Porencephaly in dogs and cats: magnetic resonance imaging findings and clinical signs

Magnetic resonance imaging (MRI) features of brain lesions in 5 dogs and 2 cats characterized by extensive cystic changes of the cerebral hemispheres in terms of a porencephaly are presented. Age at diagnosis ranged from 12 weeks to 7 years. MRI findings were confined to the forebrain. Porencephalic lesions appeared as wedge-shaped parenchymal defects connecting the ventricular system and the subarachnoid space or as large cystic defects in the cerebral hemispheres. Although in two adult dogs the porencephalic lesions were asymptomatic, the other animals showed clinical symptoms depending on the affected cerebral area. Three animals had seizures. Interestingly, four animals showed neurological signs normally not localized to the forebrain (nystagmus, hypermetria, ataxia). Whether these clinical signs are related to impaired function of the cerebral cortex or to not recognizable lesions in the cerebello-vestibular system could not be further clarified. Although the defects develop intrauterine or postnatal, the clinical symptoms can occur later in life. The definition of porencephaly as well as its subclassification is not uniform in veterinary medicine. We suggest the term encephaloclastic porencephaly unregarding the underlying cause of the defect, which cannot be further specified by diagnostic imaging.     

Gliomatosis cerebri in six dogs

Gliomatosis cerebri is a well-recognized entity in human medicine characterized by unusually widespread infiltration of the neuraxis by neoplastic glial cells with relative preservation of brain architecture. This report describes the pathologic features of the disease in six dogs. The dogs ranged from 3 to 9 years of age (mean 6.1 years) without evidence of breed predilection; five of the six dogs were neutered or intact males. The clinical findings were mixed (including depression, circling, cranial nerve deficits), reflecting the diffuse nature of the disease. Histologically, there was remarkably diffuse infiltration of the white and gray matter of the brain by small numbers of elongated neoplastic cells. Areas of greater cellularity formed grossly visible lesions in four cases. Anisocytosis and pleomorphism were greater in areas of higher cellularity. Other features of tumor growth included subpial accumulation, neuronal satellitosis, perivascular cuffing, and tropism for cranial nerve and brain stem nuclei. Neoplastic cells were negative on immunohistochemical stains for glial fibrillary acid protein (GFAP) and leukocyte markers, reflecting the uncertain histogenesis of these unusual neoplasms.     

Aortic and iliac thrombosis in six dogs

Six dogs had signs of pelvic limb weakness, pain and collapse as a result of occlusion of the distal aorta and/or the iliac arteries by a thrombus. Antemortem diagnosis was made on the basis of clinical signs, angiography and ultrasonography. Five dogs had concurrent disease that probably predisposed to thrombosis, including hyperadrenocorticism (three dogs), neoplasia and cardiac disease. Two dogs died shortly after the episode of thrombosis. Dogs that survived the acute episode received aspirin in an attempt to prevent thrombosis occurring again and all regained pelvic limb function. For dogs that survived longer than one month after the acute episode, repeat thrombosis was uncommon; hence the prognosis was related to the underlying disease. Aortic and iliac thrombosis in dogs is an uncommon condition that usually arises secondarily to a predisposing disease process; it carries a more favourable prognosis than feline aortic thromboembolism.     

Hyalinizing pancreatic adenocarcinoma in six dogs

Exocrine pancreatic carcinoma is a particularly malignant neoplasm of the dog. Clinical and pathologic findings of an unusual variant of exocrine pancreatic neoplasia termed hyalinizing pancreatic adenocarcinoma were evaluated in 6 dogs. On microscopic examination, neoplasms were composed of tubules and acini of epithelial cells, with bright eosinophilic granular apical cytoplasm. Tubular lumina and tumor stroma contained abundant hyaline material that resembled amyloid. The hyaline material was not congophilic, and tumor cells and hyaline material were immunohistochemically negative for amyloid A, immunoglobulin light chains (kappa and lambda), amylin (islet amyloid polypeptide), laminin, and alpha(1)-antitrypsin. Two patients survived longer than 15 months after diagnosis; one of these dogs was untreated and had grossly evident metastasis at the time of diagnosis. The deaths of the other 4 dogs occurred as a result of poor recovery after partial pancreatectomy or in association with other concurrent life-threatening conditions. Two dogs were diagnosed with panniculitis, a condition rarely associated with pancreatic disease. Further evaluation is needed to determine the composition and biologic significance of intratumor hyaline material. Studies that associate exocrine pancreatic carcinoma grade and histologic subtype with prognostic outcomes in the dog are warranted such that appropriate therapy can be elected.     

