Systemic histiocytosis in a Bernese mountain dog

Systemic histiocytosis was diagnosed at post mortem examination in a three-year-old Bernese mountain dog born in the United Kingdom. The dog presented with a progressive nodular skin disease, chemosis and periocular swelling occurring over six months. It was unresponsive to topical corticosteroids, antibiotics and oral azathioprine. Elective euthanasia was performed. Post mortem examination revealed extensive histiocytic infiltration of the skin, subcutis and skeletal muscles, particularly of the head.     

Malignant histiocytosis of Bernese mountain dogs

A second histiocytic proliferative disorder, which resembled malignant histiocytosis of man, was identified in 13 Bernese mountain dogs. Malignant histiocytosis was clearly distinct from systemic histiocytosis, which was reported earlier in this breed. Eleven cases involved male dogs. Ten dogs occurred in the same family line as the dogs afflicted with systemic histiocytosis. Clinical or radiological evidence of pulmonary involvement was present in nine dogs. Neurological disturbances were present in five dogs. Anemia was observed in five dogs and was associated with prominent erythrophagocytosis in two instances. The clinical course was rapidly progressive. Necropsy examinations revealed that infiltrates were especially frequent in the lungs and hilar lymph nodes. Other lymph nodes, liver, spleen, and central nervous system were also frequently involved. Evidence for primary pulmonary involvement was present in seven dogs. The original diagnosis in seven cases was large cell anaplastic carcinoma of the lung by light microscopy only. The infiltrates were composed of large, pleomorphic, phagocytic mononuclear cells and multinucleated giant cells which also manifested marked cytological atypia and numerous, frequently bizarre, mitotic figures. Ultrastructural studies and the immunohistochemical demonstration of lysozyme and alpha 1-antitrypsin in the tumor cells in the majority of cases were consistent with a macrophage origin.     

Systemic histiocytosis in the Bernese mountain dog

Systemic histiocytosis is a rare familial histiocytic disorder seen in the Bernese mountain dog. This article documents six confirmed cases of the disease seen at the Animal Medical Centre between June 1992 and June 1994 and describes the different presentations of the disease, response to therapy and progression. Three of the dogs are still alive; of these, two are in remission six and 18 months later and in one case the owner refused treatment. Three of the cases were euthanased for humane reasons.     

Malignant histiocytosis in Bernese Mountain dogs

Malignant histiocytosis was diagnosed in 10 male and 1 female Bernese Mountain Dogs. Nine of these dogs were closely related. The disease was characterized by a rapidly progressive and inevitably fatal course. Clinical signs varied, but lethargy, anorexia, weight loss, and respiratory and CNS abnormalities predominated. The lungs were the primary site of tumor involvement in 10 dogs. The eleventh dog had lymphadenopathy and severe anemia. Metastatic lesions were detected in all dogs. Anaplastic pulmonary carcinoma was diagnosed originally in 6 of the 11 cases, but this diagnosis was changed to malignant histiocytosis after electron microscopic examination of tissues and immunohistochemical identification of histiocytic markers in the tumor cells.     

Systemic histiocytosis of Bernese mountain dogs

A histiocytic proliferative disorder was identified in six closely related Bernese mountain dogs. Clinical signs included anorexia, weight loss, stertorous respiration, and conjunctivitis with marked chemosis. Multiple cutaneous nodules were distributed over the entire body but were especially prevalent in the scrotum, nasal apex, nasal planum, and eyelids. Lesions consisted of perivascular infiltrates of large histiocytes as well as minor populations of lymphocytes, neutrophils, and eosinophils. Histiocytes were further characterized by enzyme histochemistry and electron microscopy. Necropsy examinations of four dogs revealed that the histiocytic infiltrates were widespread and involved skin, lung, liver, bone marrow, spleen, lymph nodes, kidneys, testes, orbital tissues, and others. However, skin and peripheral lymph nodes were more consistently involved. The disease course was punctuated by remissions and relapses not clearly influenced by conventional therapeutic measures. Preliminary results of an experimental therapeutic regimen involving administration of bovine thymic extracts in two dogs are present. The relationship of the disorder to other human and canine histiocytic proliferative disorders is discussed.     

