Dysphagia as a Missing Link Between Post-surgical- and Opioid-Related Pneumonia

PURPOSE

Postoperative pneumonia remains a common complication of surgery, despite increased attention. The purpose of our study was to determine the effects of routine surgery and post-surgical opioid administration on airway protection risk.

METHODS

Eight healthy adult cats were evaluated to determine changes in airway protection status and for evidence of dysphagia in two experiments. (1) In four female cats, airway protection status was tracked following routine abdominal surgery (spay surgery) plus low-dose opioid administration (buprenorphine 0.015 mg/kg, IM, q8-12 h; n = 5). (2) Using a cross-over design, four naive cats (2 male, 2 female) were treated with moderate-dose (0.02 mg/kg) or high-dose (0.04 mg/kg) buprenorphine (IM, q8-12 h; n = 5).

RESULTS

Airway protection was significantly affected in both experiments, but the most severe deficits occurred post-surgically as 75% of the animals exhibited silent aspiration.

CONCLUSION

Oropharyngeal swallow is impaired by the partial mu-opioid receptor agonist buprenorphine, most remarkably in the postoperative setting. These findings have implications for the prevention and management of aspiration pneumonia in vulnerable populations.

Cricopharyngeal and thyropharyngeal myectomy for management of cricopharyngeal achalasia in a 6-month-old coton de Tulear dog

A 6-week-old intact female coton de Tulear dog presented to a veterinary teaching hospital (VTH) internal medicine service for dysphagia that was persistent since birth. The patient was diagnosed with cricopharyngeal achalasia based on a fluoroscopic swallow study. To facilitate surgical intervention, a percutaneous endoscopic gastrostomy (PEG) tube was placed to bypass the upper esophageal sphincter and provide nutritional support until the dog was larger. At 6 mo of age, the dog underwent unilateral cricopharyngeal and thyropharyngeal myectomy. Marked improvement in dysphagia was noted immediately postoperatively. Improvement in dysphagia persisted in this dog, with continued marked improvement in clinical signs noted 1 y postoperatively. Key clinical message: Cricopharyngeal achalasia can be successfully managed with surgical intervention with a good long-term prognosis. Before surgical intervention, nutritional support is of critical importance. A combined procedure of cricopharyngeal and thyropharyngeal myectomy may be associated with outcomes superior to those of alternative procedures.

Intralesional steroid injection after endoluminal esophageal stricture dilatation in a cat

Background:

Benign esophageal strictures arise from various etiologies, mostly severe esophagitis. Although endoscopic balloon dilation is still the first-line therapy, refractory or recurrent strictures do occur and remain a challenge to the endoluminal treatment. The aim of this report was to communicate a recurrent esophageal stricture resolution in a cat treated with balloon dilatation and steroid injections in Ciudad de Buenos Aires, Argentina.

Case Description:

A 1-year-old spayed mix-breed female cat was consulted to the Veterinary Endoscopy Service for recurring regurgitation after two previous esophageal dilations. The cat had received doxycycline for Mycoplasma spp. infection and 20 days after the treatment consulted for dysphagia and regurgitation. Upper esophagogastroscopy (UGE) was performed with an Olympus CV-160 8.7 mm diameter endoscope; an annular 7 mm stricture was observed 3 cm caudal to the cranial esophagus sphincter. Three balloon dilatations procedures were performed with a Boston Scientific Controlled Radial Expansion (CRE) balloon 8–10–12 mm of 1 minute each. Because of ongoing clinical signs, another UGE was performed 15 days from the first procedure: a 3 mm stricture was encountered, balloon dilatation was repeated with 6–10–12 mm diameter, and a four-quadrant triamcinolone was injected in the submucosa. Clinically, the cat could eat with no alterations until day 20, where it started with mild dysphagia. Another UGE was performed, and the known stricture conserved a 11 mm diameter and balloon dilatation 12–15–16.5 mm with triamcinolone injection was repeated 30 days after the previous procedure. The cat could eat kibbles with no clinical signs in an 11-month follow-up.

Conclusion:

The alternative to triamcinolone injection after balloon dilatation presented in this clinical report was successful and it could be a therapeutic option for recurrent esophageal strictures in cats as it is in human medicine.

The effect of neonatal dysphagia on subsequent racing performance in Standardbred horses

BACKGROUND

Previously we described a clustering of dysphagic foal cases on a Pennsylvania (PA) Standardbred farm which was associated with exposure of pregnant mares to high concentrations of polycyclic aromatic hydrocarbons (PAHs) in the well water. The effect of dysphagia on future athleticism was uncertain.