Body cavity lipomas in six dogs

Histologically confirmed lipomas were surgically removed from the thoracic or abdominal cavities of six dogs. Three dogs had a large intra-abdominal mass causing severe abdominal distension. Two dogs had a mass extending into the pelvic canal, compressing the colon and causing obstipation. One dog with an intrathoracic mass had a history of coughing and intermittent cyanosis. All dogs had complete resolution of signs after surgical resection of the tumour. Recurrence occurred in one dog with an abdominal lipoma, two years after the initial surgery. This recurrent lipoma was treated successfully by surgical resection.     

Congenital anorectal abnormalities in six dogs

Congenital anorectal abnormalities were diagnosed in three male and three female dogs. One dog had anal stenosis, three had a persistent anal membrane, and the other two had an imperforate anus associated with a rectovaginal fistula. Five of the dogs were treated surgically, and four of them which were followed up for periods ranging from one to five years continued to pass faeces normally.     

Porencephaly in dogs and cats: relationships between magnetic resonance imaging (MRI) features and hippocampal atrophy

Porencephaly is the congenital cerebral defect and a rare malformation and described few MRI reports in veterinary medicine. MRI features of porencephaly are recognized the coexistence with the unilateral/bilateral hippocampal atrophy, caused by the seizure symptoms in human medicine. We studied 2 dogs and 1 cat with congenital porencephaly to characterize the clinical signs and MRI, and to discuss the associated MRI with hippocampal atrophy. The main clinical sign was the seizure symptoms, and all had hippocampal atrophy at the lesion side or the larger defect side. There is association between hippocampal atrophy or the cyst volume and the severe of clinical signs, and it is suggested that porencephaly coexists with hippocampal atrophy as well as humans in this study.     

Pathology of bartonella endocarditis in six dogs

In a 5-year retrospective study of dogs presenting to the Veterinary Medical Teaching Hospital at the University of California, Davis, there were 31 histologic diagnoses of valvular endocarditis. By polymerase chain reaction (PCR) amplification of embedded valvular tissue, Bartonella organisms were exclusively associated with 6 out of 31 cases (19%). Confirmed Bartonella cases involved the aortic valve alone (five out of six) or in combination with the mitral valve (one of six). Microscopic features of Bartonella endocarditis were compared with valves from non-Bartonella endocarditis and with valvular change unrelated to infectious agents (endocardiosis). Features of Bartonella endocarditis included a combination of fibrosis, mineralization, endothelial proliferation, and neovascularization with variable inflammation. None of these features is specific; however, the combination is distinct both from endocarditis caused by culturable bacteria and from endocardiosis. Ultrastructural analyses revealed both extracellular and intraendothelial bacteria. Clinical history, serology, and PCR are currently necessary to establish an etiologic diagnosis of Bartonella endocarditis.     

Uveitis associated with poliosis and vitiligo in six dogs

Idiopathic panuveitis with retinal detachment was associated with facial poliosis, vitiligo, and alopecia in 6 dogs; 4 were adult males. Dermatohistologic examination of affected facial sites from all dogs revealed a lichenoid dermatitis and unusual histiocytic cells. Intensive topical and systemic corticosteroid and topical mydriatic/cycloplegic therapy was successful in controlling uveitis in all dogs for variable periods. Three dogs, monitored for 12, 30, and 46 months, retained useful vision despite infrequent recurrence of uveitis. One dog was lost for subsequent examination. Two dogs were euthanatized and necropsied. Ocular histologic examination of these dogs revealed extensive granulomatous iridocyclitis and choroiditis, with retinal detachment and lenticular degeneration.     

Presumed and confirmed striatocapsular brain infarctions in six dogs

OBJECTIVE: To describe the clinical and diagnostic features of the canine sensorimotor syndrome caused by striatocapsular brain infarctions (SCI). ANIMALS STUDIED: Six dogs with diagnostic imaging or postmortem evidence of SCI. PROCEDURES: Medical records of dogs with SCI were retrospectively reviewed and the signalment, history, clinical signs, antemortem clinicopathologic test results, diagnostic imaging findings, case outcomes, and pathologic findings recorded. RESULTS: All dogs had an acute onset of nonprogressive homonymous visual field deficits and contralateral general proprioceptive (GP) deficits. Contralateral hemiparesis and facial hypalgesia were noted in 5/6 dogs. CT scans were normal in 2/4 dogs, and revealed poorly defined hypoattenuating lesions in the subcortical white matter in two dogs. MRI exams were performed in 5/6 dogs and revealed unilateral, variably sized, striatocapsular lesions consistent with nonhemorrhagic infarctions. Diagnostic imaging (6/6) and postmortem examinations (2/6) suggested that SCI resulted from lesions in the vascular territories of the rostral choriodal (6/6) and lenticulostriate arteries (2/6). Diseases predisposing to infarction were not identified in 5/6 dogs. Improvements in mentation, behavior, proprioceptive deficits, and hemiparesis were seen in surviving dogs, but persistent, symptomatic sensory deficits were noted during the follow-up period. CONCLUSIONS: SCI should be considered as a differential diagnosis for dogs with acute onset, nonprogressive homonymous hemianopia, contralateral GP deficits or hemiparesis, and facial hypalgesia. MRI is the preferred modality for the antemortem imaging diagnosis of SCI. Although partial recovery occurred in all surviving dogs, visual and facial sensory disturbances persisted.     