Inheritance of histiocytosis in Bernese mountain dogs

One hundred and twenty-seven cases of histiocytosis in Bernese mountain dogs (BMD) were evaluated to determine if the tumour is inherited. Family data ruled out autosomal recessive, autosomal dominant and sex-linked modes of inheritance. The trait was determined to be inherited with a polygenic mode of inheritance. The salient points permitting this conclusion are: pedigrees developed from independently selected propositi link up allowing the tracing of all cases through several generations; multiple cases occur in the same litter; multiple cases have been produced by given dams and sires; there is a higher frequency of the disease among offspring of affected parents when compared to offspring of normal parents that produced histiocytosis and all offspring in the general population of BMDs; the fact that histiocytosis is common in BMDs and rare in eight other breeds and accounts for 25·4 per cent of the 500 tumours studied in this breed. The heritability of this trait was calculated to be 0·298.     

Congenital renal dysplasia and psychogenic polydipsia in a Bernese mountain dog.

Congenital renal dysplasia was tentatively diagnosed, based on ultrasound and an intravenous urogram, in a 5-month-old female with polyuria and polydipsia. Creatinine clearance measurement revealed that the renal dysplasia was not the cause of the polyuria. A modified water deprivation test eliminated other differential diagnoses and confirmed psychogenic polydipsia.     

Malignant pheochromocytoma presenting as a bradyarrhythmia in a dog

Objective: To describe a case of atrioventricular block and syncope secondary to systemic hypertension in a dog with malignant pheochromocytoma. Case Summary: A 13‐year‐old spayed female mixed‐breed dog presented following an acute onset of collapse. The dog was hypertensive and had paradoxical high‐grade second‐degree atrioventricular block with concurrent syncope. Initial emergent therapy included a nitroprusside infusion for the systemic hypertension and vagolytic therapy for the bradyarrhythmia. A left adrenal mass was seen on abdominal ultrasound and was further characterized by MRI. Following medical stabilization with phenoxybenzamine and propantheline, a left adrenalectomy was performed. Histological diagnosis was consistent with a malignant pheochromocytoma. Following tumor removal there has been no further hypertension, atrioventricular block or syncope. Unique information provided: This is the first documented case of a malignant pheochromocytoma presenting as syncope secondary to hypertension induced atrioventricular block.     

Recognition of 'trembler', a hypomyelinating condition in the Bernese mountain dog

An account is given of a hypomyelinating condition, 'trembler', in the Bernese mountain dog. The condition is manifested clinically as a tremor of the limbs and head which becomes more intense with excitement or stress and which disappears with sleep. The tremor, which is first noticeable between two and eight weeks old, may persist throughout life but decline with age. Examination of plastic embedded tissue obtained post mortem from two, nine-week-old animals showed hypomyelination of the spinal cord. Preliminary examination of breeding data suggests that the condition may be inherited as an autosomal recessive.     

Atlantoaxial cartilaginous exostosis causing spinal cord compression in a mature Bernese mountain dog

Cartilaginous exostosis developed in the atlantoaxial region of a three-and-a-half-year-old Bernese mountain dog. The dog exhibited ataxia in the hindlimbs and flailing movements in the forelimbs. On survey radiographs of the cervical spine there was a focal calcified mass between the dorsal arch of the atlas and the spinous process of the axis. Lumbar myelography revealed severe dorsal spinal cord compression. The mass was removed surgically and the dog made a complete recovery. Histopathology of the excised mass was consistent with a diagnosis of cartilaginous exostosis.     

Obstructive struvite ureterolithiasis in 4-month-old intact male Bernese mountain dog

A 4-month-old, 7 kg, intact male, Bernese mountain dog was presented for obstructive struvite ureterolithiasis. Multiple urethroliths, ureteroliths, and urocystoliths were present. Based on an abdominal ultrasound, there was severe left hydronephrosis and hydroureter from distal ureterolith obstruction, just proximal to the vesicoureteral junction. The dog was not azotemic. Successful treatment was accomplished via ventral cystotomy. Bladder wall culture revealed a methicillin-resistant Staphylococcus spp. No predisposing cause was identified. There are no known genetic predispositions in Bernese mountain dogs for struvite urolithiasis. The urinary tract infection resolved with surgical retrieval of the uroliths and antibiotic treatment. The dog remained clinically normal after the cystotomy but developed a subclinical urinary tract infection 4 mo post-operatively.Key clinical message:Urolithiasis is rare in pediatric veterinary patients. To the authors’ knowledge, this is the first report of obstructive ureterolithiasis in a puppy. There is no known genetic predisposition for urolithiasis in Bernese mountain dogs.     

