[Treatment of chronic recurrent idiopathic pyoderma in the dog with vaccines containing bacterial antigens]

Staphylococcal vaccines are a good therapeutic alternative to the classic antibacterial treatments in dogs with chronic recurrent pyoderma without detectable underlying diseases. At the beginning of this therapy, the vaccine should be combined with other antimicrobial treatments for several weeks. Treatment success should be judged after 10, or better, 18 weeks. Differences in the production processes of the vaccine will influence the adverse effects and the success rate.

[Evidence-based treatment of canine demodicosis]

This article briefly reviews pathogenesis, clinics and diagnosis of canine demodicosis and summarizes treatment options for this disease based on published evidence. The disease is caused by excessive proliferation of Demodex mites in the hair follicles that may be due to genetic factors or immunosuppressive diseases or treatments. The disease is characterized by alopecia, papules, pustules and crusts. Diagnosis is confirmed by detection of several mites in deep skin scrapings or trichograms. Based on published studies, licensed successful treatments for many patients are weekly amitraz rinses in a concentration of 0.05% and (in dogs with mild to moderate clinical signs) weekly spot-ons containing moxidectin. In severe, treatment-resistant cases, daily oral macrocyclic lactones such as milbemycin oxim (1-2 mg/kg), ivermectin or moxidectin (0.3 mg/kg after daily gradual dose increases from 0.05mg/kg) may be used. Doramectin orally or subcutaneously at 0.6 mg/kg has also been reported as successful therapy. Secondary bacterial skin infections are common and should be treated with antimicrobial shampoos and possibly oral antibiotics.

[Evidence-based medicine - academic bubble or practical relevance?]

In this short overview the principles of evidence-based medicine are introduced and their relevance for small animal practice is discussed. The hierarchic order of evidence is presented, with meta-analyses of many studies or systematic reviews being the most reliable evidence possible, followed by randomized controlled trials, case series, case reports and published expert committee opinions and lastly personal experiences. Evidence of higher quality should overrule contradictory evidence of lower quality, always considering the individual circumstances of the patients and the owner's wishes.

Breed and site predispositions of dogs with atopic dermatitis: a comparison of five locations in three continents

The objectives of this multicentre study were to analyse and compare breed predispositions and lesion distributions of 552 dogs diagnosed with atopic dermatitis from five different dermatologic referral centres located in Australia, Germany (2) and the United States (2). Breeds were compared with the canine population in the respective locations. Breed predispositions varied from geographical site, although golden retrievers and German shepherd dogs were predisposed in three of five practices. Lesions were present most commonly on the paws (62%), ventrum (51%), ears (48%) and face (39%). Various breeds had specific site predilections. Based on this study, breed predispositions can vary greatly both between continents and also between different locations on the same continent. In addition, some breeds showed predispositions for certain body sites which also varied in some instances with the geographical location.

[Treatment options for canine atopic dermatitis]

In this review evidence for efficacious treatments of canine atopic dermatitis is summarized on the basis of randomised controlled studies. For severely affected cases topical or systemic glucocorticoids or calcineurin inhibitors such as cyclosporin or tacrolimus can be used in addition to avoidance of flare factors, allergen-specific immunotherapy, a good flea control, dietetic measures, essential fatty acids and shampoos. To prevent recurrences long-term use of especially allergen-specific immunotherapy, essential fatty acids and antihistamines can be helpful. In some cases intermittent therapy with topical or systemic glucocorticoids at low dose may also be useful. Essential fatty acids and antihistamines may reduce the needed glucocorticoid dose.

Cutaneous epitheliotropic T-cell lymphoma with dissemination to the liver in an eastern chipmunk (Tamias striatus)

Cutaneous epitheliotropic T-cell lymphoma with liver metastasis was diagnosed in a 10-year-old eastern chipmunk (Tamias striatus). Physical findings included intracutaneous swellings, ulcerated plaques and nodules, hypotrichosis and erythema of the skin. Fine needle aspiration from the skin lesions showed a population of large lymphocytes and lymphoblasts, and was helpful in establishing the diagnosis antemortem. The post-mortem examination revealed epitheliotropic lymphoma with liver metastasis. Immunohistochemistry proved the T-cell origin both in the liver and skin tumours. Electron microscopy did not reveal any viral particles within the tumour. To the authors' knowledge, this is the first case of lymphoma described in this species.

