Sensory polyganglioradiculoneuritis in a dog.

Generalized reduction of nociception and conscious and unconscious proprioception were found in an approximately eight-year-old, male, Maltese mixed-breed dog presented for difficulty prehending food and experiencing ataxia of three months duration. Results of needle electromyogram, motor nerve conduction velocity, and cerebrospinal fluid analysis were normal. A diagnosis of sensory polyneuropathy was suspected. No underlying cause could be determined. Neurological signs progressed to quadriparesis over the following four months despite treatment attempts with prednisone and procarbazine. Necropsy confirmed a sensory polyganglioradiculoneuritis, but no inciting cause could be established.     

First confirmed canine case of Ehrlichia canis infection in Japan

An 11-year-old castrated Pekinese dog that had been moved from Indonesia to Japan eight years previously was diagnosed with an Ehrlichia canis infection by haematological characteristics (normocytic anaemia, mild thrombocytopenia and hypergammaglobulinaemia) and serological findings (antibody titre to E canis 1:3,200 or more). The dog did not respond to treatment with tetracycline and died from renal failure. The diagnosis was confirmed postmortem by pathological evaluation and polymerase chain reaction (PCR) followed by sequencing of the 16S rRNA gene. Typical morulae of Ehrlichia were detected in the cytoplasm of macrophages in spleen tissue by immunohistological staining. Ehrlichia-like organisms were also detected in the spleen by electron microscopy. E canis-specific PCR analysis of DNA extracted from the spleen gave a positive signal, and sequence analysis of the fragment revealed that it was identical to part of the 16s rRNA gene of E canis. The dog was the first confirmed clinical case of E canis infection in Japan.     

Multiple myeloma in a dog with multiple concurrent infectious diseases and persistent polyclonal gammopathy

A 12‐year‐old, spayed female, mixed‐breed dog was presented for acute hematuria, stranguria, polyuria, and polydipsia, as well as lameness for 8 days. Previous medical history included treatment for infection with Ehrlichia canis, Anaplasma phagocytophilum, Leishmania infantum, and Dirofilaria immitis 6.5 years prior to presentation. Besides persistently increased antibody titers to E canis and A phagocytophilum, polyclonal gammopathy with a monoclonal spike and moderate hypercalcemia were observed. There was marked hematuria, and Staphylococcus aureus was cultured from urine. Two weeks after successful treatment of the urinary tract infection, radiographs showed an extensive destructive monostotic lesion of the right humerus. Cytologic examination of fine‐needle aspirates of this lesion revealed a neoplastic round cell population suggestive of multiple myeloma. The dog was treated with melphalan and prednisolone for suspected multiple myeloma and doxycycline for suspected ehrlichiosis and anaplasmosis. Treatments lead to resolution of the clinical signs, hypercalcemia, and monoclonal gammopathy, and there was radiographic improvement of bone lesions; polyclonal gammopathy persisted. About one year after presentation the dog was still in clinical remission. This is a rare report of a dog with suspected multiple myeloma and a history of multiple chronic infectious diseases, suggesting that chronic infection and uncontrolled long‐term stimulation of the immune system could contribute to the pathogenesis of multiple myeloma.     

Unusual IgM-secreting multiple myeloma in a dog

A 4-year-old castrated male dog was evaluated because of multiple-limb lameness. Signs of pain were elicited during palpation of the regions of the proximal tibial metaphyses and distal left radial diaphysis. Radiography revealed osteolytic lesions of the long bones. Blood analyses revealed hypercalcemia and transient cytopenias. Serum protein electrophoresis did not reveal a monoclonal gammopathy; however, urine protein electrophoresis revealed Bence Jones proteinuria. Serial diagnostic sampling of bone lesions, immunohistochemical staining methods, and serum and urine protein immunoelectrophoresis were required to establish a diagnosis of multiple myeloma. Two IgM components were identified via serum protein immunoelectrofixation. The dog improved clinically after initiation of chemotherapy with melphalan and prednisone; however, the dog ultimately was euthanatized because of pathologic fracture. The case was unique because there was lack of vertebral involvement, an unusual gammopathy, and difficulty in identifying myeloma cells via serial sampling.     

