Efficacy of pre-treatment with lufenuron for the prevention of Microsporum canis infection in a feline direct topical challenge model

Oral lufenuron is reportedly an effective treatment for some cats with dermatophytosis. The purpose of this study was to determine if lufenuron, when used as a pre-treatment prior to challenge exposure, would be protective against the development of infection after the direct topical application of fungal macrocondia (Microsporum canis spores). Three groups (n = 6/group) of juvenile cats were treated with either monthly oral lufenuron (30 or 133 mg/kg) or placebo. After 2 months of treatment, kittens were challenged using 10(5)Microsporum canis spores applied to the skin under occlusion. Cats were examined weekly and the following data collected: Wood's lamp examination; scoring for scale/crust, erythema and induration; lesion size; and the development of satellite lesions. Fungal cultures were performed bi-weekly. All cats became infected; the infections progressed, and then regressed, in a similar fashion in all groups. There were no consistent statistically significant differences in weekly infection scores between treated and untreated cats throughout the study. Treated cats did not recover faster than untreated cats. We conclude that oral lufenuron at the dosing schedule and conditions used in this study did not prevent dermatophytosis or alter the course of infection by direct topical challenge.     

The prevalence of immediate and delayed type hypersensitivity reactions to Microsporum canis antigens in cats

Spontaneous recovery from Microsporum canis infections in cats is thought to be dependent on the development of a competent immune response. The purpose of this study was to determine the prevalence of positive delayed type hypersensitivity reactions in cats with and without dermatophytosis. Four groups of cats were intradermally skin tested with M canis extract and test sites were evaluated both subjectively and objectively at 0, 24 and 48 h after injection. Delayed intradermal testing (IDT) reactions were absent in cats not exposed to dermatophytosis (n=20); infected-recovered cats (n=38 culture negative lesion negative and n=43 lesion negative but culture positive) had significantly larger IDT reactions than unexposed cats and cats that were still actively infected (n=18). Based on the results of this study, IDT with M canis extract can be used to assess the cellular immune response of cats with dermatophytosis.     

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.     

A recombinant 31.5 kDa keratinase and a crude exo-antigen from Microsporum canis fail to protect against a homologous experimental infection in guinea pigs

A Microsporum canis recombinant 31.5 kDa keratinase and a M. canis crude exo-antigen were tested as vaccines in an experimental infection model in guinea pigs. Animals were vaccinated subcutaneously three times at two-week intervals with either the keratinase, the exo-antigen or the adjuvant alone. Cutaneous challenge was performed blindly. Both humoral and cellular-specific immune responses to M. canis antigens were evaluated every 14 days, while a blind evaluation of clinical lesion development and fungal persistency in skin were monitored weekly. Vaccination induced very high and significant (P < 0.01) antibody responses towards both antigens. High cell-mediated immune responses to both immunogens were also induced by vaccination. After challenge, however, scores reflecting the severity of dermatophytic lesions did not differ significantly between vaccinated and control groups at any time after challenge. These results suggest that, in the guinea pig, the induction of specific immune responses against the M. canis-secreted antigens used in this study are not protective against challenge exposure.     

Adult-onset demodicosis in two dogs due to Demodex canis and a short-tailed demodectic mite

Infestation with a short-tailed demodectic mite and Demodex canis was diagnosed in both a six-and-a-half-year-old and a four-year-old dog. The clinical picture was compatible with generalised demodicosis complicated by staphylococcal pyoderma (case 1), or localised demodicosis (case 2). In both cases, the short-tailed demodectic mite outnumbered D canis in superficial skin scrapings. The laboratory findings (lymphopenia, eosinopenia, increased serum alkaline phosphatase and alanine aminotransferase activities, diluted urine and proteinuria) and the results of a low dose dexamethasone suppression test were suggestive of underlying hyperadrenocorticism in the first case. Hypothyroidism was considered a possibility in the second case, owing to the sustained bradycardia and the extremely low basal total thyroxine value. Systemic treatment with ivermectin and cephalexin (case 1), or topical application of an amitraz solution in mineral oil, along with sodium levothyroxine replacement therapy (case 2), resulted in a complete resolution of the skin lesions and the disappearance of both types of demodectic mite after two and one and a half months, respectively.     