OBJECTIVES

To determine if, as adults, dysphagic foals were less likely to race and if athleticism (age of first race, Speed Index and Earnings Per Start Index) differed from that of healthy foals that raced as adults.

STUDY DESIGN

Prospective cohort study.

METHODS

All foals born during the study period (2014-2017) on the affected PA or an unaffected New York (NY) farm with the same proprietor were eligible for inclusion in the study. Foals with dysphagia attributed to causes other than PAH environmental exposure were excluded. The proportion of foals from both farms that raced, their age of first race, Earnings Per Start Index and Speed Index were compared between the dysphagic and normal foals using Chi-Square and Wilcoxon Rank Sum Tests. Significance level was P < .05.

RESULTS

A total of 116 foals met the inclusion criteria. No significant difference was found in the percentages of foals that raced from each farm: On the PA farm, 54% of healthy and 72% of dysphagic foals raced; 70% of healthy NY farm foals raced. Median (interquartile range) age of first race, Earnings Per Start Index or Speed Index for dysphagic foals (2 years (2, 2); 57 (49, 60); 60 (45, 66) was not different from those of healthy foals from both farms (2 years (2, 3); 55 (39, 78)) or the PA farm (2 years (2, 2); 61(24, 73); 68 (57, 85)). All P > .05.

MAIN LIMITATIONS

Small sample size and unique type of dysphagia.

CONCLUSIONS

The athleticism of formerly dysphagic foals does not appear to be negatively impacted compared with normal foals as measured by age of first race, Earnings Per Start Index and Speed Index.

Reversible dysphagia secondary to guttural pouch mycosis in a gelding treated medically with voriconazole and surgically with carotid occlusion and esophagostomy

A gelding was diagnosed with dysphagia and left guttural pouch mycosis. Treatments included topical antifungal drugs, systemic voriconazole, and balloon occlusion of the internal carotid artery. Ongoing dysphagia of neurological origin necessitated extra-oral feeding through an esophagostomy tube. Complementary case management included acupuncture. Clinical remission occurred over 10 weeks.

Fluoroscopic and endoscopic diagnosis of a lower esophageal ring causing foreign body impaction in a dog

A dog was presented because of regurgitation over a 3-day period. Radiographic examination revealed a bean-shaped filling defect and an annular narrowing at the level of the gastroesophageal sphincter. The contractile ring-like structure was sharply demarcated, and its appearance varied according to gastroesophageal distension. Endoscopic findings revealed lower esophageal ring and foreign body impaction.

Buccal feed impaction and surgical correction in captive reindeer

An 8-year-old female captive reindeer (Rangifer tarandus) (1) was presented for evaluation of bilateral protrusion of the cheeks of 1-month duration. Several members of the herd displayed similar clinical signs. Examination revealed stretching and laxity of the cheek muscles and buccal food impaction. The defect of each cheek was surgically repaired in the field under heavy sedation and local anesthesia in staged procedures; no surgical complications were encountered. The patient recovered uneventfully and long-term prognosis is good. This report describes a surgical treatment for individual animals with cheek laxity and buccal food impaction.

Chronic oesophageal foreign body in a cat

An 11-year-old cat was presented with an approximately 2-month history of dysphagia, intermittent regurgitation and weight loss. An oesophageal foreign body was identified on plain radiographs, and an oesophagotomy was performed to remove a large V-shaped bone from the caudal cervical oesophagus. A gastrostomy feeding tube was placed to allow nutritional support postoperatively. Medical treatment for oesophagitis was initiated after surgery. No complications were encountered and the cat was discharged 4 days after surgery.

Feasibility of flexible endoscopic evaluation of swallowing in healthy dogs

OBJECTIVE

To assess feasibility of flexible endoscopic evaluation of swallowing (FEES) in awake dogs, determine whether specific variables associated with the oropharyngeal phase of swallowing can be recognized, and evaluate the safety and tolerability of FEES.

ANIMALS

6 healthy client-owned large- and giant-breed adult dogs.

PROCEDURES

A topical anesthetic was applied to the nasal passage of each dog, and a fiberoptic endoscope was passed transnasally until the tip of the scope was positioned in the oropharynx. All dogs voluntarily drank colored water followed by consumption of a commercial canned diet and then a kibble diet mixed with food color. During each swallow, laryngeal and pharyngeal anatomic structures were evaluated and depth of bolus flow prior to the pharyngeal phase of swallowing was assessed. Evidence of bolus retention in the vallecula or pyriform sinuses and laryngeal penetration of the bolus were recorded.