A review of allergen-specific immunotherapy in human and veterinary medicine

This article reviews allergen-specific immunotherapy in human and veterinary medicine. Current hypotheses of possible mechanisms of actions are outlined. Indications, success rates, adverse effects and factors influencing outcome of therapy are discussed in humans, dogs, cats and horses.

Comparison of the prevalence of enteric viruses in healthy dogs and those with acute haemorrhagic diarrhoea by electron microscopy

Objectives: To evaluate prevalence of enteric viruses in healthy dogs and to compare it with prevalences in dogs with acute haemorrhagic diarrhoea.

Methods: Faecal samples were collected from 200 healthy dogs and examined by electron microscopy for presence of viral particles. Data were compared with viral prevalences that had been determined retrospectively by electron microscopy for 936 dogs with acute haemorrhagic diarrhoea.

Results: There were significantly more negative faecal samples among the healthy dogs (82·0 per cent) compared with 55·8 per cent in dogs with acute haemorrhagic diarrhoea (P<0·001). With a prevalence of 17·5 per cent, significantly more healthy dogs were shedding coronavirus compared with 11·6 per cent in dogs with acute haemorrhagic diarrhoea (P=0·034). Parvovirus was only detected in one healthy dog (0·5 per cent), thus with a prevalence that was significantly lower than 16·0 per cent detected in the dogs with acute haemorrhagic diarrhoea (P<0·001). Paramyxovirus was not found in any of the healthy dogs but was found in 9·3 per cent of dogs with acute haemorrhagic diarrhoea (P<0·001).

Clinical Significance: Results suggest that shedding of parvovirus and paramyxovirus is strongly associated with acute haemorrhagic diarrhoea. However, coronavirus seems to be even more prevalent among healthy dogs, raising the need for further studies to investigate the strain‐associated pathogenicity of this virus.

Pradofloxacin in the treatment of canine deep pyoderma: a multicentred, blinded, randomized parallel trial

A multicentre, randomized, blinded study compared the efficacy of pradofloxacin with that of a combination of amoxycillin/clavulanic acid in the treatment of deep pyoderma in dogs. Dogs with clinical lesions of deep pyoderma and a positive bacterial culture were included in the study. At each visit, they were evaluated with lesion, pruritus and general condition scores. Dogs were treated either with pradofloxacin at 3 mg kg-1 once daily or with amoxycillin at 10 mg kg-1 and clavulanic acid at 2.5 mg kg-1 twice daily and evaluated weekly for 3 weeks and every 2 weeks thereafter until 2 weeks past clinical remission. Maximal treatment duration was 9 weeks, and maximal evaluation period was 11 weeks. Of the 56 dogs treated with pradofloxacin (group 1), 48 dogs (86%) achieved clinical remission, four dogs improved, four dogs did not respond and a recurrence of clinical signs was not seen in any patient after 11 weeks. Of the 51 dogs treated with amoxycillin/clavulanic acid (group 2), 37 dogs achieved clinical remission (73%), three dogs showed improvement, five dogs showed no response and in six dogs, clinical signs recurred within 2 weeks of cessation of therapy. These results indicate that pradofloxacin is an efficacious therapy comparable to amoxycillin/clavulanic acid for deep bacterial pyoderma in dogs.

Pemphigus Foliaceus in 91 Dogs

A retrospective study of 91 dogs with pemphigus foliaceus was performed. Clinical signs of the disease included crusts (n=79), pustules (n=36), and alopecia (n=33). Lesions were most common on the trunk (n=53), inner pinnae (n=46), face (n=37), and foot pads (n=32). Cytological evaluation revealed acantholytic keratinocytes in 37 of 48 dogs. Results of combination treatment with prednisolone and azathioprine were comparable to results with prednisolone therapy alone. More than half of the dogs achieved remission with appropriate therapy, and another 25% significantly improved.

Results of allergen-specific immunotherapy in 117 dogs with atopic dermatitis

The success of the treatment of 117 dogs with atopic dermatitis with allergen-specific immunotherapy for up to 48 months was assessed. An excellent response (remission with exclusive immunotherapy) was recorded in 18 of the dogs, a good response (more than 50 per cent reduction in medication and improvement of clinical signs) was recorded in 57, a moderate response was recorded in 24 and a poor response in 18. The mould antigens in the allergen extract were stored in a separate vial before administration and the success rate of the immunotherapy including mould antigens was much higher than in an earlier study in which mould and pollen antigens had been stored in one vial. The success rate was not affected significantly by the age of the dogs when the disease developed, or by their age or the period for which they had shown clinical signs when the treatment began; it was also unaffected by whether pollens, moulds or dust mites were used as antigens, or by whether the offending allergens had been identified by intradermal testing or by serum testing for allergen-specific immunoglobulin E.

