FC‐24 Risk factors for atopic dermatitis in a Swedish population of insured dogs

Studies into the epidemiology of canine atopic dermatitis (CAD) are in great demand. Estimates of the prevalence and incidence of CAD are commonly based on hospital studies where no reference population is defined. Such studies tend to overestimate the disease frequency due to referral bias and a higher proportion of complicated cases at secondary care centres than in the general population. The aim of this paper was to present better estimates of the incidence of CAD. The Swedish dog population offers unique opportunities to study the epidemiology of CAD due to several characteristics: a large proportion of dogs are purebred, fleas and flea allergies are rare, and a secondary database of disease records is available through an insurance company that covers approximately 30% of all Swedish dogs. By accessing insurance‐claims records for the years 1995–2000, the true incidence rate of CAD was estimated as 10 cases per 10,000 dog years at risk. Univariate analysis showed that the incidence was the same across genders. Additionally, large differences in the risk of being diagnosed with CAD existed among breeds. In this study, breeds with the highest risk were the bull terrier (88 cases/10,000 dog years at risk), Staffordshire bull terrier (58/10,000), West Highland white terrier (51/10,000), Welsh terrier (50/10,000) and boxer (50/10,000). Decreased risk was observed among sighthounds; no cases were recorded among the Borzoi, Saluki and Whippet breeds. A proportional hazards (survival) model was developed in order to take sex, breed, age and geographical region into account in a multivariate analysis. Funding: Swedish University of Agricultural Sciences, The Foundation for Research.     

FC‐39 Successful management of canine atopic dermatitis using a plant extract: a randomized,double‐blinded,placebo‐controlled trial

This study evaluated the efficacy of Phytopica^TM, a proprietary blend of standardised plant extracts, in canine atopic dermatitis (AD). One hundred twenty dogs with perennial AD were recruited on the basis of history and clinical signs, and a positive intradermal allergen test or rFcεRIα serology to perennial allergens. Other pruritic dermatoses were eliminated by antimicrobial treatment, skin scrapings, Sarcoptes serology, flea control and a 6‐week food trial. Exclusion criteria included antimicrobial therapy within 7 days, antihistamines within 14 days, oral/topical glucocorticoids or cyclosporin within 28 days, and parenteral glucocorticoids, essential fatty acids or immunotherapy within 56 days of entry into the study. Dogs [minimum Canine Atopic Dermatitis Extent and Severity Index (CADESI) = 25] were randomly allocated to receive placebo, 100, 200 or 400 mg/kg Phytopica^TM daily for 12 weeks. Their CADESI was assessed every 4 weeks. A modified intention‐to‐treat population was analysed. The mean reductions in CADESI scores at the end of treatment compared to baseline were 4.4% (100 mg/kg; n = 30), 23.4% (200 mg/kg; n = 29, P < 0.01), 8.5% (400 mg/kg; n = 29) and 3.9% (placebo; n = 29). For more severely affected dogs (minimum CADESI ≥ 50 at baseline), there was significant reduction in mean CADESI score (29.3%, P = 0.038) only in the 200 mg/kg treatment group (n = 14). In conclusion, this study demonstrates that Phytopica^TM is an effective nonsteroidal treatment for canine AD. Funding: Phytopharm plc.     

FC‐51 Comparison of intradermal test and antigen‐specific IgE test in 22 cases of feline allergic dermatitis

The usefulness of the intradermal test (IDT) and the serological allergy test (SAT) for detecting antigen‐specific IgE in allergic cats has not yet been established. In this study, we compared the results of IDT with those of SAT and evaluated the clinical usefulness of the two tests for detecting possible allergens in allergic cats. IDT and SAT using eight antigens were performed on 22 cats with intense pruritus after excluding ectoparasites and performing diet elimination tests. Approximately 50% of the cats reacted to at least one allergen by either IDT or SAT, and 36.4% of the cats reacted on both IDT and SAT. In contrast, seven healthy cats did not show any reactions on IDT or SAT. The most commonly detected allergen in both tests was house dust mites (IDT, 36.4%; SAT, 40.9%). Five cats reacted to one allergen and the others reacted to more than one allergen with IDT. Three cats reacted to one allergen with SAT. The following percentage agreement between the results of the two tests was calculated: house dust mites (86.4%), cat fleas (63.6%), grass mix (86.4%), common mugwort (81.8%), cat epithelia (90.9%), ragweed (86.4%), Japanese cedar (90.9%), and plantain (81.8%). The overall mean percentage agreement was 83.5%. In summary, the present study showed good agreement between IDT and SAT for cats, and SAT may be more sensitive than IDT, but less specific for detecting sensitized allergens. Funding: Self‐funded.     