RESULTS

FEES was completed without major adverse events and was tolerated well by all 6 dogs. Mild, self-limiting epistaxis was noted for 2 dogs. The nasopharynx, oropharynx, and hypopharynx were observed in all dogs; movement of food boluses through the esophagus was observed in 2 dogs, and food boluses in the stomach were visible in 1 dog. Pharyngeal and laryngeal function was considered physiologically normal in all dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

FEES appeared to be a feasible diagnostic tool for use in large- and giant-breed dogs. Studies are warranted in dogs with oropharyngeal dysphagia to determine whether FEES can be tolerated and whether it can augment videofluoroscopy findings.

Successful treatment of cricopharyngeal dysphagia with bilateral myectomy in a dog

An 8-month-old golden retriever/standard poodle mixed breed dog was diagnosed with cricopharyngeal dysphagia and possibly asynchrony. After failing standard unilateral cricopharyngeal myectomy, the dog underwent a second surgery to completely resect the contralateral musculature resulting in immediate and complete resolution of clinical signs. Bilateral myectomy can be considered for dogs with cricopharyngeal dysphagia that fail unilateral myectomy.

Phenobarbital-responsive ptyalism, dysphagia, and apparent esophageal spasm in a German shepherd puppy

A 10-week-old, male German shepherd dog was presented with a primary complaint of episodic ptyalism, dysphagia, vomiting, and mandibular salivary gland enlargement. An esophagram with fluoroscopy showed normal pharyngeal and esophageal function; however, upper gastrointestinal endoscopy and cervical ultrasonography revealed a focal circumferential thickening of the midcervical esophageal muscular wall, consistent with esophageal spasm. The puppy responded dramatically and completely to phenobarbital treatment. An unusual syndrome of phenobarbital-responsive hypersialosis was consistent with this dog's clinical presentation and the finding of apparent esophageal spasm. The pathogenesis of this syndrome is unclear, but it may represent a form of limbic epilepsy or peripheral autonomic dysfunction.

Standing surgical removal of inspissated guttural pouch exudate (chondroids) in ten horses

OBJECTIVE

To report use of a modified Whitehouse approach in standing horses for management of inspissated guttural pouch empyema.

STUDY DESIGN

Retrospective study.

ANIMALS

Adult horses (n=10) with guttural pouch empyema.

METHODS

Inspissated exudate in 1 or both guttural pouches was removed surgically through a modified Whitehouse approach, with the horses standing and sedated. Medical records of affected horses were reviewed to determine history; physical, endoscopic, and radiological examination findings; surgical technique; complications, and outcome.

RESULTS

All horses had purulent nasal discharge; 3 horses had dysphagia, 2 had recurrent laryngeal neuropathy on the side affected by guttural pouch empyema, and 1 had persistent soft palate displacement. Inspissated exudate was removed safely without causing apparent discomfort. Eight horses returned to their previous level of athletic activity after surgery; 1 horse dysphagic before surgery, was euthanatized because of persistent dysphagia after surgery, and 1 horse died 1 week after surgery for unknown reasons. Streptococcus equi subsp equi was isolated from the affected guttural pouch of 3 horses.

CONCLUSIONS

Inspissated exudate can be removed surgically from the guttural pouch in standing horses through a modified Whitehouse approach.

CLINICAL RELEVANCE

To eliminate risks associated with general anesthesia and avoid surgical suite contamination, removal of chondroids can be performed in standing sedated horses through a modified Whitehouse approach.

Suspected clindamycin-associated oesophageal injury in cats: five cases

The clinical findings, treatment and outcome of suspected clindamycin-associated oesophageal injury in five cats are reported. All cats were treated with one 75 mg clindamycin capsule twice daily (dose range 12-19 mg/kg). Capsules were administered without food or a water bolus. Dysphagia, regurgitation, choking or gagging were seen 3-9 days after starting clindamycin. On oesophagoscopy, three cats had oesophagitis, one of which progressed to stricture formation. Two cats had an oesophageal stricture at first presentation. This is the first report of suspected clindamycin-associated oesophageal injury in cats. It serves to further alert practitioners to the potential for drug-induced oesophageal disorders (DIOD) in cats treated with oral medications and to urge prevention by promoting a change in dosing practices.

