Application of ventriculoperitoneal shunt as a treatment for hydrocephalus in a dog with syringomyelia and Chiari I malformation

A twenty-month-old Chihuahua male dog was presented to us suffering with ataxia. Based on the physical examination, X-ray and magnetic resonance imaging (MRI) examinations, we diagnosed the dog with hydrocephalus, Chiari I malformation and syringomyelia. Treatment consisted of internal medical treatment and the placement of a ventriculoperitoneal (VP) shunt. The ventricular dilatation was relieved and the dog improved neurologically; however, the Chiari I malformation and syringomyelia remained after surgically positioning the VP shunt.     

Treatment of congenital hydrocephalus in a foal using a ventriculoperitoneal shunt

Objective: The objective of this report is to describe the presentation, diagnostic imaging findings, management, and complications of surgical shunt placement in a foal with congenital hydrocephalus. Case summary: A 3‐day‐old Quarter Horse colt was diagnosed with hydrocephalus on the basis of clinical signs and computed tomographic scan. A surgical shunt was placed from the right cerebral ventricle to the peritoneum. The foal demonstrated significant improvement in clinical signs until shunt complications occurred. New or unique information provided: To the authors' knowledge, the placement of a ventriculoperitoneal shunt to manage equine hydrocephalus has not been described. This case report provides a foundation for understanding the techniques and possible complications of surgical shunt placement in hydrocephalic foals.     

Imaging diagnosis--cervical spine chondroma in a dog

An extradural chondroma originating in the cervical spine was diagnosed in an 8-year-old, intact male Chow-Chow that presented acute cervical pain and chronic right thoracic limb lameness. Myelographic images were within normal limits. With magnetic resonance (MR) imaging, an extradural mass was identified at the level of the C4-C5 vertebrae. This mass was excised, and the histologic diagnosis was chondroma. Fifteen months after surgery, the dog was clinically normal, and no regrowth of the mass was identified on follow-up MR images. Spinal chondromas are rare tumors in the dog, but should be considered as a rule out for contrast-enhancing extradural vertebral masses.     

Imaging diagnosis--Complex intrahepatic portosystemic shunt in a dog.

An unusual form of congenital intrahepatic portosystemic shunt was identified in a 3 1/2-month-old female Labrador Retriever with neurologic signs. Ultrasonography and contrast-enhanced computed tomography were used to characterize the shunt morphology. An unusual, looping right-divisional shunt connected back to the portal vein that formed an ampula in the right-central portion of the liver. An irregularly shaped window-like opening connected the combined right-divisional loop and aneurysmal portal vein, and the caudal vena cava, while this vascular pool gradually fused more cranially. Imaging features of this complex vascular anomaly, which has not been previously reported, are presented.     

Imaging diagnosis: biliopleural fistula in a dog

A 3-year-old intact male Brittany Spaniel was admitted for thoracic gunshot wounds. Despite continued supportive care, the dog's condition deteriorated. Thoracic/abdominal ultrasound revealed a biliopleural fistula. Following fistula repair, the dog made a complete recovery. This case represented a diagnostic challenge because of the uncommon clinical presentation of a severe bile pleuritis in the absence of significant bile peritonitis. Biliopleural fistula is a rare condition but should be considered as a differential diagnosis in trauma patients with pleural effusion, especially those with penetrating thoracic injuries. Ultrasonography can be used to diagnose this disorder preoperatively.     

