Disseminated protothecosis causing acute blindness and deafness in a dog

A 3-year-old Collie bitch was euthanatized two weeks after the onset of blindness and deafness. The hearing deficit had been localized by clinical signs, brain stem auditory evoked responses, and impedance audiometry. Protothecosis was diagnosed by cytologic and histologic examinations. The organism was identified as Prototheca zopfii . Organisms and granulomatous lesions were found in kidney, heart, liver, skeletal muscle, thyroid gland, colon, bronchial lymph node, brain, and cochlea.     

Generalised protothecosis in a Collie dog

A case of generalised protothecosis in a Collie dog is discussed. A long-standing history of severe colitis was the major clinical sign. Dissemination to many organs was confirmed histologically. Possible pathogenesis is discussed along with a review of the literature. The possibility of a breed disposition in Collie dogs is discussed. The organisms are ubiquitous in the environment and generalised disease suggests the possibility of immune competence.     

Unsuccessful treatment of disseminated protothecosis in a dog

Systemic protothecosis was diagnosed in a 7-year-old dog that had only ocular manifestations. During the 3-month course of disease, a variety of drugs was administered, including amphotericin B, gentamicin, and ketoconazole. The ocular signs initially abated, but subsequently worsened during this period. The dog was found dead 3 months after initial examination, and systemic protothecosis was confirmed at necropsy.     

Sudden cardiac death associated with occult hypertrophic cardiomyopathy in a dog under anesthesia

A 6-year-old, 3.0 kg, neutered female, Yorkshire terrier was referred for orthopedic surgery. Cardiac arrest followed unsuccessful treatment of bradycardia and systemic arterial hypotension under general anesthesia. Postmortem examination revealed hypertrophic cardiomyopathy. A possible relationship between treatment of bradycardia, systemic arterial hypotension, and sudden cardiac death is described.     

Disseminated protothecosis diagnosed by evaluation of CSF in a dog

A 5-year-old female spayed Shetland Sheepdog Mix dog was evaluated for a history of recent seizure activity, progressive hind limb ataxia, polyuria, and polydipsia and no history of gastrointestinal signs. Physical examination findings included conscious proprioceptive deficits, ataxia, and anterior uveitis along with a hypermature cataract in the right eye. Results of a CBC, serum biochemical profile, urinalysis, and computed tomography scan of the brain were unremarkable. Cerebrospinal fluid (CSF) analysis revealed marked eosinophilic pleocytosis and rare organisms consistent with Prototheca spp within neutrophils and macrophages. On postmortem histologic examination, mononuclear inflammation and numerous intralesional algal organisms, similar to those seen on the cytologic preparation of CSF, were found in the brain, eyes, kidneys, and heart. Abnormalities were not detected on gross and histologic examination of the gastrointestinal tract. Cultures of CSF and subdural/olfactory bulb, but not intestinal tract, yielded growth of Prototheca spp, and PCR analysis and DNA sequencing confirmed the organism as Prototheca zopfii genotype 2. We have reported a rare case of disseminated protothecosis that was diagnosed by evaluation of CSF in a dog presented with neurologic signs and no overt enteric disease. Protothecosis should be considered as a rare cause of seizures, even in the absence of obvious enteric signs, and should be included in the differential diagnosis of eosinophilic pleocytosis.     

Placentitis associated with leishmaniasis in a dog

A 1.5-year-old Coonhound from Maryland aborted 7 fetuses. Placenta and internal tissues of 1 fetus were examined histologically. The predominant lesion was placentitis characterized by necrosis and infiltration of mixed leukocytes. Numerous Leishmania spp amastigotes were identified in placental trophoblasts, and the diagnosis was confirmed by use of immunohistochemical staining with Leishmania-specific antibodies. Protozoa were not found in the fetal tissues. An indirect fluorescent antibody test yielded a serum titer of 1:100, and a recombinant K39 immunoassay of serum yielded positive results for the K39 Leishmania antigen.     

