Total ear canal ablation in the cat: indications, morbidity and long-term survival

Fifty-two total ear canal ablation (TECA) procedures in 44 cats were reviewed. The indication for surgery was neoplasia in 41 per cent of the cats, 86 per cent of which had ceruminous gland adenocarcinoma. Chronic inflammatory or polypoid disease accounted for 50 per cent of surgical procedures. Postoperative complications included Horner's syndrome (42 per cent) and facial paralysis (56 per cent) and these were permanent in 14 per cent and 28 per cent of cases, respectively, with the rest resolving in the ensuing weeks or months. The higher incidence of Horner's syndrome and facial paralysis in the cat, compared to the dog, was attributed to greater fragility of the feline tympanic plexus and facial nerve. The median survival time of cats with ceruminous gland adenocarcinoma was 50-3 months, and did not differ significantly from that for inflammatory or polypoid disease. A potential prognostic indicator for this tumour was the mitotic index (MI): cases with MI < or = 2 survived significantly longer than those with MI > or = 3.     

MRI characteristics of suspected acute spinal cord infarction in two cats, and a review of the literature

A 10-year-old neutered male Persian cat and a 4-year-old spayed female domestic shorthair (DSH) cat were evaluated for acute-onset severe lateralising tetraparesis and hemiplegia, respectively. Both cats also had left-sided Horner's syndrome. Neurological examination of the cats localised the lesion to cranial to C5 in the Persian and the left cervical intumescence (C6-T2) in the DSH. Physical examinations were otherwise generally unremarkable. Routine laboratory tests and spinal radiography were normal for the Persian cat and were not performed for the DSH cat. A cerebrospinal fluid (CSF) tap was attempted for the Persian cat but aborted because of gross blood contamination, and was not performed for the DSH cat. Magnetic resonance imaging (MRI) of the Persian cat revealed a lesion within the spinal parenchyma at segments C1 to C3 (slightly more left-sided) which was iso- to hypointense on T1-weighted scans and hyperintense on T2-weighted scans, and which enhanced slightly with gadolinium. MRI of the DSH cat revealed a lesion within the spinal parenchyma at segment C7 (predominantly left-sided) which was hypointense on T1-weighted scans and hyperintense on T2-weighted gradient echo scans. Contrast was not administered. The MRI findings in both cases were highly suggestive of acute spinal cord infarction, based upon comparison to human cases. Both cats made full neurological recoveries with supportive treatment only. This paper describes two cases of suspected acute spinal cord infarction in the cat, demonstrates the potential diagnostic value of MRI, and discusses the clinical syndrome of this condition with a brief review of published cases.     

Transient Horner's syndrome following routine intravenous injections in two horses

Horner's syndrome developed in 2 horses after routine jugular venipuncture. Signs included unilateral sweating of the face in both horses and ptosis in 1 horse. The signs resolved within 14 hours. Signs of a perivascular injection did not develop in either horse. Although Horner's syndrome has been reported after perivascular jugular injections these cases illustrate that the syndrome may develop following routine intravenous injections.     

Horner's syndrome in dogs and cats: 49 cases (1980-1986)

Medical records of 49 dogs and cats with Horner's syndrome were reviewed. Causes included head, neck, and chest trauma, chronic otitis, cranial thoracic mass, and injury attributable to cleaning of the external ear canal. Cause could not be delineated in 54.5% of the dogs. Numerous diagnostic tests and pharmacologic challenge exposure with epinephrine were used to localize the site of injury. Resolution of all clinical signs was observed in 36 animals and required a mean of 7.7 weeks.     

Trigeminal and polyradiculoneuritis in a dog presenting with masticatory muscle atrophy and Horner's syndrome

A 9-year-old, spayed female, Airedale Terrier was euthanatized and necropsied after a progressive clinical course that included Horner's syndrome of the left eye and unilateral atrophy of the masticatory muscles. Although gross lesions were limited, a polyradiculoneuritis and ganglionitis that was most severe in the trigeminal nerves and ganglia were confirmed histologically. The inflammatory infiltrate consisted predominantly of macrophages and B and T lymphocytes that were phenotypically confirmed by immunostaining. Horner's syndrome was the result of damage to postganglionic sympathetic fibers that were incorporated in segments of the inflamed trigeminal nerve and its ophthalmic branch. Histologically, the character and distribution of the inflammation was similar to previously described syndromes of suspected immune-mediated etiology in humans and animals.     

