Hair fragility (trichorrhexis nodosa) in alopecic Pomeranian dogs.

BACKGROUND: While alopecia associated with hair cycle arrest (HCA, Alopecia X) is well-recognised in Pomeranian dogs, the authors are unaware of reports of concurrent hair fragility. HYPOTHESIS/OBJECTIVES: Following the observation of frequent hair shaft abnormalities in alopecic Pomeranians, we hypothesised that hair fragility events would be more frequent in dogs with a phenotype of HCA when compared to dogs with normal coats. ANIMALS: Eight alopecic Pomeranian dogs or crosses with a phenotype of HCA and 36 unaffected Pomeranians with owner-reported normal hair coats. MATERIALS AND METHODS: All affected dogs underwent dermatological examination and clinicopathological evaluations. Hair samples, plucked from affected areas or obtained by brushing from unaffected dogs, were examined microscopically for structural abnormalities. Hair fragility events were characterised as trichorrhexis nodosa (TN) or longitudinal splits and were expressed per 10 mg of hair. A reference interval was calculated from the number of hair fragility events in the samples from unaffected dogs. RESULTS: The upper reference limit (with 90% confidence) from samples of 35 unaffected Pomeranians (one outlier excluded) was 9.75 hair fragility events per 10 mg of hair. The median (range) of fragility events in eight dogs with a phenotype of HCA was 66.0 (30.2-166.7) per 10 mg of hair. CONCLUSIONS AND CLINICAL RELEVANCE: Clinicians should routinely perform trichography in Pomeranians with HCA because abundant hair abnormalities, particularly TN, may contribute to poor hair coat quality. Further studies are required to establish the pathophysiology of and treatments for these fragility events and to determine their predictive value for HCA.

Malassezia otitis unresponsive to primary care: outcome in 59 dogs.

BACKGROUND: Otitis externa (OE) is a common disorder in dogs. Infection by the commensal yeast, Malassezia pachydermatis, may result in chronic disease that does not respond to standard primary care. Chronic infectious OE may be associated with otitis media (OM). HYPOTHESIS/OBJECTIVE: To report medical management, clinical outcomes and frequency of middle ear involvement, in dogs with Malassezia otitis unresponsive to primary care. ANIMALS: Fifty-nine dogs from one referral veterinary hospital from January 2007 to September 2018. METHODS AND MATERIALS: Retrospective analysis of medical records of dogs referred with chronic otitis and treated for Malassezia otitis at a referral veterinary hospital. RESULTS: Chronic Malassezia OE was treated successfully in 91% of ears, in 87% of these cases with one ear flush intervention. Median time-to-resolution was 27 days after ear flush intervention. Neither duration of otitis, presence of neutrophils in aural discharge nor administration of oral itraconazole affected clinical outcome. Malassezia OM occurred concurrently in 17% of ears. CONCLUSIONS AND CLINICAL RELEVANCE: These findings assist clinicians and carers of affected dogs in decision-making, by documenting that most cases of canine Malassezia otitis that have not resolved with standard primary care, can be treated successfully with a well-staged and intense medical treatment plan. Malassezia OM should be suspected to occur concurrently in around a fifth of affected ears.

Prescribing practices of primary-care veterinary practitioners in dogs diagnosed with bacterial pyoderma.

BACKGROUND: Concern has been raised regarding the potential contributions of veterinary antimicrobial use to increasing levels of resistance in bacteria critically important to human health. Canine pyoderma is a frequent, often recurrent diagnosis in pet dogs, usually attributable to secondary bacterial infection of the skin. Lesions can range in severity based on the location, total area and depth of tissue affected and antimicrobial therapy is recommended for resolution. This study aimed to describe patient signalment, disease characteristics and treatment prescribed in a large number of UK, primary-care canine pyoderma cases and to estimate pyoderma prevalence in the UK vet-visiting canine population. RESULTS: Of 54,600 dogs presented to 73 participating practices in 2010, 683 (1.3%) had a pyoderma diagnosis recorded in available electronic patient record (EPR) data. Antimicrobials were dispensed in 97% of cases and most dogs were prescribed systemic therapy (92%). Agents most frequently prescribed were amoxicillin-clavulanate, cefalexin, clindamycin and cefovecin. Systemic antimicrobials were prescribed for fewer than 14 days in around 40% of study cases reviewed in detail. Prescribed daily doses were below minimum recommended daily dose (MRDD) in 26% of 43 dogs with sufficient information for calculation of minimum dose. CONCLUSIONS: Antimicrobial prescribing behaviour for treatment of canine pyoderma was variable but frequently appeared inconsistent with current recommendations. Use of clinical data from primary practice EPRs can provide valuable insight into common clinical conditions and associated prescribing.