Transient neuromyopathy after bromide intoxication in a dog with idiopathic epilepsy

A seven-year old Australian Shepherd, suffering from idiopathic epilepsy under treatment with phenobarbitone and potassium bromide, was presented with generalised lower motor neuron signs. Electrophysiology and muscle-nerve biopsies revealed a neuromyopathy.The serum bromide concentration was increased more than two-fold above the upper reference value.Clinical signs disappeared after applying diuretics and reducing the potassium bromide dose rate. This is the first case report describing electrophysiological and histopathological findings associated with bromide induced lower motor neuron dysfunction in a dog.     

Anaplastic atypical myeloma with extensive cutaneous involvement in a dog

A 7-year-old, male, mixed breed dog was referred to the Veterinary Teaching Hospital at Kitasato University because of anorexia, lameness and multiple cutaneous lesions. Observation of bone marrow plasmacytosis, osteolytic bone lesions, serum myeloma protein and cutaneous infiltration of myeloma cells led us to a diagnosis of multiple myeloma (MM) with cutaneous involvement. Polymerase chain reaction and sequence analysis for the rearranged genes of immunoglobulin and T-cell receptor demonstrated that the neoplastic cells found in skin lesions or bone marrow are of B-lymphocyte lineage and share a common original precursor cell. The dog was treated with UW-Madison protocol or melphalan/prednisone protocol and survived 175 days. This is rare case of anaplastic MM with cutaneous involvement in dog.     

Blindness in a dog with IgA-forming myeloma

A 9-year-old dog with a 2-month history of weight loss and a 1-week history of blindness had an IgA-forming myeloma. Seemingly, the blindness was a result of bilaterally detached retinas. The dog also had leukopenia, anemia, hypoalbuminemia, hyperglobulinemia, and proteinuria as well as lytic lesions in the cervical portion of the spine and high IgA concentrations in serum and urine. Evaluation of aspirates from the subretinal spaces revealed lymphocytes in a proteinaceous fluid. Histologically, retinal lesions consisted of vascular endothelial cell damage and intraretinal cysts and hemorrhages.     

ATYPICAL LYTIC PROLIFERATIVE SKELETAL LESIONS ASSOCIATED WITH PLASMA CELL MYELOMA IN A DOG

A 10-year-old female Labrador Retriever with intermittent lameness, lethargy, pancytopenia, hyper-calcemia, and severe hyperproteinemia was diagnosed as having plasma cell myeloma. Diagnosis was confirmed by finding a monoclonal gammopathy, extensive plasmacytic bone marrow infiltration, and radiographic evidence of skeletal disease. Survey radiography revealed atypical lytic proliferative osseous lesions involving the spinous process of the third thoracic vertebrae, left third rib, and both left and right fifth ribs. Nutritional support and specific chemotherapy with Melphalan have resulted in long-term clinical remission. This report describes the radiographic and clinicopathologic features of plasma cell myeloma in the dog. A discussion of the previously reported radiographic features of this neoplasm is also included.     

Multiple myeloma associated with the heavy chains of immunoglobulin A in a dog

On the basis of microscopic evaluation of bone marrow aspirate, multiple myeloma and secondary marrow hypoplasia was diagnosed in a 7-year-old female Doberman Pinscher. Electrophoresis, radial gel diffusion, and immunoaffinity chromatography indicated that serum and urine specimens contained alpha immunoglobulins without kappa or lambda light chains. Whole immunoglobulins (Ig) A, IgG, or IgM were not found. The dog was treated with prednisolone and melphalan for 11 weeks, after which time the owner refused examination and treatment of the dog.     

Distal peripheral polyneuropathy in a great dane

A spayed female five year old Great Dane dog was diagnosed as having a chronic, progressive, symmetrical distal polyneuropathy and concurrent hypothyroidism. Axonal degeneration and segmental demyelination were evident in teased nerve fiber preparations. Clinical signs included hindlimb weakness and muscle atrophy of the head and distal limbs. Diagnosis was based on clinical, electrophysiological, and nerve and muscle biopsy findings. Thyroxine supplementation for one month was of no benefit. The etiology of the polyneuropathy was not established but several causes were considered. The extent of demyelination in our case was of greater magnitude than described in a previous report of a similar idiopathic distal symmetrical polyneuropathy in a Great Dane.     