Hyperalbuminemia associated with hepatocellular carcinoma in a dog

Abstract: A 12‐year‐old, neutered male, mixed‐breed dog was presented to The Ohio State University Veterinary Teaching Hospital with a history of weight loss and weakness. Laboratory abnormalities reported by the referring veterinarian during the past year included increased alkaline phosphatase (ALP) activity, hyperalbuminemia, and nonregenerative anemia. On referral, the dog appeared hydrated and had moderate muscle wasting and hepatomegaly. A large lobular hepatic mass was observed ultrasonographically. Laboratory results included mild to moderate nonregenerative anemia, urine‐specific gravity of 1.035, 3+ proteinuria, increased serum activities of alanine aminotransferase (229 U/L, reference interval 10–55 U/L), ALP (813 U/L, reference interval 15–120 U/L), and the steroid‐induced isoform of ALP (676 U/L, reference interval 0–6 U/L), marked hyperalbuminemia (5.3 g/dL, reference interval 2.9–4.2 g/dL), and an increased A/G ratio (1.7). Hyperalbuminemia was confirmed by reanalysis on 2 different analyzers and by agarose gel electrophoresis, and colloid osmotic pressure (COP) was markedly increased (42.5 mmHg, reference interval 20–25 mmHg). Cytologic examination of a fine‐needle aspirate of the hepatic mass indicated hepatocellular proliferation; histologic examination of an excisional biopsy confirmed hepatocellular carcinoma. Three weeks after surgery, the albumin concentration, A/G ratio, COP, and ALT activity had normalized, but ALP activities remained high. We hypothesized that hyperalbuminemia developed secondary to hepatocellular carcinoma due to increased synthesis of albumin by malignant hepatocytes or due to decreased negative feedback from impaired hepatocellular osmoreceptivity. Hepatocellular carcinoma has been associated with paraneoplastic secretion of other proteins, but hyperalbuminemia has been reported only once in a human patient and has not previously in dogs.     

Imaging diagnosis--acquired pectus excavatum secondary to laryngeal paralysis in a dog

A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral laryngeal paralysis. Radiographically, there was pectus excavatum with a mediastinal shift to the right. Arytenoid lateralization was performed, relieving the upper respiratory obstruction, and the sternal deformity also resolved. Chronic upper respiratory obstruction should be considered in dogs with pectus excavatum. Furthermore, correction of upper respiratory obstruction has the potential to result in resolution of pectus excavatum.     

Keratoconjunctivitis associated with Toxoplasma gondii in a dog

A 12-year-old Pug presented with a 3-mm corneal mass OD. The dog was currently being treated for keratoconjunctivitis sicca (KCS) and pigmentary keratitis OU. A superficial keratectomy followed by cryotherapy was performed OD. A histopathologic diagnosis of epithelial dysplasia and suppurative keratitis was made and the lesion resolved. Two months later, a yellow/tan conjunctival mass, diffuse chemosis and conjunctival thickening was discovered OD. Necrotizing conjunctivitis with protozoal parasites was diagnosed with histopathology. Complete blood count and a serum biochemistry panel were normal. Neospora caninum and Toxoplasma gondii titers were negative. The conjunctivitis resolved after a 6-week course of oral clindamycin. Two months later, the patient presented with a similar conjunctival mass OS. Toxoplasma gondii was confirmed as the etiologic agent with immunohistochemical staining. Repeat T. gondii titers were negative. Oral clindamycin was re-instituted. The corneal biopsy was re-reviewed and protozoal organisms were discovered. Three months later, a recurrence was suspected and oral ponazuril was initiated for 28 days. There has been no evidence of recurrence since this treatment. Ocular toxoplasmosis is rare in the dog but reports have included episcleritis, scleritis, retinitis, anterior uveitis, ciliary epithelium hyperplasia, optic neuritis and polymyositis. To our knowledge, this is the first confirmed report of toxoplasmosis causing only corneal and conjunctival disease in the dog. We hypothesize that these localized lesions may be associated with topical immunomodulating therapy for KCS. Toxoplasmosis should be considered as a differential for canine conjunctivitis and corneal disease and has the potential to manifest in one or both eyes.     

