Laryngeal Paralysis In Dogs Research Articles

Clinical, pathological and genetic aspects of laryngeal paralysis in dogs

The review article discusses the main clinical signs of paralysis of the larynx and pathological changes associated with it and other neurological pathologies. These hereditary canine neuropathies form a group of degenerative diseases affecting motor and/or sensory and autonomic peripheral nerves and have similar symptoms.Axonal forms associated with generalized polyneuropathy and paralysis of the larynx have been described in several dog breeds: Dalmatians, Alaskan Malamutes, Rottweilers, Labrador Retrievers, Leonbergers, St. Bernards, Italian Spinols, Pyrenean Mountain Dogs, Podhale Sheepdogs, Cocker Spaniels, Great Danes, American Staffordshire Terriers, Staffordshire Bull Terriers, Bouvier de Flandres, Siberian Huskies and Siberian Husky crosses. Candidate genes for association with the disease are considered: ARHGEF10, RAPGEF6, ADAMTS3, CNTNAP1, DCTN1. The age of onset of the disease can be different, the manifestation of signs of paralysis of the larynx occurs both in young dogs, and the geriatric form also occurs. The prognosis of the complex of paralysis of the larynxpolyneuropathy is from cautious to unfavorable. One case of euthanasia due to intractable regurgitation and aspiration pneumonia has been described. Some authors point to a possible association of the disease with white coat color. Two main types of inheritance of paralysis of the larynx in dogs have been established - autosomal recessive and X -linked recessive. In humans, the dominant type of inheritance of this anomaly is known. Early diagnosis will make it possible to identify the hereditary nature of paralysis of the larynx, reduce the incidence of severe forms of the disease with timely surgical correction of the cartilage of the larynx and symptomatic treatment, as well as the spread of carriers of mutant alleles in dog populations. This is relevant today in connection with the spread of this anomaly in many breeds.

Assessment of survey radiography as a method of diagnosing bilateral laryngeal paralysis in dogs.

The gold standard for diagnosis of laryngeal paralysis is laryngoscopy under light anesthesia. This prospective analytical cross-sectional study aimed to determine whether a radiographic assessment of the larynx could be used as a non-invasive screening tool for diagnosing laryngeal paralysis in non-sedated animals, as the laryngeal ventricles may appear wider in affected animals. The laryngeal ventricles of 18 dogs with bilateral laryngeal paralysis composing the affected group and 25 non-sedated dogs presenting no respiratory abnormality composing the control group were evaluated using right lateral radiography of the larynx. Three observers measured the ratios of the maximal ventricular length and surface to the body length of the third cervical vertebra (MVL/LC3 and VS/LC3, respectively). They also subjectively assessed the ventricular shape as either normal or rounded. The most accurate criterion was found to be MVL/LC3, as the respective areas under the ROC curves were 0.96 (95% confidence interval [CI]: 0.95-0.97), 0.89 (95% CI: 0.87-0.91), 0.80 (95% CI: 0.65-0.95) for MVL/LC3, VS/LC3, and ventricular shape evaluation, respectively. Based on ROC curve analysis, two thresholds of clinical interest were set for the MVL/LC3; bilateral laryngeal paralysis was very unlikely for values<0.3 and very likely for values>0.5. The findings of this study support the use of lateral laryngeal radiography as a screening tool for diagnosing bilateral laryngeal paralysis. However, further diagnostic tests remain required if MVL/LC3 lies between these threshold values or if clinically indicated. Further studies are warranted to explore the use of laryngeal radiography in unilateral paralysis and other laryngeal or oropharyngeal diseases.

A model of transient laryngeal hemiplegia in dogs through conduction blockade of the recurrent laryngeal nerve.

