Intraluminal tracheal stenting for treatment of tracheal narrowing in three cats

OBJECTIVE: To describe the use of intraluminal tracheal stenting in 3 cats with either benign or malignant tracheal obstruction. STUDY DESIGN: Retrospective clinical study. ANIMALS: Three client-owned cats. METHODS: Medical records were reviewed and information regarding signalment, clinical signs, physical examination findings, diagnostic tests performed, treatment, outcome and follow-up were retrieved. Intraluminal tracheal stent placement was performed as previously described in the literature. RESULTS: Three cats received intraluminal tracheal stents for the treatment of tracheal obstruction due to 3 different underlying causes: stricture secondary to traumatic endotracheal intubation, stricture secondary to a previous tracheotomy, and neoplasia. Self-expanding metallic stents of varying sizes were placed, and all cats recovered uneventfully from the procedures. The cat with tracheal neoplasia was euthanized because of pulmonary metastatic disease 6 weeks post-stent placement. The two cats with tracheal obstructions secondary to benign strictures are currently 39 months and 32 weeks post-stent placement, respectively. No complications were noted during the post-stent period in any of the 3 cats. CONCLUSIONS: Intraluminal tracheal stenting was easily, safely, and rapidly performed without complications and resulted in immediate improvement in clinical signs in all three cases. None of the cats in this study developed significant stent-associated complications during the study period. CLINICAL RELEVANCE: Intraluminal tracheal stenting has the potential to be a viable option for the treatment of tracheal obstruction in cats and perhaps for similar disease processes in other veterinary patients.     

Intrathoracic tracheal rupture

This paper reports five new cases of intrathoracic tracheal rupture in cats, and summarizes these cases in conjunction with 11 cases from the literature. Most cats had no obvious respiratory signs at the time of injury, and in half of them the tracheal rupture was the only injury. The interval from trauma to onset of dyspnoea ranged from 1 to 28 days (median 12.5 days). Radiographic findings include loss of continuity of the trachea, often with a gas-filled diverticulum present between separated tracheal rings. With careful attention to surgical technique and anaesthetic management the prognosis for these cats is excellent. All eight of the cats reported in the last 14 years having surgical correction survived and returned to normal. The surgical anatomy, approach and tracheal anastomosis technique is described and recommendations for anaesthetic management are made.     

Surgical management of intrathoracic tracheal avulsion in cats: long-term results in 9 consecutive cases

OBJECTIVE: To evaluate the outcomes and complications in a consecutive series of cats undergoing surgical repair of intrathoracic tracheal avulsion injuries. STUDY DESIGN: Retrospective clinical study. ANIMALS: Nine client-owned cats. METHODS: The medical records of all cats undergoing surgical repair of intrathoracic tracheal avulsion injuries from 1994 to 1997 were reviewed. The results of physical examination, laboratory evaluations, radiography, tracheoscopy, surgery, and patient follow-up were reviewed. Complications that arose and long-term outcome were noted. RESULTS: Long-term resolution of clinical signs was achieved in all cats after resection of the damaged trachea and its repair by end-to-end anastomosis. Follow-up periods ranged from 12 months to 2.9 years. One cat developed unilateral left-sided laryngeal paralysis 2 to 3 months after surgery; however, this was transient and resolved without intervention within 6 months of surgery. CONCLUSIONS: Surgical management of intrathoracic tracheal avulsion injuries in cats can be accomplished via a right lateral thoracotomy. Careful anesthetic technique is an integral part of the surgical procedure if a successful outcome is to be achieved. The incidence of both short-term and long-term complications was low. Care should be exercised to visualize and protect the left recurrent laryngeal nerve if postoperative iatrogenic unilateral left-sided laryngeal paralysis is to be prevented. CLINICAL RELEVANCE: This retrospective study documents the successful surgical correction of a series of clinical cases of intrathoracic tracheal avulsion in cats.     

Macrophakia in three cats

This report describes three cases of bilateral macrophakia in 3-, 5-, and 9-year-old cats, respectively. All cats were presented because of visual deficits. Ophthalmic examination revealed macrophakia (the vitreous was replaced by the lens) and retinal changes (tapetal hyper-reflectivity, attenuation of retinal vessels, and retinal folds) in all cats. In addition, bilateral subconjunctival orbital fat prolapse in one cat and microphthalmos in another cat were present. To confirm the ophthalmologic diagnosis of macrophakia, gross pathology examination in one cat and ultrasound examination in another cat were performed.     

