Disseminated Neospora caninum infection in a dog with severe colitis.

A 12-y-old spayed female Schipperke dog with a previous diagnosis of inflammatory bowel disease was presented with a 2-mo history of severe colitis. The patient's condition progressed to hepatopathy, pneumonia, and dermatitis following management with prednisolone and dexamethasone sodium phosphate. Colonic biopsies identified severe necrosuppurative colitis with free and intracellular parasitic zoites. Postmortem examination confirmed extensive chronic-active ulcerative colitis, severe acute necrotizing hepatitis and splenitis, interstitial pneumonia, ulcerative dermatitis, myelitis (bone marrow), and mild meningoencephalitis with variable numbers of intracellular and extracellular protozoal zoites. PCR on samples of fresh colon was positive for Neospora caninum. Immunohistochemistry identified N. caninum tachyzoites in sections of colon, and a single tissue cyst in sections of brain. Administration of immunosuppressive drugs may have allowed systemic dissemination of Neospora from the intestinal tract.

Evaluation of magnetic resonance imaging for the differentiation of inflammatory, neoplastic, and vascular intradural spinal cord diseases in the dog.

Magnetic resonance imaging (MRI) is a common test for dogs with suspected intradural spinal cord lesions, however studies on diagnostic performance for this test are lacking. Objectives of this multi-institutional, retrospective, case-control study were to estimate sensitivity and specificity of MRI for (1) distinguishing between histopathologically confirmed intradural spinal cord disease versus degenerative myelopathy in dogs, (2) categorizing intradural spinal cord diseases as neoplastic, inflammatory, or vascular; and (3) determining tumor type within the etiologic category of neoplasia. Additional aims were to (1) determine whether knowledge of clinical data affects sensitivity and specificity of MRI diagnoses; and (2) report interrater agreement for MRI classification of intradural spinal lesions. Cases were recruited from participating hospital databases over a 7-year period. Three reviewers independently evaluated each MRI study prior to and after provision of clinical information. A total of 87 cases were sampled (17 degenerative myelopathy, 53 neoplasia, nine inflammatory, and eight vascular). Magnetic resonance imaging had excellent (>97.6%) sensitivity for diagnosis of intradural spinal cord lesions but specificity varied before and after provision of clinical data (68.6% vs. 82.4%, P = 0.023). Magnetic resonance imaging had good sensitivity (86.8%) and moderate specificity (64.7-72.5%) for diagnosing neoplasia. Sensitivity was lower for classifying inflammatory lesions but improved with provision of clinical data (48.1% vs. 81.5%, P = 0.015). Magnetic resonance imaging was insensitive for diagnosing vascular lesions (25.0%). Interrater agreement was very good for correctly diagnosing dogs with intradural lesions (ĸ = 0.882-0.833), and good (ĸ = 0.726-0.671) for diagnosing dogs with neoplasia.

SUSCEPTIBILITY ARTIFACTS ON T2*-WEIGHTED MAGNETIC RESONANCE IMAGING OF THE CANINE AND FELINE SPINE.

The T2*-weighted gradient recalled echo sequence is a sensitive means to detect blood degradation products. While not a routine sequence in magnetic resonance imaging of the spine in small animals, it can provide additional valuable information in select cases. The goal of this retrospective, cross-sectional study was to describe findings when acquiring this sequence during magnetic resonance imaging examination of the spine in small animals. The University of Tennessee's veterinary radiology database was searched for dogs and cats that underwent magnetic resonance imaging for suspect spinal disease in which a T2*-weighted gradient recalled echo sequence was acquired and susceptibility artifact was identified. The following information was recorded: signalment, clinical signs, location and appearance of susceptibility artifact, and final diagnosis. Thirty-nine cases were included in the study. Extradural susceptibility artifacts were observed in cases of intervertebral disc herniation with or without associated hemorrhage (n = 28), extradural hemorrhage associated with spinal trauma (n = 2), hemophilia (n = 1), and in a cystic extradural mass (n = 1). Remaining lesions displaying susceptibility artifact were intramedullary and included presumptive acute noncompressive nucleus pulposus extrusion (n = 2), hematoma (n = 1), hemangiosarcoma metastasis (n = 1), intramedullary disc extrusion (n = 1), presumptive meningomyelitis (n = 1), and a mass of undetermined etiology (n = 1). Inclusion of a T2*-weighted gradient recalled echo sequence may be helpful in spinal magnetic resonance imaging when standard imaging sequences are ambiguous or intramedullary lesions are observed.