Experimental infection of ponies with Borrelia burgdorferi by exposure to Ixodid ticks

Seven specific-pathogen-free (SPF) ponies, 1-5 years old, were exposed to Borrelia burgdorferi-infected adult ticks while being treated with dexamethasone over 5 consecutive days. One SPF pony (pony No. 178) was first exposed to laboratory-reared nymphs without B. burgdorferi infection and 3 weeks later was exposed to B. burgdorferi-infected adult ticks with concurrent dexamethasone treatment for 5 consecutive days. Four uninfected ponies treated with dexamethasone, exposed to laboratory-reared ticks without B. burgdorferi infection served as uninfected controls. Clinical signs, bacteriologic culture, polymerase chain reaction (PCR) for bacterial DNA, immunologic responses, and gross lesions and histopathologic changes were investigated during the experiment or at necropsy 9 months after tick exposure. In all of the seven challenged ponies, infection with B. burgdorferi was detected from monthly skin biopsies and various tissues at postmortem examination by culture and by PCR. However, pony No. 178 exposed to laboratory-reared nymphs (without B. burgdorferi infection) and challenged with B. burgdorferi-infected adult ticks 2 months later did not develop a B. burgdorferi infection. All of the infected ponies seroconverted. Control ponies and pony No. 178 were negative by culture, PCR, and serology. Except for skin lesions, we failed to induce any significant histopathologic changes in this study. This is the first report of successful tick-induced experimental infection in ponies by exposure to B. burgdorferi-infected ticks. This Lyme disease model will be very useful to evaluate efficacy of vaccines against the Lyme agent and the effect of antibiotic therapy on horses infected with B. burgdorferi.     

Efficacy of Chinese Herbal Medicine Canine Acariasis Spirit on Demodex canis

In order to screen the Chinese herbal medicine for the treatment of Demodex canis, canine acariasis spirit was prepared by Foeniculum vulgare, Fructus cnidii and Bauhinia by water alcohol precipitation and distillation extraction methods. To observe the effect on Demodex canis, canine acariasis spirit was set to high, medium and low concentrations, the content of crude drug were 2.0, 1.0 and 0.5 g/mL, respectively. The experiment of killing Demodex canis was carried out by drop method. On this basis, 12 dogs inoculated with Demodex canis were treated. In order to verify the therapeutic effect, 45 clinically diagnosed dogs with Demodex canis were divided into three groups. The results showed that 3 doses of the traditional Chinese medicine canine acariasis spirit all had strong inhibition effect to kill mites, the high dose group could completely kill Demodex canis only 4 h after treatment, the action of 1% ivermectin control group was 8 h after treatment; 3 weeks later, a large number of new hair grew, rash and skin nodules disappeared, the skin lesion had healed in the affected area of high dose group, in 1% ivermectin treatment group, the dog skin improved, only a small amount of new hair grew, it couldn't cure standard; In the high and middle dose group, the average number of the ratio of skin scraping mites and the recurrence rate after drug withdrawal was 0 in one month later; The average number of mites proportion and recurrence rates of skin scrapings in 1% ivermectin treatment group were 10.63% and 9.17% in one month later; After 3 weeks of treatment, the total average eggs negative rate, cure rate and average cure days were 100.00%, 93.33% and 19.56 d in high dose traditional Chinese medicine canine acariasis spirit and 1% ivermectin combined treatment group, the results were better than the traditional Chinese medicine canine acariasis spirit and 1% ivermectin alone treatment group. The results showed that the effect of the high dose group self-made Chinese medicine canine acariasis spirit on killing Demodex canis in vitro, inoculation of Demodex canis and clinical therapeutic effect of natural infection cases were significantly better than 1% ivermectin control group, canine acariasis spirit as a traditional Chinese medicine preparation would have a good market development prospects.     