Recurrent demyelination and remyelination in 37 young Bengal cats with polyneuropathy

Background: With the exception of diabetic neuropathy, polyneuropathy associated with hyperchylomicronemia, and a few inherited polyneuropathies, peripheral neuropathies are poorly characterized in cats. A chronic polyneuropathy is described in a cohort of young Bengal cats. Objective: To characterize the clinical and histopathological features of a chronic‐relapsing peripheral neuropathy in young Bengal cats. Animals: Thirty‐seven young Bengal cats with clinical weakness consistent with peripheral neuropathy. Methods: Bengal cats were included in this study after a diagnosis of polyneuropathy was confirmed by muscle and peripheral nerve biopsy specimens. Pathological changes were characterized at the light and electron microscopic level and by morphometry. Clinical information and long‐term outcome from case records of Bengal cats with histologically confirmed peripheral neuropathy were then assessed. Results: Nerve fiber loss within distal intramuscular nerve branches was a consistent finding in young Bengal cats with polyneuropathy. The most common abnormalities in peripheral nerve biopsies included inappropriately thin myelin sheaths and thinly myelinated fibers surrounded by supernumerary Schwann cell processes, indicative of repeated cycles of demyelination and remyelination. Recovery was common. Response to treatment could not be determined. Conclusions and Clinical Importance: A chronic‐relapsing form of polyneuropathy associated primarily with episodes of demyelination and remyelination was identified in young Bengal cats. The prognosis for recovery is good, although relapses are possible and there can be residual motor deficits.     

Renal extramedullary plasmacytoma in a dog

A 10-year-old, intact male Siberian husky dog was presented for a suspected left renal cyst. Computed tomography (CT) identified a large, left kidney mass with retroperitoneal hemorrhage. A left-sided nephrectomy was performed, and histopathology confirmed a renal plasmacytoma. Perioperative screening for multiple myeloma was negative. The dog was lost to follow-up and was euthanized 11 months after surgery. A necropsy was not performed. To the authors’ knowledge, this is the first case of renal extramedullary plasmacytoma in a dog.Key clinical message:This report describes the clinical presentation, and laboratory, diagnostic imaging, and surgery findings of a case of renal extramedullary plasmacytoma in a dog.     

Osteomyelitis and arthrosynovitis associated with Leishmania donovani infection in a dog

A 10-monthold male maremma shepherd dog was presented with chronic diarrhoea, moderate polyuria/polydlpsia, lethargy, dysorexia and stiffness. Pain was elicited in the distal parts of all four limbs. Radiographs of the limbs showed increased endomedullary radiopacity and iysis, with thick periosteal proliferations at the metadlaphyseal areas of each radius-ulna and tibia and of the distal metacarpus on one side. Polyclonai hypergammaglobulinaemia was documented and a similar electrophoretic protein pattern was also found in the synovial fluid. Leishmania amastigotes were found In the macrophages In a bone marrow aspirate performed at the level of a distal radius and in a synoviai fluid sample obtained from a carpal joint. An indirect immunofluorescence test confirmed the infection. Treatment with N-methyl-glucamine antimoniate was successful and the osteoarticular changes progressively disappeared.     

Peripheral polyneuropathy in a dog with functional islet B-cell tumor and widespread metastasis

A 12-year-old female Irish Setter was examined because of recurrent episodes of hindlimb weakness. The dog was not ataxic, but had generalized muscular atrophy, decreased patellar reflexes, and slow proprioception. Blood glucose content was low (32 mg/dl) and the amended insulin-glucose ratio was high (9,600). Electromyographic studies showed evidence of polyneuropathy. The diagnosis was functional islet B-cell tumor with peripheral neuropathy. Exploratory laparotomy was performed. Widespread metastases were observed and the dog was euthanatized because of the poor prognosis. The dog was necropsied and the diagnosis was confirmed on the basis of microscopic findings.     