Neurotropic T-cell-rich B-cell lymphoma in a 14-year-old Morgan gelding.

A 14-year-old Morgan gelding was presented for progressive weakness and muscle atrophy. The horse was initially diagnosed with equine protozoal myelitis based on history, physical examination, and laboratory diagnostics. Despite therapy, the horse declined clinically and was euthanized. Necropsy revealed a rare form of neurotropic lymphoma, described in this report.

Lymphome de cellules-B riches en cellules-T neurotropes chez un hongre Morgan âgé de 14 ans. Un hongre Morgan âgé de 14 ans a été présenté pour une faiblesse progressive et une atrophie musculaire. On a d'abord diagnostiqué la myélite protozoaire équine chez le cheval en se basant sur l'anamnèse, l'examen physique et le diagnostic en laboratoire. Malgré la thérapie, l'état clinique du cheval s'est détérioré et il a été euthanasié. La nécropsie a révélé une forme rare de lymphome neutropique, qui est décrite dans ce rapport.(Traduit par Isabelle Vallières).

An unusual case of spinal cord restricted mycobacteriosis in a European mink.

Granulomatous myelitis due to infection with Mycobacterium avium was diagnosed in a 4-year-old male neutered European mink (Mustela lutreola). The causative agent was detected by an acid-fast stain and further characterized by polymerase chain reaction and DNA sequencing of the PCR product. A thorough histological evaluation of the remaining organs revealed no granulomatous lesions or detectable acid-fast organisms. Although minks are generally highly susceptible for mycobacteria, localised infections, especially of the central nervous system, are unusual and may represent an atypical chronic form of the disease.

Parasite meningomyelitis in cats in Uruguay / Meningomielites parasitária em gatos no Uruguai

Two outbreaks of progressive hind limb paresis in cats (Felis catus) caused by parasitic meningomyelitis in Uruguay are reported. The case studies occurred in 2008 and 2009 respectively, in the rural areas of Fray Bentos (33º 07' 40.39" S) and were characterized by hindquarter paralysis. This paralysis was progressive and had a chronic progression of approximately 12 months until the death or euthanasia of the animals. Clinical symptoms started with ataxia of the hindquarters with lateral side-to-side swaying and culminated in total paralysis. Two animals were sent for necropsy in 2009. The main histopathological findings were severe myelitis in the lumbar spinal cord with perivascular cuffing and white matter necrosis, severe nonsuppurative meningitis with thrombi in subarachnoid blood vessels, and intravascular presence of multiple adult parasites. From the morphological characteristics of the parasites and location in the leptomeninges, the parasite was identified as the nematode Gurltia paralysans.

São relatados dois surtos de paralisia progressiva dos membros posteriores em gatos (Felis catus), causada por meningomielite parasitária no Uruguai. Os estudos de casos ocorreram entre os anos 2008 e 2009, respectivamente, nas zonas rurais de Fray Bentos (33º 07' 40,39" S) e foram caracterizados por paralisia dos membros posteriores. Esta paralisia era progressiva e tinha evolução crônica de aproximadamente 12 meses, até que os animais vinham a óbito ou eram eutanasiados. Os sintomas clínicos começaram com ataxia dos membros posteriores, com movimentos laterais, terminado em paralisia total. Em 2009, dois animais foram encaminhados para necropsia. Os achados histopatológicos foram caracterizados por severa mielite na medula espinhal lombar com manguitos perivasculares linfocitarios e necrose da substância branca, severa meningite não supurativa com trombos nos vasos sanguíneos subaracnóideos, e presença intravascular de múltiplos parasitos adultos. De acordo com as características morfológicas dos parasitos e localização nas leptomeninges, este foi identificado como um nematóide da espécie Gurltia paralysans.

The pathogenesis and treatment of acute spinal cord injuries in dogs.

Mechanical damage to the spinal cord initiates a secondary injury cascade that results in ischemia, disturbances in ion concentrations, excitotoxicity, production of reactive oxygen species, inflammation, and apoptosis. Over weeks to months a glial scar forms, and scarring can result in the development of syringomyelia. In the early phase of the disease, treatment should focus on maintaining systemic blood pressure and oxygenation, decompression of the spinal cord, and stabilization, if indicated. There are currently no proven neuroprotective drug therapies for limiting secondary damage, but blinded clinical trials are underway. Transplantation with olfactory ensheathing cells and mesenchymal stem cells show promise, as do potassium channel antagonists. Canine clinical trials of these therapies are ongoing.

