs

Demodex injai mites were detected on trichoscopic examinations and/or deep skin scrapings in eight wirehaired fox terrier dogs with dorsal greasy skin and hair. Histological examination performed in five dogs revealed marked sebaceous gland hyperplasia with lympho-plasmacytic periadnexal dermatitis in all of them. One mite section was observed in one patient. Seven dogs were parasitologically cured after 2 to 7 months of oral ivermectin treatment. Greasy skin and hair resolved in four dogs, was partially reduced in two dogs and persisted in the remaining dog. Skin biopsies were repeated after parasitological cure in two dogs and revealed the persistence of sebaceous gland hyperplasia with mild lympho-plasmacytic periadnexal dermatitis and no parasites. Based on the findings in this case series, the terrier dog breed might be at increased risk for the development of D. injai mite infestation associated with dorsal greasy skin and hair, and microscopically with sebaceous gland hyperplasia. Persistence of sebaceous gland hyperplasia after parasitological cure in some patients suggested that this histological finding may not always be resulting from Demodex infestation. Moreover, low numbers of adult mites and variable clinical responses to acaricidal therapy suggested a contributory rather than a major role of D. injai in this skin condition. Dermatopathological diagnosis of sebaceous gland hyperplasia, particularly in case of dorsal trunk specimens from terrier dog breeds, warrants the search for D. injai mites on trichoscopic examinations and/or deep skin scrapings.     

Demodex gatoi -associated contagious pruritic dermatosis in cats - a report from six households in Finland

Background

Demodex gatoi is unique among demodectic mites. It possesses a distinct stubby appearance, and, instead of residing in the hair follicles, it dwells in the keratin layer of the epidermis, causing a pruritic and contagious skin disease in cats. Little is known of the occurrence of D. gatoi in Europe or control of D. gatoi infestation.

Case presentation

We describe D. gatoi in 10 cats, including five Cornish Rex, two Burmese, one Exotic, one Persian and one Siamese, living in six multi-cat households in different locations in Finland containing 21 cats in total. Intense pruritus was the main clinical sign. Scaling, broken hairs, alopecia and self-inflicted excoriations were also observed.Diagnosis was based on finding typical short-bodied demodectic mites in skin scrapings, skin biopsies or on tape strips. Other pruritic skin diseases, such as allergies and dermatophytoses, were ruled out. In one household, despite finding several mites on one cat, all six cats of the household remained symptomless.Amitraz used weekly at a concentration of 125-250 ppm for 2-3 months, proved successful in three households, 2% lime sulphur weekly dips applied for six weeks in one household and peroral ivermectin (1 mg every other day for 10 weeks) in one household. Previous trials in four households with imidacloprid-moxidectin, selamectin or injected ivermectin given once or twice a month appeared ineffective.

Conclusion

D. gatoi-associated dermatitis is an emerging contagious skin disease in cats in Finland. Although pruritus is common, some cats may harbour the mites without clinical signs. In addition, due to translucency of the mites and fastidious feline grooming habits, the diagnosis may be challenging. An effective and convenient way to treat D. gatoi infestations has yet to emerge.     

The clinical effect of environmental control of house dust mites in 60 house dust mite-sensitive dogs

Abstract   The purpose of this study was to evaluate the effects of benzyl benzoate, an acaricide for the control of house dust mites, in 60 house dust mite-sensitive dogs. All dogs showed positive reactions on intradermal skin testing for house dust mites ( Dermatophagoides farinae , Dermatophagoides pteronyssinus ) alone, or house dust mites with storage mites ( Acarus siro , Tyrophagus putrescentiae , Glycophagus domesticus ). House dust samples from the owners' houses were collected and sent to the clinic, where the authors performed a test (Acarex® test) to semiquantify the amount of guanine, a house dust mite product. Treatment with benzyl benzoate was repeated until the house dust samples were negative for house dust mite guanine. After treatment, 29 out of 60 house dust mite-sensitive dogs (48%) showed no skin lesions or pruritus. Moderate results were achieved in 22 dogs (36%), with reduced pruritus and minimal skin lesions, but still requiring medication. In 13 dogs, this involved regular treatment (3–4 times a year) with antibiotics and antiyeast medication, and in eight dogs, immunotherapy was used. One dog was controlled with essential fatty acids as monotherapy and one dog was controlled with immunotherapy and essential fatty acids. In the remaining nine dogs (15%), the pruritus remained the same, and these dogs were controlled with oral corticosteroids. These results indicate that house dust mite elimination is a useful tool in the management of house dust mite-sensitive dogs.     

Generalized demodicosis associated with diabetes mellitus in two cats

Generalized demodicosis with concurrent diabetes mellitus was diagnosed in 2 cats. Both cats had generalized alopecia and a bilateral brown aural exudate. Mites were seen microscopically in skin scrapings and ear swab specimens. Histologic examination of the skin showed the follicular orientation of the mites. Abnormal results on oral dexamethasone suppression tests, clinical findings, and bilateral adrenal hyperplasia found on necropsy of one of the cats suggested concurrent hyperadrenocorticism.     