中药犬螨灵对犬蠕形螨的疗效试验

为筛选具有显著治疗犬蠕形螨的中药制剂,试验将中药小茴香、蛇床子、羊蹄根采用水煮醇沉及蒸馏等提取方法制备成中药制剂犬螨灵,并观察其对犬蠕形螨的疗效。将犬螨灵设为高、中、低3个浓度,其生药含量分别为2.0、1.0和0.5 g/mL,采用点滴法进行体外抑杀蠕形螨试验,在此基础上对12只接种蠕形螨的试验犬进行治疗试验,为验证治疗效果,对临床上已确诊的45只患有蠕形螨的病犬分3组进行临床治疗试验。结果显示,中药犬螨灵3种剂量均有较强的体外抑杀螨虫作用,高剂量组作用后4 h即可完全抑杀蠕形螨,1%伊维菌素对照组则为作用后8 h;高剂量组在治疗3周后,患处有大量新毛生长,红疹结节和皮屑消失,患处皮肤已痊愈,1%伊维菌素治疗组患犬皮肤好转,仅有少量新毛生长,不能达到痊愈标准;高、中剂量组皮肤刮取物螨虫数量平均比例及停药1个月后复发率均为0,1%伊维菌素治疗组皮肤刮取物螨虫数量平均比例及停药1月后的复发率分别为10.63%和9.17%。高剂量中药犬螨灵与1%伊维菌素两种药物联合治疗组,对临床上患病犬进行3周治疗,其虫卵平均转阴率、治愈率与平均治愈天数分别为100.00%、93.33%和19.56 d,其效果均优于中药犬螨灵与1%伊维菌素单独治疗组。结果表明,高剂量自制中药制剂犬螨灵对犬蠕形螨体外抑杀作用、接种蠕形螨试验犬与临床自然感染病例均有显著的治疗效果,优于1%伊维菌素对照组,犬螨灵作为中药杀螨虫制剂具有较好的市场开发前景。     

A Short-tailed Demodectic Mite and Demodex canis Infestation in a Chihuahua Dog

Abstract— Infestation with short-tailed demodectic mites and Demodex canis was diagnosed in an 8-month-old male Chihuahua dog. Skin lesions were characterized by alopecia and scaling on the ventral aspects of the chest, all four limbs, the ventral aspect of the neck and around the eyes. Both Demodex canis and a short-tailed demodectic mite were observed on skin scrapings. After 4 months of amitraz dip treatments, skin scrapings were negative and hair regrowth appeared.
Résumé— Une infestation à Demodex (forme courte) et à Demodex canis est diagnostiquée sur un Chihuahua, mâle de 8 mois. Les lésions cutanées sont caractérisées par une alopécie squameuse du thorax, des quatre membres, du cou et autour des yeux. Les raclages cutanés montrent la présence de Demodex canis et de Demodex sp. (forme courte). Après 4 mois de traitement à l'amitraz, les raclages cutanés sont négatifs et une repousse des poils est observée. [Chen, C. A short-tailed demodectic mite and Demodex canis infestation in a Chihuahua dog (Infestation à Demodex canis et à Demodex (forme courte) chez un Chihuahua).     

Injection site lesions of footrot vaccines in sheep

Three trials were conducted to assess the size and frequency of lesions induced by an oil-based and an alum-precipitated aqueous B. nodosus commercial footrot vaccine at two injection sites (neck and brisket) with or without prior skin swabbing with methanol. Animals used were previously unvaccinated and clean and dry at time of vaccination. Trial 1 contained 57 2-tooth Booroola Merino x Coopworth ewes, trial 2 contained 60 mixed-age Corriedale ewes, and trial 3 contained 39 rams of mixed age and sex. Firm nodules or plaques with indurated edges and with a maximum dimension of 1cm or more appeared soon after vaccination and were still very common (50-100% of sheep vaccinated) 5-6 weeks after injection. A variable proportion exhibited a liquefied central area of necrosis and later discharged necrotic material. The oil-based vaccine produced significantly larger lesions than the alum-precipitated aqueous vaccine. Lesion size at the brisket site was significantly larger than the neck site in ewes but not in rams. Skin preparation with methanol had no effect on lesion frequency or size.     