Hematologic changes associated with Adderall toxicity in a dog

A 1-year-old intact male Boxer was presented to the Texas Veterinary Medical Center for emergency treatment following suspected ingestion of a large number of tablets of Adderall, a pharmaceutical amphetamine. The dog had a temperature of 41.7 degrees C, heart rate of 192 beats per minute, and a respiratory rate of 100 breaths per minute. The dog was anxious and agitated with bilaterally dilated pupils, and shortly thereafter became recumbent and incontinent. Initial CBC results included mild leukopenia and mild thrombocytopenia. The dog was not anemic (HCT 39.9%) and had only slight polychromasia, but had 48 nucleated RBCs/100 WBC (7500/microL). Moderate numbers of neutrophils had hypersegmented nuclei and several pyknotic cells were noted. The metarubricytosis persisted for approximately 56 hours while hypersegmentation and pyknotic cells were no longer found at 8 hours after presentation. The dog received supportive care and recovered uneventfully. We hypothesized that hyperpyrexia associated with Adderall toxicity resulted in inappropriate metarubricytosis due to damaged bone marrow endothelium, and resulted in hypersegmentation and pyknosis due to damaged or accelerated aging of neutrophils in peripheral blood. Metarubricytosis has been reported previously in dogs with heat-induced illness, such as heat stroke.     

Orbital cellulitis associated with Toxocara canis in a dog

Reports of Toxocara canis ocular larva migrans are uncommon in animals, with only a few cases reported. Most reports involve larval migration into the retina and choroid, with parasitic invasion of the orbit reported only in experimental studies. This is the first clinical case of Toxocara canis infection in the retrobulbar region of a 10-year-old, cross-bred male dog presenting with unilateral orbital cellulitis. Ophthalmic signs included protrusion of the nictitating membrane, chemosis, exophthalmos and hypertropia. The parasite was diagnosed by histologic and parasitologic examination of orbital tissues, which were removed during enucleation.     

Outbreak of ocular disease associated with naturally-acquired canine herpesvirus-1 infection in a closed domestic dog colony

Objective  To describe clinical and virological findings of an outbreak of ocular disease attributed to naturally-acquired primary canine herpesvirus-1 (CHV-1) infection in a closed domestic dog colony.
Animals studied  Twenty-seven 10- to 16-week-old laboratory Beagles.
Procedure  Complete ophthalmic examinations were performed and ocular samples collected for CHV-1 polymerase chain reaction and virus isolation.
Results  The prevalence of ocular morbidity was 100% in examined dogs. Lesions were restricted to the ocular surface and included bilateral conjunctivitis (100% of dogs); punctate, dendritic, or geographic ulcerative keratitis (26% of dogs); and non-ulcerative keratitis (19% of dogs). Conjunctival petechiae were detected in 22% of dogs. Punctate and dendritic corneal ulcers were frequently organized into discrete groups or linear arrangements. Non-ulcerative keratitis appeared clinically as a perilimbal ring of superficial corneal vascularization and leukocyte infiltration. CHV-1 was detected in ocular samples by polymerase chain reaction or virus isolation in all dogs sampled.
Conclusions  In susceptible populations of domestic dogs, CHV-1 may be associated with outbreaks of highly contagious ocular infection in the absence of concurrent overt systemic disease. This naturally-acquired outbreak of CHV-1 infection provides an opportunity to report the spectrum and prevalence of ocular lesions associated with primary ocular CHV-1 infection in dogs. Conjunctivitis was the most frequent ocular lesion detected. Ulcerative and non-ulcerative keratitis were less prevalent and of variable clinical appearance. Dendritic ulcerative keratitis, a classic and relatively specific ocular lesion associated with alphaherpesvirus infection, was detected in < 20% of dogs.     

Disseminated Mycobacterium avium infection in a dog with chronic diarrhoea

A 3-year-old Maltese-cross dog presented with a 4-month history of chronic diarrhoea and inappetence. Poorly regenerative anaemia, leukocytosis and hypoproteinaemia were evident on several occasions. Biopsies of stomach, duodenum and colon revealed marked infiltration of mucosae by macrophages containing many acid-fast bacilli. Similar organisms were numerous in a faecal smear. Melaena, hematochezia and severe abdominal pain developed and were unresponsive to therapy. Following euthanasia and necropsy, histiocytic cells containing acid-fast bacilli were found throughout the gastrointestinal tract, mesenteric and peripheral lymph nodes, spleen, liver, kidney and lungs. The organism was identified as Mycobacterium avium by bacterial culture and polymerase chain reaction testing.     