FC‐30 Presence of dust mites in the environment of dust mite‐sensitized atopic dogs

Dust mites (DM) are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM load of households with atopic dogs (Group A, n = 8) that had positive intradermal test reactions to Dermatophagoides farinae, D. pteronyssinus, Acarus siro, Lepidoglyphus destructor and/or Tyrophagus putrescentiae to the DM load of households with nonatopic dogs (Group B, n = 4) and of nonpet households (Group C, n = 8). Group A dogs presented with perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria of atopic dermatitis. All Group B dogs tested intradermally negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from the human (all groups) and dog mattresses (Groups A and B) or from the couch (Group C) four times, once for each season of the year. The presence of DM was assessed with a commercial test (Acarex test) and stereoscopically. At least one DM was found in all Group A houses. The DM load was not significantly different between the seasons or the three animal groups. The sensitivity of the Acarex test was significantly lower than that of stereoscopic examination (P < 0.001). In conclusion, the environmental DM load was similar between atopic and nonatopic dogs, the presence of dogs in a household didn't increase DM numbers, and stereoscopy was more sensitive than the Acarex test for the detection of DM. Funding: Self‐funded.     

FC‐61 The role of a liquorice preparation in healing of experimental wounds in calves: a histopathologic study

Liquorice, a derivative of the root of Glycyrrhizia glabra, has been proposed as a treatment for gastric ulcers. Here, a preparation of liquorice combined with sesame oil was evaluated in experimental wound healing. The study was carried out in two female 10‐month‐old Holstein calves. An area of 10 × 10 cm on each side of the thorax of the animals was surgically prepared and infiltrated with local anaesthetic. Eight uniform skin wounds were created in two rows with an 8‐mm biopsy punch on each prepared area. Each side of an animal was used to evaluate one treatment (Groups 1–4). To make the mixture, powdered and sieved liquorice (16 g) was mixed with sesame oil (36 g) to make a suspension. The wounds were treated for 7 days. The wounds of Groups 1–3 were rinsed daily with normal saline, after which the mixture of liquorice and sesame oil (Group 1) or only the sesame oil (Group 2) was applied to the wounds. In Group 4, no treatment was applied. All wounds were left open. On day 8, skin biopsies were taken from the wounds for histopathologic study. In Group 1, seven wounds (87%) showed moderate granulation tissue, mild scab formation, and complete re‐epithelialization. In Group 2, there was massive scab formation with no granulation tissue and minimal re‐epithelialization. In Groups 3 and 4, mild granulation tissue, severe scab formation and very limited re‐epithelialization were observed. We conclude that a preparation of liquorice and sesame oil can be an effective remedy for wound healing. Funding: Self‐funded.     

FC‐33 Expression of IL‐12 receptor β2 gene in atopic dogs

Atopic dermatitis (AD) is very common in dogs, but its pathogenesis is not yet fully understood. It has been suggested that a Th2‐dominant status may be associated with the occurrence of canine AD. IL‐12 is thought to be important for the differentiation of Th1 cells. The IL‐12 receptor β2 (IL‐12Rβ2) gene is considered to play a critical role in signal transduction and is attracting attention as one of the causative genes of AD in humans. The purpose of this study was to investigate the relationship between IL‐12Rβ2 gene expression and canine AD. The canine IL‐12Rβ2 gene was cloned by RT‐PCR and its nucleotide sequences were determined. Canine IL‐12Rβ2 showed 76.8% homology at the amino acid level with human IL‐12Rβ2, and its structural motifs were well conserved. cDNA with a 91 bp deletion including the transmembrane region was also cloned, which consequently produced a frame shift and an early stop codon. The deletion region corresponded to exon 14 of the human IL‐12Rβ2 gene on chromosome 1. The expression of deleted canine IL‐12Rβ2 mRNA in phytohemagglutinin‐stimulated peripheral blood mononuclear cells was examined in seven healthy dogs and 11 AD dogs. Both deleted and intact mRNAs were expressed at constant ratios in healthy and AD dogs. The results indicate that the deletion of the transmembrane region is not associated with the occurrence of AD, and that the expression of the deleted mRNA may be constitutive and produced by alternative splicing. Funding: Self‐funded.     