Progressive dysphagia in a dog caused by a scirrhous, poorly differentiated perioesophageal carcinoma

Investigation of canine dysphagia is performed by a combination of diagnostic imaging, direct visualisation of the upper gastrointestinal tract, and ancillary diagnostic testing to differentiate between structural and functional causes. Video fluoroscopy may be especially helpful. The case of a seven-year-old Border collie that presented with a history of progressive pharyngeal dysphagia is described. Fluoroscopic investigation was initially suggestive of functional pharyngeal disease, but magnetic resonance imaging and surgical exploration demonstrated the presence of a diffuse, scirrhous, poorly differentiated carcinoma with extensive oesophageal involvement. This case highlights that, in some circumstances, fluoroscopy may occasionally be of limited use in the investigation of dysphagia in the dog.

L-thyroxine responsive cricopharyngeal achalasia associated with hypothyroidism in a dog

An eight-year-old, male boxer dog was presented with a one-month history of hindlimb weakness followed by compulsive ineffective drinking, dysphagia, regurgitation and nasal reflux during drinking. A neurological examination revealed weakness and conscious proprioception deficits in both hindlimbs with normal spinal reflexes. The dog's swallowing function was examined by fluoroscopy. This showed normal prehension of the barium paste, bolus formation and contraction of the pharyngeal muscle, but no opening of the upper oesophageal sphincter was detected. A serum thyroid stimulating hormone level of 0.402 ng/dl and serum total T4 of 0-01 microg/dl were determined. The dog fully recovered one month after L-thyroxine therapy. The association found between cricopharyngeal achalasia and hypothyroidism suggests that hypothyroidism should be included in the list of differential diagnoses for dogs with cricopharyngeal achalasia.

The effect of bilateral glossopharyngeal nerve anaesthesia on swallowing in horses

REASONS FOR PERFORMING STUDY

Dysfunction of the glossopharyngeal nerve has been implicated as a cause of dysphagia in horses. However, recent studies have indicated that this is not the case.

OBJECTIVES

To determine whether bilateral glossopharyngeal nerve anaesthesia would cause dysphagia in horses or result in measurable alterations in the timing, function, or sequence of swallowing.

METHODS

Swallowing was evaluated in 6 normal horses with and without bilateral glossopharyngeal nerve anaesthesia. Swallowing dynamics were assessed subjectively and objectively based on time from prehension of food until swallowing, number of tongue movements until initiation of swallowing, depth of bolus at the base of the tongue prior to initiation of swallow and evidence of tracheal aspiration using fluoroscopy and endoscopy.

RESULTS

There was no evidence of aspiration or dysphagia in horses before or after bilateral glossopharyngeal nerve block. No observed or measured differences in swallowing sequence or function could be detected in blocked compared to unblocked horses. However, there was a trend in blocked horses for the number of tongue pushes and the time to swallowing to be increased.

CONCLUSIONS

Glossopharyngeal nerve function may not be essential for normal swallowing function in otherwise healthy horses.

POTENTIAL RELEVANCE

Clinically, normal swallowing is not an appropriate test of glossopharyngeal nerve function and dysphagic horses should not be assumed to have glossopharyngeal nerve dysfunction.

Masseter myodegeneration as a cause of trismus or dysphagia in adult horses

The medical records of eight horses with histological evidence of myodegeneration of the masseter muscles were examined. While they were alive their most common clinical signs had included difficulty in eating or opening their mouths, weight loss, difficulty in moving, and noticeable atrophy of the masseter muscles. The serum activities of muscle enzymes were abnormally high in all of the horses. Whole blood and/or liver selenium and vitamin E concentrations were less than the reference ranges in some of the horses. The lesions varied with the stage of the disease and consisted of swelling and discoloration, or muscle atrophy and fibrosis. Histologically, the muscle changes ranged from acute to subacute degeneration, with regenerative changes accompanying ongoing degeneration, to chronic degeneration with fibrotic replacement of muscle tissue. There were changes in the masseter muscle of all the horses, but some had widespread lesions in skeletal muscle, and a few also had myocardial lesions.

Dysphagia as the primary clinical abnormality in two dogs with inflammatory myopathy

Two adult Boxers were evaluated because of chronic dysphagia of several years' duration. Serum creatine kinase activity was high in both dogs, but other hematologic or serum biochemical abnormalities were not detected. Esophagraphy revealed abnormalities of the cricopharyngeal phase of swallowing in both dogs, and electromyography of the pharyngeal and laryngeal muscles revealed complex repetitive discharges, positive sharp waves, and fibrillation potentials characteristic of primary myopathy or neuropathy. Because of the severity of their condition, both dogs were euthanatized. Histologically, mixed-cell infiltrates were seen in sections of the masseter and thyropharyngeal muscles. Results of indirect immunofluorescence staining for proteins associated with dystrophic myopathy were unremarkable, except for decreased staining for integrin alpha7. A diagnosis of chronic inflammatory myopathy was made. The clinical importance of reduced staining for integrin alpha7 could not be determined but was considered to be a result of the myopathy.

