Encephalitozoonosis in New Zealand rabbits and potential transmission risk

Encephalitozoon cuniculi is a small protozoan parasite in the phylum Microspora. It has been shown to naturally infect several host species, including humans. Encephalitozoonosis is routinely diagnosed in vivo by serological examination or post mortem by histopathology. In a conventional rabbit colony, two animals suddenly showed clinical signs (torticollis and asthenia of limbs). Serum samples of these rabbits were seropositive for E. cuniculi after definitive diagnosis (Toxoplasma gondii and Listeria monocytogenes). The animals in the same breeding facility were also clinical examined, and the present study evaluated the prevalence of specific anti-E. cuniculi antibodies using serological testing, both in animals and in people working with animals, after two clinical cases. The rabbits showed no clinical symptoms of the disease. Blood samples were taken for E. cuniculi infection from 50 clinically healthy rabbits. Anti-E. cuniculi antibodies were found in two asymptomatic and two clinically affected animals belonging to the same rabbit colony. Finally, the present study found that the 7.7% (4/52) prevalence of CIA, test positive in rabbits. E. cuniculi spores were detected in the urine of one clinically affected rabbit, and one seropositive animal caretaker after staining with the modified trichrome stain. In conclusion, the presence of seropositive, but apparently healthy rabbits indicates the need for screening examinations to detect the anti-E. cuniculi antibody in rabbits, especially considering the potential zoonotic risk. Therefore, persons should avoid contact with the urine of infected or healthy animals, and always use good personal hygiene when handling animals.     

Clinical development and serological antibody responses in sheep and rabbits experimentally infested with Psoroptes ovis and Psoroptes cuniculi

Psoroptes ovis of sheep origin, and Psoroptes cuniculi of rabbit origin were used in experimental infestations. In experiment I, groups of four rabbits and four sheep were infested with 50-100 mites of each isolate on the skin of the back (skin infestation, SI) or in the external auditory canal (aural infestation, AI). In rabbits, SI and AI with P. cuniculi and AI with P. ovis induced in all animals typical ear lesions and pronounced antibody reactions to P. cuniculi antigens in ELISA. After SI of rabbits with P. ovis no clinical signs were detected, no mites could be reisolated and no specific antibodies were detected. In sheep, P. ovis SI induced mange whereas AI did not induce typical clinical signs and mites could not be reisolated. In both these animal groups, ELISA revealed pronounced and comparable specific antibody reactions. After SI and AI with P. cuniculi no clinical symptoms were observed and no mites could be reisolated. Nevertheless, low levels of specific antibody were detected. In experiment II, clinical progression and antibody reactions to P. ovis SI in naive sheep were compared with sheep previously exposed to P. ovis or P. cuniculi. In both pre-exposed groups of animals, clinical signs appeared within 2 days after challenge infestation and three days earlier than in primarily infested sheep. Subsequently, no obvious difference in the clinical progression was observed between the three groups of animals. The results of this study document antigenetic crossreactivity of the two morphologically and genetically distinguishable Psoroptes species but differences in their biological behaviour and virulence which both are of epidemiological and taxonomic relevance.     

兔螨病的诊断与治疗

兔螨病通常是由兔疥螨和兔痒螨寄生于兔的表皮内或体表所引起以皮肤损伤、搔痒、消瘦、中耳炎、石灰脚为主的一种慢性接触性寄生虫病.笔者对四川省桂花镇某养殖场的一起兔螨病进行了诊断与治疗.根据流行病学、临床症状、病理变化,结合实验室诊断,确诊为疥螨和痒螨混合感染,部分病例因抓伤引起溶血性链球菌病造成死亡.采用伊维菌素、灭虫丁、双甲脒、敌百虫等杀虫药结合抗菌消炎进行比较治疗,结果表明,伊维菌素结合抗菌消炎对兔螨病的治愈率达到100%.     