Feline spinal cord diseases.

The objective of this article is to review the recent literature that reports on the most common diseases affecting the spinal cord of cats, and to draw some general conclusions that will be useful to formulate diagnosis and prognosis for feline spinal patients. The most common types of feline spinal cord diseases documented were inflammatory/infectious diseases, and feline infectious peritonitis was the most common disease, representing approximately 50% of all feline myelitis. Neoplasms were documented in approximately 25% of cases; lymphosarcoma was the most common tumor affecting the spinal cord of cats, with reported prevalence between 28% and 40%. Cats diagnosed with spinal lymphosarcoma were significantly younger (median age 4 years) than cats with other spinal cord tumors (median age 10 years). Cats with clinical signs of intervertebral disc disease had a median age of 8 years, and 67% had Hansen type I disc protrusions. The most commonly affected intervertebral disc was at the L4 to L5 intervertebral disc space. Fibrocartilaginous embolism-affected older cats (median age 10 years), seemed to predominate in the cervicothoracic intumescence, and clinical signs were markedly lateralized, especially when the cervical region was affected.

Myelitis due to reactivated spinal toxoplasmosis in a cat.

The diagnosis, management, and subsequent post-mortem confirmation of a case of suspected reactivated spinal toxoplasmosis in a 10-year-old female neutered Cornish Rex are described. While an ante-mortem diagnosis of toxoplasmosis was considered possible based on the neuroanatomical diagnosis of central nervous system (CNS) disease primarily involving spinal cord segment C6-T2 and the progressive elimination of other potential causes, Toxoplasma gondii antibody titres were consistent with previous exposure rather than active infection. A poor response to appropriate therapy did not support a diagnosis of toxoplasmosis. A post-mortem morphological diagnosis of marked segmental non-suppurative myelitis and necrosis, and an aetiological diagnosis of toxoplasmosis were made. The clinical and pathological findings are supportive of CNS inflammation due to reactivation of latent tissue T gondii cysts.

Verminous myelitis in a pit bull puppy.

A 10-week-old, male pit bull dog presented to the referring veterinarian with hind limb paresis and epaxial muscle atrophy. No spinal lesions were identified at gross necropsy; however, histologically there was marked granulomatous myelitis in the spinal cord between T13 and L2 with occasional, intralesional nematode larvae. Based on morphologic characteristics, the nematode larvae were identified as Strongyloides spp., possibly Strongyloides stercoralis.

Meningomyelitis in dogs: a retrospective review of 28 cases (1999 to 2007).

OBJECTIVES: To characterise dogs with meningomyelitis and to compare signalment, body temperature and vaccination status to a representative control group. METHODS: Dogs with meningomyelitis were identified retrospectively. Signalment, history, vaccination status, body temperature, severity of neurological dysfunction (modified Frankel score), diagnostic procedures, aetiology, survival to discharge and long-term survival were analysed. RESULTS: Affected dogs were younger (P<0.05) and more frequently hound or toy breeds (P<0.05) when compared with controls. Hound and toy breed dogs less than or equal to three years of age had a 13 times higher odds of meningomyelitis compared with other breeds (P<0.001). General proprioceptive ataxia, limb paresis and paraspinal hyperaesthesia were the most common clinical signs. Meningomyelitis of unknown aetiology and granulomatous meningomyelitis were the most common diagnoses. The median time to death or continued follow-up in dogs alive at discharge was 213 days. Meningomyelitis resulted in death or euthanasia in 14 of 28 dogs. Clinical signs improved or resolved in seven of 28 dogs. CLINICAL SIGNIFICANCE: Meningomyelitis is a differential diagnosis for dogs with clinical signs of myelopathy. Young dogs and toy or hound breeds seem to be predisposed. Clinical signs of meningomyelitis improve or resolve in some dogs.

Magnetic resonance imaging characteristics of ascending hemorrhagic myelomalacia in a dog.

A 4-year-old neutered female terrier-cross was evaluated for an acute onset of paraplegia. Utilizing magnetic resonance (MR) imaging, the cause of the neurologic deficits was determined to be a lumbar intervertebral disc extrusion. The MR study additionally demonstrated parenchymal hyperintensity on T2-weighted images and similarly located diffuse hypointensity on gradient echo images, cranial and caudal to the compressive extradural lesion. Hemorrhagic myelomalacia was suspected based on these MR characteristics, which was subsequently confirmed surgically and histopathologically.