To create a model of transient unilateral laryngeal paralysis (LP) that will allow the study of cricoarytenoideus dorsalis dysfunction and a method for quantification of varying degrees of LP in dogs. 5 castrated male research Beagles. Between January and February 2018, dogs were anesthetized and instrumented with a laryngeal mask airway and a flexible endoscope to record the rima glottidis. The left or right recurrent laryngeal nerve (RLn) was localized using ultrasonography and electrical stimulation, then conduction blockade was induced with perineural lidocaine. The normalized glottal gap area (NGGA) was measured before and every 15 minutes after the block. Inspired 10% carbon dioxide (CO2) was administered for 1 minute at each sampling time. The inspiratory increase in NGGA (total and each side) was measured at peak inspiration. The change in hemi-NGGA for the control side versus the anesthetized side was evaluated with a mixed-effect model. During CO2 stimulation, the increase in inspiratory hemi-NGGA was consistently less (P < .001) for the treated side (-8% to 13%) versus the control side (49% to 82%). A compensatory increase (larger than at baseline) in the control hemi-NGGA was observed. The total NGGA remained unaffected. Unilateral local anesthesia of the RLn produced transient unilateral LP with a compensatory increase in the hemi-NGGA for the contralateral side. This model could facilitate the evaluation of respiratory dynamics, establishment of a grading system, and collection of other important information that is otherwise difficult to obtain in dogs with LP.

Laryngeal silicone stent as a treatment option for laryngeal paralysis in dogs: a preliminary study of 6 cases.

BackgroundLaryngeal paralysis is a common idiopathic degenerative neurological disease in older medium-to-large breed dogs, with surgical correction of the obstruction being the treatment of choice.ObjectivesThis study evaluated the use of laryngeal silicone stents to treat canine laryngeal paralysis in dogs where classic surgical treatment was not accepted by the owners.MethodsDogs diagnosed with laryngeal paralysis, for which the owners refused arytenoid lateralization surgery as a first-line treatment, were treated with laryngeal silicone stents.ResultsSix dogs with bilateral laryngeal paralysis were included in the study. All dogs showed improvement in clinical signs immediately after the procedure. No clinical signs or radiographic changes were noted in four out of six dogs in the follow-up visit performed 1 wk later. One dog was suspected of aspirating water while drinking, but the signs disappeared after repositioning the stent. Another dog had a relapse of stridor due to caudal migration of the stent. This dog underwent arytenoid lateralization surgery because larger stents are not commercially available. At the time of writing, between seven and 13 mon after stent placement, no significant incidents have occurred in four dogs, and all owners report a satisfactory quality of life.ConclusionsLaryngeal silicone stenting is an interesting alternative for treating dogs with acquired laryngeal paralysis when the owners refuse classic arytenoid lateralization surgery. Furthermore, stent placement can be a temporary solution to stabilize these dogs until a permanent surgical treatment can be performed.

Laryngeal stent for acute and chronic respiratory distress in seven dogs with laryngeal paralysis

Background:Laryngeal paralysis, failure of arytenoid cartilage, and vocal fold abduction are commonly seen in older medium to large breed dogs. Observation of laryngeal function in dogs and cats is performed by transoral visualization. There are a variety of surgical techniques; aspiration pneumonia is the most common complication associated with surgical correction of laryngeal paralysis. The aim of this case series is to report on the placement of a laryngeal silicone stent in seven dogs with laryngeal paralysis and its use as an alternative treatment of respiratory distress caused by laryngeal paralysis and/or its use for laryngeal stenosis as complication of laryngeal paralysis surgery.Case description:Seven dogs presented with either episode of gagging, mild-to-severe inspiratory distress, or cyanosis because of a laryngeal paralysis or laryngeal stenosis. In each case, the laryngeal paralysis was diagnosed by direct laryngoscopy. They were treated with a silicone laryngeal stent (Stening®) that substantially improved the clinical signs. Each dog had a different outcome because of other pathologies; however, the laryngeal pathology was successfully treated with the stent.Conclusion:The placement of the laryngeal stent is an easy technique to learn and practice, it could avoid the life-threatening complications of the laryngeal paralysis at the acute phase, and it could be a noninvasive and long-term alternative therapy for laryngeal paralysis in dogs. The results in these clinical cases are encouraging for considering the laryngeal stent as a therapeutic alternative.

A RAPGEF6 variant constitutes a major risk factor for laryngeal paralysis in dogs.