Clinical and histological evaluation of immediate and delayed flea antigen intradermal skin test and flea bite sites in normal and flea-allergic cats

Seven cats diagnosed as flea allergic by specific criteria and seven normal control cats were exposed to flea bites in a controlled manner and were given intradermal injections of 1:1000 w/v flea antigen. Subjective evaluation of gross lesions and documentation of histological changes at flea antigen intradermal skin test (IDST) and flea bite sites were performed at 15 min, 24 h and 48 h after IDST or flea exposure. Control cats did not develop an immediate gross reaction to either flea bites or the intradermal injection of flea antigen. All seven flea-allergic cats had an immediate gross reaction at the site of IDST with flea antigen; five of these cats also developed immediate gross reactions to flea bites. Three of seven flea-allergic cats developed a gross 24 h and/or 48 h delayed reaction at the flea antigen IDST sites. These three and one other cat had both an immediate and delayed gross reaction to flea bites. Histological examination of 15 min skin specimens from IDST and flea bite sites of flea-allergic cats were similar with a mild lymphocytic, histiocytic and mastocytic superficial perivascular dermatitis. Histological examination of 24 h and 48 h skin specimens from IDST and flea bite sites of flea-allergic cats showed that they were often indistinguishable. Histological features of IDST and flea bite sites of flea-allergic cats at 24 h consisted of a perivascular to diffuse predominately eosinophilic dermatitis and mural folliculitis with variable epidermal necrosis and ulceration.     

Survey of flea infestation in dogs and cats in the United Kingdom during 2005

During 2005, 31 uk veterinary practices participated in a survey of flea infestation, during which 2653 dogs and 1508 cats were examined for evidence of flea infestation and skin disease compatible with flea allergy dermatitis (fad). The prevalence of flea infestation in the cats was 21.09 per cent, significantly (P<0.001) higher than in the dogs (6.82 per cent). The prevalence of skin lesions compatible with fad in the cats (8.02 per cent) was also significantly (P<0.001) higher than in the dogs (3.32 per cent). Flea infestations were more common in households with cats and with more than one pet. Of 467 fleas identified from the cats, 462 (98.93 per cent) were Ctenocephalides felis, one was Ctenocephalides canis, one was Archaeopsylla erinacei, two were Pulex irritans, and one was Spilopsyllus cuniculi. Of 336 fleas identified from the dogs, 313 (93.15 per cent) were C felis, five were C Canis, 12 were A erinacei, five were P irritans, and one was Ceratophyllus (Nosophyllus) fasciatus. Almost half of the owners of the dogs and cats were unaware of their pet's flea infestation. The overall prevalence of fleas and/or skin lesions that could potentially be compatible with fad was 7.46 per cent in the dogs and 22.28 per cent in the cats.     

Observations on the potential for natural transfer of Psoroptes cuniculi and Chorioptes bovis (Acari: Psoroptidae) between goats and sheep

Goats and sheep were pastured together and held in close contact in yards twice a month for 21 months. The goats had a high prevalence of both the rabbit ear canker mite, Psoroptes cuniculi and the chorioptic mange mite, Chorioptes bovis. The sheep were not infested with P. cuniculi at the beginning of the study and viable C. bovis could not be detected. At no time during the study did P. cuniculi establish in the ears of sheep, despite a maximum prevalence of >95% P. cuniculi in goats. This may have been related to the viscous nature of sheep cerumen. Levels of cerumen in goats' ears increased with increasing prevalence of the mite in the flock. The prevalence of C. bovis in the sheep flock did not exceed 10%, despite a maximum prevalence of >90% infested goats. The difficulty of detecting light infestations of mites means that it was not clear whether the C. bovis infestation of sheep was derived from goats or was present when the study began. Whatever the source, close contact with goats with an active and extensive C. bovis infestation seems unlikely to seriously influence populations of the ectoparasite in sheep. Psoroptes cuniculi was found to he established in goats as young as five days and post-mortem examination of goats' ears was more successful at revealing P. cuniculi than was use of an otoscope during life.     

Microsporidia (Encephalitozoon cuniculi) in wild rabbits in Australia

Objective To determine the prevalence of infection with Encephalitozoon cuniculi i n wild rabbit populations in Western Australia, and to isolate the organism from seropositive rabbits.
Design Serological screening of wild and clinically affected domestic rabbit populations.
Sample population Eighty-one wild rabbits from southwestern Western Australia and 29 laboratory rabbits.
Procedure Indirect immunofluorescence antibody technique and in-vitro amplification of parasite isolates in fibroblast cultures.
Results Of the 81 wild rabbits and 29 laboratory rabbits, 20 and 22 respectively, had antibodies to E cuniculi . E cuniculi from the urine of one seropositive laboratory rabbit and from brain and kidney tissues of eight and five seropositive laboratory and wild rabbits respectively were isolated in fibroblast cultures.
Conclusion E cuniculi infection has been shown for the first time to be prevalent in wild rabbits in Australia. Techniques have been developed for the isolation and culture of the causative agent. Comparative studies can now be undertaken to determine risk factors for clinical disease in domestic rabbits and the relationship among E cuniculi isolates from wild and domestic rabbits.     

