Deafness In Dogs Research Articles

Dépistage et diagnostic de la surdité chez le chien

Screening and diagnosis of deafness in dogs is based on Brainstem Auditory Evoked Response or BAER recording. Deafness is usually classified according to five criteria : determinism, onset, severity, symmetry, and anatomical-functional stage reached. In breeds at risk for hereditary deafness, with white or piebald robes (Dalmatian Dogo argentino, Bull terrier, Australian cattle dog, etc.) or merle (Border collie, Australian shepherd, etc.), screening of breeding animals and newborns should be encouraged to reduce the prevalence of deafness in these breeds. In dogs with acute deafness, hearing impairment should be confirmed by BAERs recording and lesions should be in-vestigated by medical imaging (CT-scan and/or magnetic resonance imaging). Acquired causes of deafness are nu-merous : inflammatory (especially otitis media), toxic (or ototoxicity), traumatic, degenerative (or presbycusis). In acute deafness in dogs, total bilateral deafness is most often irreversible.

Brain auditory evoked response test, the standard method for the diagnosis of the hereditary deafness in dogs

Hearing deficiency is one of the most common hearing impairments that affect humans and other mammalian alike. Hearing loss is not painful or a life-threatening change but can endanger the patient by taking into account a large number of breeds predisposed to hereditary deafness, this short communication aims to synthesize the steps and the method for BAER test. For the affected breeds, the BAER test is recommended starting at the age of two months

Prevalence, heritability and genetic correlations of congenital sensorineural deafness and coat pigmentation phenotype in the English bull terrier.

BackgroundCongenital sensorineural deafness (CSD) is the most common type of deafness in dogs and it occurs in numerous canine breeds including the English bull terrier. This study estimates prevalence, heritability and genetic correlations of CSD and coat pigmentation phenotypes in the English bull terrier in England.ResultsHearing status was assessed by brainstem auditory evoked response in 1060 English bull terrier puppies tested at 30–78 (mean 43.60) days of age as complete litters. Gender, coat and iris colour and parental hearing status were recorded.The prevalence of CSD in all 1060 puppies was 10.19 % with 8.21 % unilaterally deaf and 1.98 % bilaterally deaf. The coat was predominately coloured in 49.15 % puppies and white with or without a patch in 50.85 % puppies. The majority (96.29 %) of deaf puppies had a white coat (with or without a patch); 19.29 % of the puppies with a white coat (with or without a patch) were deaf.Heritability and genetic correlations were estimated using residual maximum likelihood. Heritability of hearing status as a trichotomous trait (bilaterally normal/unilaterally deaf/bilaterally deaf) was estimated at 0.15 to 0.16 and was significantly different to zero (P < 0.01). Heritability of coat pigmentation phenotype (all white/white with patches/coloured) was 0.49 (standard error 0.077). Genetic correlation of CSD with coat pigmentation phenotype was estimated at −0.36 to −0.37 (CSD associated with all white coat), but was not significantly larger than zero (P > 0.05). Analysis of CSD in all white and white patched puppies only estimated the heritability of CSD as 0.25 and was significantly greater than zero (P < 0.01), and the heritability of coat colour (all white/white with patches) as 0.20 (standard error 0.096). The genetic correlation was estimated at −0.53 to −0.54 (CSD associated with all white coat) but was just above the statistical threshold determining significant difference to zero (P = 0.06).ConclusionsThese results indicate that CSD occurs predominantly in white English bull terriers and there is genetic variation in CSD beyond that associated with coat colour.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0777-6) contains supplementary material, which is available to authorized users.