Persistent haematuria and proteinuria due to glomerular disease in related Abyssinian cats

Eight cases of glomerular disease in young, related Abyssinian cats are described. Haematuria was the most consistent feature. Six cats developed the nephrotic syndrome. The short-term prognosis was good for cats with haematuria and fair for cats with the nephrotic syndrome as oedema resolved in three of the six cats. Light microscopic examination of renal biopsies from three cats was considered normal or revealed only mild abnormalities. In the three cases subjected to necropsy, histological abnormalities included mild mesangial hypercellularity and adhesions between the glomerular tuft and Bowman's capsule consistent with a focal proliferative glomerulopathy. Further investigation into this glomerulopathy will require ultrastructural and immunohistochemical studies to characterise the glomerular abnormality and genetic analyses to investigate its potential to be an inherited disease. Glomerular disease, potentially a familial one, should be considered in the investigation of persistent haematuria or proteinuria in Abyssinian and related cats.     

Horner's syndrome and ipsilateral laryngeal hemiplegia in three cats

Horner's syndrome is described in three cats associated with wounds to the ventrolateral neck. In each case, ipsilateral laryngeal hemiplegia was observed on laryngoscopy. This finding provided strong evidence to support a diagnosis of second order Horner's syndrome due to disruption of the cervical sympathetic trunk, as motor fibres innervating laryngeal abductors also traverse the neck; both as descending fibres within the contiguous cervical vagus and as ascending fibres within the recurrent laryngeal nerve. Notably, the ability to vocalise was unimpaired in all cases and, in two cats, neck wounds were not apparent until the neck had been clipped and closely examined. These findings indicate that assessment of laryngeal function is of value when localising the site of the neural defect responsible for selected cases of second order Horner's syndrome.     

Horner's syndrome in dogs and cats: 100 cases (1975-1985)

The medical records of 74 dogs and 26 cats with Horner's syndrome (HS) that were admitted to the New York State College of Veterinary Medicine between January 1975 and October 1985 were reviewed. In dogs, but not cats, HS was associated significantly (P less than 0.01) with increasing age. Dogs with hypothyroidism (defined liberally but not rigorously), intracranial neoplasia, or thoracic neoplasia, cats with otitis media/interna (defined liberally), and dogs and cats with brachial plexus root avulsion were at greater risk for developing HS than were animals that were hit by a car. Dogs and cats with otitis externa were at less risk of developing HS than were animals that were hit by a car. The cause of HS could not be determined in 50% of dogs and 42.3% of cats. The results of topical adrenergic drug testing in dogs were inconclusive in localizing lesion site. In dogs and cats, HS appeared to be unassociated with gender, breed, or right vs left side. The important causes of HS in dogs and cats were trauma (hit by car), brachial plexus root avulsion, intracranial and thoracic neoplasia, and otitis media/interna.     

Idiopathic facial paralysis in the dog

Facial nerve paralysis of acute onset is reported in seven mature dogs, five of which were cocker spaniels. The clinical signs were characterised by ear drooping, lip commissural paralysis, sialosis, and collection of food on the paralysed side of the mouth. All dogs showed absent menace responses and trigeminofacial/acousticofacial reflexes. Horner's syndrome was not present in any dog. In four dogs, bilateral facial paralysis developed. The facial paralysis was unrelated to otitis media. Electrodiagnostic studies revealed denervation potentials and absent evoked muscle potentials. Facial nerve biopsies from two cases showed nerve fibre degeneration and apparent loss of larger diameter myelinated fibres. The condition has been termed idiopathic facial paralysis since the aetiopathogenesis is presently unknown.     