Ectopic Psoroptes cuniculi infestation in a pet rabbit

A case of Psoroptes cuniculi infestation of the ears and body of a pet rabbit, with severe lesions on the skin of the caudoventral abdomen, is reported. Treatment with ivermectin injection followed by fipronil application appeared to be safe and was successful in eliminating infection.     

Immediate intradermal flea antigen reactivity in clinically normal adult dogs from south Florida, USA

Eighty-six clinically normal adult dogs from southern Florida, USA, with no history of dermatitis, were intradermally skin tested with Greer flea antigen 1:1000 w/v to determine the prevalence of positive immediate intradermal reactivity. This study describes the test group of animals and reports the prevalence of sensitivity to the Greer whole-body flea antigen in normal dogs living in a flea-rich environment. Similar to previous research, the highest prevalence of reactivity to flea antigen occurred at 3–4 years of age. The results indicate that 24% of clinically normal dogs from a flea-rich environment exhibited positive immediate skin test reactivity. These dogs had no clinical signs of flea allergic dermatitis (FAD) in spite of ongoing flea exposure. A 2-year follow-up telephone call to the owners of these flea antigen intradermal skin test (IDST)-positive dogs indicated that only two of 21 dogs had developed clinical signs of FAD.     

Serological survey for antibodies to Encephalitozoon cuniculi in rabbits in Taiwan

Encephalitozoon cuniculi (E. cuniculi) is a microsporidian parasite commonly found in rabbits that can infect humans, causing encephalitozoonosis. Our laboratory recently confirmed the first case of encephalitozoonosis in a rabbit in Taiwan; the prevalence of encephalitozoonosis is not well documented, even when many clinics suspect pet rabbits as being infected. This study surveys the seropositivity of E. cuniculi using carbon immunoassay (CIA) and enzyme-linked immunosorbent assay (ELISA). Serological examination of 171 rabbits using CIA and ELISA showed that 63.2% (108/171) and 67.8% (116/171) were seropositive against E. cuniculi, respectively. Thirteen of the 14 rabbits (92.9%) with neurological symptoms were seropositive. Except for gender, health status and location had a significant effect on E. cuniculi seropositivity (p<0.05). Adult rabbits aged older than 4 months exhibited significantly higher seropositivity for E. cuniculi than young rabbits (p<0.05). In conclusion, this study shows that E. cuniculi is present and widespread among healthy rabbits in Taiwan. Therefore, the fields of veterinary and human medicine in Taiwan should be aware of this zoonotic issue and the resulting public health concern of encephalitozoonosis.     

Use of selamectin for the treatment of psoroptic and sarcoptic mite infestation in rabbits

Selamectin, a novel avermectin compound, was evaluated for its efficacy against naturally occurring infestations of Psoroptes cuniculi and Sarcoptes scabiei. A total of 42 New Zealand rabbits with psoroptic mange and 37 Angora rabbits with sarcoptic mange were used in the present study. On day 0, infested rabbits were treated topically with either selamectin at minimum dose of 6 mg kg(-1) (6-18 mg kg(-1) for New Zealand rabbits, n = 31 and 10-12 mg kg(-1) for Angora rabbits, n = 23) or vehicle only (control groups, n = 11 for New Zealand rabbits, n = 14 for Angora rabbits). The efficacy of selamectin was assessed both clinically and parasitologically by the presence or absence of viable mites. Rabbits were scraped for sarcoptic mites on days 7, 14, 28, 42 and 56 and had otoscopeic and/or microscopic examination for the detection of Psoroptes mites on days 7, 14, 42 and 56. Fisher's exact test was used to assess differences between the vehicle and selamectin treatment in the number of rabbits without mites (cure rates) on each assessment date. It was found that significantly fewer selamectin-treated rabbits had mites detected on skin scrapings (for S. scabiei) or otoscopeic and/or microscopic examination (for P. cuniculi) (P < 0.01) than the vehicle group. Results of the present study suggest that selamectin is effective against naturally infestations of P. cuniculi and S. scabiei in rabbits.     