Food-specific serum IgE and IgG reactivity in dogs with and without skin disease: lack of correlation between laboratories.

BACKGROUND: Despite conflicting data on their utility and no reports on interlaboratory reproducibility, serum food-specific antibodies are commonly assayed in first-opinion canine practice. HYPOTHESIS/OBJECTIVES: To determine both the variability of test results between two laboratories and the frequencies and magnitudes of food reactivity in dogs of different disease status. ANIMALS: Sera were obtained from eight dogs with cutaneous adverse food reaction (Group A), 22 with nonfood-induced atopic dermatitis (Group B), 30 with an allergic/inflammatory phenotype (Group C), 12 with miscellaneous skin diseases (Group D) and nine healthy dogs (Group E). METHODS: Paired sera were submitted to two laboratories (A and B) for assays of food-specific IgE and IgG antibodies. RESULTS: Numbers of positive IgE and IgG tests determined by each laboratory in Groups A, B, D and E were comparable (Group C not included). Significant differences in the magnitude of IgE reactivity between groups for each allergen were seen only for lamb (Laboratory A, P = 0.003); lamb reactivity in Group D exceeded Group E (P = 0.004) but was comparable between all other groups. Agreement (kappa statistic) between the two laboratories' tests was 'moderate' for one antigen (potato IgE), 'fair' for four (corn IgE, rice IgE and IgG and soya bean IgG), 'slight' for eight (six IgE and two IgG) and 'less than chance' for the remaining six antigens (three IgE and three IgG). CONCLUSIONS AND CLINICAL IMPORTANCE: These laboratories' tests appear to have dubious predictive clinical utility because they neither correlate nor distinguish between dogs of different disease status.

UK-based multicentre cross-sectional study assessing advice requests veterinary dermatologists received from general practitioners.

BACKGROUND: There is little currently little information available regarding the nature of the advice requests veterinary dermatologists receive from general practitioners. Collation of such data could direct continuing veterinary development in the future. METHODS: Dermatologists completed hand-written recording sheets during or after enquiries. Information recorded included the route of enquiry, nature of advice, material provided, practice type and location, animal signalment, presenting signs, diagnosis/differential diagnosis, treatment and referral recommendations, time taken and if charges were made. RESULTS: Twelve dermatology services recorded 768 advice requests over a 6-month period. Most requests were submitted via email and related to canine dermatology (81%). An average of 9.5 minutes was spent replying to requests. Charges were made in 2% of cases. Advice regarding otitis was most commonly sought, followed by pruritus, alopecia and crusting. The most frequently discussed diagnoses included allergy, otitis, pyoderma, demodicosis, dermatophytosis and neoplasia. Antibiotics, anti-pruritics and topical otic medications were the most commonly discussed therapeutics. LIMITATIONS: This is an initial study and therefore there are limitations involving the depth of the data. Additional studies should be completed which identify why advice is sought, decision-making regarding referral, and if advice should be charged similarly to other disciplines. CONCLUSIONS: These findings highlight that veterinarians mostly frequently seek advice on management of common dermatological problems, including allergy, otitis and pyoderma.

The effectiveness of systemic antimicrobial treatment in canine superficial and deep pyoderma: a systematic review.