Hypothyroidism in a dog associated with trimethoprimsulphadiazine therapy

Abstract Hypothyroidism and a neuromuscular disorder developed in a 4-year-old Golden Retriever after it received potentiated sulphonamide and metronidazole for 18 and 14 weeks, respectively. Serum total T4 concentrations were non-detectable before and 6 h after exogenous administration of 4IU bovine thyroidstimulating hormone. Thyroid gland biopsy revealed changes consistent with diffuse hyperplastic goitre. Serum T4 concentrations were normal 7 days after discontinuation of therapy. The long-term trimethoprim-sulphadiazine therapy was considered the most likely cause of this dog's hyperplastic goitre. The cause of the neuromuscular disorder was not determined. It is recommended that discontinuation of potentiated sulphonamide takes place at least 7 days prior to any assessment of thyroid function. Résumé— Une hypothyroïdie et des troubles neuromusculaires sont observés sur un Golden Retriever de 4 ans, après une thérapeutique à base de sulfonamides potentialisés et de métronidazole, respectivement de 18 et 14 semaines. Des concentrations sériques de T4 totale ne sont pas détectables avant et après 6 heures d'une stimulation à la TSH bovine (4 UI). Des biopsies de la thyroïde montrent un goitre hyperplasique diffus. Les concentrations sériques de T4 sont de nouveau normales 7 jours après l'arrêt du traitement. L'administration à long terme de triméthoprim-sulphadiazine semble être la cause la plus vraisemblable du goitre hyperplasique. La cause des troubles neuromusculaires n'a pas été déterminée. Il est recommandé d'arrêter l'administration de sulfonamides potentialisés au moins 7 jours avant une exploration de la function thyroïdienne. [Torres, S.M.F. Hypothyroidism in a dog associated with triméthoprim-sulphadiazine therapy (Hypothyroi'die en relation avec un traitement triméthoprim-sulphadiazine chez un chien). Veterinary Dermatology 1996; 7 : 105–108.] Resumen Un perro Golden Retriever de 4 años desarrolló hipotiroidismo y una afección neuromuscular después de recibir un tratamiento con sulfonamidas potenciadas y metronidazol 18 y 14 semanas, respectivamente. Las concentraciones séricas totales de T4 eran indetectables antes y a las 6 horas después de la administración exógena de 4 UI de TSH bovina. La biopsia de tiroides mostró alteraciones indicativas de gota hiperplásica difusa. Las concentraciones séricas de T4 fueron normales a los 7 dias de retirar la terapia. La terapia prolongada con trimetoprim-sulfadiazina fue considerada la causa más probable de gota hiperplásica en este perro. No se determinó la causa del cuadro neuromuscular. Se recomienda retirar la terapia con sulfonamida potenciada al menos 7 días antes de la evaluación de la función tiroidea. [Torres, S.M.F. Hypothyroidism in a dog associated with trimethoprim-sulphadiazine therapy (Hipotiroidismo en un perro asociado a la terapia con trimetoprim-sulfadiazina). Veterinary Dermatology 1996; 7 : 105–108.] Zusammenfassung— Hypothyreose und eine neuromuskuläre Störung entwickelten sich bei einem 4 Jahre alten Golden Retriever, nachdem er potenzierte Sulfonamide und Metronidazol über 18 beziehungsweise 14 Wochen erhalten hatte. Die Gesamt T4-Konzentrationen waren vor und 6 Stunden nach exogener Verabreichung von 4 IE bovinen TSH nicht meßbar. Eine Biopsie der Schilddrüse zeigte Veränderungen, die parallel mit diffusem hyperplasischem Kropf auftreten. Die Serum T4-Konzentrationen waren 7 Tage nach Abbruch der Therapie wieder normal. Die Langzeit-Trimethoprim-Sulfadiazin-Therapie wurde als wahr-scheinlichste Ursache dieses hyperplastischen Kropfes beim Hund angesehen. Die Ursache der neuro-muskulären Störung konnte nicht festgestellt werden. Es wird empfohlen, potenzierte Sulfonamide mindestens 7 Tage vor einer überprüfung der Schilddrüsenfunktion abzusetzen. [Torres, S. M. F. Hypothyroidism in a dog associated with trimethoprim-sulphadiazine therapy (Hyperthyreose bei einem Hund in Verbindung mit einer Trimethoprim-Sulfadiazin-Therapie). Veterinary Dermatology 1996; 7 : 105–108.]     