Laryngeal paralysis (LP) is the inability to abduct the arytenoid cartilages during inspiration, resulting in a partial to complete airway obstruction and consequent respiratory distress. Different forms of LP with varying age of onset exist in dogs. Hereditary early onset forms were reported in several dog breeds. In most breeds, hereditary LP is associated with other neurologic pathologies. Using a genome-wide association study and haplotype analyses, we mapped a major genetic risk factor for an early onset LP in Miniature Bull Terriers to a ~1.3 Mb interval on chromosome 11. Whole genome sequencing of an affected Miniature Bull Terrier and comparison to 598 control genomes revealed a 36 bp insertion into exon 15 of the RAPGEF6 gene (c.1793_1794ins36). The imperfect genotype-phenotype correlation suggested a complex mode of inheritance with a major genetic risk factor involving a recessive risk allele. Homozygosity for the insertion was associated with a 10- to 17-fold increased risk for LP. The insertion allele was only found in Miniature Bull Terriers and Bull Terriers. It was absent from >1000 control dogs of other dog breeds. The insertion sequence contains a splice acceptor motif leading to aberrant splicing in transcripts originating from the mutant allele (r.1732_1780del). This leads to a frameshift and a premature stop codon, p.(Ile587ProfsTer5), removing 64% of the open reading frame. Our results suggest an important role of RAPGEF6 in laryngeal nerve function and provide new clues to its physiological significance.

Effects of chemical and mechanical stimulation on laryngeal motion during alfaxalone, thiopentone or propofol anaesthesia in healthy dogs

ObjectiveTo compare the effect of chemical and mechanical stimulation on arytenoid cartilage motion during anaesthetic induction with alfaxalone, thiopentone or propofol. Study designMasked, randomized, crossover study. AnimalsA group of eight adult Beagle dogs. MethodsAnaesthesia was induced with thiopentone (7.5 mg kg–1), propofol (3 mg kg–1) or alfaxalone (1.5 mg kg–1) intravenously (IV), which were concurrently paired with either chemical (doxapram at 2.5 mg kg–1 IV) or mechanical (gentle pressure to the corniculate process of the right arytenoid cartilage using a cotton bud) stimulation for enhanced assessment of laryngeal motion, in random order, with a 1 week wash-out period between treatments. If deemed inadequately anaesthetized, supplemental boli of thiopentone (1.8 mg kg–1), propofol (0.75 mg kg–1) or alfaxalone (0.4 mg kg–1) were administered. Assessment of number of arytenoid motions and vital breaths, among others, was initiated immediately after induction. Chemical (doxapram) and mechanical stimulation were begun 2 minutes after anaesthetic induction. Data were collected at 2, 3 and 5 minutes after anaesthetic induction and the Friedman rank-sum or repeated-measures analysis of variance tests were used when applicable for statistical analysis. ResultsThe duration of examination time was shorter among treatments combined with chemical stimulation (p=0.001). Examination time during induction was longer for alfaxalone-chemical (8.9 minutes) and -mechanical (10.9 minutes) compared to both induction with thiopentone-chemical (3.8 minutes) and propofol-chemical (4.0 minutes). The median number of arytenoid motions for both thiopentone (67) and propofol (59) induction combined with chemical stimulation was significantly higher in comparison to that of alfaxalone (1), thiopentone (2) and propofol (2), when combined with mechanical stimulation at 3 minutes after induction. Conclusion and clinical relevanceAmong the regimens for assessing laryngeal motion assessed in the present study, combinations of thiopentone or propofol with doxapram are the most effective means of stimulating arytenoid motion and could improve the accuracy of diagnosis of laryngeal paralysis in dogs.

Laryngeal mask airway and transient hypercapnic hyperpnea for video-endoscopic assessment of unilateral laryngeal paralysis in dogs.