FC‐18 Pemphigus foliaceus in 97 dogs

Medical records of 97 dogs with pemphigus foliaceus were evaluated. The average age of onset was 6.3 years (range 0.5–16 years). Crusts were the most common lesions in 79 dogs; pustules were observed in 36 dogs. No gender predisposition was identified. The trunk was the most commonly involved area (51 dogs), followed by the inner pinnae (46), dorsal muzzle (37), footpads (32), periocular area (26), outer pinnae (23) and planum nasale (23). Facial involvement only was noted in 15 dogs. Of the 48 dogs in which cytology was recorded, concurrent infections were identified in 32 dogs, acantholytic cells were seen in 37 dogs, numerous neutrophils in 35 dogs, and numerous eosinophils in eight cases. Final control of the disease was achieved with: glucocorticoids (24 dogs); azathioprine (9); chlorambucil (1); aurothioglucose (1); a combination of glucocorticoids and azathioprine (31); glucocorticoids and aurothioglucose (2); tetracycline/doxycycline and niacinamide (8); prednisolone, tetracycline and niacinamide (1); fatty acid supplementation (2); and tacrolimus (1). One dog was completely tapered off drugs and stayed in remission. Average time to improvement was 6 weeks, and average time to remission was 9.3 months. Forty‐three dogs were followed for <12 months, and 12 of these were euthanized: eight for other diseases and four due to a lack of response or adverse effects of treatment. In 54 dogs, the follow up was >12 months; four of these dogs were euthanized (one due to an unrelated cause, one due to neoplastic disease and two related to pemphigus foliaceus). Funding: Self‐funded.     

FC‐60 The role of a fresh oleaster leaf preparation in healing of experimental wounds in calves: a histopathologic study

Oleaster (Elaeagnus angustifolia) is a small tree that grows throughout Iran. Using smashed tree leaves combined with olive oil is proposed in one ancient Iranian text as a good remedy for wound healing. Our objective was to evaluate this remedy experimentally. The study was carried out in two female 10‐month‐old Holstein calves. An area of 10 × 10 cm on each side of the thorax was surgically prepared and infiltrated with local anaesthetic. Eight uniform skin wounds were created in two rows with an 8‐mm biopsy punch on each prepared area. Each side of an animal was used to evaluate one treatment (Groups 1–4). To make the mixture, fresh oleaster leaves (50 gm) were smashed with a pestle and mixed with olive oil (25 gm). The wounds were treated for 7 days. The wounds of Groups 1–3 were rinsed daily with normal saline, after which the mixture of oleaster and olive oil (Group 1) or only the olive oil (Group 2) was applied. In Group 4, no treatment was applied. All wounds were left open. On day 8, skin biopsies were taken from the wounds for histopathologic study. Group 1 wounds all showed mild granulation tissue, scab formation and complete re‐epithelialization. In Group 2, there was mild granulation tissue, massive scab formation and minimal re‐epithelialization. In Groups 3 and 4, mild granulation tissue, severe scab formation and very limited re‐epithelialization were observed. We conclude that a fresh oleaster leaf preparation can be an effective remedy for wound healing. Funding: Self‐funded.     

Long-term use of cyclosporine in the treatment of canine atopic dermatitis

This retrospective study of 51 dogs with atopic dermatitis (AD) treated with cyclosporine (CsA) for a minimum of 6 months assessed the frequency of dosing and the need for continual treatment to control clinical signs. The study evaluated both medical records and information supplied by the owners in the form of written questionnaires and telephone follow-up. Laboratory parameters, possible adverse effects and owner satisfaction were assessed. The dose of CsA was 5 mg/kg orally per day and dogs received CsA for 6-30 months. At the conclusion of the study period, 28 dogs (55%) needed ongoing CsA to control clinical signs of AD: 8 (15%) received CsA 2-3 days per week, 10 (20%) 4-5 days per week, and 10 (20%) daily. CsA was discontinued in 23 dogs (45%) after 6-24 months due to either a limited response (22%) or after achieving a clinical response (24%). The results suggest that some dogs with AD treated with CsA may not require daily or even ongoing treatment to control clinical signs. Laboratory abnormalities were detected in 13 dogs (25%) during their CsA treatment. Two dogs developed oral growths and three developed hirsuitism. Forty owners (78%) reported no adverse events in their dogs during the treatment period. Thirty-six owners (71%) were satisfied with CsA as treatment for their atopic dog.     