Review of 15 cases of pemphigus foliaceus in horses and a survey of the literature

The records of 15 horses with pemphigus foliaceus diagnosed on the basis of their history, clinical signs, histopathology and the exclusion of differential diagnoses were evaluated with respect to the age of onset, the clinical signs and the diagnostic tests used. There was no apparent breed predisposition. The horses' mean age was nine years, with a range from three months to 25.5 years, three were foals up to six months old and eight were nine years old or older. The most frequent lesions were scaling in 11, crusting in 10 and alopecia in 10, and they appeared most commonly on the face, neck and trunk, in 10 horses for each of these sites. The extremities were involved in nine of the horses, pruritus occurred in seven, and four of the horses had pustules. The clinical signs mostly corresponded with those described in previous reports, but signs of pain were not a prominent feature. Acantholytic cells were identified cytologically in four of six of the horses.

Plasma and skin concentrations of polyunsaturated fatty acids before and after supplementation with n-3 fatty acids in dogs with atopic dermatitis

OBJECTIVE

To determine essential fatty acid concentrations in plasma and tissue before and after supplementation with n-3 fatty acids in dogs with atopic dermatitis.

ANIMALS

30 dogs with atopic dermatitis.

PROCEDURE

Dogs received supplemental flaxseed oil (200 mg/kg/d), eicosapentaenoic acid (EPA; 50 mg/kg/d)-docosahexaenoic acid (DHA; 35 mg/kg/d), or mineral oil as a placebo in a double-blind, placebo-controlled, randomized trial. Clinical scores and plasma and cutaneous concentrations of linoleic acid, arachidonic acid, alpha-linolenic acid (alpha-LLA), EPA, DHA, prostaglandin E2, and leukotriene B4 were determined.

RESULTS

Total plasma concentrations of alpha-LLA and EPA increased and those of arachidonic acid decreased significantly with administration of EPA-DHA, and concentrations of alpha-LLA increased with flaxseed oil supplementation; nevertheless, there was no significant change in the concentrations of these fatty acids or eicosanoids in the skin. There was no correlation between clinical scores and plasma or cutaneous concentrations for any of the measured fatty acids or eicosanoids.

CONCLUSION AND CLINICAL RELEVANCE

Results indicated that at the dose used, neither the concentrations of fatty acids in skin or plasma nor a decrease in the production of inflammatory eicosanoids was a major factor involved in the mechanism of action in dogs with atopy that responded to fatty acid supplementation.

Intradermal testing with the storage mite Tyrophagus putrescentiae in normal dogs and dogs with atopic dermatitis in Colorado

The purpose of this study was to evaluate reactions to intradermal injections of Tyrophagus putrescentiae extract in healthy dogs and dogs with atopic dermatitis and to compare the prevalence of positive reactions in the two groups. Twenty-one healthy dogs and 26 atopic dogs were tested intradermally with T. putrescentiae extract at 1000, 500, 250, 125, 63, 32 and 16 PNU/mL. Reactions were evaluated objectively and subjectively. A Mann-Whitney test was used to determine differences in grade of reaction to storage mites between healthy dogs and dogs with atopic dermatitis. Positive reactions to storage mite extract were most common at 1000 PNU/mL with approximately one third of normal and atopic dogs showing a positive reaction to T. putrescentiae. There was no significant difference in the incidence of positive reactions between normal and atopic dogs for any of the Tyrophagus extract concentrations.