Inheritance of cricopharyngeal dysfunction in Golden Retrievers

OBJECTIVE

To characterize a genetic component to cricopharyngeal dysfunction (CD) in Golden Retrievers.

ANIMALS

117 dogs.

PROCEDURE

The CD phenotype was determined by videofluoroscopy, and dogs were classified as affected if the upper esophageal sphincter (UES) did not open, if there were morphologic abnormalities of the UES, or if opening of the UES was delayed for > or = 6 videofluoroscopic frames (0.2 seconds) after closure of the epiglottis. All survey radiographic and videofluoroscopic studies were reviewed by the same radiologist.

RESULTS

Of the 117 dogs (47 males and 70 females) with a CD phenotype determined via videofluoroscopy, 21 dogs (18.0%) had abnormalities of the UES (affected). Of these 21 dogs, 9 were males (19.1% of all males) and 12 were females (17.1% of all females). The heritability of CD in a threshold model was estimated as 0.61, which established that CD could be passed from parent to offspring. Results of complex segregation analysis suggested that a single recessive allele of large effect contributed to the expression of this disease in Golden Retrievers.

CONCLUSIONS AND CLINICAL RELEVANCE

The determination that CD is inherited in Golden Retrievers is an important step in providing information for veterinarians attending dogs with this disorder. Breeders also require this information to make informed breeding decisions.

Cricopharyngeal achalasia in a dog

A 4-month-old, female terrier-poodle cross was presented with a chronic history of dysphagia. Fluoroscopic swallowing studies localized the problem to the upper esophageal sphincter. A diagnosis of cricopharyngeal achalasia was made. After cricopharyngeal and thyropharyngeal myectomy, the dog was able to eat soft food without difficulty.

Surgical management of cricopharyngeal dysphagia in dogs: 14 cases (1989-2001)

OBJECTIVE

To determine outcome of and complications associated with cricopharyngeal myotomy or myectomy for treatment of cricopharyngeal dysphagia (CPD) in dogs.

DESIGN

Retrospective study.

ANIMALS

14 dogs.

PROCEDURE

Medical records of dogs with CPD that underwent cricopharyngeal myotomy or myectomy were examined. Follow-up information was obtained through telephone interviews with owners and referring veterinarians and clinical examinations when feasible.

RESULTS

16 surgical procedures were performed on the 14 dogs. Dysphagia was completely resolved immediately after surgery in 1 dog, and clinical signs did not recur (follow-up time of 8 years); a second dog also had immediate complete resolution of dysphagia, but follow-up time was only 10 days. Three dogs had transient complete resolution with a mean time to recurrence of dysphagia of 12.3 weeks (range, 2 to 36 weeks). Three dogs had permanent partial resolution. Six dogs had no improvement after surgery. Eight of the 14 dogs were euthanatized because of problems related to CPD, including persistent dysphagia (n = 8) and aspiration pneumonia (5).

CONCLUSIONS AND CLINICAL RELEVANCE

The failure rate for dogs undergoing surgical treatment of CPD may be high, particularly if concurrent aspiration pneumonia or malnutrition is not addressed prior to surgery. For those dogs with concurrent diseases, more aggressive medical management, such as enteral tube feeding, may be warranted rather than surgery. In dogs with CPD complicated by other anatomic or functional conditions, such as myasthenia gravis, laryngeal paralysis, and esophageal stricture, surgery may also not be indicated.

Dystrophin-deficient muscular dystrophy in a Labrador retriever

Sex-linked muscular dystrophy associated with dystrophin deficiency has been reported in several breeds of dogs and is best characterized in the golden retriever. In this case report, a young, male Labrador retriever with dystrophin-deficient muscular dystrophy is presented. Clinical signs included generalized weakness, lingual hypertrophy, and dysphagia. Electromyographic abnormalities including complex repetitive discharges were present. Serum creatine kinase concentration was dramatically elevated. Histopathological changes within a muscle biopsy specimen confirmed a dystrophic myopathy, and dystrophin deficiency was demonstrated by immunohistochemical staining. While X-linked muscular dystrophy has not previously been reported in the Labrador retriever, a hereditary myopathy with an autosomal recessive mode of inheritance has been characterized. A correct diagnosis and classification of these two disorders are critical for breeders and owners since both the mode of inheritance and the prognosis differ.

