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.     

Comparative study of doramectin and fipronil in the treatment of equine chorioptic mange

In equids, chorioptic mange is a common dermatitis for which there are no licensed medications in the uk. Doramectin and fipronil are licensed for the control of ectoparasites in other species and were evaluated for the treatment of 17 cases of chorioptic mange in 13 equids. Equids were included if clinical findings were indicative of chorioptic mange, chorioptes mites were positively identified and concurrent disease that could affect response to disease was not evident. A random number table was used to allocate subjects to receive doramectin (group D, eight animals) or fipronil (group F, nine animals). Each of the horses in group D were given 0.3 mg/kg doramectin (Dectomax; Pfizer) on two occasions 14 days apart by subcutaneous injection. All limbs of the horses in group F were sprayed with fipronil 0.25 per cent solution (Frontline; Merial) to the level of the stifles and elbows. Both groups were examined on the day of treatment and 14 and 28 days later to assess the behavioural signs of pruritus and the severity of the dermatological lesions. Acetate tape impressions were collected from the distal limbs and the degree of mite infestation was assessed. By day 28 there were no behavioural signs of chorioptic mange in any of the animals, and there were significant reductions in the numbers of mites in both groups. However, there were no significant reductions in the mean lesion score in either group. There was no significant difference between the effectiveness of the two treatments.     

Combined moxidectin and environmental therapy do not eliminate Chorioptes bovis infestation in heavily feathered horses

Chorioptes bovis infestation is a common cause of pastern dermatitis in the horse, with a predilection in draft horses and other horses with thick hair ‘feathers’ on the distal limbs. The treatment of this superficial mite is challenging; treatment failure and relapse are common. Furthermore, C. bovis infestation may affect the progression of chronic pastern dermatitis (also known as chronic proliferative pastern dermatitis, chronic progressive lymphoedema and dermatitis verrucosa) in draft horses, manifesting with oedema, lichenification and excessive skin folds that can progress to verruciform lesions. An effective cure for C. bovis infestation would therefore be of great clinical value. In a prospective, double‐blind, placebo‐controlled study, the efficacy of oral moxidectin (0.4 mg/kg body weight) given twice with a 3 week interval in combination with environmental treatment with 4‐chloro‐3‐methylphenol and propoxur was tested in 19 heavily feathered horses with clinical pastern dermatitis and C. bovis infestation. Follow‐up examinations over a period of 180 days revealed significantly more skin crusting in the placebo group than in the treatment group. However, no other differences in clinical signs or the numbers of mites detected were found between the two groups. The results of this study suggest that moxidectin in combination with environmental insecticide treatment as used in this study is ineffective in the treatment of C. bovis in feathered horses.     

Feline atopy in three littermates

This case report describes the history, clinical signs and diagnosis of a pruritic skin disease in three sibling cats living the same household. Clinical signs consistent with pruritus (i.e. hair pulling, hair loss, excessive grooming and face rubbing) were first noted when the cats were 6 months of age. The cats were treated for a possible ear mite and/or flea infestation; there was no response to treatment and clinical signs progressed. Although the presence of pruritus in a multiple cat household suggested an infectious or contagious aetiology, none could be identified. There was no improvement in clinical signs after a 60‐day flea control trial, three treatments of ivermectin, an 8‐week restricted diet or removal from the home for 10 days. A diagnosis of feline atopy was made on the basis of elimination of other causes of pruritus, consistent history and clinical signs, a positive intradermal skin test and response to therapy.     

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.     

The finding of the cat fur-mite Lynxacarus radovskyi in New Zealand

extract

In the letter: A New Zealand record for the cat fur-mite, Lynxacarus (Felistrophorus) radovskyi Tenorio (Acarina: Astigmata: Listrophoridae) by Heath and Mariadass (1999), it is briefly reported “that prior to the cat’s intended release on 31/01/97, a hair sample was taken and mites found”.     