Use of immunostimulatory liposome-nucleic acid complexes in allergen-specific immunotherapy of dogs with refractory atopic dermatitis - a pilot study

This pilot study evaluated the effects of immunostimulatory liposome-plasmid-DNA complexes combined with specific allergens for immunotherapy of refractory canine atopic dermatitis. Seven dogs with previously diagnosed atopic dermatitis and unsatisfactory response to at least 12 months of conventional allergen-specific immunotherapy underwent a series of six intradermal injections (weeks 0, 2, 4, 6, 10 and 14), with patient-specific allergen extracts contained in cationic liposome-DNA complexes. Degree of pruritus was assessed on a visual analogue scale. Lesion scores were determined using the Canine Atopic Dermatitis Extent and Severity Index (CADESI) and medication usage was recorded at weeks 0 and 14. Canine cytokine mRNA expression in peripheral blood mononuclear cells collected prior to treatment and at the completion of the study was determined for IFN-gamma, IL-4, TNF and IL-10 genes using quantitative reverse transcription competitive polymerase chain reaction. Repeated intradermal injections of specific allergens incorporated into liposome-nucleic acid complexes were well tolerated in all seven dogs. There was a significant improvement in pruritus scores (P = 0.0277) and concurrent significant decrease in IL-4 production (P = 0.0428) at the completion of the trial compared to pretreatment values. Medication scores, CADESI and production of other cytokines did not change significantly with treatment. These early results suggest that antigen-specific immunotherapy using a novel liposome-nucleic acid complex vaccine may be beneficial for treatment of established atopic dermatitis in dogs using lower antigen doses. Further investigations in larger numbers of dogs with earlier stages of disease are warranted.

Cross reactivity of airborne allergens based on 1000 intradermal test results

OBJECTIVE

The purpose of this study was to evaluate concurrent positive reactions of related versus nonrelated allergens based on 1000 intradermal tests of dogs with atopic dermatitis.

PROCEDURE

Pairs of closely related allergens (based on botanical relations and results of research in human allergic disease) and nonrelated allergens were evaluated. Significance of the difference between group means of log odds ratios was estimated using a Bootstrap percentile confidence interval.

RESULTS

There was a significant difference in the mean log odds ratio between related and nonrelated allergen pairs. However, there was also a significant difference between most groups consisting of nonrelated allergen pairs.

CONCLUSION

These results provide conflicting evidence and emphasise the need for further studies. Numbers of concurrent reactions of related allergens indicate that immunotherapy should be formulated based on testing with single allergens to avoid exposure to allergens not involved in the dog's atopic disease.

Effect of omega-3 fatty acids on canine atopic dermatitis

Twenty-nine dogs were included in a double-blinded, placebo-controlled, randomised trial and were orally supplemented for 10 weeks with either flax oil (200 mg/kg/day), eicosapentaenoic acid (50 mg/kg/day) and docosahexaenoic acid (35 mg/kg/day) in a commercial preparation, or mineral oil as a placebo. For each dog, clinical scores were determined based on a scoring system developed prior to the trial. Total omega-6 and omega-3 intake and the ratio of omega-6:omega-3 (omega-6:3) were calculated before and after the trial. The dogs' clinical scores improved in those supplemented with flax oil and the commercial preparation, but not in the placebo group. No correlation was identified between total fatty acid intake or omega-6:3 ratio and clinical scores. Based on the results of this study, the total intake of fatty acids or the omega-6:3 ratio do not seem to be the main factors in determining the clinical response.

Treatment protocols for demodicosis: an evidence-based review

Publications discussing the treatment of demodicosis in the dog and cat are reviewed. Based on the evidence in the literature, amitraz rinses at 0.025-0.06% every 7-14 days, and oral daily ivermectin at 300 micro g kg(-1), milbemycin at 2 mg kg(-1) and moxidectin at 400 micro g kg(-1), respectively, can all be recommended for the treatment of generalized canine demodicosis. Ivermectin and moxidectin should be initiated at lower doses and patients monitored for possible adverse effects during therapy. In cats, 2% lime sulfur dips and amitraz rinses at 0.0125-0.025% have been used successfully.

Evidence-based veterinary dermatology: a systematic review of the pharmacotherapy of canine atopic dermatitis

The efficacy of pharmacological interventions used to treat canine atopic dermatitis, excluding fatty acid supplementation and allergen-specific immunotherapy, was evaluated based on the systematic review of prospective clinical trials published between 1980 and 2002. Studies were compared with regard to design characteristics (randomization generation and concealment, masking, intention-to-treat analyses and quality of enrolment of study subjects), benefit (improvement in skin lesions or pruritus scores) and harm (type, severity and frequency of adverse drug events) of the various interventions. Meta-analysis of pooled results was not possible because of heterogeneity of the drugs evaluated. Forty trials enrolling 1607 dogs were identified. There is good evidence for recommending the use of oral glucocorticoids and cyclosporin for the treatment of canine atopic dermatitis, and fair evidence for using topical triamcinolone spray, topical tacrolimus lotion, oral pentoxifylline or oral misoprostol. Insufficient evidence is available for or against recommending the prescription of oral first- and second-generation type-1 histamine receptor antagonists, tricyclic antidepressants, cyproheptadine, aspirin, Chinese herbal therapy, an homeopathic complex remedy, ascorbic acid, AHR-13268, papaverine, immune-modulating antibiotics or tranilast and topical pramoxine or capsaicin. Finally, there is fair evidence against recommending the use of oral arofylline, leukotriene synthesis inhibitors and cysteinyl leukotriene receptor antagonists.