Xerostomia, xerophthalmia, and plasmacytic infiltrates of the salivary glands (Sjögren's-like syndrome) in a cat

A 2.5-year-old domestic shorthair cat was evaluated because of dysphagia and weight loss of 4 weeks' duration. MIld blepharospasm and conjunctival hyperemia were evident in both eyes, oral mucous membranes were tacky on palpation, and salivary glands were enlarged. Results of a Schirmer tear test were 0 mm/min for both eyes. Administration of atropine did not cause salivation or caused secretion fo thick rope-like saliva. Examination of biopsy specimens of salivary glands revealed a plasmacytic infiltrate. Sjögren's syndrome (SS) was diagnosed. Oral administration of prednisone was instituted but was discontinued after a minimal positive response was evident 6 weeks after initiation of treatment. Palliative treatment with a 6% solution of pilocarpine 4 to 5 times/d, cyclosporine, hylan A, and neomycin-polymyxin-bacitracin ophthalmic ointment resulted in clinical improvement in the cat. Although reported rarely in animals, SS may be more common than currently is recognized. Most treatment regimens for SS are aimed at alleviating clinical signs.

Resolution of dysphagia following cricopharyngeal myectomy in six young dogs

Six young dogs were presented with a history of dysphagia and nasal regurgitation since birth. Following cranial nerve examination and assessment of swallowing with fluoroscopy, a diagnosis of cricopharyngeal achalasia was made in each case. In four dogs, concomitant aspiration pneumonia was present. Sectioning and removal of part of the cricopharyngeal muscle resulted in immediate and continued resolution of all signs of dysphagia and nasal regurgitation over follow-up periods of two to eight years. Postoperative complications were not seen in any case. In five of the six dogs, the cricopharyngeal muscle was approached laterally, a technique not previously described.

Extramedullary plasmacytoma in a horse with ptyalism and dysphagia

A Clydesdale mare was examined for weight loss, inappetence, ptyalism, and dysphagia. The main abnormality revealed by serum biochemistry was a marked hyperglobulinemia, and protein electrophoresis revealed a monoclonal gammopathy in the gamma region. The urine was positive for Bence Jones proteins. These findings suggested a plasma cell tumor. The neoplasm could not be located with extensive antemortem examination. At postmortem, neoplastic cells morphologically compatible with plasma cells and positive for equine IgG with imunoperoxidase staining infiltrated the pericardium, mediastinal stromal tissues, adrenal glands, meninges, atrioventricular valves, aorta, abdominal and thoracic fat, and nerves, including the trigeminal nerve. The neoplastic cells invading the cranial nerves were responsible for many of the presenting signs.

Hyperkalaemic periodic paralysis in homozygous and heterozygous horses: a co-dominant genetic condition

Historical, clinical and experimental data were collected from 9 horses homozygous for HYPP (H/H). All showed episodes of respiratory stertor, described as a rattling or honking sound, usually within the first week post partum. Five horses had one or more episodes of dysphagia, in 3 horses this was accompanied by drooling and in 3 by weight loss. In comparison, only one of 35 contemporaneous half siblings (of which approximately half would be expected to be of the H/N genotype and half N/N) was observed to have respiratory stertor prior to weaning and none had problems with dysphagia. One mature homozygous stallion was infertile secondary to urospermia. Six homozygous horses died or were subjected to euthanasia; 4 age less than a year, one age 20 months and one age 5 years. The remaining 3 cases were still alive at the end of the study. A comparison of homozygous and heterozygous horses using standardised potassium chloride challenge testing indicated that during attacks homozygotes showed significantly more frequent signs of drooling, prolapse of the third eyelid, respiratory stridor and weakness than heterozygous horses. Homozygotes also had significantly more total abnormalities (including myotonic discharges, high frequency repetitive discharges, and spontaneous activity) on electromyographic examination than heterozygotes. These data imply that HYPP is inherited as a codominant genetic defect, because the homozygotes showed more severe clinical signs of disease than heterozygotes. Homozygous foals would be expected to be produced in 25% of matings in which both parents are heterozygous. Owners and veterinarians should be aware of the risks of this mating.

Rhabdomyosarcoma of the tongue in a dog

A lingual rhabdomyosarcoma was diagnosed in a six-year-old Staffordshire bull terrier with clinical signs of dysphagia. The unsuccessful response to initial chemotherapy, to surgical resection and subsequent surgical resection and radiation therapy is documented. The accurate diagnosis and prognosis of such tumours is also discussed. Lingual rhabdomyosarcoma has not previously been reported in the dog.