Fat malassimilation in three cats

Three cats were thin despite eating well. Steatorrhoea was confirmed in each by 72-hour fat assimilation tests. Fat digestibility in all 3 increased twofold when the diet was supplemented with pancreatic enzymes, suggesting the possibility of exocrine pancreatic insufficiency. However, examination of stained faecal smears gave evidence of both maldigestion and malabsorption of fat, without maldigestion of starch, and only one case had indications of protein maldigestion. In the latter cat, fat digestibility normalised with pancreatic enzyme supplementation and exocrine pancreatic insufficiency was considered likely. However, at post-mortem examination enteropathy and pancreatitis, but not exocrine pancreatic insufficiency, were found. The cause of fat malassimilation in these cats was unknown. The evaluation of malassimilation in cats is difficult because investigative tests used in other species are either unsuitable or have not been evaluated in cats.     

Cutaneous cryptococcosis in three cats

Cutaneous cryptococcosis was diagnosed in 3 cats. No other organ involvement was found. One cat has remained healthy after surgical excision of the cryptococcal skin lesion. One cat was euthanatized after diagnosis. The third cat was treated successfully with a 5-month course of ketoconazole.     

Congenital tarsal hyperextension in three cats

CASE DESCRIPTION: 3 kittens were examined because of a malformation affecting the hind limbs, resulting in an inability to bear weight or ambulate normally. CLINICAL FINDINGS: 2 kittens were younger than 6 weeks of age, and 1 was 4 months of age at the time of initial examination. The congenital abnormality was characterized by severe tarsal hyperextension in which weight was borne on the cranial aspect of the tarsus, and the plantar surface of the metatarsus faced dorsally. In 2 kittens, the condition affected both hind limbs, and in the older kitten, the condition was unilateral. In the 2 kittens in which radiographs were obtained, no bone abnormalities were detected. Full-cylinder fiberglass casts were applied and changed weekly to accommodate growth. Owners administered physical therapy after final cast removal. TREATMENT AND OUTCOME: Conservative management involving external coaptation and physical therapy led to favorable results in all 3 cats. CLINICAL RELEVANCE: Although further studies are needed to determine the etiology of the disorder, affected kittens may be successfully treated with conservative management. Owners should be committed to the necessity for returning cats for serial cast changes, care for pressure sores, and administration of physical therapy after cast removal.     

Mitral valve stenosis in three cats

Two-dimensional and M-mode echocardiography were used to diagnose mitral stenosis in two cats with heart failure. This appeared to be related to mitral valve complex malformation. Ultrasound findings included thickened mitral valve leaflets with inhibited mobility, reduced mitral valve orifice size, abnormal upward (cranial) motion of the caudal mitral leaflet during diastole and severe left atrial enlargement. Colour-flow and spectral Doppler imaging helped characterise this condition. Colour-flow Doppler mapping showed turbulence and increased mitral filling velocity (aliasing) at the site of stenosis and related jets of mitral regurgitation. Spectral Doppler recordings showed increased diastolic mitral filling velocities with spectral broadening and prolonged pressure half-time. Mitral stenosis should be included in the differential diagnosis of cats with severe left atrial enlargement when congenital or acquired mitral valve disease is detected; it may represent an advanced form of mitral valve complex malformation in some cases.     

Monocytic leukemia in three cats.

Of 3 cats with monocytic leukemia, 1 responded favorably to treatment with cytosine arabinoside. With supportive therapy, it lived 78 days from the time of diagnosis, at which time it developed dyspnea and signs of toxicosis and died. The other 2 cats did not respond to treatment and died 4 and 16 days from time of diagnosis. Prior to death, they were bleeding from injection sites, and their blood had greater than 200,000 WBC/mm3. Necropsy of those 2 cats revealed extensive perivascular hemorrhagic infarcts within the cerebellum, medulla, and cerebrum.     

Hemophilia A in three unrelated cats

Factor VIII deficiency, consistent with hemophilia A, was detected in 3 unrelated male domestic short-haired cats. Clinical history of each case differed and illustrated the spectrum of clinical manifestations of this disease in cats. Clinical expression of feline hemophilia A was similar to that of man and other animals, in which the degree of factor VIII deficiency tends to determine the severity and frequency of bleeding. All 3 cats had severe protracted bleeding after minor surgical procedures. Hemorrhage was eventually controlled in each case by transfusions of fresh whole blood.     