AIM: To identify and evaluate existing evidence for the effectiveness of systemic antimicrobial treatments for naturally occurring superficial and deep canine pyoderma. METHOD: Electronic searches of PubMed, MEDLINE and CAB Direct were carried out (25 May 2011) without date or language restrictions. Proceedings of ESVD/ECVD, AAVD/ACVD, NAVDF and WCVD annual congresses were searched. Unpublished studies were sought via the Veterinary Dermatology discussion list and Veterinary Information Network. RESULTS: Seventeen full-length, peer-reviewed controlled trials reporting clinical outcomes of systemic antimicrobial treatment for canine pyoderma were identified. Outcomes specific to superficial or deep pyoderma were reported in nine and five studies, respectively. Five studies reported outcomes only for nondifferentiated pyoderma depth. Heterogeneity of study designs and outcome measures made meta-analysis inappropriate. A good level of evidence was identified supporting the high efficacy of subcutaneously injected cefovecin in superficial pyoderma and for oral amoxicillin-clavulanic acid in deep pyoderma. A fair level of evidence was identified for moderate to high efficacy of oral amoxicillin-clavulanic acid, clindamycin, cefadroxil, trimethoprim-sulphamethoxazole and sulfadimethoxine-ormetoprim in superficial pyoderma and oral pradofloxacin, oral cefadroxil and subcutaneously injected cefovecin in deep pyoderma. Eleven trials reported observations of adverse effects in treated pyoderma cases by intervention group; four dogs were withdrawn owing to the severity of adverse effects. CONCLUSIONS: There is a need for greater numbers of adequately sized, blinded, randomized controlled trials evaluating systemic antimicrobial interventions for canine pyoderma. Improved differentiation between superficial and deep pyoderma in outcome reporting, outcome measure standardization and association of outcomes with causative bacterial species and their resistance patterns are required.

Ironing out the wrinkles and folds in the epidemiology of skin fold dermatitis in dog breeds in the UK.

Skin fold dermatitis (intertrigo) is an inflammatory process of closely apposing skin surfaces. Extreme conformations towards folded skin in many dog breeds are linked with higher risk. Using anonymised primary-care veterinary data from the VetCompass Programme, this study aimed to report the frequency, demographic risk factors and clinical management for skin fold dermatitis in the UK. Risk factor analysis used random effects multivariable logistic regression modelling. From a study population of 905,553 dogs, the one-year period prevalence in dogs overall was 0.37% (95% CI 0.35-0.39). Diagnosis was supported by laboratory testing in 4.21% cases. Systemic antibiosis was used in 42.30% cases. Compared with crossbreed dogs, the most highly predisposed breeds were English Bulldog (odds ratio [OR] 49.07, 95% CI 37.79-63.70), French Bulldog (OR 25.92, 95% CI 19.62-34.26,) and Pug (OR 16.27, 95% CI 12.20-21.69). The most protected breeds were Yorkshire Terrier (OR 0.14, 95% CI 0.03-0.56), Border Collie (OR 0.31, 95% CI 0.11-0.84), Jack Russell Terrier (OR 0.53, 95% CI 0.30-0.92) and Labrador Retriever (OR 0.57, 95% CI 0.35-0.93). This study adds further evidence to the welfare concerns around high popularity of dog breeds with extreme conformations. The three breeds with by far the highest odds of skin fold dermatitis represent an extreme brachycephalic conformation.

Non-neoplastic anal sac disorders in UK dogs: Epidemiology and management aspects of a research-neglected syndrome.

BACKGROUND: Non-neoplastic anal sac disorders (ASD) are frequent presentations for dogs in primary-care practice but evidence-based information on disease occurrence and risk is sparse. This study estimates prevalence, breed associations and other risk factors as well as reporting on clinical management. METHODS: A cohort study of dogs attending VetCompass practices between 1 January 2013 and 31 December 2013. Risk factor analysis used multivariable logistic regression methods. RESULTS: Of 104,212 dogs attending 110 UK practices, the 1-year period prevalence of ASD was 4.40% (95% CI: 4.22-4.57). Compared to crossbreds, six breeds showed increased odds of ASD (Cavalier King Charles spaniel, King Charles spaniel, Cockapoo, Shih-tzu, Bichon Frise and Cocker spaniel), and six breeds showed reduced odds (Labrador Retriever, Border collie, Staffordshire Bull Terrier, Lurcher, German Shepherd Dog and Boxer). Brachycephalic types had 2.6 times the odds for ASD compared to dolichocephalic types. Medication prescribed for ASD included antimicrobials (n = 480, 20.24%) and analgesics (n = 284, 11.97%). Anal sacculectomy was performed in under 1% of cases. CONCLUSIONS: High prevalence, strong breed predispositions and evidence of severity suggested from the antimicrobial and analgesic therapies combined with current substantial knowledge gaps identify ASD as a key research-neglected syndrome in dogs.

West Highland White Terriers under primary veterinary care in the UK in 2016: demography, mortality and disorders.