Persistent right aortic arch in a yearling horse

A 14-month-old filly with chronic pharyngitis was diagnosed with incomplete esophageal constriction and megaesophagus due to a persistent right aortic arch. This report is unusual because clinical signs of respiratory dysfunction secondary to chronic regurgitation occurred prior to the recognition of dysphagia.

Laryngospasm, dysphagia, and emaciation associated with hyperkalemic periodic paralysis in a horse

An 18-month-old Quarter Horse gelding was examined because of weight loss and dysphagia of 1 month's duration. Clinical signs included lethargy, dehydration, ptyalism, and probable aspiration pneumonia. Severe dyspnea and cyanosis were evident after mild exercise. Endoscopy revealed laryngospasm and pharyngospasm. Because clinical signs and endoscopic findings were suggestive of hyperkalemic periodic paralysis (HPP), acetazolamide treatment was instituted. Marked improvement was observed within 48 hours. The horse was determined to be homozygous for HPP. It is likely that this horse's dysphagia, with resultant weight loss and aspiration pneumonia, were clinical manifestations and consequences of HPP. Regardless of age and serum potassium concentration, HPP should be considered as a differential diagnosis for pharyngeal and laryngeal abnormalities and dysphagia in horses with Quarter Horse breeding.

Use of intraoperative ultrasonography in six horses

Intraoperative ultrasonography was used in six horses to aid localization and removal of bone fragments (3 horses) and foreign bodies (3 horses). The ultrasound transducer was enclosed in a sterile sleeve containing sterile aqueous gel and the examination was performed after aseptic preparation of the surgical site. Using ultrasound guidance a needle was placed in contact with the bone fragment or foreign body and an incision was made along the path of the needle to expose and remove the object. This technique resulted in decreased operative time and minimal tissue dissection.

Canine Lyme disease in Belgium

Lyme borreliosis is a multisystem disease caused by the tick-borne spirochaete Borrelia burgdorferi. In addition to causing human illness, borreliosis has been recorded in many species of mammals, including domestic animals which come into contact with the infected tick vector. This paper describes the first two cases to the authors' knowledge of Lyme borreliosis in dogs in Belgium. Both animals suffered recurrent lameness and general prostration. In addition, one of the dogs had recurrent paralysis of nerves V, VII, IX and X, leading to dysphagia and total bilateral paralysis of the mandibular muscles. This complication of Lyme borreliosis has been well documented in human pathology, but has not previously been recorded in the veterinary literature.

Dysphagia-associated muscular dystrophy: a familial trait in the bouvier des Flandres

Among a group of dysphagic dogs the bouvier des Flandres was overrepresented. The results of a clinical examination, contrast videofluorography and electromyography of the pharyngeal, laryngeal and oesophageal muscles were similar in all the bouviers, and a histological examination of tissues from 10 of them revealed muscular dystrophy as the cause of the dysphagia. A study of the affected dogs' pedigrees revealed that they were descendants of one closely related group of ancestors, and that the inbreeding levels for this ancestor group were higher than in a control population of 136 bouviers. The homozygosity due to inbreeding for this ancestor group was higher in the affected dogs than in the control dogs, but the homozygosity due to all other ancestry was equal in the two groups. The relative risk of developing dysphagia-associated muscular dystrophy was up to 16 times greater in these bouviers, depending on the level of inbreeding for the closely related ancestor group.

Neurologic evaluation of the equine head and neurogenic dysphagia

Neurologic evaluation should be performed in horses with diseases of the head. Although neurologic examination should focus on assessing behavior, mental status, and cranial nerve evaluation, evaluation of neurologic function of other body regions should be performed. Neurologic evaluation of the head can be performed expediently by practitioners to provide useful diagnostic and prognostic information. The numerous causes of dysphagia can be classified as obstructive, painful, or neurogenic. Common causes of neurogenic dysphagia are summarized, and methods for initial diagnosis and management are described. Maintaining adequate nutrition and preventing aspiration pneumonia are principal concerns in managing horses with neurogenic dysphagia.