Electro-acupuncture and Chinese herbs for treatment of cervical intervertebral disk disease in a dog

A non-ambulatory dog with tetraparesis following a pain episode that had evolved over 2 months was submitted for medical treatment and diagnosed with intervertebral disk disease at C3-C4 and dorsal extradural compression at C1-C2 and C3-C4 using myelography and computed tomography. The dog experienced ambulation recovery after 15 days of treatment with only electroacupuncture and Chinese herbal medicine, with marked improvement occurring after only 10 treatments. Six months of follow-up demonstrated that the dog was stable and had no recurrence of symptoms. Therefore, it was concluded that the combination of electroacupuncture and Chinese herbal medicine was responsible for motor rehabilitation.     

Inability to experimentally produce a polyneuropathy in dogs given chronic oral low level lead.

Electromyographic examinations were performed at various times over a 40 week period in four mature dogs receiving chronic oral low doses of lead acetate and a control dog receiving sodium acetate. Blood lead levels in the four dogs were elevated (mean values 1.15, 2.18, 1.13 and 1.72 mumol/liter). No clinical signs of lead intoxication were present. Two dogs had evidence of a nonregenerative anemia. Neither needle electromyographic nor nerve conduction velocity studies showed evidence of a polyneuropathy. Teased nerve fiber preparations of proximal and distal segments of the ulnar and tibial nerves and muscle biopsies of distal appendicular muscles were normal in all dogs. Light microscopic examination of the brain, kidneys and liver revealed no abnormalities in the two dogs necropsied. In conclusion, a polyneuropathy was not produced experimentally in dogs ingesting low doses of inorganic lead for up to 40 weeks.     

Hemifacial spasm associated with an intracranial mass in two dogs

Two dogs were presented with hemifacial spasm. Computed tomography images of both the dogs revealed an intracranial mass. In the first dog, a lesion at the level of the medulla oblongata was thought to cause primary irritation of the facial nucleus, with consequently permanent contraction of the ipsilateral facial muscles. In the second dog, a mass seemingly arising from the middle cranial fossa presumably isolated the facial motor neurons from upper motor neuron control, which resulted in hemifacial spasm as a result of loss of inhibitory interneuronal activity.     

Stabilisation with dorsal and ventral fixation of a traumatic cervical instability in a dog

This case study reports the outcome of dorsal and ventral stabilisation of a traumatic cervical instability in a dog. A 2-year-old, male Pointer was admitted following a motor vehicle accident. Clinical examination revealed non-ambulatory tetraparesis, severe neck pain and upper motor neuron changes in all limbs. Deep pain response was present. Subluxation of C2/3 and fractures of the dorsal spinous process and lamina of C2 were observed on radiographs. Ventral stabilisation was performed with screws and bone cement (polymethylmethacrylate). For dorsal fixation of the fractures, screws and cerclage wire were used. The dog stood up independently after 1 month, was able to walk 1.5 months postoperatively and had recovered completely at 1 year following surgery. We conclude that combined stabilisation techniques are effective for this type of cervical fracture in which the dorsal, middle and ventral structures of the vertebra are severely disrupted.     

Salinomycin-induced polyneuropathy in cats: morphologic and epidemiologic data

In April 1996, an outbreak of toxic polyneuropathy in cats occurred in the Netherlands. All cats had been fed one of two brands of dry cat food from one manufacturer. Chemical analyses of these foods, stomach contents, and liver and kidney of affected cats revealed contamination with the ionophor salinomycin. Epidemiologic and clinical data were collected from 823 cats, or about 1% of the cats at risk. In 21 affected cats, postmortem examination was performed. The affected cats had acute onset of lameness and paralysis of the hindlimbs followed by the forelimbs. Clinical and pathologic examination indicated a distal polyneuropathy involving both the sensory and motor nerves.     

Presumptive trimethoprimsulphamethoxazole associated thrombocytopenia and anaemia in a dog

A two-year-old Scottish terrier was referred for investigation of a chronic skin problem. A diagnosis of generalised demodectic mange with a deep pyoderma was made and treatment commenced with trimethoprirn-sulphamethoxazole and amitraz washes. On the sixth week of treatment the owner reported that the dog had developed haematuria. Investigations revealed that the dog was thrombocytopenic and anaemic. Antimicrobial treatment was stopped and the platelet count returned to normal over a three week period. A diagnosis of trimethoprim-sulphamethoxazole associated thrombocytopenia was made.