BACKGROUND: The West Highland White Terrier (WHWT) is a relatively common breed in the UK, although Kennel Club registrations have declined in recent years. The VetCompass™ Programme collates de-identified clinical data from primary-care veterinary practices in the UK for epidemiological research. Using VetCompass clinical data, this study aimed to characterise the demography, longevity and common disorders of WHWTs under primary veterinary care in the UK. RESULTS: WHWTs comprised 6605/905,544 (0.7%) dogs under veterinary care during 2016 from 886 clinics. Mean adult bodyweight was 9.6 kg (standard deviation [SD] 1.8 kg). Males (10.1 kg, SD 1.8 kg) were heavier than females (9.0 kg, SD 1.6 kg) (P < 0.001). Median age was 7.8 years (interquartile range [IQR] 4.3-11.1). Median longevity was 13.4 years (IQR 11.0-15.0). Males (13.8 years) outlived females (12.9 years) (P = 0.045). The most common grouped causes of death were lower respiratory tract (10.2, 95% CI: 5.5-16.7), neoplastic (10.2, 95% CI: 5.5-16.7) and spinal cord disorder (7.8, 95% CI: 3.8-13.9). Overall, 71.5% WHWTs had > 1 disorder recorded during 2016. The most prevalent specific disorders were periodontal disease (15.7, 95% CI: 14.1-17.3), otitis externa (10.6, 95% CI: 9.3-12.0), overgrown nails (7.2, 95% CI: 6.2-8.4), allergic skin disorder (6.5, 95% CI: 5.5-7.7) and obesity (6.1, 95% CI: 5.1-7.2). The most prevalent grouped disorders were cutaneous (22.7, 95% CI: 20.9-24.6), dental (17.8, 95% CI: 16.2-19.6) and aural (12.3, 95% CI: 11.0-13.8). The median age of dogs affected with the 27 most common disorders varied from 6.7 (pododermatitis) to 13.9 years for cataracts. CONCLUSIONS: These findings highlight that, despite a recent decline in popularity, WHWTs are still relatively common in the UK. Dental disease, ear disease, overgrown nails, allergic skin disorder and obesity were identified as common health issues within the breed. Cutaneous disorders were the most common disorder group in the breed but showed a lower prevalence than might be expected. These results can be used by breeders, veterinary practitioners and owners as an evidence base to predict, prevent and manage key health and welfare issues for WHWTs.

Correction to: West Highland White Terriers under primary veterinary care in the UK in 2016: demography, mortality and disorders.

[This corrects the article DOI: 10.1186/s40575-019-0075-2.].

Cornification defect in the golden retriever: clinical, histopathological, ultrastructural and genetic characterisation.

Veterinarians have recognised a nonpruritic skin disease in the Golden retriever breed characterised by excessive scaling of large, variably pigmented flakes of skin in otherwise healthy dogs. This prospective case series describes clinical, histopathological, ultrastructural and genetic features of this cornification defect in 17 affected dogs. The condition affects young dogs of either sex and is characterised by symmetrical, predominantly ventro-lateral scaling and hyperpigmentation of the trunk. Histopathological and ultrastructural changes of the stratum corneum are suggestive of delayed degradation of corneodesmosomes. A genetic aetiology is proposed and a single-trait autosomal recessive mode of inheritance discussed.

Impact of facial conformation on canine health: corneal ulceration.

Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio <0.5) were twenty times more likely to be affected than non-brachycephalic dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.

Impact of Facial Conformation on Canine Health: Brachycephalic Obstructive Airway Syndrome.

The domestic dog may be the most morphologically diverse terrestrial mammalian species known to man; pedigree dogs are artificially selected for extreme aesthetics dictated by formal Breed Standards, and breed-related disorders linked to conformation are ubiquitous and diverse. Brachycephaly--foreshortening of the facial skeleton--is a discrete mutation that has been selected for in many popular dog breeds e.g. the Bulldog, Pug, and French Bulldog. A chronic, debilitating respiratory syndrome, whereby soft tissue blocks the airways, predominantly affects dogs with this conformation, and thus is labelled Brachycephalic Obstructive Airway Syndrome (BOAS). Despite the name of the syndrome, scientific evidence quantitatively linking brachycephaly with BOAS is lacking, but it could aid efforts to select for healthier conformations. Here we show, in (1) an exploratory study of 700 dogs of diverse breeds and conformations, and (2) a confirmatory study of 154 brachycephalic dogs, that BOAS risk increases sharply in a non-linear manner as relative muzzle length shortens. BOAS only occurred in dogs whose muzzles comprised less than half their cranial lengths. Thicker neck girths also increased BOAS risk in both populations: a risk factor for human sleep apnoea and not previously realised in dogs; and obesity was found to further increase BOAS risk. This study provides evidence that breeding for brachycephaly leads to an increased risk of BOAS in dogs, with risk increasing as the morphology becomes more exaggerated. As such, dog breeders and buyers should be aware of this risk when selecting dogs, and breeding organisations should actively discourage exaggeration of this high-risk conformation in breed standards and the show ring.