Bluetongue virus-induced hydranencephaly in cattle

Direct inoculation of bluetongue virus into 125-day bovine fetuses resulted in development of hydranencephaly. The earliest lesions after virus inoculation were a severe necrotizing encephalitis, which was most prominent in the cerebrum, and an associated nonsuppurative meningitis. At birth, the brains of infected fetuses had thin-walled cerebral hemispheres, dilated lateral ventricles, and cerebral cysts. No gross lesions were observed in the brain stem or cerebellum. Two morphologically different lesions were present in the brain of a fetus sacrificed 20 days after virus inoculation. There were discrete foci of hemorrhagic cerebral necrosis that resembled infarcts and widespread microcavitations of the intermediate and subventricular zones. Changes consistent with vascular damage were present in the brains of fetuses sacrificed 12 and 20 days after virus inoculation. Calves with bluetongue virus-induced hydranencephaly would have poor viability, but they would not be expected to have any significance as virus reservoirs.     

Cutaneous plasmacytomas with amyloid in six dogs.

Cutaneous plasmacytomas associated with local deposition of amyloid were diagnosed by light microscopy in a series of six older dogs (mean age 10.7 years) consisting of two Cocker Spaniels, a Poodle, a Weimeraner, and two mixed-breed dogs. The neoplasms occurred on the digits (2 dogs), forelimb (2 dogs), lip (1 dog), and ear (1 dog). In most cases, groups of neoplastic plasma cells were widely separated by large homogeneous islands of amyloid. The neoplastic cells had characteristic plasmacytoid features, but the degree of pleomorphism varied greatly between different neoplasms. In four of the six tumors, the diagnosis of plasmacytoma was confirmed by the demonstration of a monoclonal plasma cell population using immunofluorescent staining for anti-canine immunoglobulins. In these tumors, the neoplastic cells reacted with only one class of immunoglobulins (IgG). The amyloid did not react with any of the reagents used. The suspicion that the amyloid was of immunoglobulin origin (primary amyloid) was supported by its retention of birefringence under polarized light after treatment with potassium permanganate and staining with Congo red.     

Assessment of balloon pulmonary valvuloplasty in six dogs

The effectiveness of balloon valvuloplasty was assessed, clinically and haemodynamically, in six dogs with moderate to severe pulmonic stenosis. The haemodynamic assessment was based on Doppler echocardiography, with colour flow mapping, in the conscious dog and by direct catheterisation in the anaesthetised dog, before and after balloon valve dilatation. Four of the six dogs were presented with exercise intolerance, of which two were in congestive heart failure. Balloon valvuloplasty resulted in improved exercise tolerance and resolution of congestive heart failure in these dogs. The average Doppler and catheter transvalvular pressure gradients were reduced to 43 per cent and 46 per cent of the preoperative gradient, respectively. The average pressure gradient obtained by catheter, in the anaesthetised dog, was 59 per cent of the pressure gradient obtained by spectral Doppler echocardiography in the conscious dog. Balloon valvuloplasty was considered successful in five out of the six dogs. Postoperative pulmonic regurgitation was not found to be a complication of balloon valvuloplasty.     

Pulmonary arteriopathy and idiopathic pulmonary arterial hypertension in six dogs

Pulmonary arteriopathy (PA) is the pathologic hallmark in human medicine of diffuse constrictive (medial and intimal remodeling) or multifocal complex (plexiform and dilatative lesions) arterial lesions, or both, that lead to irreversible obliteration of the arterial lumen. Clinically, PA leads to pulmonary arterial hypertension (PAH), of which idiopathic (IPAH) is one of the 5 subsets, and ultimately, to right-sided heart failure (RHF). Clinical and pathologic findings from 6 dogs with diagnosis of IPAH and PA were reviewed. These dogs were of various pure (5/6, 83%) and mixed (1/6, 17%) breeding, 5 months to 9 years (mean 5.2 years) old, and predominantly female (4/6, 67%) and reproductively intact (4/6, 67%). Doppler echocardiography (n = 5) indicated increased pulmonary arterial pressures during systole (70-135 mm Hg, mean 98 mm Hg) and diastole (35-80 mm Hg, mean 58 mm Hg). All 6 dogs had right ventricular pressure overload, right ventricular eccentric hypertrophy, and RHF. Histologic examination confirmed the clinical diagnosis of IPAH in all dogs, revealing PA characterized by 1 of the 4 main human histologic subsets: 1) isolated medial hypertrophy (1/6, 17%); 2) medial hypertrophy-intimal thickening without the plexiform lesion (1/6, 17%); 3) medial hypertrophy-intimal thickening concurrent with the plexiform lesion, which often was regionally clustered and situated near branching points of the respiratory artery, the poststenotic dilatation lesion, and vasculitis (4/6, 66%); and 4) isolated arteritis (1/6, 17%). Ancillary lesions similar to those in humans also complicated the PA (5/6, 83%). The complex lesions and ancillary exudative alveolitis seemed to be important indicators of severe, likely rapidly progressive and fatal, IPAH.     