A retrospective study regarding the treatment of lupoid onychodystrophy in 30 dogs and literature review

The treatment records of 30 dogs with lupoid onychodystrophy were evaluated retrospectively. Dogs were treated with fatty acid supplementation (n=18), doxycycline and niacinamide (n=12), tetracycline and niacinamide (n=10), pentoxifylline (n=6), prednisolone (n=5), azathioprine (n=1), clofazimine (n=1), or with combinations thereof. An excellent response was seen in almost half of the patients treated with tetra- or doxycycline in combination with niacinamide. Six of the dogs were maintained successfully on fatty acid supplementation. Spontaneous remissions and recurrences made evaluation of success rates difficult and emphasized the varied and often unclear etiology and natural course of the syndrome.

Evaluation of cross-reactivity of allergens by use of intradermal testing in atopic dogs

OBJECTIVE

To examine cross-reactivity of aeroallergens in Colorado and surrounding states by evaluating concurrent positive reactions of related and nonrelated allergens of intradermal tests in dogs.

SAMPLE POPULATION

Intradermal test results of 268 atopic dogs.

PROCEDURE

A retrospective evaluation of skin test results for 268 dogs was performed. Pairs of closely related and nonrelated allergens were evaluated. Group 1 consisted of closely related allergens with demonstrated antibody cross-reactivity in humans. In group 2, allergens of the same plant group (ie, trees, grasses, or weeds) that were not closely related were paired. In group 3, allergen pairs were of different plant groups. Plant allergens were paired with dust mite allergens, animal dander, or mold spores in group 4. In the last group, allergens not derived from plants were paired. Data were evaluated twice by use of a different definition of a positive reaction. Significance of the difference between group means of log odds ratios was estimated by use of a boot-strap percentile confidence interval.

RESULTS

Significant differences in the number of concurrent positive reactions were not found between related versus nonrelated grass, weed, or tree allergens. Significant differences in the number of concurrent positive reactions were found between plant allergens of different groups (ie, grasses, weeds, and trees) and plant allergens of the same groups, related or nonrelated, as well as between plant-derived and nonplant-derived allergens. Many dogs reacting to a specific allergen did not react to a closely related allergen at the same time.

CONCLUSION

These results provide evidence against clinically relevant cross-reactivity and suggest that allergen-specific immunotherapy should be formulated on the basis of single allergen test results.

Influence of long-term treatment with tetracycline and niacinamide on antibody production in dogs with discoid lupus erythematosus

OBJECTIVE

To evaluate the effect of long-term treatment with tetracycline and niacinamide on antibody production in dogs by measuring postvaccinal serum concentrations of antibodies against canine parvovirus and canine distemper virus.

ANIMALS

10 dogs receiving long-term treatment with tetracycline and niacinamide (treatment group) and 10 healthy dogs (control group).

PROCEDURE

The treatment group included 9 dogs with discoid lupus erythematosus and 1 dog with pemphigus foliaceus on long-term treatment (> 12 months) with tetracycline and niacinamide. The control group included 10 healthy dogs with no clinical signs of disease and no administered medications for the past 3 months. Blood samples were obtained from all dogs by jugular venipuncture. Serum antibody titers against canine parvovirus and canine distemper virus antigens were measured, using hemaglutination inhibition and serum neutralization, respectively, and compared between groups.

RESULTS

A significant difference in antibody titers between treatment- and control-group dogs was not found. All dogs had protective antibody titers against canine distemper virus, and 8 of 10 dogs from each group had protective titers against canine parvovirus infection.

CONCLUSION AND CLINICAL RELEVANCE

These results provide evidence that long-term treatment with tetracycline and niacinamide does not interfere with routine vaccinations and thus does not seem to influence antibody production in dogs.