To evaluate the ability to assess laryngeal function and to diagnose unilateral laryngeal paralysis (uLP) via airway endoscopy and carbon dioxide (CO2 ) stimulation. Experimental study. Six healthy, adult beagles. Dogs were anesthetized with sevoflurane and dexmedetomidine. Laryngeal activity was observed via endoscopy placed through a laryngeal mask airway (LMA). The absolute and normalized glottic gap areas (AGGA and NGGA, respectively) and the glottic length (GL) were measured at inspiration and before and after surgically induced uLP. Measurements were obtained at eupnea and during hypercapnic hyperpnea produced by the administration of CO2 . Values for each hemilarynx were also measured. Video recordings were observed by 2 surgeons who scored function as normal or uLP. The AGGA and NGGA increased similarly during CO2 administration in intact dogs and in dogs with uLP; the GL increased in dogs with uLP but not in intact dogs. The AGGA and NGGA of the intact hemilarynx increased more than those of the affected hemilarynx in dogs with uLP. uLP was correctly identified more frequently by observers at hypercapnic hyperpnea than during eupnea. The increase in AGGA and NGGA at peak inspiration during CO2 administration was not limited by uLP, but asymmetry in hemilarynx AGGA and NGGA was observed in dogs with uLP. CO2 administration facilitated the identification of uLP. Laryngeal endoscopy through an LMA coupled with administration of CO2 in anesthetized dogs facilitates the observation of arytenoid function and may improve the diagnosis of naturally occurring mild laryngeal paralysis.

Less Invasive Unilateral Arytenoid Lateralization: A Modified Technique for Treatment of Idiopathic Laryngeal Paralysis in Dogs: Technique Description and Outcome

To (1) describe a modification of conventional unilateral cricoarytenoid lateralization (UCAL), called less-invasive unilateral cricoarytenoid lateralization (LI-UCAL) for treatment of idiopathic laryngeal paralysis (LP); (2) report clinical outcome of LI-UCAL; and (3) describe the effect of early discharge after surgery. Retrospective clinical study. Dogs (n = 22). Medical records (January 2009 to October 2011) of dogs diagnosed with idiopathic LP that had LI-UCAL were reviewed. Signalment, clinical signs, laboratory tests, imaging, concurrent medical conditions, information from the anesthesia record, and hospitalization time were documented. Follow-up was obtained by direct examination, questionnaire, and review of medical records from referring veterinarians. Dogs included in the study had variable degrees and duration of respiratory distress before surgery. Median surgery time was 32 minutes. Median hospitalization was 6 hours, and median follow-up was 427 days. Long-term respiratory function, as reported by owners at last follow-up, improved in 95.5% of dogs after surgery; exercise tolerance improved by 90%. Major complications included death secondary to aspiration pneumonia (9%), aspiration pneumonia from which dogs recovered within 3 days after administration of antimicrobials (9%), and development of right-sided laryngeal collapse that required right sided LI-UCAL (4.5%). At long-term follow-up, 95.5% of owners were satisfied with the surgical outcome. LI-UCAL is a feasible surgical technique and resulted in improvement of clinical signs related to LP. Calm recoveries without adverse effects such as respiratory distress were associated with early discharge. LI-UCAL could be considered an alternative to conventional UCAL.

Video-assisted unilateral cricoarytenoid laryngoplasty in 14 dogs with bilateral idiopathic laryngeal paralysis

Background: Unilateral cricoarytenoid laryngoplasty is commonly performed for treatment of idiopathic laryngeal paralysis in dogs. Determination of the appropriate tension applied to the suture can be difficult, particularly for the novice surgeon.Objective: To describe a technique for video-assisted unilateral cricoarytenoid laryngoplasty (VAUCAL) and to report short-term outcome in dogs undergoing VAUCAL.Animals and methods: Dogs (n = 14) with bilateral idiopathic laryngeal paralysis undergoing VAUCAL between August 2011 and May 2013 were evaluated. A cricoarytenoid suture was tensioned under video observation of the rima glottidis using a 5-mm rigid endoscope. Real-time visualization of arytenoid abduction during suture tensioning, and final arytenoid position were assessed. Requirement for additional intravenous anesthestic, intra- and post-operative complications and short-term outcomes were documented.Results: Adequate, real-time visualization of the larynx during tensioning of the cricoarytenoid suture was accomplished in 13/14 dogs. Additional intravenous anesthesia was required in 5/14 dogs to facilitate reintubation. Final arytenoid position was considered inadequate in two dogs on post-operative trans-oral laryngeal examination. Recurrence of clinical signs occurred in one dog three months following initial surgery. Owner outcome was deemed good (n = 8) or excellent (n = 6).Conclusions: VAUCAL is a feasible technique to permit direct real-time visualization of the larynx during tensioning of the cricoarytenoid suture, and enables assessment of final arytenoid position intra-operatively by the operating surgeon.Clinical importance: VAUCAL allows the operating surgeon to assess arytenoid abduction intra-operatively, at the time of knot placement. This technique may be particularly useful for the novice surgeon or surgeon in training.