A sedação sobre os potenciais evocados auditivos em cães

O potencial evocado auditivo de tronco encefálico (Brainstem Auditory Evoked Potential - BAEP) avalia a atividade elétrica do sistema auditivo, desde a cóclea até o tronco encefálico, permitindo diagnóstico de surdez em cães. Como alguns animais não permitem a obtenção do BAEP sem contenção química, o objetivo deste trabalho foi analisar a influência da sedação com morfina e acepromazinano BAEP de 16 cães com audição normal. Os potenciais foram obtidos antes e durante a sedação com administração intramuscular de morfina (0,5mgkg-1) e acepromazina (0,05mgkg-1). O protocolo de sedação utilizado permitiu contenção efetiva e segurança dos animais. A sedação causou prolongamento nas latências das ondas II, III e intervalos I-III e I-V, mas não dificultou as suas identificações. O uso deste protocolo de sedação não interferiu com a interpretação do potencial evocado e pode ser útil em cães. Pelo que se pode observar na literatura compilada, este é o primeiro estudo avaliando a influência da sedação no BAEP em cães no Brasil.

Deafness in dogs and cats. 1st edn. by GM Strain. CABI Wallingford Oxon, UK and Cambridge MA, USA, 2011. Price A$71.00 ISBN 9781845937645.

Australian Veterinary JournalVolume 91, Issue 7 p. 260-260 BOOK REVIEW Deafness in dogs and cats. 1st edn. by Strain, GM. CABI Wallingford Oxon, UK and Cambridge MA, USA, 2011. Price A$71.00 ISBN 9781845937645. Susan F Sommerlad, Susan F SommerladSearch for more papers by this author Susan F Sommerlad, Susan F SommerladSearch for more papers by this author First published: 20 June 2013 https://doi.org/10.1111/avj.12063Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume91, Issue7July 2013Pages 260-260 RelatedInformation

Congenital deafness in Jack Russell terriers: Prevalence and association with phenotype

Congenital hereditary sensorineural deafness is the most common form of deafness in dogs. The objectives of this study were to determine a reliable measure of the prevalence of deafness in Jack Russell terriers, an affected breed, and associations between deafness and phenotypic characteristics. Brainstem auditory evoked response recordings and phenotypic parameters (coat color, coat texture, sex, eye color, sire and dam hearing status) were recorded for 1009 Jack Russell terriers. The prevalence of unilateral and bilateral deafness was 3.57% and 0.50%, respectively, lower by a factor of three to four than in earlier reports based on smaller and closely related kindreds. Significant association with deafness was identified with white coat color and parental hearing status, but not with sex or coat type. Lack of significant sex or coat type associations and the significant association with white coat color are consistent with previous reports. In conclusion the prevalence of deafness in Jack Russell terriers is lower than initially reported. Deafness was associated with white coat color and parental hearing status. The association with parental hearing status supports this form of deafness being a heritable trait in the breed and the association with white coat color supports an inheritance linked to pigmentation genes.

Transient Evoked Otoacoustic Emissions Testing for Screening of Sensorineural Deafness in Puppies

Transient evoked otoacoustic emissions (TEOAE) are widely used for human neonatal deafness screening, but have not been reported for clinical use in dogs. To investigate the feasibility of TEOAE testing in conscious puppies and the ability of TEOAE testing to correctly identify deaf and hearing ears, as defined by brainstem auditory evoked response (BAER). Forty puppies from 10 litters. Prospective study on puppies presented for hearing assessment as part of a congenital deafness BAER screening program. Hearing status was determined using BAER. TEOAE testing was performed after the BAER assessment and the results of the TEOAE testing were compared with the hearing status for each ear. Parameters were tested for normality using the D'Agostino Pearson test and comparisons between the deaf and hearing ears were made using Mann-Whitney tests. TEOAE testing was readily performed in puppies presented for congenital deafness screening. Using analysis parameters based on those used in human neonatal hearing screening, TEOAE testing correctly identified all deaf ears, as defined by BAER testing, with a sensitivity of 100% (95% CI: 56-100%) for diagnosing deafness and specificity of 78% (95% CI: 66-87%). TEOAE testing is an effective screening modality for identifying congenital sensorineural deafness in dogs. In light of the simpler and less expensive equipment, TEOAE testing has the potential to improve access to hearing screening and through this reduce the prevalence of congenital deafness in the dog.