Pseudomycetoma caused by Microsporum canis in a Persian cat: lack of response to oral terbinafine.

An eight-year-old neutered female Persian cat with a four-year history of relapsing skin disease, characterised by ulcerated nodules with a yellow granular discharge, was examined. A diagnosis of granulomatous dermatitis and panniculitis (pseudomycetoma) caused by Microsporum canis was made on the basis of history, clinical signs, histopathological examination of skin biopsy specimens and culture of macerated tissue. Because previous therapy, comprising repeated surgical excision and the administration of griseofulvin and itraconazole, had not been successful, terbinafine was administered for an eight-month period. However, lesions progressed despite this treatment and the cat was euthanased.     

Topical (pour-on) ivermectin in the treatment of chronic generalized demodicosis in dogs

Twelve privately owned dogs with chronic generalized demodicosis were treated topically along the dorsal midline with 1.5 mg kg⁻¹ of 0.5% pour-on ivermectin for cattle three times per week for 3–6 months. All 12 dogs had a substantial reduction in clinical signs and in the number of Demodex canis mites found on skin scrapings. Only two dogs, however, became skin-scrapings negative after 3 and 5 months of treatment, respectively. In these two dogs treatment was prolonged for an additional 4 weeks past the negative scrapings. One dog relapsed 2 months after cessation of therapy; the other is still free of symptoms 1.5 years later. The cure rate, based on the lack of recurrence of clinical signs for 12 months after discontinuation of ivermectin administration, was 1 of 12 dogs (8%). Adverse reactions were not seen.     

Cutaneous angiomatosis in a young dog

A 1-year-old, spayed, female, mixed-breed dog had two reddish-purple cutaneous lesions, one on the right dorsal antebrachium and the other on the right shoulder. The lesions consisted of approximately 13 x 3 cm and 15 x 10 cm, irregular, patchy regions of 0.5-3.0 cm, circular, sometimes raised, reddish-purple swellings resembling ecchymoses. The lesion on the antebrachium had been noticed since the dog was adopted at 6 months of age and appeared to have increased in size over an 11-week period, at which time skin punch biopsy revealed an infiltrative pattern of well-differentiated blood vessels leading to an interpretation that the lesion was a well-differentiated hemangiosarcoma. The second lesion was revealed when the dog had its fur shaved in that area during surgical preparation to excise the antebrachial lesion. No other skin lesions were found on the dog. Microscopically, there was a widely disseminated and infiltrative-like pattern of benign-appearing small blood vessels, which were throughout the superficial and deep dermis and subcutis. Although the disseminated nature suggested malignancy, the histologic appearance of well-differentiated small blood vessels and nonprogressive clinical features indicate that the lesions were benign. The dog has been followed for 6 years and to date has no evidence of progression of the antebrachial lesion or shoulder lesion. To the authors' knowledge, this is the first report of a congenital angiomatosis-like lesion in a young dog, with extensive involvement of the forelimb.     

Dermal mass aspirate from a Persian cat

A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5–1.0 μm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis , and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.     

Squamous cell carcinoma associated with a periorbital mass in a veiled chameleon (Chamaeleo calyptratus)

This report describes a squamous cell carcinoma in a 1-year-old female veiled chameleon (Chamaeleo calyptratus). The lesion developed as a small (1 by 1 mm) left periocular discoloration of a scale never involving the eye. The mass was first diagnosed as an abscess, increased in size (4 by 8 by 3 mm), and recurred after two surgical resections combined with antibiotic therapy. Poor nutritional condition and egg production by the chameleon complicated management of this condition. The mass was removed surgically a third time at which point histopathologic evaluation revealed a locally invasive squamous cell carcinoma. Bacterial culture of the mass isolated a pure culture of Pseudomonas aeruginosa. Ceftazidime was administered at 20 mg/kg IM every 48 h for 20 days. The animal died 3 months later from complications during an ovariohysterectomy for pregnancy toxemia and oviduct inertia. Necropsy showed no local recurrence or metastasis of the tumor.     

