Upper airway obstruction in Norwich Terriers: 16 cases.

BACKGROUND: Norwich Terriers have grown increasingly popular as show animals and pets, and awareness of respiratory problems within the breed is growing. OBJECTIVE: To describe components of obstructive upper airway syndrome in a nonbrachycephalic terrier breed. ANIMALS: Sixteen Norwich Terriers; 12 with and 4 without clinical signs of respiratory disease. METHODS: Prospective case series. Physical and laryngoscopic examinations were performed by 1 investigator in all dogs. Medical and surgical interventions were summarized and results of follow-up examination or owner reports were recorded. RESULTS: The study population was comprised of 9 females (6 intact) and 7 males (5 intact). Median age was 3.0 years (range, 0.5-11 years). Of 12 dogs presented for a respiratory complaint, physical examination was normal in 4 dogs. Laryngoscopic examination was abnormal in 11/12 dogs with redundant supra-arytenoid folds, laryngeal collapse, everted laryngeal saccules, and a narrowed laryngeal opening in most. Of 4 dogs lacking clinical signs, all had normal physical examination; however, 3/4 dogs had similar appearance of the larynx to dogs with clinical signs. Response to surgical intervention was minimal to moderate in all dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Norwich Terriers suffer from an upper airway obstructive syndrome that differs from that encountered in brachycephalic breeds. Affected dogs are difficult to identify without laryngoscopic examination because of the lack of clinical signs and abnormalities in physical examination findings, despite severe airway obstruction. Care is warranted when anesthetizing Norwich Terriers because of the small size of the laryngeal opening.

Nonenteric Escherichia coli isolates from dogs: 674 cases (1990-1998).

OBJECTIVE: To determine nonenteric sites associated with Escherichia coli isolates in dogs and the antimicrobial susceptibilities of the isolates. DESIGN: Retrospective study. SAMPLE POPULATION: 17,000 canine specimens. PROCEDURE: Medical records of 17,000 canine specimens submitted for bacteriologic culture were examined and the number of isolations of E coli was determined. For these cases, records were further examined with respect to body system involvement, sex, concurrent infection with other species of bacteria, and antimicrobial susceptibility. RESULTS: 674 E coli isolates (424 from urine, 62 from the skin, 52 from the respiratory tract, 45 from the ear, 43 from the female reproductive tract, 25 from the male reproductive tract, and 23 from other organ systems) were identified. There was a significantly higher proportion of isolates from urine specimens from spayed females than from sexually intact females or males. Escherichia coli was isolated in pure culture from 65.9% of the specimens. Most E coli isolates were susceptible to norfloxacin (90%), enrofloxacin (87.5%), gentamicin (90.7%), and amikacin (85.9%). CONCLUSIONS AND CLINICAL RELEVANCE: Most nonenteric E coli infections in dogs involve the urinary tract. Amikacin, gentamicin, norfloxacin, and enrofloxacin have the highest efficacy against canine E coli isolates. For E coli isolates from dogs, in vitro susceptibility to commonly used antimicrobial agents has remained fairly stable during the past decade.

Quantitative bacterial cultures and cytological examination of bronchoalveolar lavage specimens in dogs.

Cytology and quantitative bacterial cultures of lower respiratory tract secretions are widely used in human medicine to differentiate airway infection from simple bacterial colonization. A retrospective study was conducted to determine the usefulness of quantitative aerobic cultures and Gram stain intracellular bacteria counts from bronchoalveolar lavage (BAL) specimens in dogs in diagnosing lower respiratory tract infection (LRTI) and to determine whether chronic bronchitis is associated with marked bacterial growth in dogs. The threshold determined to define clinically relevant bacterial growth was 1.7 x 10(3) colony-forming units per milliliter of BAL fluid. We used this threshold and found that diagnostic sensitivity and specificity were 86% and 100%, respectively. With a threshold for infection of >2 intracellular bacteria observed in any of 50 fields, microscopic examination of Gram stain BAL preparations had a sensitivity of 71% and a specificity of 97% in establishing LRTI. There was a high correlation between bacterial morphology on BAL Gram stain and bacterial cultures. Combining the results of intracellular bacteria counts from the BAL Gram stain with those from the quantitative cultures, the sensitivity in diagnosing LRTI was 87% and the specificity was 97%. BAL quantitative cultures as well as quantitating intracellular bacteria on Gram stain BAL cytology were revealed to be useful in identifying LRTI in dogs. Chronic bronchitis does not appear to be associated with marked bacterial growth in dogs.