Presumptive meningoencephalitis secondary to extension of otitis media/interna caused by Streptococcus equi subspecies zooepidemicus in a cat

A 5-year-old castrated male domestic longhair cat was presented with neurological signs consistent with a central vestibular lesion and left Horner's syndrome. Computed tomography images revealed hyperattenuating, moderately contrast-enhancing material within the left tympanic bulla, most consistent with left otitis media/interna. Marked neutrophilic pleocytosis was identified on cerebrospinal fluid analysis. Streptococcus equi subspecies zooepidemicus (SEZ) was isolated from the cerebrospinal fluid. Intracranial extension of otitis media/interna is relatively infrequent in small animals. There are no reports of otitis media/interna caused by SEZ in dogs or cats. This is the first report of otitis media/interna and presumptive secondary meningoencephalitis caused by SEZ in a cat.     

Horner's syndrome in ten horses

Ten cases of equine Horner's syndrome were reviewed. None of the clinical signs in this series were transient (<48 hours). Sweating and ptosis were consistently observed by the attending clinician in over half of the affected horses. Enophthalmos and prolapse of the third eyelid were not reported consistently. The average duration of the clinical signs was 4.94 months and ranged from 14 days to 15 months. Eight of the ten horses developed associated complications, some of which affected performance. Airway obstruction and impedance of passage of a fiberoptic endoscope due to nasal mucosal edema occurred in five horses. Facial paralysis (4/10) and laryngeal hemiplegia (2/10), which are not direct features of Horner's syndrome, were also observed.     

Histopathology of experimental plague in cats

Formalin-fixed paraffin-embedded archival tissues of seven adult cats of both sexes that died after being experimentally infected with Yersinia pestis were examined light microscopically to characterize the lesions. The cats were exposed in two groups using two routes of infection: ingestion of Y. pestis-infected rodent or a subcutaneous injection of Y. pestis to simulate a flea bite. Immunohistochemistry was performed on tissues from all organ systems from a representative cat from each group to determine the distribution of Y. pestis bacilli during infection. In all seven cats, bubonic plague lesions were seen. The lesions of pneumonic plague were present in two cats. Septicemic plague was confirmed in all seven cats by bacteriologic culture. Aggregations of bacteria were seen in lymphoid tissue in all cats and in lung tissues from the two cats with pneumonic plague. The most consistent histologic finding was necrosuppurative inflammation in the lymph nodes. Invariably, Y. pestis bacteria were present in large numbers at affected sites. Orally infected cats had more numerous lesions in the lymph nodes of the head and neck regions. These experimentally induced cases of feline plague document that cats are unique among carnivores in exhibiting bubonic, pneumonic, and septicemic plague following exposure to Y. pestis. The lesions of the orally infected cats were consistent with those previously described for naturally occurring Y. pestis infections in cats and corroborate the contention that cats most commonly contract plague by eating Y. pestis-infected rodents and not via flea bite. The histopathology of Y. pestis disease in these cats is comparable to that described for human plague.     

Percutaneous ultrasound-guided radiofrequency heat ablation for treatment of hyperthyroidism in cats

OBJECTIVE: To determine efficacy and safety of percutaneous radiofrequency heat ablation for treatment of hyperthyroidism in cats. DESIGN: Prospective study. ANIMALS: 9 cats. PROCEDURE: Hyperthyroidism was diagnosed via clinical signs and high serum total (TT4) and free thyroxine (fT4) concentrations. One or 2 hyperfunctional cervical thyroid nodules were detected by use of scintigraphy and ultrasonography. If cats had 1 abnormal thyroid lobe, heat ablation was performed on that lobe; if cats had 2 abnormal lobes, heat ablation was applied to the larger lobe. Overall, heat ablation was performed 14 times in the 9 cats. Clinical signs and serum TT4, fT4, and calcium concentrations were monitored daily for 2 days after the procedure, weekly for the first month, and then monthly. Laryngeal function was evaluated and cervical ultrasonography and thyroid scintigraphy were also performed. Monitoring continued for as long as 9 months after heat ablation if a cat became euthyroid or until an owner chose an alternative treatment because of recurrence of hyperthyroidism. RESULTS: Serum TT4 and fT4 concentrations transiently decreased after all 14 heat ablation procedures (< or = reference range after 10 of 14 treatments) within 2 days after the procedure. Cats were euthyroid for 0 to 18 months (mean, 4 months). Hyperthyroidism recurred in all cats. Adverse effects included transient Horner's syndrome (2 cats) and laryngeal paralysis without clinical signs (1 cat). CONCLUSIONS AND CLINICAL RELEVANCE: Percutaneous heat ablation as a treatment for hyperthyroidism in cats is effective transiently but not permanently.     