Value of the pinnal-pedal reflex in the diagnosis of canine scabies

The potential value of the pinnal-pedal scratch reflex as an aid to diagnosing canine scabies was assessed in 588 dogs with skin disease. The reflex was assessed by vigorously rubbing the tip of one earflap on to the base of the ear for five seconds, and it was considered positive if the ipsilateral hind leg made a scratching movement. A diagnosis of scabies was based on the dog's history, a physical examination and either positive skin scrapings or the complete resolution of pruritus and dermatitis after treatment with ivermectin or milbemycin, with no relapse for at least 12 months. Scabies was diagnosed in 55 of the dogs, allergic skin disease in 463, and 70 had other miscellaneous skin diseases. There was a positive pinnal-pedal scratch reflex in 45 (82 per cent) of the 55 dogs with scabies. Forty (73 per cent) of the dogs with scabies had pinnal dermatitis, and 36 (90 per cent) of these had a positive pinnal-pedal scratch reflex. There was a positive pinnal-pedal scratch reflex in 33 (6.2 per cent) of the other 533 dogs. On the basis of these results, the specificity of testing for scabies by the pinnal-pedal scratch reflex was 93.8 per cent, and the sensitivity was 81.8 per cent The test's positive predictive value was 0.57 and its negative predictive value was 0.98.

The use of compound 48/80 and codeine phosphate as positive controls for intradermal skin testing in dogs

The mast cell secretagogues compound 48/80 and codeine phosphate were evaluated as potential positive controls for intradermal skin testing in dogs. Wheal responses to both agents were compared with responses to histamine and saline in 11 normal dogs, and were strong and not significantly different from histamine responses in nine dogs (P < 0.01), and significantly weaker than histamine in two dogs (P < 0.05). Wheal responses to compound 48/80 (1 mg mL-1) were evaluated in 82 suspected atopic dogs and were similar to histamine in 79 dogs and markedly weaker than histamine in three dogs. Of nine confirmed atopic dogs with weak responses to injected allergens, seven had strong responses to compound 48/80, and eight had strong responses to histamine. Compound 48/80 and codeine phosphate appear unreliable positive controls for skin testing in normal dogs. Compound 48/80 (1 mg mL-1) may be a reliable positive control in atopic dogs but is a poor indicator of skin reactivity to allergens.

Evaluation of the safety of an abbreviated course of injections of allergen extracts (rush immunotherapy) for the treatment of dogs with atopic dermatitis

OBJECTIVE

To evaluate the safety of an abbreviated course of injections of allergen extracts (rush immunotherapy) for the treatment of dogs with atopic dermatitis.

ANIMALS

30 dogs with atopic dermatitis examined at a veterinary dermatology referral practice for treatment with allergen-specific immunotherapy.

PROCEDURE

A catheter was placed in a vein in each dog. Dogs were constantly observed throughout the procedure. Allergen extracts were administered in increasing concentrations every 30 minutes for 6 hours to a maintenance concentration of 20,000 protein nitrogen units/ml. Epinephrine, oxygen, and emergency treatment were available as needed.

RESULTS

In 22 (73%) dogs, rush immunotherapy safely replaced the prolonged induction period (15 weeks) of weekly injections that consists of increasing concentrations of allergen extract. In 7 (23%) dogs, the induction period was abbreviated to 4 weeks. Of the 8 dogs that developed problems during rush immunotherapy, increased pruritus necessitated premature cessation of rush immunotherapy in 7, and 1 developed generalized wheals. Oral administration of prednisolone (1 mg/kg of body weight) resulted in resolution of adverse effects in all 8 dogs.

CONCLUSION AND CLINICAL RELEVANCE

Rush immunotherapy performed by personnel at a veterinary hospital is a safe method for treatment of dogs with atopic dermatitis.

Aero-allergens in canine atopic dermatitis in southeastern Australia based on 1000 intradermal skin tests

OBJECTIVE

To determine the most relevant aero-allergens involved in canine atopic dermatitis in southeastern Australia and provide information about these aero-allergens to the general practitioner.

PROCEDURE

Dogs presented to the Animal Skin & Allergy Clinic with history and clinical signs of atopic dermatitis were injected intradermally with 38 different allergens and negative and positive control. Intradermal skin tests in 1000 dogs were retrospectively evaluated.