Surgical excision of mycotic (Cladosporium sp.) granulomas from the mantle of a cuttlefish (Sepia officinalis).

An adult female European cuttlefish (Sepia officinalis) from a public aquarium presented with an eruptive skin lesion of the dorsal mantle. Radiographs, hemolymph collection, and excisional biopsy were performed using anesthesia with ethanol 1.5-3% in seawater. Elastic and freely mobile skin permitted closure with minimal tension following wide excision around the lesions, which did not appear to penetrate deep to the underlying cuttlebone. Biopsy revealed hemocyte granulomas surrounding thin, septate, infrequently branching fungal hyphae, and culture yielded Cladosporium sp. Itraconazole was administered postoperatively in food items. The cuttlefish recovered to normal feeding and activity levels with complete surgical site healing. Two months following the procedure, the animal was found dead in exhibit. Histopathologic examination revealed multisystemic fungal infection.     

Efficacy of oral terbinafine in feline dermatophytosis due to Microsporum canis

Microsporum canis is the dermatophyte most commonly responsible for ringworm in cats. The purpose of this paper was to evaluate the in vivo efficacy of oral terbinafine (Lamisil; Sandoz) in the treatment of feline ringworm caused by M canis, and to consider this drug as an alternative to griseofulvin or imidazoles. Fifteen cats infected with M canis were treated orally once daily with 30 mg/kg of terbinafine over a 2-week period. All treated animals were checked for dermatophytes on the last day of treatment, a month later and 3 months after the last administration of the drug. Only 12 cats could be used in the whole trial and 11 of these (92%) showed a complete cure. Terbinafine could be an effective alternative to griseofulvin when fungal resistance or idiosyncrasic intolerance are shown and, compared with griseofulvin, could give a faster rate of cure and less relapses.     

Isolation of equine coital exanthema virus (equine herpesvirus 3) from the nostril of a foal

The virus causing equine coital exanthema (equine herpesvirus 3) was isolated from a lesion on the nostril of a 2-month-old foal. One week after the mare had returned from a stallion station, vesicular lesions developed on her vulva. They were diagnosed clinically as coital exanthema, and 5 days later a lesion developed on the nostril of her foal. This case is an example of horse-to-horse transmission of coital exanthema virus without coitus. A laboratory diagnosis is necessary to differentiate viruses that cause vesicular lesions about the oral and nasal cavities of horses.     

Acquired syringomyelia in a dog.

Acquired syringomyelia was diagnosed in an 11-year-old Fox Terrier with progressive paresis in the left pelvic limb. Myelography and magnetic resonance imaging confirmed an intramedullary lesion involving the left dorsolateral portion of the spinal cord at the level of L-2 and L-3 vertebrae. Clinical signs improved after surgical syringotomy. Microscopic evaluation of a biopsy specimen from the cyst wall did not establish a definitive histologic diagnosis. The cyst was decreased in size on magnetic resonance imaging 7 months later.     

Symmetrical alopecia, scaling and hepatitis in a rabbit

A 5-year-old rabbit with inappetence, symmetrical alopecia and skin lesions was examined. No mites or Malassezia were found in skin scrapings and tape impressions and dermatophyte culture was negative. Trial therapy with ivermectin did not reduce skin lesion severity, and euthanasia was performed because of anorexia after 1 month. Histopathology of the skin showed hyperkeratosis, lymphocytic exocytosis, cell-poor interface dermatitis (lymphocytic infiltration and apoptotic cells in basal layer of epidermis), absence of sebaceous glands and lymphocytic mural folliculitis comparable to sebaceous adenitis and thymoma-associated exfoliative dermatitis previously described in rabbits. The liver exhibited an interface hepatitis, comparable to autoimmune hepatitis in man. The occurrence of morphological similarities to exfoliative dermatitis and sebaceous adenitis in rabbits, in association with an autoimmune hepatitis, has not been described before.