Dermatitis in a horse associated with the poultry mite (Dermanyssus gallinae)

This is the first documented case report of dermatitis associated with the poultry mite (Dermanyssus gallinae) in a horse. It occurred in a 16-year-old horse that was in contact with domestic hens. Clinical signs consisted of severe pruritus, with self-induced hair loss mainly on the head. Despite the multiple skin scrapings performed during both day- and nighttime, mites were only isolated from the in-contact poultry and from the horse's environment, and not the horse. The animal was treated using a 2% permethrin solution, sprayed on the entire body once a week for 4 weeks, and by decontamination of the horse's immediate environment. Although eradication of the mites and elimination of further contact between the horse and the poultry were not achievable, recurrence of dermatitis was prevented by regular applications of permethrin on the horse and biannual decontamination of the horse's stable.     

Prevalence of house dust mites and dermatophagoides group 1 antigens collected from bedding, skin and hair coat of dogs in south-west England

The house dust mites Dermatophagoides farinae (Df) and D. pteronyssinus (Dpt) are commonly implicated as allergens causing canine atopic dermatitis in the UK. However, there are few studies that characterize the exposure of UK pet dogs to these mites. The objectives of this study were to determine the prevalence of the mite species on the skin, hair coat and bedding of a population of pet dogs. Dust samples (n = 68) were collected from both dogs and their beds using a standardized vacuuming technique and stored at -20 degrees C. Mites were identified using accepted morphological criteria. House dust mite allergen concentrations were assayed using standardized ELISA for Dpt and Df group 1 allergens (Der p 1 and Der f 1). Mites were identified in 15/68 samples (22%) and Dpt was the most common. Df mites were not present. Der p 1 allergens were detected in 60% of samples, and Der f 1 in 6% of samples. There were no significant differences between the number of Der p 1 positive samples from dogs and the number of those from their bedding, or between the average Der p 1 concentrations from dogs and the number of those from their bedding. Contrary to studies elsewhere in Europe and the USA, these findings support studies of human asthma patients in the UK, where exposure to Df is rare, but to Dpt is common. As the prevalence of positive intradermal and serological reactions to Df in atopic dogs is high, further investigations are warranted to clarify true Df hypersensitivity or potential immunological cross-reactivity between mite allergens.     

Epitheliotropic T-cell lymphoma in a guinea pig

A 4-year-old female guinea pig was presented with pruritic, erythematous, hypotrichotic and scaling skin lesions, mainly involving the abdomen and the hindlegs. Clinical abnormalities were limited to the skin, and the guinea pig was otherwise healthy. The dermatological diagnostic work-up excluded ectoparasites, dermatophytosis and an endocrinopathy as differential diagnoses for the pruritus and hair loss. An allergic dermatitis was under investigation when the general and skin condition deteriorated. A neoplastic skin disorder was suspected, and skin biopsies revealed changes consistent with a cutaneous epitheliotropic T-cell lymphoma. Pautrier's microabscesses and immunophenotyped CD3(+) CD79(-) lymphocytes were identified. Owing to the deteriorating condition of the animal and the unknown but most likely poor prognosis of this disease, the guinea pig was euthanized. To the authors' knowledge, this is the first case report of cutaneous epitheliotropic T-cell lymphoma in the guinea pig with characteristic histopathological and immunohistochemical features.     

Leporacarus gibbus and Spilopsyllus cuniculi infestation in a pet rabbit

A one-year-old male, chequered giant rabbit had a simultaneous infestation with both Leporacarus gibbus and Spilopsyllus cuniculi. Recurrent episodes of mild to severe pruritus had been noted over a period of two months. On clinical examination, partial alopecia and slightly erythematous skin with flea faeces was evident, although microscopic and cultural examinations of skin scrapings were negative for fungi. Parasitological examination, including adhesive tape strips of the rabbit's skin and fur, revealed L gibbus surface dwelling mites and the rabbit flea S cuniculi. The rabbit was successfully treated against both parasites with topical pyrethrin applied three times over a three-week period, and the clinical signs resolved in four weeks.     

Prospective open pilot study on the use of ciclosporin for feline allergic skin disease

OBJECTIVES: To evaluate the efficacy of ciclosporin in cats with allergic skin disease. METHODS: Ten cats with signs of allergic skin disease were administered ciclosporin daily at a dose of 3.6 to 8.3 mg/kg for one month. None of these cats had previously responded to a hypoallergenic diet trial, and all animals had previously been treated with endectoparasiticidal drugs, with no improvement two weeks before entering the trial. On days 0 and 30, owners assessed pruritus with a visual analogue scale, and veterinarians evaluated cutaneous lesions. RESULTS: All the cats had pruritus and erythema, five had alopecia, two had an eosinophilic plaque, one had miliary dermatitis and two had both alopecia and an eosinophilic plaque. Good or excellent improvement was observed in 40 per cent of cats for pruritus, 57 per cent of cats for alopecia and 60 per cent of cats for erythema. A significant decrease in mean scores was observed for pruritus only, while for erythema and alopecia, it was close to being significant (P < 0.052). CLINICAL SIGNIFICANCE: Ciclosporin may be helpful in symptomatically treating signs of feline allergic skin disease. However, it is important to remember that ciclosporin is not licensed for use in cats.