Serological survey for antibodies to Encephalitozoon cuniculi in pet rabbits in Italy

Pet rabbits (n = 125) from Southern Italy were submitted to a serological screening for Encephalitozoon cuniculi, using an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA). Seventy-eight examined rabbits showed clinical signs suggestive of encephalitozoonosis (head tilt, ataxia, paralysis, cataracts, uveitis, polyuria and polydipsia), whereas 47 were healthy rabbits. Antibodies anti-E. cuniculi were found in 84/125 (67.2%) sera analysed. The results of the chi-squared test showed that sex and health status had no significant effect (P > 0.05) on E. cuniculi seropositivity; however, rabbits older than 4 months had a seropositivity for E. cuniculi significantly (P < 0.05) higher than that of rabbits aged up to 4 months. The results of the present survey reinforce the assumption that rabbit may be indicated as the main reservoir of E. cuniculi; therefore, routine screening examinations in pet rabbits are strongly advised considering the zoonotic potential of this parasite.     

阿苯达唑对自发性兔脑炎原虫病的治疗

为了有效地治疗兔脑炎原虫病,本研究根据脑炎原虫的生物学特点和对组织损伤的特征选用阿苯达唑进行了治疗试验。将28只3～4月龄隐性感染的獭兔,随机分为对照组和治疗组进行试验。治疗组按30mg／kg剂量（首次给药量为50mg／kg）,每隔12h给药1次,连续用药10d,停药1周为1个治疗期,共治疗3个疗程。对照组按正常饲养。每1疗程之后,均采血和尿液进行ELISA检测和尿沉渣虫体检查。结果,治疗组的病兔用阿苯达唑治疗3个疗程后,ELISA检测的D值均低于标准值（〈0．044）,即抗脑炎原虫血清抗体呈阴性反应,从尿沉渣中也不能检出虫体。而对照组病免的D值则大大高于正常值．从尿沉渣中均易检出虫,并有1只对照兔出现典型的神经症状,剖检后从脑组织中检出脑炎原虫性肉芽肿。经方差分析,2组间差异非常显著（P〈0．01）。试验证明,阿苯达唑对兔脑炎原虫有良好治疗作用,用药的时机以脑炎原虫还未进入脑组织时最合适,用药的剂量一定要保持有效的杀虫浓度。     

Induction of feline flea allergy dermatitis and the incidence and histopathological characteristics of concurrent indolent lip ulcers

The objectives of this study were to characterize the role of intermittent vs. continual flea exposure in the development of flea allergy dermatitis (FAD) in cats, assess the accuracy of intradermal skin testing (IDST) and in vitro testing, and document the incidence and histopathological features of indolent lip ulcers. Ten flea‐naive cats were divided into two groups. One group received intermittent flea exposure for 120 days. Thereafter, both groups of cats received continuous flea exposure for 120 days. In vitro testing for flea salivary antibody and IDST utilizing both whole flea antigen and flea salivary antigen were performed. Eight of 10 cats developed clinical signs of FAD within 3 months and five of these eight cats developed lip ulcers which where characterized histopathologically by ulceration with predominantly neutrophilic inflammation and surface bacterial colonization. There was no association between the presence or absence of clinical signs and positive IDST or in vitro results, and no difference in the development of clinical signs was noted between the two groups of cats.     

Diagnosis of flea allergy dermatitis: comparison of intradermal testing with flea allergens and a FcepsilonRI alpha-based IgE assay in response to flea control

The objective of this study was to evaluate the accuracy of in vivo and in vitro tests in the diagnosis of flea allergy dermatitis in comparison with history, clinical signs and response to flea control. Intradermal testing using four different sources of flea allergens and FcepsilonRIalpha-based immunoglobulin (Ig)E assays were performed in 15 flea-allergic dogs, 15 atopic dogs and 15 dogs infested with fleas but showing no clinical signs of skin disease. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy were calculated for all five tests and results varied greatly. Sensitivity, specificity and overall accuracy were 27, 83 and 64%, respectively, for one extract (Isotec), 67, 90 and 82% for another extract (Greer), 93, 90 and 91% for flea saliva, 40, 90 and 73% for the recombinant Cte f 1 both produced by Heska Corp. and 87, 53 and 64% for a FcepsilonRIalpha-based IgE assay. These results indicate that intradermal testing with flea extracts is more accurate in the diagnosis of flea allergy dermatitis than in vitro tests. Moreover, pure flea saliva used as a reagent for intradermal testing provided the best results in terms of sensitivity, specificity and overall accuracy although the Greer extract, a whole body flea extract, also allowed a good correlation between intradermal testing results and clinical approach to flea allergy dermatitis diagnosis.     