Frequency of superantigen-producing Staphylococcus intermedius isolates from canine pyoderma and proliferation-inducing potential of superantigens in dogs.

This preliminary study investigated the potential role of staphylococcal superantigens in the pathogenesis of canine pyoderma. The staphylococcal enterotoxins A (SEA), SEB, SEC and SED, and the toxic shock syndrome toxin-1 (TSST-1) were assayed in isolates from skins of dogs with pyoderma. Culture supernatants from 25 of 96 isolates were positive for multiple superantigens, with SEA and SEC being the most frequently detected. In in vitro stimulation of canine peripheral blood mononuclear cells and quantitative flow cytometry revealed that low concentrations of SEA and SEB were potent stimulators of blastogenesis of T cells.

Evaluation of red cell distribution width in dogs with pulmonary hypertension.

OBJECTIVES: To compare red cell distribution width (RDW) between dogs with different causes of pulmonary hypertension (PH) and a control dog population to determine whether RDW was correlated with severity of PH as measured by echocardiography. A further aim was to determine the prognostic significance of increased RDW for dogs with PH. ANIMALS: Forty-four client-owned dogs with PH and 79 control dogs presented to a single tertiary referral institution. METHODS: Signalment, clinical pathological and echocardiographic data were obtained retrospectively from the medical records of dogs with PH, and RDW measured on a Cell-Dyn 3500 was compared between dogs with pre- and post-capillary PH and a control population. Referring veterinary surgeons were contacted for follow-up information and Kaplan-Meier analysis was conducted to investigate differences in survival time between affected dogs with different RDW values. RESULTS: The RDW was significantly greater in dogs with pre-capillary PH compared to control dogs. There was no difference in median survival times between dogs with PH divided according to RDW values. The RDW was positively correlated with mean corpuscular volume and haematocrit in dogs with PH, but did not correlate with echocardiographic variables. CONCLUSIONS: An association was found between dogs with PH and increased RDW; however there was considerable overlap in values between control dogs and dogs with PH. The RDW was not associated with survival in this study.

How long and low can you go? Effect of conformation on the risk of thoracolumbar intervertebral disc extrusion in domestic dogs.

Intervertebral disc extrusion (IVDE) is a common neurological disorder in certain dog breeds, resulting in spinal cord compression and injury that can cause pain and neurological deficits. Most disc extrusions are reported in chondrodystrophic breeds (e.g. Dachshunds, Basset Hounds, Pekingese), where selection for 'long and low' morphologies is linked with intervertebral discs abnormalities that predispose dogs to IVDE. The aim of this study was to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out. Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging ± surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. Therefore, selection for longer backs and miniaturisation should be discouraged in high-risk breeds to reduce IVDE risk. In higher risk individuals, maintaining a lean body shape is particularly important to reduce the risk of IVDE. Results are reported as probabilities to aid decision-making regarding breed standards and screening programmes reflecting the degree of risk acceptable to stakeholders.

Two loci on chromosome 5 are associated with serum IgE levels in Labrador retrievers.

Crosslinking of immunoglobulin E antibodies (IgE) bound at the surface of mast cells and subsequent mediator release is considered the most important trigger for allergic reactions. Therefore, the genetic control of IgE levels is studied in the context of allergic diseases, such as asthma, atopic rhinitis, or atopic dermatitis (AD). We performed genome-wide association studies in 161 Labrador Retrievers with regard to total and allergen-specific immunoglobulin E (IgE) levels. We identified a genome-wide significant association on CFA 5 with the antigen-specific IgE responsiveness to Acarus siro. We detected a second genome-wide significant association with respect to the antigen-specific IgE responsiveness to Tyrophagus putrescentiae at a different locus on chromosome 5. A. siro and T. putrescentiae both belong to the family Acaridae and represent so-called storage or forage mites. These forage mites are discussed as major allergen sources in canine AD. No obvious candidate gene for the regulation of IgE levels is located under the two association signals. Therefore our studies offer a chance of identifying a novel mechanism controlling the host's IgE response.