Post–anesthesia deafness in dogs and cats following dental and ear cleaning procedures

ObjectiveThe present study was performed to document hearing loss in dogs and cats following procedures performed under anesthesia. Most cases of reported hearing loss were subsequent to dental and ear cleaning procedures. Study designProspective and retrospective case survey. AnimalsSubjects were dogs and cats with deafness, personally communicated to one author, cases discussed on a veterinary information web site, and cases communicated through a survey of general practice and dental specialist veterinarians. MethodsReported deafness cases were characterized by species (dog, cat), breed, gender, age, and dog breed size. ResultsSixty–two cases of hearing loss following anesthesia were reported between the years 2002 and 2009. Five additional cases were reported by survey respondents. Forty–three cases occurred following dental procedures. Sixteen cases occurred following ear cleaning. No relationship was observed between deafness and dog or cat breed, gender, anesthetic drug used, or dog size. Geriatric animals appeared more susceptible to post–anesthetic, post–procedural hearing loss. ConclusionsDeafness may occur in dogs and cats following anesthesia for dental and ear cleaning procedures, but the prevalence is low. The hearing loss appears to be permanent. Clinical relevanceDeafness can be a consequence following anesthesia for dental or ear cleaning procedures. Older animals may have greater susceptibility.

Prevalence of Deafness in Dogs Heterozygous or Homozygous for the Merle Allele

Deafness in dogs is frequently associated with the pigment genes piebald and merle. Little is known about the prevalence of deafness in dogs carrying the merle allele. To determine the prevalence of deafness in dogs heterozygous and homozygous for the merle allele of the mouse Silver pigment locus homolog (SILV) gene. One hundred and fifty-three privately owned merle dogs of different breeds and both sexes. Hearing was tested by brainstem auditory-evoked response and classified as bilaterally hearing, unilaterally deaf, or bilaterally deaf. DNA from buccal cells was genotyped as either heterozygous or homozygous for the merle allele. Deafness association tests among merle genotype, eye color, and sex were performed by the chi(2) test. Deafness prevalence in merles overall was 4.6% unilaterally deaf and 4.6% bilaterally deaf. There was a significant association between hearing status and heterozygous versus homozygous merle genotype. For single merles (Mm), 2.7% were unilaterally deaf and 0.9% were bilaterally deaf. For double merles (MM), 10% were unilaterally deaf and 15% were bilaterally deaf. There was no significant association with eye color or sex. Deafness prevalence in merle dogs was greater than that in some dog breeds homozygous for the piebald gene, such as the English Cocker Spaniel, but comparable to, or lower than, that in the Dalmatian and white Bull Terrier. Dogs homozygous for the merle allele were significantly more likely to be deaf than heterozygotes.

Congenital sensorineural deafness in dogs: a molecular genetic approach toward unravelling the responsible genes

Deafness is often diagnosed in different dog breeds and has been identified as a significant problem for breeders, owners and clinicians. The aetiology can be inherited or acquired, and a distinction must be made between sensorineural and conductive forms of deafness. This paper provides a brief overview of the varieties of findings in different dog breeds and in one breed in particular including prevalence, phenotypic and gender associations, histology, modes of inheritance and the number of contributing genes in congenital sensorineural deafness. We have also described molecular genetic approaches to canine hearing loss and discuss how comparative genomics could help reduce the prevalence of deafness in affected breeds leading to new insights into the molecular mechanisms of auditory function in both dogs and humans.

Chromosomal assignment of 20 candidate genes for canine congenital sensorineural deafness by FISH and RH mapping

The analysis of inherited diseases in the domestic dog (Canis familiaris) provides a resource for the continued use of this species as a model system for human diseases. Many different dog breeds are affected by congenital sensorineural deafness. Since mutations in various genes have already been found causative for sensorineural hearing impairment in humans or mice, 20 of these genes were considered as candidates for deafness in dogs. For each of the candidate genes a canine BAC clone was isolated by screening with heterologous human or murine cDNA probes. The gene-containing BAC clones were physically assigned to the canine genome by FISH and the BAC-derived STS-markers were positioned with the RHDF5000 panel on the canine RH map. The mapping data, which confirm the established conservation of synteny between canine and human chromosomes, provide a resource for further association studies in segregating canine populations and the basis for new insights into this common canine and human disease.