Diagnosis and treatment of canine chronic bronchitis. Twenty years of experience.

Chronic bronchitis is a frustrating disease because the cause is rarely determined, the pathologic changes that accompany and define the disease are usually nonreversible and often progress to life-threatening disorders, and there is a lack of direct scientific evidence for the treatment recommendations that have been offered for the management of this disease in dogs. This article reviews the pathophysiology, clinical presentation, diagnosis, and evaluation of chronic bronchitis in dogs. Important diagnostic tools for use in diagnosis are discussed, including clinical pathology, chest radiographs, and culture and cytology of airway fluid samples.

Calcinosis cutis associated with systemic blastomycosis in three dogs.

Three dogs treated for systemic blastomycosis with intravenous amphotericin B (one case) or amphotericin B lipid complex (two cases) developed mild to severe calcinosis cutis two to six weeks after the initiation of treatment. Abnormalities in serum calcium and phosphorus during treatment for blastomycosis or at the time of diagnosis of calcinosis cutis were slight or absent. The calcification was not associated with lesions of cutaneous blastomycosis. Calcification was limited to the skin in two cases and may have also involved the kidneys in one. The calcinosis cutis resolved completely in all three dogs with no (two cases) or only palliative (one case) therapy.

Use of corticosteroids for treating dogs with airway obstruction secondary to hilar lymphadenopathy caused by chronic histoplasmosis: 16 cases (1979-1997).

OBJECTIVE: To examine use of corticosteroids in treating dogs with airway obstruction secondary to hilar lymphadenopathy caused by chronic histoplasmosis. DESIGN: Retrospective study. ANIMALS: 16 dogs. PROCEDURE: Records for dogs with airway obstruction examined from January 1979 through December 1997 were reviewed. Dogs were included in the study if they had hilar lymphadenopathy documented radiographically and bronchoscopically, had serum antibodies against Histoplasma capsulatum, and did not have organisms in any cytologic or histologic samples. Dogs were assigned to groups on the basis of treatment given (5 dogs, corticosteroids only; 5 dogs, corticosteroids and antifungal medication; 6 dogs, antifungal medication only). RESULTS: Clinical signs resolved in < 1 week in dogs treated only with corticosteroids. In dogs treated with corticosteroids and an antifungal medication, improvement was evident in a mean of 2.6 weeks. In 5 of 6 dogs treated with only an antifungal medication, clinical signs resolved in a mean of 8.8 weeks. Dogs receiving corticosteroids did not develop active or disseminated histoplasmosis. CLINICAL IMPLICATIONS: Corticosteroids can be used successfully in the treatment of dogs with hilar lymphadenopathy secondary to histoplasmosis. Affected dogs must be carefully evaluated for active infection. Specimens obtained by means of bronchoalveolar lavage, tracheal washing, or other methods should be examined to exclude the possibility of an active infection, which could result in corticosteroid-induced dissemination of disease.

Choanal atresia and secondary nasopharyngeal stenosis in a dog.

A 20-month-old, intact male shih tzu was evaluated for chronic upper airway disease. Endoscopic examination established a diagnosis of choanal atresia, a developmental anomaly of the posterior nasal cavity. Although surgical intervention provided temporary relief, stenosis of the nasopharynx by obstructive scar tissue was confirmed within four weeks. A permanent tracheostomy provided long-term relief of the respiratory difficulty. This is the first report of choanal atresia or nasopharyngeal stenosis in a dog.

Endoscopically placed tubes for administration of enilconazole for treatment of nasal aspergillosis in dogs.

An endoscopic method for administering commercial-grade enilconazole for treatment of nasal aspergillosis in dogs is described. Six dogs with confirmed nasal aspergillosis were anesthetized and feeding tubes were placed endoscopically into caudal sinuses. Commercial-grade enilconazole was infused into turbinates and sinuses for a total dwell time of 45 to 60 minutes. Dogs did not have recurrence of disease at final rhinoscopic examination and were markedly improved a mean of 13.3 months after treatment.

Neuronal vacuolation and spinocerebellar degeneration in young Rottweiler dogs.