Intraoperative Evaluation of the Larynx Following Unilateral Arytenoid Lateralization for Acquired Idiopathic Laryngeal Paralysis in Dogs

The purposes of this study were to describe a modified surgical technique in which intraoperative extubation was performed to evaluate abduction of the arytenoid cartilage prior to tying the suture and to assess outcome and complication rates associated with this procedure. Medical records from 30 client-owned dogs with acquired idiopathic laryngeal paralysis were retrospectively reviewed. All clients were contacted by telephone to obtain follow-up information regarding their dog. Six of the 30 surgeries required additional dissection (primarily around the craniodorsal aspect of the cricoarytenoid joint) after the initial intraoperative laryngeal examination. The procedures in 29 of the 30 dogs were deemed a success by the owners. Three (10%) dogs developed postoperative aspiration pneumonia. One of these dogs required long-term antibiotic therapy. Twenty-nine dogs returned to normal activity, and none of the dogs had any exercise intolerance associated with respiratory difficulties. Three owners reported that their dogs were able to swim, and one dog hunted postoperatively. Results of this study suggest that intraoperative laryngeal examination may help limit postoperative complications by allowing for direct, intraoral visualization of the arytenoid cartilage. This enables a surgeon to modify the soft tissue dissection around the cricoarytenoid joint to ensure that adequate abduction is apparent.

Comparison of Three Clinical Techniques for the Diagnosis of Laryngeal Paralysis in Dogs

To evaluate laryngeal function using 3 diagnostic techniques: echolaryngography (EL), transnasal laryngoscopy (TNL), and laryngoscopy per os (LPO). Prospective clinical study. Dogs with laryngeal paralysis (n=5) and control dogs (n=10); 5 age- and breed-matched dogs and 5 young, breed-matched dogs. Laryngeal function was evaluated in conscious dogs using EL. All examinations were recorded and evaluated by separate, blinded observers upon completion of the study. The methods were compared with a standard evaluation incorporating all clinical knowledge of the case (STD) using sensitivity, specificity, positive, and negative predictive values. Three dogs with bilateral laryngeal paralysis requiring surgery were diagnosed as unilaterally affected or normal on EL. Three dogs had paradoxic motion on TNL and LPO, 2 of those were considered normal on EL, and 1 had no motion on EL. Paralysis was diagnosed in 1 age-matched and 3 young control dogs on EL. LPO and TNL falsely diagnosed lack of arytenoid movement in 2 age-matched controls and 1 young control. Two age-matched and 1 young control dog were misdiagnosed as paralyzed with TNL and LPO. Direct observation of the larynx allowed better evaluation of laryngeal function compared with EL. TNL did not require induction of anesthesia, but did not improve the ability to assess laryngeal function compared with LPO. EL was not as effective as direct observation of the larynx. TNL did not improve the evaluation of laryngeal function compared with LPO. We use LPO combined with knowledge of the clinical history and physical examination to diagnose laryngeal paralysis in preference to EL and TNL.

Bilateral Thyroarytenoid Cartilage Lateralization and Vocal Fold Excision with Mucosoplasty for Treatment of Idiopathic Laryngeal Paralysis: 67 Dogs (1998–2005)