Benign cranial mediastinal lesions in three cats

Cranial mediastinal lesions were detected in three cats, associated with respiratory impairment (case one), spontaneous pneumothorax (case two) and myasthenia gravis (case three), respectively. On gross and histological examination, the first case was considered either a lymphangioma or a branchial cystic mass of the thymic region of the mediastinum; a cystic lesion was suggested by sonographic detection of multiple anechoic cavitations within a circumscribed mass, while fine needle aspiration cytology excluded lymphosarcoma. The second case was diagnosed histologically as a cystic thymoma, but the third case was not examined microscopically. The masses were amenable to surgical excision in the first two cats, while this proved unnecessary in the third case because of resolution following treatment with dexamethasone. Corticosteroid responsiveness was unhelpful in distinguishing between these benign lesions and lymphosarcoma, as in two cases there was a partial or complete response to dosing with prednisolone or dexamethasone. These cases are presented to emphasise that conditions other than lymphosarcoma can produce cranial mediastinal lesions in cats, and that the prognosis for surgical treatment of lymphangiomas, multilocular thymic cysts and cystic thymomas can be excellent.     

Acute tularemia in three domestic cats.

Acute Francisella tularensis infection in 3 domestic cats was presumptively diagnosed on the basis of clinical signs and lesions and confirmed by culturing or immunofluorescent demonstration of the organism. Clinical findings include marked signs of depression, oral/lingual ulceration, regional or generalized lymphadenomegaly, hepatosplenomegaly, panleukopenia with severe toxic change of neutrophils, and hyperbilirubinemia with bilirubinuria. Lesions found at necropsy included icterus, oropharyngeal and lingual ulceration, multiple foci of necrosis in lymph nodes, spleen, liver, and lung, and severe segmental or diffuse enterocolitis. Results of serologic testing for F tularensis was positive in only 1 of the 3 cats. The organism was cultured aerobically from several tissues, including aspirated bone marrow obtained before death in 1 cat. Results of an indirect fluorescent antibody test, performed on fresh and formalin-fixed tissues of all cats, were positive. Because of the severe clinical course, opportunity to evaluate therapeutic regimens was not possible. Until now, confirmed diagnosis of feline tularemia only has been made retrospectively, in instances when cats were suspected to have transmitted infection to human beings in whom the primary diagnosis was made. The findings in this report provide a basis for presumptive diagnosis that will help to minimize public health risk associated with this potentially fatal zoonotic disease.     

Fungal rhinitis and sinusitis in three cats

Localized infection of the nasal or paranasal cavities caused by Aspergillus spp or Penicillium spp was diagnosed in 3 cats. Clinical signs included chronic mucopurulent nasal discharge, epistaxis, and mandibular lymphadenopathy. Rhinoscopic and diagnostic imaging findings were compatible with severe inflammation of the nasal mucosa and destruction of the turbinates. Fungal plaques were observed rhinoscopically in 2 cats, and histologic examination of biopsy specimens revealed fungal colonies with surrounding inflammatory infiltrates in all 3. Results of fungal culture were negative for all 3 cats. Results of serum immunoelectrophoresis for antibodies against Aspergillus spp were positive in 2 cats. Treatment with itraconazole was effective in controlling clinical signs in 1 cat, but hepatotoxicosis developed. A single intranasal infusion of clotrimazole subsequently led to long-term resolution of clinical signs in this cat. Localized aspergillosis-penicilliosis is clinically indistinguishable from other pathologic conditions of the nasal and paranasal cavities in cats and should be considered when examining cats with chronic nasal discharge.     

Obstructive inflammatory laryngeal disease in three cats

Three cats with upper respiratory tract obstruction due to laryngeal inflammation are presented. Cervical radiography showed the presence of a soft tissue mass in the laryngeal region in all cases, and laryngoscopy allowed direct visualization of a mass associated with the larynx. Laryngeal samples were obtained by a combination of fine needle aspiration, cutting biopsy forceps, by ventral laryngotomy, and at post-mortem. Histopathology of the laryngeal samples showed the presence of a predominantly granulomatous inflammation, with macrophage and lymphocyte infiltration. One case was euthanased due to severe dyspnoea. The remaining two cases underwent combined medical (corticosteroid and antibiotic) and surgical (permanent tracheostomy or excision of laryngeal tissue by ventral laryngotomy) treatment. One case died of an undetermined cause 15 weeks after surgery while the other case remains clinically well 20 months after diagnosis. Recognition of the existence of granulomatous laryngitis is important as clinical signs and radiographic findings are indistinguishable from laryngeal neoplasia.