Circumcaval ureter associated with an intrahepatic portosystemic shunt in a dog

CASE DESCRIPTION: A 4-month-old Bernese Mountain Dog was examined because of shifting hind limb lameness and lethargy of 2 weeks' duration. CLINICAL FINDINGS: The lameness was attributed to hypertrophic osteodystrophy. Portosystemic shunting was suspected on the basis of low serum albumin concentration and high serum bile acids concentration, and an intrahepatic shunt was identified ultrasono-graphically. Celiotomy was performed, and the shunt was partially closed with a cellophane band. During follow-up ultrasonography 7 months later, dilation of the left renal pelvis and proximal portion of the left ureter was identified. During exploratory celiotomy, the left ureter was found to pass dorsal to the caudal vena cava, and circumcaval ureter was diagnosed. TREATMENT AND OUTCOME: The ureter was transected, repositioned ventral to the vena cava, and anastomosed. Follow-up ultrasonographic examinations revealed gradual resolution of the hydronephrosis and hydroureter. CLINICAL RELEVANCE: Findings suggest that circumcaval ureter should be considered in the differential diagnosis for hydronephrosis and hydroureter in dogs. Partial obstruction of the middle segment of the ureter on ultrasonograms or contrast radiographs should increase the index of suspicion for this condition.     

Presumptive Nocardia spp. infection in a dog treated with cyclosporin and ketoconazole

Abstract

CASE HISTORY: A dog that had received 8 months of cyclosporin and ketoconazole therapy for treatment of atopic dermatitis subsequently developed severe neurological disease, that failed to respond to treatment with trimethoprim-sulphadiazine and clindamycin.

HISTOPATHOLOGICAL FINDINGS: Histopathological examination of the pulmonary parenchyma and spinal cord revealed loose aggregates of Gram-positive, partially acid-fast, fine, beaded, filamentous bacteria, most consistent with Nocardia spp.

DIAGNOSIS: A presumptive diagnosis was made of disseminated nocardiosis of the spinal cord and lungs.

CLINICAL RELEVANCE: Nocardia spp. is an opportunistic actinomycete that may cause disseminated disease, particularly in immunocompromised animals. Cyclosporin is used in veterinary medicine to control immune-mediated and allergic disorders, with few reported adverse side effects. This case gives further evidence that involvement of the spinal cord in nocardiosis of the central nervous system (CNS) carries a poor prognosis, and opportunistic infection by Nocardia spp. may be a potential complication of immunosuppressive cyclosporin therapy in the dog.     

Imaging diagnosis: CT findings in a dog with intracranial hemorrhage secondary to angiostrongylosis

A seven-month-old Cocker Spaniel had a cough, acute lethargy, decreased responsiveness, and episodes of hyperexcitability. There were bilateral generalized increased lung sounds, bilateral episcleral hemorrhage, and systemic hypertension. Prolonged buccal mucosal bleeding time and elevated D-dimer concentrations were detected. Radiographically, there was a generalized moderate unstructured interstitial pattern. In thoracic CT images, there was a diffuse moderate hyperattenuating appearance of the bronchial walls and interstitium and diffuse areas of moderate bronchiectasis. The brain CT images were characterized by marked hyperattenuating well-defined masses. In addition, there were smaller hyperattenuating and hypoattenuating masses scattered throughout the cerebral and cerebellar parenchyma. A zinc sulphate flotation test confirmed large numbers of Angiostrongylus vasorum L1 larvae. Despite therapy the dog continued to deteriorate and underwent euthanasia. Postmortem examination confirmed the presence of multiple intracranial and extracranial hemorrhages. Angiostrongylosis should be considered as one of the differential diagnoses in dogs presenting with neurologic signs consistent with acute intracranial haemorrhage.