To evaluate combined bilateral thyroarytenoid cartilage lateralization, vocal fold excision, and mucosoplasty technique (BTAL) through ventral median laryngotomy for treatment of laryngeal paralysis in dogs. Design- Retrospective study. Animals- Dogs (n=67) with laryngeal paralysis. Medical records were reviewed for dogs with idiopathic laryngeal paralysis that had BTAL between January 1998 and March 2005. Retrieved data included signalment, history, physical and laryngoscopic examination findings, clinicopathologic tests, and results of recheck examination findings. BTAL was performed by a single surgeon. Short-term (<6 months) follow-up information was available for 67 dogs and long-term (>12 months) for 40 dogs. Major postoperative complications were surgical failures (13; 7 short term, 6 long term) and aspiration pneumonia (1). Mean recurrence of clinical signs was at 19 weeks (range, 2-30 weeks). Minor complications occurred in 22 (33%) dogs including occasional coughing or gagging, stridorous breathing during exercise, panting, noisy or heavy breathing, and aspiration pneumonia (3 dogs) that did not require hospitalization. All owners reported an improved quality of life and had no regrets with surgical outcome. BTAL is seemingly an effective procedure for treatment of laryngeal paralysis. Clinical Relevance- BTAL is associated with a low incidence of aspiration pneumonia; however, there is substantial risk of recurrence of clinical signs associated with narrowing of the glottis. Consequently, unilateral arytenoid lateralization currently represents the accepted approach to the treatment of laryngeal paralysis.

Postoperative results of unilateral arytenoid lateralization for treatment of idiopathic laryngeal paralysis in dogs: 39 cases (1996–2002)

To evaluate postoperative results for dogs with idiopathic laryngeal paralysis that underwent unilateral arytenoid lateralization (UAL). Retrospective case series. 39 dogs with idiopathic laryngeal paralysis. Medical records were reviewed, and information on surgical technique, hospitalization time, postoperative treatment, and complications was obtained. Owners were contacted by telephone for additional information if necessary. In all dogs, UAL had been performed by a single surgeon who used a standard surgical technique. Long-term follow-up information was available for all 39 dogs; mean follow-up time was 29.6 months (range, 3 to 61 months). Seven (18%) dogs developed postoperative pneumonia, and 6 of the 7 recovered with treatment. Twenty-two of the 39 (56%) dogs had minor complications, including unresolved coughing or gagging, continued exercise intolerance, vomiting, and seroma formation. Owners of 35 of the 39 (90%) dogs reported an improvement in postoperative quality-of-life score. Median survival time was 12 months; only 1 dog was euthanized because of respiratory tract disease following surgery. Results suggest that UAL will improve quality of life in most dogs with idiopathic laryngeal paralysis. However, the complication rate is high, with postoperative pneumonia being the most important major complication. Minor complications were common but did not adversely affect owner-assigned quality-of-life scores in most dogs.

Sound Signature for Identification of Tracheal Collapse and Laryngeal Paralysis in Dogs

The aims of this study were to investigate whether upper airway sounds of dogs with laryngeal paralysis and tracheal collapse have distinct sound characteristics, compared with unaffected dogs. The sounds of 5 dogs with laryngeal paralysis and 5 dogs with tracheal collapse were recorded. Honking sound appeared as predominant clinical signs in dogs with tracheal collapse. Laryngeal stridors appeared as predominant clinical signs in dogs with experimentally produced laryngeal paralysis by resection of laryngeal nerve, in which two types of stridor, I and II, were recorded. All these sounds were analyzed using sound spectrogam analysis. There were significant differences in duration (sec), intensity (dB), pitch (Hz), first formant (Hz), second formant (Hz), third formant (Hz), fourth formant (Hz) of sounds between the normal bark and two types of stridor or honking sound, indicating that the sound analysis might be a useful diagnostic modality for dogs with tracheal collapse and laryngeal paralysis.

Transnasal laryngoscopy for the diagnosis of laryngeal paralysis in dogs.

Four dogs with clinical signs of laryngeal paralysis and three normal dogs were evaluated with transnasal laryngoscopy. Six of these dogs subsequently underwent standard laryngoscopy. For transnasal laryngoscopy, a video endoscope was passed through the left nasal passage after intramuscular sedation and topical anesthesia. The laryngeal opening was observed during spontaneous ventilation. Laryngeal paralysis was diagnosed in four dogs and was confirmed with traditional laryngoscopy in three dogs. Normal motion of the arytenoid cartilages was present in the other three dogs; however, two required mechanical stimulation of the laryngeal mucosa for full evaluation. Transnasal laryngoscopy provided a means for diagnosing laryngeal paralysis in dogs without general anesthesia.