Asymmetrical focal neurological deficits in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus): 27 cases (1999-2006)

OBJECTIVE: To describe basic epidemiological features, clinical characteristics and outcomes of asymmetrical focal neurological deficits identified in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus). DESIGN: A retrospective study. PROCEDURE: Computer records were reviewed for all dogs and cats treated for tick paralysis between July 1999 and June 2006 at a suburban veterinary hospital in Newcastle, New South Wales. RESULTS: Neurological deficits were identified in 17/197 dogs and 10/89 cats and included unilateral facial paralysis (14 dogs; 2 cats), anisocoria (4 dogs; 7 cats), unilateral loss of the cutaneous trunci reflex (1 dog; 1 cat) and Horner's syndrome in 2 cats with anisocoria. Occurrence of deficits was not linked to season, severity of tick paralysis, breed, age, sex or body weight. With facial paralysis and anisocoria, the site of tick attachment was invariably on the head or neck and always ipsilateral to the facial paralysis. By contrast, with anisocoria alone, no consistent relationship was noted between any one pupillary dimension and the side of tick attachment. With cutaneous trunci deficits the site of tick attachment was the ipsilateral caudal axilla. Compared with recovery times from generalised signs of tick paralysis, those for facial paralysis were significantly longer (days to weeks; P < 0.001), those for anisocoria showed no significant difference (P = 0.25) and those for cutaneous trunci deficits lagged by 6 and 7 days. CONCLUSIONS: Asymmetrical focal neurological deficits are a consistent finding in a proportion of dogs and cats with naturally occurring tick paralysis due to I. holocylcus.     

Use of percutaneous ethanol injection for treatment of bilateral hyperplastic thyroid nodules in cats

OBJECTIVE: To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of hyperthyroidism caused by bilateral hyperplastic thyroid nodules in cats. DESIGN; Prospective study. ANIMALS: 7 cats. PROCEDURE: Hyperthyroidism was diagnosed on the basis of clinical signs and increased serum total thyroxine (TT4) concentrations. The presence of 2 cervical thyroid nodules was confirmed by use of ultrasonography and technetium Tc 99m albumin thyroid scans. After the death of 1 cat that received PEI in both thyroid nodules at the same time, the protocol was changed to injecting ethanol into 1 nodule at a time, with at least 1 month between injections. Clinical signs, serum TT4 concentrations, serum ionized calcium concentrations, laryngeal function, findings on ultrasonographic examinations of the ventral cervical region, and results of thyroid scans were monitored. RESULTS: Serum TT4 concentrations transiently decreased in all 6 cats (into the reference range in 5 of 6 cats) within 4 days of the first staged ethanol injection. Each subsequent injection resulted in a transient decrease in serum TT4 concentration. The longest period of euthyroidism was 27 weeks. Adverse effects included Horner's syndrome, dysphonia, and laryngeal paralysis. One cat died of unrelated causes. One cat underwent bilateral thyroidectomy, 2 cats were treated with methimazole, and 2 cats that had increased serum TT4 concentrations were not treated further, because they remained clinically normal. CONCLUSIONS AND CLINICAL RELEVANCE: Percutaneous ethanol ablation of bilateral thyroid nodules as a treatment for cats with hyperthyroidism is not recommended. This treatment is not as efficacious as the medical and surgical treatments presently used.     