Chylothorax associated with blastomycosis in a dog

Respiratory distress caused by pleural effusion resulted from chylothorax. Thoracic drainage and lowfat dietary therapy was effective in removing and preventing significant recurrence of the chylothorax; however, the patient died unexpectedly. At necropsy a blastomycotic granuloma found at the precava was considered the cause of the chylothorax. There had been no recognizable antemortem signs of blastomycosis. Blastomycosis can be considered as a rare cause of chylothorax.     

Acute blindness in a dog caused by an explosive blast

A 3-year-old, intact male, mixed breed dog was presented with a complaint of acute blindness. Ten days previously, the area where the dog was walking came under a rocket attack, and a rocket landed and exploded 300 meters away from the dog. Physical examination was unremarkable. Ophthalmoscopic examination revealed posterior segment fibrin clots and extensive vitreal hemorrhage in the right eye. A total retinal detachment (360 degrees retinal dialysis) with no evidence of hemorrhage was noted in the left eye. There was no sign of any penetrating ocular trauma, and it was assumed that the posterior segment findings were primary injuries caused by the blast wave itself. Following anti-inflammatory treatment, partial vision was restored in the right eye. Surgical re-attachment of the retina was discussed and declined by the owner. This report describes, for the first time, vitreal hemorrhage and retinal detachment as the sole injuries caused by an explosive blast wave.     

Hyperthyroidism associated with a thyroid adenoma in a dog

Hyperthyroidism associated with thyroid adenoma was diagnosed in a dog. Typical clinical signs of hyperthyroidism were resolved with surgical excision of the adenoma. Hyperthyroidism in dogs usually is associated with thyroid carcinoma, which has a poor prognosis. This case emphasizes the importance of obtaining a histologic diagnosis of thyroid tumors in hyperthyroid dogs before giving a prognosis.     

Thrombocytosis associated with a myeloproliferative disorder in a dog

A dog with a myeloproliferative disorder and thrombocytosis had clinical signs that were consistent with a diagnosis of essential thrombocythemia. The dog was treated with aspirin, radioactive phosphorus, and melphalan. Eighteen months after referral, the disorder progressed to chronic granulocytic leukemia, and treatment was switched to hydroxyurea. Fourteen months later, the dog was euthanatized because of uncontrollable atrial fibrillation.     

Pneumopericardium associated with a pulmonary-pericardial communication in a dog

A 6-year-old 18-kg (39-lb) spayed female Standard Poodle was referred for treatment of pneumopericardium. The dog did not have severe clinical signs relating to the pneumopericardium, and the diagnosis was made incidentally while investigating the cause of a cough. Computed tomography revealed an air-filled structure consistent with a bulla to the right of the heart base that appeared to communicate with the pericardial cavity Because spontaneous resolution of the pneumopericardium seemed unlikely and cardiac tamponade was a possibility, exploratory thoracotomy was performed. A lobulated bulla was found at the hilus of the right middle lung lobe adhered to the underlying pericardial sac, and a 4-cm-diameter communication from the pericardium to the pulmonary bulla was found. Right middle lung lobectomy was performed, and the pericardiotomy and pericardial opening were sutured. The dog recovered without complications. In previously reported cases of pneumopericardium involving a cat and a dog, the condition resolved spontaneously. In this dog, in contrast, surgical resection of the affected lung lobe with pericardial reconstruction was required for resolution of the pneumopericardium.     

Diarrhea associated with myenteric ganglionitis in a dog

Diarrhea in a Border Terrier was associated with inflammatory lesions of the myenteric plexus. This lesion has been documented rarely in dogs. It is speculated that the myenteric plexus lesions were responsible for an autonomic nervous system dysfunction, which resulted in extreme intestinal hypermotility and subsequent diarrhea. Suggested tests for dogs suspected to have autonomic dysfunction are given.