A retrospective study of unilateral arytenoid lateralisation in the treatment of laryngeal paralysis in 100 dogs (1992-2000).

To determine the effectiveness of unilateral arytenoid lateralisation as a surgical treatment for laryngeal paralysis in dogs. The case records of 100 dogs that received a unilateral arytenoid lateralisation for laryngeal paralysis between 1992 and 2000 were reviewed. The results of questionnaires on surgical outcome, formulated for the animal owner and the referring veterinarian, were analysed. Information obtained for dogs under 10 kg and dogs over 10 kg was analysed separately. The Labrador Retriever was the most commonly affected breed. The male:female ratio was 1.56:1 and the average age of presentation was 9.9 years. The most common month in which surgery was performed was October. The majority of owners (87.7%) felt that their dog's quality of life was improved in the 6 months after surgery. Thirty-three percent of dogs revisited the referring clinic with a respiratory problem following unilateral arytenoid lateralisation, and 10.7% of dogs were reported as having a post-surgical complication associated with the procedure. Following surgery, dogs under 10 kg revisited the referring veterinarian with a respiratory complication more often than dogs over 10 kg. Significantly fewer owners of dogs under 10 kg than owners of dogs over 10 kg felt that their dogs quality of life was improved by surgery (55% versus 93%). The majority of owners surveyed reported that unilateral arytenoid lateralisation had improved the quality of their dog's life during the first 6 postoperative months. Owner dissatisfaction with the results of surgery and the reported rate of re-presentation (for respiratory disease) may be higher for small (< 10 kg) dogs. A prospective study comparing the results of unilateral arytenoid lateralisation surgery in large and small dogs may be worthwhile in the future.

A review of laryngeal paralysis in dogs

Laryngeal paralysis is now a frequently recognized disorder, particularly in older dogs of certain breeds such as the Labrador retriever, Afghan Hound and Irish Setter. The presenting signs may consist of exercise intolerance, inspiratory stridor, inspiratory dyspnoea, gagging, coughing and dysphonia. Two forms of laryngeal paralysis exist, hereditary and acquired. The hereditary form is found in young dogs and transmitted by an autosomal dominant gene. At present little is known about the aetiology of acquired laryngeal paralysis and therefore treatment is directed at relieving the laryngeal obstruction. Recent reports indicate that arytenoid lateralization achieves the best results as a method of surgical correction.

Laryngeal paralysis in dogs: An evaluation of the bilateral arytenoid lateralisation procedure

ABSTRACTWithin the past decade, the number of reported cases of laryngeal paralysis in dogs has increased markedly. The disease is characterised by laryngeal obstruction caused by the inadequate abduction and instability of the arytenoid cartilages, aryepiglottic folds and vocal cords. Therefore, surgery performed to alleviate the clinical signs should ideally aim to reduce the airway obstruction and to prevent dynamic collapse. This paper presents the effectiveness of bilateral arytenoid lateralisation in 19 dogs with bilateral laryngeal paralysis. The procedure was effective in alleviating the clinical signs of laryngeal obstruction in all 19 dogs, with most surviving for several years. Postoperative laryngoscopic observations showed that the arytenoid cartilages were held in a satisfactory abducted position. A comparison of PaO2 values before and after surgery demonstrated a significant (P 0·001) fall in the PaO2 measurement between the pre‐ and postoperative blood samples. Postoperative complications included suture prosthesis failure in two dogs and a single non‐fatal incident of aspiration pneumonia in two dogs.

Neurogenic laryngeal paralysis in the dog

Idiopathic laryngeal paralysis in dogs is now a frequently recognised disorder, particularly in certain breeds such as the Labrador retriever, Afghan hound and Irish setter. Since it occurs in the older animal, distinguishing the clinical signs and their significance from lower respiratory tract or cardiac disease can be challenging. At present little is known about its aetiology and therefore the treatment is directed at relieving the clinical signs. Recent work indicates that arytenoid cartilage lateralisation achieves the best results as a method of surgically correcting the laryngeal obstruction. However, it should be remembered that the potential benefits of surgery should be assessed for each individual, taking into account the presence of concurrent disease and lifestyle of the dog.