Evaluation of a standardised questionnaire for the detection of dysphagia in 69 dogs

The diagnosis of dysphagia in the dog requires an evaluation of a variety of signs that can be caused not only by a 'swallowing disorder' but also by several other pathological conditions. Most owners mention coughing, vomiting, regurgitation and nasal discharge, and the clinician must decide whether these signs are related to dysphagia. In this study a standardised questionnaire for the diagnosis and localisation of dysphagia was evaluated for its accuracy by comparing the results with contrast videofluorography as the definitive standard. The purpose of the study was to optimise the selection of dogs for more expensive diagnostic procedures such as videofluorography and electromyography. In a group of 69 dogs with 'swallowing problems' the questionnaire had a sensitivity of 0.97 and a positive predictive value of 0.94 for dysphagia in general. The questionnaire was also useful for the exclusion of oral phase dysphagia, with a specificity of 0.70 and a negative predictive value of 0.97. Most dogs with pharyngeal phase dysphagia could be detected by using the questionnaire (sensitivity 0.91). The questionnaire was not of specific value for the detection or exclusion of oesophageal phase dysphagia, for which it had a sensitivity of 0.69, a specificity of 0.57 and predictive values for positive and negative tests of 0.79 and 0.44, respectively.

Surgical management of pharyngeal disorders in the dog and cat

Disorders of the pharynx are relatively uncommon in the dog and cat. There are a number of potential causes of pharyngeal problems, but the underlying presenting clinical sign is that of dysphagia. This chapter will discuss the differential diagnosis of dysphagia with emphasis on oropharyngeal swallowing disorders. A separate discussion of special considerations to be made in the placement of pharyngostomy tubes also will be presented.

Dysphagia in Bouviers associated with muscular dystrophy; evaluation of 24 cases

Twenty-four Bouviers with dysphagia were examined between October 1986 and October 1988. The type of dysphagia was characterised by the results from the clinical examination, the videofluorographic examination and the electromyographic recordings from the oral, pharyngeal, and esophageal muscles. Electromyography indicated neurogenic as well as myogenic causes of dysphagia. Tissues from 10 dogs were available for histopathologic examination. In nine dogs there was a progressive muscular degeneration of the pharyngeal and/or esophageal muscles, resembling muscular dystrophy. In two of these dogs the same abnormalities were also noticed in the masseter and temporalis muscles and in the intrinsic laryngeal muscles. In one dog small areas with hyalin degeneration and fragmentation of muscle fibres were found in the cricopharyngeal muscle. No abnormalities in nerve tissue were found. Muscular dystrophy is a hereditary disease. The mode of transmission in these Bouviers is not yet known.

Use of a liquid diet as the sole source of nutrition in six dysphagic horses and as a dietary supplement in seven hypophagic horses

Six horses with dysphagia (attributable to botulism, glossitis, or guttural pouch mycosis) were given a commercially available liquid diet as the sole source of nutrition. Seven horses with hypophagia caused by severe bacterial pleuropneumonia or peritonitis were given the liquid diet to supplement food consumed voluntarily. The liquid diet was administered through a nasogastric tube 2 or 3 times daily. Body weight did not change significantly, and pertinent laboratory values remained at satisfactory concentrations throughout the feeding period. Serious complications were not encountered. Three horses developed loose, low-volume feces, but did not require treatment.

Surgical excision of ectopic thyroid carcinoma involving the base of the tongue in dogs: three cases (1980-1987)

Localized thyroid carcinoma involving the base of the tongue was diagnosed in 3 dogs examined because of a midline cervical mass rostroventral to the larynx. These masses had been present for 4 to 12 months and were firm, nonsensitive, and fixed in position. One dog had progressive dysphagia and dyspnea. Masses were surgically excised together with the base of the tongue and portions of the hyoid apparatus. Severe dyspnea that developed immediately after surgery in 1 dog was managed by tracheostomy intubation for 4 days. Transient dysphagia developed in all dogs. Hydration was maintained by IV fluid administration until water and food of gruel consistency could be swallowed 1 to 6 days after surgery. Consistency of food was gradually thickened to normal, as swallowing improved 6 days to 2 months after surgery. One dog developed aspiration pneumonia that resolved after antimicrobial administration and improved swallowing that prevented further aspiration. After 9 months, 3 years, and 6 years, the dogs were clinically normal.

Staphylectomy for treatment of dorsal displacement of the soft palate in two foals

Dorsal displacement of the soft palate associated with dysphagia and aspiration pneumonia was diagnosed in 2 young foals. The displacement appeared to be congenital. Clinical signs associated with the condition were resolved after staphylectomy. Dorsal displacement of the soft palate is usually recognized in adult animals as an upper respiratory tract disease, but may be a contributing factor to dysphagia and lower respiratory tract disease in young animals.