Clinical and genetic investigations of idiopathic epilepsy in the Bernese mountain dog

A study was conducted to investigate the clinical aspects and to define the mode of inheritance of idiopathic epilepsy in the Bernese mountain dog. Pedigree analyses were carried out on an open, non-preselected population of 4005 dogs. Five different subpopulations with 50 epileptic dogs from 13 generations were included. Almost all epileptic patients showed generalised seizures of the grand-mal type with a well-defined prodromal and postictal phase. The majority (62 per cent) of the epileptic dogs had had their first seizures at between one and three years of age and it was found that the age at first seizure was significantly (P < 0.05) lower in dogs from affected parental animals than in dogs from healthy parental animals. A clear predisposition for males was also noted. Additionally, there was no correlation between inbreeding coefficient and age at first seizure or incidence rate of seizures. The increased occurrence of the disease in different subpopulations and different families of the same sires or dams showed that there was a genetic basis for the condition in the Bernese mountain dog. Furthermore, the results of the pedigree analyses and binomial test support the hypothesis that idiopathic epilepsy has a polygenic, recessive mode of inheritance in the breed. Additional objective test-mating programmes would however be necessary to define the exact mode of inheritance.     

Multivariate genetic analysis of canine hip and elbow dysplasia as well as humeral osteochondrosis in the Bernese mountain dog

In the present study genetic parameters for canine hip dysplasia (CHD), canine elbow dysplasia (CED) and osteochondrosis dissecans of the humeral head (OCD) were analysed in Bernese mountain dogs. The data set included the official scores for CHD and CED from 5534 Bernese mountain dogs born in the years 1995-2008. A multivariate linear animal model was employed to estimate heritabilities, additive genetic and residual correlations using residual maximum likelihood (REML). Heritability estimates were h2 = 0.26 for CHD, h2 = 0.22 for CED and h2 = 0.40 for OCD. The additive genetic correlation between CHD and CED was 0.31, between CHD and OCD 0.25, and between CED und OCD -0.49. A further multivariate analysis of the prevalence of the FCP (fragmented coronoid processus), CHD and OCD revealed a heritability of h2 = 0.59 for FCP. The additive genetic correlations among FCP and CHD as well CED except FCP were positive, but negative with OCD. Multivariately estimated breeding values will lead to higher genetic progress because the correlation structure of the traits can be taken into account and possible genetic antagonisms among traits are better reflected in the breeding values.     

Renal pathology and urinary protein excretion in a 14-month-old Bernese mountain dog with chronic renal failure

The renal pathology and urinary protein pattern of a 14-month-old female Bernese mountain dog with chronic renal failure was investigated. Sodium dodecyl sulphate-polyacrylamid gel electrophoresis and subsequent Western blot analysis of urine showed the presence of heavy and light chains of immunoglobulin, transferrin, albumin, vitamin D-binding protein, transthyretin and retinol-binding protein (RBP), but no excretion of Tamm-Horsfall protein (THP). Histopathological examinations of the kidneys revealed severe membranous glomerulonephritis accompanied by tubular dilatation, tubular atrophy and interstitial fibrosis. The renal expression of megalin, the main endocytic receptor for the re-uptake of proteins in proximal tubules, RBP and THP was reduced or completely absent, indicating severe tubular dysfunction. The identified urinary proteins may be of interest as additional markers for the diagnosis of juvenile nephropathy in Bernese mountain dogs.     

Suspected primary pure red cell aplasia in a 4-month-old intact male mixed breed Bernese mountain dog

A 4-month-old, 31-kg intact male mixed-breed Bernese mountain dog was presented for evaluation of severe non-regenerative anemia after several days of lethargy, inappetence and pale mucous membranes. Bone marrow evaluation and complete response to immunosuppressive therapy were suggestive of primary pure red cell aplasia (PRCA). Primary PRCA is a rare immune-mediated non-regenerative anemia that is overrepresented in middle-aged to older spayed female dogs and has not previously been described in an intact male puppy.