P‐24 Efficacy of selamectin in canine scabies and ear mite infestation in Korea

A randomized and controlled field study was performed in canine patients to evaluate the efficacy of selamectin in the treatment of naturally occurring Sarcoptes scabiei and Otodectes cynotis infestations in dogs. A total of 227 dogs from six veterinary practices in South Korea were included. Dogs were randomly assigned to treatment with selamectin or a positive‐control product. Selamectin was administered as a unit dose providing a minimum of 6 mg/kg in a topical preparation applied to the skin in a single spot on days 0 and 30 [S. scabiei (n = 113) and O. cynotis (n = 114)]. The presence of parasites was assessed before treatment and at 14, 30 and 60 days after the initiation of treatment. The animals were evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin against S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60. Against O. cynotis, selamectin eliminated mites in 100% of dogs by day 60. However, clinical signs of pruritus, erythema, scale, and crusted papules did not diminish concomittantly with resolution of S. scabiei in skin scrapings. The positive‐control products achieved similar results. Therefore, selamectin was safe and effective against sarcoptic mange and ear mites in dogs. Funding: Pfizer Animal Health.     

Atypical actinobacillosis affecting hind limbs and lungs in a single beef cattle herd

Actinobacillosis usually is a sporadic infection that affects the tongue in cattle (“wooden tongue”) with possible spread to the digestive tract. Two 4‐year‐old Rouge‐des‐Prés cows from a single French beef herd were referred for chronic (2‐6 months) swelling and cutaneous nodules in the distal hind limbs. In addition to cutaneous signs, physical examination disclosed cachexia, lameness, lymphadenitis of the hind limbs, and pneumonia in both cows. Cytologic examination of direct skin smears was inconclusive, and no parasites were observed in examination of multiple skin scrapings. Histopathological examination of skin and lung biopsy specimens identified chronic, diffuse, severe pyogranulomatous dermatitis, associated with Splendore‐Hoeppli phenomenon and intralesional Gram‐negative bacteria. Cultures from skin, lymph nodes, and lungs (both cows were euthanized for welfare reasons) identified a Pasteurellaceae organism, confirmed as Actinobacillus lignieresii by partial sequencing of the rpoB gene. This report emphasizes that actinobacillosis can appear as a small outbreak in cattle with cutaneous and respiratory signs.     

Trixacarus caviae Fain,Howell & Hyatt 1972 (Acari: Sarcoptidae) as a cause of mange in guinea-pigs and papular urticaria in man

The clinical symptoms of infestation with Trixacarus caviae in guinea-pigs are described. In general large areas of thickened, denuded skin, with a heavy secondary bacterial infection, and sometimes neurological signs, are observed in mangy cases. Antiparasitic therapy was successful with one or several washings with 0.15% trichlorphon or 0.07% lindane solutions.Histological examination of the skin of mangy guinea-pigs revealed acanthosis, pronounced thickening of the epidermis and increased indentations of the cutis. The mites were embedded in epidermal debris in the folds of the skin. They were often found in the superficial part of the hair follicles. Inflammation of the subcutis was pronounced.Healthy guinea-pigs developed mild signs of mange approximately 10 days after exposure by skin contact to heavily infested animals. These experimentally infested guinea-pigs recovered without treatment. An itching papular urticarial condition in three human patients was found associated with trixacariasis of guinea-pigs. The lesions were usually located on the skin areas in frequent contact with the infected animals. This human affliction cleared after terminating contact with the mangy pig or after antiparasitic treatment of the animal.     

Oral administration of moxidectin for treatment of murine acariosis due to Radfordia affinis

A field trial was conducted to assess the safety and efficacy of oral administration of moxidectin in mice naturally infected with the fur mites Radfordia affinis. The natural infection was diagnosed in two colonies within a large academic institution by direct hair examination. Animals received moxidectin (1% Cydectin, FortDodge) at an oral dosage of approximately 2 mg/kg body weight by micropipette; administration was repeated after 15 days. Forty mice served as an untreated control group. Moxidectin treatment resulted in clinical improvement within a few days after initial treatment, and mites were eradicated from all infested animals at day 30. No side effects or signs of ill health were observed in any of the treated animals. To our knowledge, this is the first report of oral moxidectin for treatment of murine acariosis.     