Arthroscopic biceps tenodesis: technique and results in six dogs

Biceps tenodesis was performed using an arthroscopic-assisted technique on six dogs diagnosed with chronic bicipital tendon pathology. The technique was performed using two different fixation methods (i.e., cannulated interference screw, cannulated screw and tissue washer). All six dogs had successful outcomes in terms of return to full function at a mean follow-up time of 11.7 months after surgery. Arthroscopic biceps tenodesis is a feasible option for surgical management of biceps tendon pathology, and it may have advantages over open tenodesis and open or arthroscopic tenotomy. Further study is needed before definitive recommendations regarding indications, complications, and prognosis associated with arthroscopic biceps tenodesis can be made.     

Generalized Microsporum canis dermatophytosis in six Yorkshire terrier dogs

Six Yorkshire terrier dogs with generalized, chronic dermatophytosis caused by Microsporum canis were seen over a 3-year period. Specific tests showed that they also had concurrent leishmaniosis (four cases), leishmaniosis and ehrlichiosis (one case) or diabetes mellitus (one case). Although specific therapy for these infectious diseases was instituted and the dogs were treated systemically and topically with appropriate antifungal drugs, only partial clinical resolution of the dermatophytosis was achieved. M. canis infection resolved in the dog with diabetes mellitus after stabilizing the diabetes mellitus. Although immunological studies were not performed in these cases, it is theorized that the immune disregulation caused by leishmaniosis, ehrlichiosis or diabetes mellitus may have favoured generalization of the infection and prevented favourable responses to appropriate treatment of the M. canis infection.     

Organic diseases mimicking acral lick dermatitis in six dogs

Acral lick dermatitis ("lick granuloma") in dogs is often thought to have a behavioral etiology. However, other diseases may cause lesions on the distal legs, mimicking acral lick dermatitis. In this report, six dogs were presented with acral lick dermatitis-like lesions from different underlying causes-namely lymphoma, an orthopedic pin, deep pyoderma, mast cell tumor, leishmaniasis, and (presumptive) sporotrichosis.     

Soft palate hypoplasia and concurrent middle ear pathology in six dogs

This retrospective clinical study describes six consecutive cases of bilateral hypoplasia/malformation of the soft palate in dogs in which associated middle ear disease was investigated and the palatine defects were surgical repaired. Radiographic abnormalities of the tympanic bullae were seen in both ears of all six dogs (12 of 12). Negative tympanocentesis findings were recorded in 11 of 12 ears. A purulent otitis media was confirmed in one ear of one dog, and loss of hearing was also demonstrated in this ear on brainstem auditory evoked response hearing assessment. There was no evidence of hearing loss on brainstem auditory evoked response in any of the remaining ears. Surgical repair of the soft palate defect was undertaken in all six dogs. Long-term assessment of the clinical outcome was considered excellent in five dogs and reasonable in one dog (mean 18 months, range seven to 27 months). It would appear that surgical intervention for the treatment of bilateral palatine malformation/hypoplasia may be associated with a better prognosis than reported previously. The lack of middle ear effusion and associated hearing impairment suggests that the underlying aetiology of middle ear pathology in dogs suffering from congenital palatine defects may be different from that observed in human beings. The true nature of the radiographic bullae changes seen in dogs with soft palate defects remains unclear.     

Surgical treatment of hypospadias. Techniques and results in six dogs

Various types of hypospadias and methods of surgical treatment of this anomaly in 6 dogs was described in this article. Methods of surgical treatment were set up individually for each case and depended on the type of hypospadias and coexisting anomalies. Shortening of the penis was performed in two dogs, amputation in three cases and an urethral reconstruction in one patient. Castration was performed in three cases. Persistent frenulum of the prepuce was found in two dogs. Additionally three patients were submitted to the plastic surgery of the prepuce anomalies. In one dog, the loose and free falling part of the prepuce was suspended and attached to the abdominal integument according to the original own method. In all dogs, uncomplicated wound healing was observed. Surgical procedures resulted in improved cosmesis with reducing clinical signs of hypospadias and other coexistent anomalies.