Assignment of the canine cadherin related 23 gene (CDH23) to chromosome 4q12→q13 by fluorescence in situ hybridization and radiation hybrid mapping

Cadherin related gene (CDH23), which encodes otocadherin is a novel member of the cadherin gene superfamily. CDH23 mutations were found in families with nonsyndromic autosomal recessive deafness (DFNB12), and in families with deafness associated with vestibular dysfunction and retinitis pigmentosa (USH1D), respectively (Bolz et al., 2001; Bork et al., 2001; Petit, 2001). DFNB12 has been located on HSA10q21→ q22 by linkage mapping (Chaib et al., 1996). In the waltzer mouse it was shown that mutations in the orthologous Cdh23 gene cause disorganization of inner ear stereocilia leading to deafness (Di Palma et al., 2001). Cdh23 expression was detected in the murine neurosensory epithelium. Otocadherin is a critical component of hair bundle formation and in Cdh23 deficient mice the stereocilia organization was disrupted during early hair cell differentiation (Di Palma et al., 2001). Congenital sensorineural deafness in dogs may result from degeneration of the hair cells of the organ of Corti (Strain, 1996; Coppens et al., 2000; Poncelet et al., 2000). Therefore, CDH23 might be a suitable candidate gene for congenital nonsyndromic hearing loss in dogs. To facilitate future linkage studies we report here the assignment of the canine CDH23 gene to CFA4q12→q13 by FISH and RH mapping. Materials and methods

Congenital Deafness and its Recognition

Congenital deafness in dogs and cats is primarily of the hereditary sensorineural form associated with white pigmentation genes, although acquired forms of deafness are possible. Highest prevalence is seen in white cats, especially those with blue eyes, and the Dalmatian, with many other dog breeds affected to some extent. This deafness results from degeneration of the cochlear blood supply at age 3-4 weeks, presumably resulting from suppression of melanocytes by the white (cat) or merle or piebald (dog) genes. Mechanism of inheritance is not understood for most breeds. Such animals should not be bred and may present liabilities for their owners. Objective diagnosis of deafness, especially when unilateral, relies on the brainstem auditory evoked response, an electrodiagnostic test where electrical activity in response to a click stimulus is recorded from the scalp using needle electrodes and a special purpose computer. Client counseling guidelines are presented.

Deafness in the Dog and Cat

Deafness in dogs and cats can be divided into two major categories: (1) conduction deafness and (2) sensorineural deafness. History and otic examination will often provide a diagnosis. Electrodiagnostic testing will confirm the deafness and further elucidate the specific cause. Therapy depends on the cause of the deafness and extent of involvement.

Brain stem auditory evoked potentials from bone stimulation in dogs

Summary Brain stem auditory evoked potential (baep) testing with air-conducted click stimuli can be used to diagnose sensorineural deafness in dogs if conductive deafness can be ruled out. Detection of conductive deafness can be performed by recording baep elicited by a vibratory stimulus transducer placed against the skull. Air- and bone-conducted baep were compared in dogs, varying bone stimulator placement, click polarity, and stimulus intensity. Optimal bone stimulator placement was determined to be over the mastoid process, followed by the mandible and the zygomatic arch. Condensation polarity clicks gave responses preferable to those elicited by rarefaction or alternating polarity. Bone-conducted baep peak latencies were significantly longer than air-conducted latencies after correction of the latencies for the air conduction time accompanying air-conducted stimuli. Significant differences between stimulus modalities were not seen for baep peak amplitudes or interpeak latencies. Latency-intensity and amplitude-intensity regressions had similar effects for both modalities: latencies decreased and amplitudes increased as stimulus intensity increased.

LXV End-Organ Deafness in Dogs Due to the Application of Certain Chemicals to the round Window Membrane

LXV End-Organ Deafness in Dogs Due to the Application of Certain Chemicals to the round Window Membrane