RESULTS

One third of all patients reacted to the house dust mite Dermatophagoides farinae. Allergens reacting in more than 15% of the patients were wheat (Triticum aestivum), sweet vernal (Anthoxanthum odoratum), English couch (Agropyron repens), yellow dock (Rumex crispus), Mexican tea (Chenopodium ambrosioides), plantain (Plantago lanceolata), melaleuca (Melaleuca quinquenervia) and peppercorn (Schimus spp).

CONCLUSION

House dust mites are the most common allergens in canine atopic dermatitis in southeastern Australia and D farinae is involved most frequently. However, a number of grass, weed and tree pollens also are involved regularly.

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.

Diagnosis and management of canine claw diseases

The diagnostic workup for canine claw disease consists of a good history and complete clinical examination which may provide clues for a possible underlying disorder. In dogs with claw disease but no other clinical or historical signs, further recommended diagnostic procedures include cytological evaluation of impression smears or discharge from the claw fold, bacterial culture and sensitivity testing, biopsy of the claw matrix, and an elimination diet for 6 to 8 weeks. If no underlying disease can be identified, trial treatment with essential fatty acid supplementation, vitamin E, or a combination of doxycycline hydrochloride and niacinamide may be useful. In some patients, onychectomy of all claws may be considered.

Comparison of intradermal testing and serum testing for allergen-specific IgE using monoclonal IgE antibodies in 84 atopic dogs

OBJECTIVE

To compare an ELISA measuring serum allergen-specific IgE with intradermal skin testing in canine atopic dermatitis.

PROCEDURE

Eighty-four dogs with the clinical diagnosis of atopic dermatitis underwent intradermal skin testing and serum testing for allergen-specific IgE. Tests were performed in a blinded fashion. Positive reactions were compared and the sensitivity and specificity of the serum test (using intradermal skin test as the standard) were determined overall and for individual allergen groups (grass pollens, weed pollens, tree pollens, house dust mites and fleas).

RESULTS

The sensitivity of the ELISA overall was 90.4%. Evaluating the individual allergen groups, the sensitivity for dust mite hypersensitivity was 95.1%, for fleas 85.4%, for tree pollens 84.3%, for grass pollens 95.1% and for weed pollens 96.4%. The specificity was 91.6% overall, for dust mites 96.3%, for fleas 92.7%, for tree pollens 95.2%, for grass pollens 94% and for weed pollens 80.7%.

CONCLUSION

The evaluated ELISA seemed reliable for the diagnosis of atopy in practice and can be recommended as a screening test prior to intradermal skin testing or for use in dogs when immunotherapy is not a therapeutic option.

A proposed new therapeutic protocol for the treatment of canine mange with ivermectin

Ivermectin was used orally for the treatment of generalized demodicosis or scabies in 222 dogs. The dose was increased gradually from 50 microg/kg body weight on day one, 100 microg/kg body weight on day two, 150 microg/kg body weight on day three, 200 microg/kg body weight on day four, to the final dose of 300 microg/kg body weight on day five. This dose was continued daily until resolution for demodicosis and given four times at seven-day intervals for scabies. Two patients developed clinical ivermectin toxicity after two and 10 days, respectively, and recovered once the drug was discontinued. A gradual increase of the ivermectin dose into the therapeutic range and thorough monitoring of patients during treatment are recommended when using this drug to treat patients with generalized demodicosis or scabies.

Serum and skin IgA concentrations in normal and atopic dogs

OBJECTIVE

To compare serum and skin surface IgA concentrations from atopic and normal dogs.

PROCEDURE

IgA concentrations in sera and skin washings of 20 clinically normal dogs that had no history of pruritus or skin disease were compared to those obtained in 20 dogs with a diagnosis of atopy determined by history, clinical examination and positive intradermal skin test.

RESULTS

There was no significantly difference in the mean serum IgA concentration in normal dogs (252 +/- 187 mg/L) versus atopic animals (314 +/- 327). When skin washings from all sites in both groups were compared, atopic dogs had significantly greater concentrations of IgA in their skin washings than normal dogs as evaluated by an enzyme-linked immunoassay (P < 0.001). However, there was no significant difference between the individual sites of the skin washings of atopic and normal dogs.

CONCLUSION

IgA concentrations of skin washings in atopic dogs were greater than in normal dogs. Further investigations need to determine if the greater concentrations were caused by nonspecific inflammation or by secretion of allergen-specific IgA onto the skin surface.