Myasthenia gravis and hypothyroidism in a dog with meningomyelitis.

A 12-year-old, spayed female miniature poodle was evaluated because of a 4-day history of paraparesis, dysuria, and tenesmus. Neurological assessment suggested peripheral nervous system dysfunction, predominantly pelvic limb weakness with a possible concurrent sixth lumbar (L(6)) to second sacral (S(2)) myelopathy. Further studies supported the diagnoses of myasthenia gravis, hypothyroidism, and meningomyelitis. To the authors' knowledge, this is the first reported case of concurrent myasthenia gravis and meningomyelitis in the dog. It was unclear whether the identified conditions evolved from a shared etiopathogenesis or were merely coincidental.

Dermoid sinus at the lumbosacral junction in an English springer spaniel.

A dermoid sinus was identified in a springer spaniel that presented with hindlimb neurological deficits. The sinus was continuous with the dura mater at the level of the lumbosacral junction. The presence of hair and debris adjacent to neural tissue had elicited a myelitis. A dorsal laminectomy was required to allow complete surgical resection of the sinus. The dog's neurological status improved after treatment and this improvement was maintained over a five-month follow-up period.

Spinal cord swelling as a myelographic indicator of prognosis: a retrospective study in dogs with intervertebral disc disease and loss of deep pain perception.

The association of myelographic spinal cord swelling with neurological outcome was examined in 46 dogs with intervertebral disc disease and absence of deep pain perception (DPP). Spinal cord swelling was measured by calculating a ratio of the length of the loss of the myelographic dye column to the length of the second lumbar vertebra (L2). A positive neurological outcome was defined as return of voluntary motor function. A cut-off value for swelling:L2 of 5.0 was established by the creation of a receiver operator characteristic curve. Using a swelling:L2 ratio of 5.0 as a cutoff for indication of neurological recovery yielded a sensitivity of 74% and a specificity of 61%. Overall neurological recovery rate was 43%. Dogs with spinal cord swelling:L2 ratios less than 5.0 had a recovery rate of 61%, whereas dogs with a ratio greater than or equal to 5.0 had a recovery rate of 26%. Evaluation of these data by chi square analysis confirmed that a ratio less than 5.0 was associated with a positive outcome, and a ratio greater than or equal to 5.0 was associated with a negative outcome, (P < .05). Although other factors, such as duration of neurological signs, affect neurological outcome in dogs with no DPP, evaluation of myelographic spinal cord swelling can assist in establishing a prognosis.

Equine protozoal myelitis in Panamanian horses and isolation of Sarcocystis neurona.

Schizonts of Sarcocystis neurona were identified microscopically in hematoxylin-eosin-stained spinal cord sections from 2 native Panamanian horses that exhibited clinical signs of equine protozoal myelitis (EPM). Spinal cord homogenate from a third Panamanian horse with EPM was inoculated onto monolayers of cultured bovine monocytes (M617). Intracytoplasmic schizonts containing merozoites arranged in rosette forms surrounding a central residual body first were observed 13 wk postinoculation. Parasites divided by endopolygeny and lacked rhoptries. Schizonts from each horse reacted with Sarcocystis cruzi antiserum in an immunohistochemical test.

Myelitis in a cat infected with Toxoplasma gondii and feline immunodeficiency virus.

Severe necrotizing myelitis secondary to localization and reactivation of Toxoplasma gondii within the spinal cord of a domestic shorthair cat was diagnosed by use of light and electron microscopy and immunohistochemistry. The cat also was infected with feline immunodeficiency virus. This case may have useful comparative features to T gondii infections in human patients with acquired immunodeficiency syndrome.

Neospora caninum-like protozoon associated with fatal myelitis in newborn calves.

Neospora caninum-like organisms were found in histologic sections of spinal cord of 4 paralyzed calves as reported by Parish et al. (1987). Tachyzoites divided by endodyogeny. Tissue cysts were up to 62 microns wide and the cyst wall was up to 2.5 microns thick. The organism in calves was structurally distinct from Toxoplasma gondii and Sarcocystis species and reacted positively with anti-N. caninum serum in an immunoperoxidase test.