With the recent epizootic of bovine spongiform encephalopathy in Europe, the differential diagnosis of neuronal vacuolation and spongiform change in other species has become critically important. Four Rottweiler puppies of both sexes, presented at 3-8 months of age, had clinical signs of generalized weakness and ataxia that started at 6 weeks of age. In all pups, neurologic examination detected an ataxia and tetraparesis, most severe in the pelvic limbs, and slowed proprioceptive placing reactions. Subsequently, there was rapid progressive neurologic deterioration, with severe placing deficits, knuckling, severe ataxia, and quadraparesis by 8 months of age. At necropsy, no gross lesions were observed. Microscopic lesions were restricted to the nervous system. The major lesion in all dogs was an intracytoplasmic neuronal vacuolation that was most prominent in the cerebellar roof nuclei and in nuclei of the extrapyramidal system. Similar vacuolation was found in neurons in both dorsal nerve root ganglia, myenteric plexus, and other ganglia of the autonomic nervous system. The single or multiple empty vacuoles were between 1 and 45 microm in diameter. A mild spongiform change was seen in the adjacent neuropil. Purkinje cell vacuolation and degeneration with segmental cell loss was seen in the oldest dog. In ventromedial and dorsolateral areas of the spinal cord white matter, there was mild bilaterally symmetrical axonal degeneration. Immunoblotting and immunocytochemical staining of the brain for protease-resistant scrapie prion protein was negative. All forms of vacuoles were negative for immunohistochemical staining with a variety of lectins. Ultrastructurally, the vacuoles were bound by a single membrane and contained granular material and sometimes membranous profiles. There was mild distension of the cytocavitary network but no unequivocal connection with the vacuoles was found. Axosomatic and axodendritic synapses in affected neurons were intact both ultrastructurally and with synaptophysin immunostaining. The clinicopathologic findings were different from those seen in the other neurologic diseases of Rottweilers. The age of the dogs, distribution and type of the lesions, ultrastructural findings, and negative immunoblotting most likely rule out the possibility of a scrapie agent-associated spongiform encephalopathy. However, the etiology of this new disease was not determined.

Comparison of unilateral arytenoid lateralization and ventral ventriculocordectomy for the treatment of experimentally induced laryngeal paralysis in dogs.

This study evaluated changes in respiratory function in dogs with experimentally induced laryngeal paralysis treated with either unilateral arytenoid lateralization or ventral ventriculocordectomy, and compared the effectiveness of these procedures. Evaluation consisted of clinical assessment and tidal breathing flow volume loop and upper airway resistance measurements. Carbon dioxide and doxapram hydrochloride were used as respiratory stimulants. Initially, all dogs improved clinically after corrective surgery. However, by the end of the study, laryngeal collapse had developed in 2 of 5 dogs corrected by ventral ventriculocordectomy. No statistical differences in upper airway mechanics testing were seen between the surgical procedures. With both groups combined, many measurements of upper airway obstruction improved after surgical correction. Based on this study, these surgical procedures yield comparable results, although additional studies are needed to evaluate both the cause of laryngeal collapse and the role of upper airway mechanics testing in the evaluation of canine laryngeal paralysis.

Bilateral recurrent laryngeal neurectomy as a model for the study of idiopathic canine laryngeal paralysis.

The purposes of this study were to develop an experimental model of canine laryngeal paralysis that mimicked the naturally occurring disease and to document the upper airway changes produced, both clinically and with pulmonary function testing. Ten dogs had bilateral recurrent laryngeal neurectomy performed and were recovered from anesthesia. Tidal breathing flow-volume loop analysis and upper airway resistance measurements were taken before and after the development of clinical laryngeal paralysis while dogs breathed room air and after the individual administration of 2 respiratory stimulants. Clinical signs of laryngeal paralysis developed 38 days (median) following denervation. Although some variations were present, tidal breathing flow-volume loop analyses on room air, following denervation, were similar to those reported in naturally occurring cases. Upper airway resistance increased following denervation and was significantly increased with both respiratory stimulants. We concluded that bilateral recurrent laryngeal neurectomy resulted in clinical signs and respiratory changes similar to those of idiopathic canine laryngeal paralysis.

Pulmonary lobectomy in the management of pneumonia in dogs: 59 cases (1972-1994).