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.     

Cheyletiella infestation in the dog: observations on diagnostic methods and clinical signs

The aims of this study were to evaluate the ability of diagnostic methods to detect naturally occurring Cheyletiella infestation in dogs, and to quantify and relate the number of mites and eggs present to clinical signs. Privately owned dogs with skin problems were eligible for inclusion in the study. Four diagnostic tests were performed on each dog in the following order: tape impression, hair plucking, skin scraping and vacuum cleaning. Dogs with positive test results for Cheyletiella infestation in at least one of the tests under evaluation were included in the study (n=27). The severity of pruritus and scaling was graded on a four-point fixed scale. The diagnostic findings in vacuum cleaning samples provided a semiquantitative measure of the grade of infestation. The vacuum cleaning test gave a positive test result in all dogs and was significantly more efficient than the other tests evaluated (P<0.01). The number of diagnostic findings varied considerably among the different vacuum samples. No significant relationship between the number of diagnostic findings and severity of clinical signs was detected.     

Sarcoptic mange infestation in pigs in a hilly region of Meghalaya

Skin lesions were collected from 15 adult crossbred pigs maintained at the pig farm of ICAR Research Complex for the North-Eastern Hill Region, Umiam, a hilly region of the state of Meghalaya, India. Skin scrapings of these 15 animals were examined by KOH digestion method. Presence of mites were detected in five animals which were indistinguishable from Sarcoptes scabiei var. suis. Infected pigs were treated with a single dose of Ivermectin at 200 ug/kg body weight, subcutaneously. No mites were recovered from treated pigs after a period of 10 days of post-treatment. The presence of S. scabiei var. suis in pigs from this part of the country has never been reported. This infestation has great significance because it affects the growth rate and feed conversion significantly, specially to the grower and weaned pigs. It can be concluded that S. scabiei var. suis infestation is prevalent in hilly region of Meghalaya. The pig producers are generally unaware about the severity of the problem of mite infestation, so precaution should be taken to prevent their valuable pigs from S. scabiei var. suis infestation.     

Efficacy of selamectin administered topically in the treatment of feline otoacariosis

The efficacy of a novel avermectin, selamectin (Stronghold, Pfizer), was evaluated against naturally acquired aural infestations of Otodectes cynotis. Selamectin was administered topically in a single spot to the skin of each animal's back at the base of the neck in front of the scapulae at a minimum dosage of 6mgkg(-1). Thirty cats of a cattery of 120 animals with an endemic infestation were treated on days 0 and 30. Including untreated control cats was therefore not possible because of animal welfare consideration. Clinical examination and visualization of mites by otoscopic examination of the external ear canal and microscopic examination of aural debris/exudate were performed twice weekly from days 0 to 30. On day 0 (and day 28 if the ears canals were erythematous), a swab was taken from each canal and sent to bacteriology and mycology units for detection and identification of bacteria (Staphylococcus mainly) and yeast (Malassezia pachydermatis only).Selamectin was safe, parasites were killed before day 3 and eliminated before day 17. Selamectin was 100% effective against natural aural infestations, even if erythema (26-33% of cats) and scratch reflex (23-40% of cats) persisted for 2 weeks after the cats tested negative for mites.     