Canine dysautonomia: two clinical cases

Two clinical cases of canine dysautonomia are described. Two young female neutered dogs were presented with clinical signs including vomiting, diarrhoea, faecal tenesmus, dysphagia and urinary retention. Decreased tear production, dry mucous membranes, bilateral Horner's syndrome, decreased anal sphincter tone and gastrointestinal hypomotility were also observed. Presumptive diagnoses of dysautonomia were made based on the clinical presentation and investigations. Postmortem histopathological examination in one of the cases demonstrated marked depletion of neuronal cell bodies in the intestinal myenteric plexuses and parasympathetic ganglia, confirming the diagnosis in this case. Criteria for aiding the antemortem diagnosis of this rare condition based on clinical observations and diagnostic testing are proposed.     

Extrahepatic biliary tract surgery in the cat: a case series and review

Four cases of extrahepatic biliary tract surgery in the cat are described. The causes of the disease were inflammation of the gallbladder, distal common bile duct (CBD) or major duodenal papilla, and traumatic avulsion of the CBD. Bile peritonitis was present in two of the cats. Biliary enterostomy was performed in three cats, two of which were euthanased at five weeks and three months postsurgery; the third was alive at the time of writing, four months postsurgery. Cholecystectomy was curative in one cat. A literature review reveals high early mortality following biliary diversion, with only 50 per cent of cases surviving more than two weeks, and 23 per cent surviving more than six months. Surviving cats had repeated intermittent vomiting and anorexia that responded to antibiotics. No postoperative mortality was seen when biliary diversion was avoided. Whenever biliary enterostomy or temporary diversion methods are performed, a poorer prognosis should be offered due to the increased likelihood of postoperative complications and mortality.     

Hypertensive encephalopathy in cats with reduced renal function

The clinical, hemodynamic, and pathologic features of hypertensive encephalopathy in two cats with reduced renal mass are described. The cats developed a progressive syndrome of lethargy, ataxia, blindness, stupor, and seizures following an abrupt increase in blood pressure associated with a surgical reduction in renal mass. The cats had severe gross brain edema, evidenced by cerebellar changes of caudal coning and cranial displacement over the corpora quadrigemina and cerebral changes of widening and flattening of the gyri. Histologically, interstitial edema was most pronounced in the cerebral white matter. Hypertensive vascular lesions were present as hyaline arteriolosclerosis in one cat and hyperplastic arteriolosclerosis in the other. Rare foci of parenchymal microhemorrhages and necrosis were also observed. Systemic hypertension (especially severe or rapidly developing) accompanied by neurologic signs and the pathologic findings of diffuse brain edema with cerebral arteriolosclerosis are consistent with an etiologic diagnosis of hypertensive encephalopathy.     

Congenital porto-systemic shunts in sixteen dogs and three cats

Congenital porto-systemic shunts in sixteen dogs and three cats are described. A major symptom was hepato-encephalopathy. In most cases diagnosis was based on elevated venous ammonia levels, abnormal ammonia tolerance and results of operative mesenteric portography. Clinical signs, laboratory findings, results of portography, and pathologic findings in the liver and the central nervous system are described. A diagnostic schedule is proposed to aid in recognition of this syndrome.     

Hypereosinophilic syndrome in cats: a report of three cases.

The clinical, clinicopathological and pathological findings in three cats with hypereosinophilic syndrome are described. The cats chosen for the study had marked eosinophilia and evidence of tissue infiltration by eosinophils. Necropsies were performed on two cats, biopsy and blood samples were provided for the third cat. At necropsy, there was diffuse reddening of femoral bone marrow with ulceration and thickening of the duodenum. The livers had an enhanced lobular pattern with multiple, white, 1-3 mm nodules throughout the parenchyma. One cat had splenomegaly and the other had several enlarged, white, firm lymph nodes. Histopathologically, there was eosinophil infiltration of intestine, lymph nodes, liver, spleen, adrenal medulla and beneath the endocardium. Ultrastructurally, the eosinophils from lymph node and bone marrow of cat II were morphologically normal. The rigid criteria for eosinophilic leukemia were not fulfilled by these cases and the etiology of the eosinophilia in each case is not known. Possible pathogenic mechanisms are discussed.