OBJECTIVE: To evaluate the risk and efficacy of pulmonary lobectomy in dogs with pneumonia. DESIGN: Retrospective study. ANIMALS: 59 dogs with pneumonia. PROCEDURE: Review of medical records and telephone conversations. RESULTS: 54.2% of dogs had resolution of pneumonia after lobectomy, 20.3% died in the perioperative period, and 25.4% survived the perioperative period but pneumonia did not resolve. Pneumonia was caused by bacteria (25 dogs), fungi (12), foreign bodies (8), parasites (1), viruses (1), and allergies (1). In 11 dogs, the etiologic agent was not isolated. Bacterial or fungal pneumonias were significantly less likely to resolve compared with foreign body pneumonia or when an etiologic agent was not isolated. Perioperative mortality rate increased significantly with an increase in number of pulmonary lobes removed. Complications during surgery significantly increased perioperative mortality rate. Surgical era (1972 to 1983 vs 1984 to 1994) was a significant predictor of mortality, with the odds of dying in the perioperative period being 11 times greater between 1972 to 1983. The odds of failure to resolve pneumonia was 3 times greater during 1972 to 1983. CLINICAL IMPLICATIONS: Number of pulmonary lobes removed and complications during surgery significantly affect perioperative mortality rate. Identification of etiologic agents may help in predicting dogs likely to resolve pneumonia after surgery.

Use of an amphotericin B lipid complex for treatment of blastomycosis in dogs.

OBJECTIVE: To evaluate efficacy and nephrotoxicity of amphotericin B lipid complex used for treatment of dogs with naturally developing blastomycosis. DESIGN: Prospective clinical trial. ANIMALS: 11 dogs with blastomycosis. PROCEDURE: All dogs were treated with an amphotericin B lipid complex. Two dogs received a cumulative dose of 8 mg/kg of body weight, 1 received a cumulative dose of 10 mg/kg, and 8 received a cumulative dose of 12 mg/kg. RESULTS: The 2 dogs that received a cumulative dose of 8 mg/kg and 1 of the dogs that received a cumulative dose of 12 mg/kg had a relapse of blastomycosis within 30 days after treatment. Seven of the remaining 8 dogs were clinically free of blastomycosis 6 months after treatment. One dog died of an unrelated cause 5.5 months after treatment, but did not have clinical signs of blastomycosis at the time of death. There were not any adverse clinical effects attributable to drug administration in any of the dogs in this study, and none of the dogs developed clinical signs of renal disease or failure. CLINICAL IMPLICATIONS: Amphotericin B lipid complex was a safe and effective treatment for blastomycosis in these dogs.

Bronchopulmonary disease in the cat: historical, physical, radiographic, clinicopathologic, and pulmonary functional evaluation of 24 affected and 15 healthy cats.

The results of clinical and pulmonary functional evaluation of 24 cats with bronchopulmonary disease and 15 healthy cats are presented. Affected cats had historical evidence of excessive reflexes (coughing, sneezing); physical evidence of airway secretions (crackles), obstruction (wheezing), and increased tracheal sensitivity; radiographic evidence of bronchial and interstitial lung disease; and cytological evidence of airway inflammation or mucous secretions. Bacterial isolates from healthy and affected cats were predominantly Gram-negative rods, indicating that bronchi of cats are not always sterile and that normal flora should be considered in interpreting cultures from cats with suspected bronchopulmonary disease. Cats were grouped according to relative disease severity based on scored historical, physical, and radiographic abnormalities. The mean (+/- standard deviation) baseline lung resistance measurement in healthy cats was 28.9 cm H2O/L/s (+/- 6.2 cm H2O/L/s), whereas in mildly, moderately, and severely affected cats it was 38.3 cm H2O/L/s (+/- 21.5 cm H2O/L/s), 44.8 cmH2O/L/s (+/- 7.7 cm H2O/L/s), and 105.2 cm H2O/L/s (+/- 66.9 cm H2O/L/s), respectively. In healthy cats, dynamic lung compliance was 19.8 (+/- 7.4), whereas in mildly, moderately, and severely affected cats it was 14.7 mL/cm H2O (+/- 3.8 mL/cm H2O), 17.7 mL/cm H2O (+/- 6.9 mL/cm H2O), and 13.0 mL/cm H2O (+/- 7.9 mL/cm H2O), respectively. Thus, airway obstruction was present in many of the affected cats. Based on acute response to the bronchodilator, terbutaline, airway obstruction was partially reversible in many affected cats, although the degree of reversibility varied. Furthermore, based on bronchoprovocation testing, 6 (of 7) affected cats evaluated also had increased airway responsiveness to aerosolized methacholine.