Factors affecting the frequency of ear canal and face infestation by Otodectes cynotis in the cat

Otodectes cynotis is responsible for at least 50% of canker cases diagnosed in cats world-wide. The role of Demodex cati in the pathogenesis of otitis and acne is still obscure. The aims of this study were to estimate the prevalence of O. cynoyis and D. cati infestations in clinically normal cats in northern Greece, to determine the factors that are associated with the probability and severity of infestation in the cat, and to examine the importance of these mites in the pathogenesis of feline acne. Samples from 161 cats were examined by flushing the ear canals and by taking skin scrapings of the chin and lip area. The results were combined with various factors (sex, age, living style, hair coat type and presence of pruritus, of ear discharge, of acne-like lesions) in order to carry out a risk analysis. Two separate logistic regression analyses were performed. One, on the infestation/non-infestation potential with O. cynotis and the other, on the degree of such infestation as mild-to-moderate (< or =5 mites/field) or severe (>5 mites/field). D. cati was not detected in any of the 161 cats. The prevalence of O. cynotis was estimated at 25.5% (95% confidence interval (CI) 19-32). The rate of mite infestation was higher with the presence of ear discharge (odds ratio 9, 95% CI 3.3-24.5), periaural pruritus (odds ratio 3.6, 95% CI 1.8-8) and acne-like lesions (odds ratio 3.3, 95% CI 1.2-9). Cats with mild-to-moderate degree of infestation had 18 times higher chance of exhibiting an ear discharge than those with a severe infestation. The log-odds of mild-to-moderate parasitism were linearly related to the age.     

Field efficacy of flumethrin pour-on against Psoroptes ovis in cattle.

The field efficacy of pour-on formulation of flumethrin 1 per cent was assessed in cattle naturally infested with Psoroptes ovis. In a finishing unit, 18 infested animals were selected, left untreated for one month and examined twice to monitor the progress of the infestation. They were treated twice 10 days apart with a pour-on formulation of flumethrin 1 per cent (2 mg/kg bodyweight). Skin samples were collected from the animals on days 0, 7, 14, 28 and 42 and examined for the presence of live mites. The clinical condition of the cattle was evaluated at the beginning and at the end of the trial using a standardised chart. Bodyweights were recorded on days -32, 0, 28 and 50. In addition the 65 cows in a calving unit were given the same treatment regimen and its efficacy was evaluated on days 0, 7, 14 and 28 in 11 P ovis infested animals. On the day of treatment most of the infested animals had a severe pyodermatitis. From day 7 onwards no live mites were found in the treated animals and there was a marked clinical improvement. The percentage efficacy on day 28 was 100 per cent in both units. In the finishing animals treatment was associated with a marked improvement in daily weight gains between day 0 and day 28.     

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.     

Ataxia and weakness as uncommon primary manifestations of hepatic encephalopathy in a 15‐year‐old trotter gelding

A 15‐year‐old trotter gelding was evaluated because of an acute onset of ataxia in all 4 limbs. There was no known history of trauma. The gelding showed grade 2/5 ataxia in all 4 limbs, which was localised after clinical neurological examination to the cervical vertebral spinal cord. Initial therapy consisted of oral anti‐inflammatory doses of prednisolone and antimicrobial treatment with potentiated sulphonamides. The ataxia progressed to grade 3/5 at Day 10 of hospitalisation. Additionally, the horse was slightly depressed and showed spontaneous yawning during examination. Facial sensation was blunted. Blood chemistry revealed a marked elevation of liver specific enzymes and blood ammonia levels. Transcutaneous abdominal ultrasonography revealed hepatomegaly. Due to a guarded prognosis, the horse was subjected to euthanasia. At necropsy the left lateral liver lobe was markedly enlarged and showed a firm texture, whereas the cranial part and the right and quadratic liver lobe displayed a severe and diffuse atrophy. Histopathologically, the left lateral liver lobe revealed a moderate to severe cirrhosis with a severe, diffuse hepatocellular iron‐accumulation. Increased numbers of Alzheimer type II astrocytes in the cerebral cortex and cerebral white matter vacuolisation were indicative for encephalopathy. These findings were interpreted as haemosiderosis and cirrhosis of the liver with consecutive hepatic encephalopathy. Aetiologically, haemosiderosis should be considered as a cause of liver cirrhosis with consecutive hepatic encephalopathy. Although hepatic encephalopathy in horses usually presents with predominating cerebral signs, it has to be taken into account as a differential diagnosis in cases of acute onset generalised ataxia.