Double-blind flea hyposensitization trial in cats

In a double-blind clinical trial, flea antigen was injected subcutaneously or intradermally in cats with signs of fleabite allergic dermatitis. No significant clinical improvement was noted by the investigator or the owner in either antigen-treated or control groups over a 20-week period.     

Choriocarcinoma with metastasis in a rabbit (Oryctolagus cuniculi)

A 3-year-old female rabbit (Oryctolagus cuniculi) presented with apathy and indisposition for 2-3 days. Palpation revealed a mass in the caudal abdomen, namely, in the wall of the uterus. Ovariohysterectomy was performed, and the tissues were submitted for histopathologic examination. The mass consisted of 3 different (trophoblastic, syncytiotrophoblastic, and cytotrophoblastic) neoplastic cell types originating from the uterus. Immunohistochemistry was positive for cytokeratin in all 3 neoplastic cell types, and the syncytiotrophoblasts were positive also for human chorionic gonadotropin. Together these features allow the diagnosis choriocarcinoma. This report documents the first case of a spontaneous choriocarcinoma in a rabbit.     

Resolution of skin lesions and long-term survival in a dog with superficial necrolytic dermatitis and liver cirrhosis

A nine-year-old, neutered female Shetland sheepdog was presented with crusted, ulcerative skin lesions affecting the footpads, commissures of the lips and the lateral canthi of the eyes. Histopathological examination of skin biopsies revealed changes consistent with superficial necrolytic dermatitis and biochemical analysis demonstrated elevated liver enzymes. Abdominal radiography revealed a small liver which, on ultrasonography, appeared diffusely mottled and showed changes suggestive of periportal fibrosis. On exploratory laparotomy, the pancreas appeared normal, but the liver was small and had multiple nodules throughout the parenchyma. This appearance was confirmed as cirrhosis on histopathological examination. The dog was placed on a hepatic support diet and treated with colchicine, essential fatty acid supplementation and raw egg yolks. After four weeks, the skin lesions had resolved and the dog remained free of clinical signs over a 22-month follow-up period.     

Abnormal skin fragility in a cat with cnolangio-carcinoma

An eight-year-old shorthaired cat which presented with a five-month history of bouts of anorexia and vomiting, developed a large spontaneous skin tear over the left shoulder when manipulated for clinical workup. The cat had no previous history of abnormal skin fragility and clinical examination of the skin revealed a general thinning but no scarring or hyperextensibility. After one day of hospitalisation the animal was euthanased because of its poor condition and on post mortem examination a cholangiocarcinoma with distant metastasis was identified. The skin biopsy specimens obtained from different sites revealed dermal atrophic changes, characterised in electron microscopy by disorganisation in the packing of both collagen fibrils and fibres, and by collagen fibrils with an abnormally wide range of diameters and with an irregular shape in cross section. Although no specific cause of the dermal lesions was suggested, this case differed greatly from the fragile skin conditions previously described in the cat.     

Characterization of pruritus in canine atopic dermatitis,flea bite hypersensitivity and flea infestation and its role in diagnosis

Background – In dogs, flea infestation (FI), flea bite hypersensitivity (FBH) and canine atopic dermatitis (CAD) have been mainly characterized by their lesions but never by their pruritus. In clinical practice, many of these dogs exhibit only pruritus. Hypothesis/Objectives – The purpose of this study was to evaluate the characteristics of pruritus in these dermatoses and their potential usefulness for diagnosis. Animals – Dogs included were selected from the Oniris clinical data. Cases were selected in which the dogs had only one of the three dermatoses diagnosed. The diagnosis of CAD was based on Prélaud’s criteria and positive intradermal tests except flea; for FBH by compatible clinical signs and a response to an intradermal test with flea allergen; and for FI by the presence of fleas. Moreover, in each group, other primary pruritic skin diseases were excluded. Methods – Location, behavioural manifestations, seasonality and quantification of the pruritus were evaluated. The statistical analysis used chi‐squared test with a P‐value <0.05. Results – Three hundred and forty‐six dogs were analysed, 91 with CAD, 110 FI and 145 FBH. The period (season) of onset was not statistically different either for each dermatosis or among the three dermatoses. Some locations were highly specific for one dermatosis as follows: ventral abdomen/medial surface of thigh (chewing) and radius/carpus/tibia/tarsus (chewing) in FI; back/dorsolumbar area (chewing) and tail (chewing) in FBH; and paws (chewing/licking) and face/neck (rubbing) in CAD. Conclusions and clinical importance – Some features of pruritus could be suggestive of the causal disease, with possible diagnostic value in pruritic dogs.