Pathogenesis and treatment of canine rhinitis.

Unless a systematic approach is used, evaluation of a patient with rhinitis can be frustrating to the veterinary practitioner. A complete differential list for canine rhinitis should include infectious, inflammatory, neoplastic, and traumatic causes. Other causes of rhinitis include dental disease, parasitic infestation, and ciliary dyskinesia. Diagnostic techniques that should be considered when evaluating a patient with rhinitis include obtaining a complete history, performing a thorough physical and oral examination, evaluating the patient's coagulation abilities, cytology and culture of exudate, nasal radiographs, and rhinoscopy. This article describes the pathogenesis and treatment of the various causes of canine rhinitis.

Measurement of upper airway resistance in awake untrained dolichocephalic and mesaticephalic dogs.

A technique for measuring upper airway resistance was developed in awake untrained dolichocephalic and mesaticephalic dogs. Twenty healthy dogs, 10 Collies (group A--dolichocephalic) and 10 mixed-breed dogs (group B--mesaticephalic), were studied. All dogs tolerated the procedure well, and adverse effects were not observed. Mean (+/- SEM) value for upper airway resistance was 7.1 +/- 0.50 cm of H2O/L/L/s. There was a trend toward lower upper airway resistance (R(uaw)) values in group-A dogs, compared with those in group-B dogs. Values of R(uaw) were reproducible for an individual dog. The mean individual dog coefficient of variation for R(uaw) was 7.5%. The overall R(uaw) coefficient of variation for all 20 dogs was 31.4%. This technique for measuring upper airway resistance in dogs is clinically applicable for objectively assessing response to treatment of obstructive upper airway disorders.

Surgical management of atypical lateral tracheal collapse in a dog.

Tracheal collapse is often diagnosed in small-breed dogs through use of conventional radiography or fluoroscopy, by which the dorsoventral orientation of the collapse can be seen. In the dog of this report, an unusual lateral form of tracheal collapse was diagnosed by means of bronchoscopy after multiple radiographic procedures had failed to define a cause for cough and dyspnea. Surgical reinforcement of the abnormal region of the trachea resulted in resolution of clinical signs and in reduction in dynamic airway collapse, which was documented on follow-up bronchoscopy.

Tidal breathing flow-volume loops in healthy and bronchitic cats.

Tidal breathing flow-volume loops (TBFVL) were obtained from 19 healthy cats and 7 cats with chronic bronchial disease. Peak inspiratory flow (PIF) occurred late in the inspiratory cycle and was preceded by a gradual but more linear increase in the flow rate. Peak expiratory flow (PEF) occurred early during expiration and was followed by a curvilinear decrease in flow to a point near the end of expiration where flow ceased. The loops obtained were generally reproducible. The mean coefficient of variation (CV) for TBFVL indices of healthy cats ranged from 5.6% to 21.9%. Loop indices from cats with chronic bronchial disease had a mean CV between 6.6% and 28.4%. Significant differences were noted in the bronchitic cats' TBFVLs, including an increased ratio of expiratory time to inspiratory time, lower expiratory flow rates, decreased area under total and peak expiratory flow curves, and decreased tidal breathing expiratory volumes (TBEV) at 0.1 and 0.5 seconds. Selected TBFVL indices were also significantly reduced. TBFVL evaluation in the cat is easy to perform, is reproducible, and has allowed for the detection of changes during tidal breathing in cats with histories and physical findings of chronic lower airway disease.

Oral pharmacokinetics of carbamazepine in dogs from commercial tablets and a cyclodextrin complex.

The extent of absorption of carbamazepine from a 2-hydroxypropyl-beta-cyclodextrin/carbamazepine complex was significantly greater and the rate of absorption was faster when compared with an immediate-release carbamazepine tablet in the dog. Six dogs were dosed orally in a two-way crossover study in which the tablet was compared with an equivalent dose of the complex in solution. The area under the curve of concentration versus time for the complex was 5.6 times greater than the tablet, whereas the mean time to reach maximum concentration for the tablet was 1.4 hours versus 0.5 hours for the complex. The complex, therefore, had a greater rate and extent of absorption. A rapidly acting and better absorbed carbamazepine product has the potential to decrease the daily dose of carbamazepine, increase its utility as emergency treatment of epileptic seizures, and provide an acceptable alternative dosage form in patients who are unable to swallow tablets.