Interleukin‐31: its role in canine pruritus and naturally occurring canine atopic dermatitis

Background – Interleukin‐31 (IL‐31) is a member of the gp130/interleukin‐6 cytokine family that is produced by cell types such as T helper 2 lymphocytes and cutaneous lymphocyte antigen positive skin homing T cells. When overexpressed in transgenic mice, IL‐31 induces severe pruritus, alopecia and skin lesions. In humans, IL‐31 serum levels correlate with the severity of atopic dermatitis in adults and children. Hypothesis/Objective – To determine the role of IL‐31 in canine pruritus and naturally occurring canine atopic dermatitis (AD). Animals – Purpose‐bred beagle dogs were used for laboratory studies. Serum samples were obtained from laboratory animals, nondiseased client‐owned dogs and client‐owned dogs diagnosed with naturally occurring AD. Methods – Purpose‐bred beagle dogs were administered canine interleukin‐31 (cIL‐31) via several routes (intravenous, subcutaneous or intradermal), and pruritic behaviour was observed/quantified via video monitoring. Quantitative immunoassay techniques were employed to measure serum levels of cIL‐31 in dogs. Results – Injection of cIL‐31 into laboratory beagle dogs caused transient episodes of pruritic behaviour regardless of the route of administration. When evaluated over a 2 h period, dogs receiving cIL‐31 exhibited a significant increase in pruritic behaviour compared with dogs that received placebo. In addition, cIL‐31 levels were detectable in 57% of dogs with naturally occurring AD (≥13 pg/mL) but were below limits of quantification (<13 pg/mL) in normal, nondiseased laboratory or client‐owned animals. Conclusions – Canine IL‐31 induced pruritic behaviours in dogs. Canine IL‐31 was detected in the majority of dogs with naturally occurring AD, suggesting that this cytokine may play an important role in pruritic allergic skin conditions, such as atopic dermatitis, in this species.     

FC‐14 Clonality studies of feline cutaneous lymphocytosis

A previous study described cutaneous lymphocytosis (CL) in 23 cats. The process resembles cutaneous pseudolymphoma in humans, a heterogeneous group of benign reactive proliferations of well‐differentiated lymphocytes in the skin of humans. Morphological and immunophenotypic characteristics do not offer reliable criteria to accurately predict the clinical outcome of feline CL or pseudolymphoma in humans. Presence of clonal cell populations is more consistent with a neoplastic process. In a previous study, feline CL lesions (20 cats) were evaluated for clonality using PCR, and only two cats had monoclonal T‐cell populations. Because false‐negative results may occur, the purpose of this study was to repeat the PCR using a revised primer set based on analysis of additional feline T‐cell receptor γ (TCRγ) sequences. DNA was isolated from 29 skin lesions and six internal organs of 20 cats. DNA integrity was assessed by glyceraldehyde‐3‐phosphate dehydrogenase PCR. Polymerase chain reaction clonality was performed using the revised primer set specific for feline TCRγ, and duplicate samples were evaluated. The PCR products were assessed by heteroduplex analysis. Clonal rearrangement of TCRγ was detected in 14 cats (24 of 35 tissues: 21 of 29 skin lesions and three of six internal organs); eight of these cats are still alive and six were euthanized. Monoclonal populations were seen in three of five cats that had involvement of internal organs. These findings indicate that feline CL is best considered as a slowly progressive process which may be reactive, but often evolves into a low‐grade indolent lymphoma. Funding: George H. Muller Fund for Research in Dermatology.     

FC‐42 Sarcoptic mange epidemic in a cat population

Worldwide, sarcoptic mange in cats is seldom reported, and then only in sporadic individual cases. We describe an epidemic in a household with a dog and 25 cats. From September 2002, the dog was repeatedly treated with ivermectin for sarcoptic mange. The diagnosis was confirmed by skin scrapings. Fifteen months later, cats from the same household were diagnosed with severe sarcoptic mange. Twenty‐one of the cats were euthanized and necropsies were performed. Skin samples were taken from all cats from different body sites for histology, and skin scrapings were examined for ectoparasites. Samples for bacterial and dermatophyte culture were taken from six cats. Smears for cytology were made from lesions on four cats with severe mange. Sera from 21 cats and the dog were analysed for specific antibodies to Sarcoptesscabiei. Molecular characterizations of six individual mites were done. Large numbers of S.scabiei were isolated from the infected skin of most of the cats. Two‐thirds of the cats showed skin lesions compatible with chronic sarcoptic mange. Macroscopically, internal organs exhibited no obvious pathology. Yeast organisms and coccoid bacteria were found in the smears; penicillinase‐negative Staphylococcus aureus was isolated from all samples and Malassezia pachydermatis was identified from four cats. Sarcoptes scabiei was seen histologically in all cats showing chronic skin lesions. No other ectoparasites were found. All analysed cats had specific antibodies against S. scabiei. Twenty‐one cats tested negatively for FeLV and FIV. The mites had DNA sequences identical to S. scabiei from naturally infected dogs and Swedish wildlife. Funding: Self‐funded.