Steroid-responsive myelitis in dogs - comparison with steroid-responsive meningitis-arteritis

Background: Myelitis is the inflammation of the spinal cord parenchyma alone, whereas meningitis is the inflammation of the meninges. Steroid-responsive meningitis-arteritis (SRMA) is a meningomyelitis in which the major lesions involve the meninges, not the spinal cord parenchyma, and respond well to glucocorticoid treatment. However, myelitis in dogs has rarely been reported, and myelitis with a good response to glucocorticoid treatment without relapse has not been reported. This report describes 5 cases of steroid-responsive myelitis (SRM) in dogs. Cases: Case 1. A 8-year-old intact female Cocker Spaniel presented with progressive nonambulatory paraplegia. Whole spinal parenchymal lesions were identified using magnetic resonance imaging (MRI) scan. Mononuclear pleocytosis with increased total protein levels was the only abnormal finding on cerebrospinal fluid (CSF) analysis. Prednisolone (PDS) was administered followed by dose tapering according to therapeutic response. Cyclosporine was administered until the termination of PDS. Since then, no recurrence of neurological symptoms has been observed. Follow-up MRI and CSF analysis revealed resolution of previously observed abnormal findings. Case 2. A 2-year-old intact female Maltese presented with non-progressive paraparesis. A spinal parenchymal lesion in the lumbosacral region was observed on MRI. PDS was administered and slowly tapered at approximately 3-week intervals. No recurrence of neurological symptoms was observed after the treatment. Case 3. A 6-year-old intact female Miniature Pinscher presented with neck pain, along with leukocytosis and neutrophilia. Cervical spinal parenchyma lesions were revealed through MRI. Increased total protein concentration with mixed cell pleocytosis was observed on CSF analysis. Immunomodulatory therapy, similar to that in case 2, was initiated. A second MRI and CSF analysis revealed an improvement in the previously observed abnormalities. Case 4. A 2-year-old, intact female Toy Poodle presented with acute paraplegia and back pain. Lesions were observed in the spinal parenchyma at the T12-L3 levels on MRI. The treatment was conducted as in case 2. During treatment, neurological symptoms, including paraplegia and back pain, were not observed. Follow-up MRI revealed improvement in the spinal lesion. Case 5. A 6-month-old, castrated male Standard Poodle presented with progressive paraparesis. On MRI, lesions were observed in the T11-T13 regions. Immunomodulation therapy, similar to that in case 2, was initiated. No recurrence of neurological symptoms was observed after treatment initiation Discussion: SRM is similar to SRMA in terms of good steroid-responsiveness and noninfectious inflammation etiology; however, it does not exactly satisfy the diagnostic criteria for SRMA, nor does it progress similarly. The characteristics of SRM that do not satisfy the diagnostic criteria of SRMA include the absence of fever, C-reactive protein elevation, hyperglobulinemia, and relapse, and the presence of spinal parenchymal lesions without parenchymal or meningeal enhancement on MRI. It is also a seemingly different from spinal cord-only meningoencephalomyelitis of unknown origin due to its better treatment response and prognosis. However, the dogs in the present report with SRM satisfied the diagnostic criteria for transverse myelitis in human patients. Therefore, SRM, including good steroid responsiveness and good prognosis without relapse, may represent a novel type of meningomyelitis.

Recurrent thyroid carcinoma in a dog - diagnosis by 18F-fluorodeoxyglucose positron emission tomography

Background: Thyroid tumor is a common endocrine tumor that accounts for up to 3.8% of all tumors in dogs. Most of them are malignant and usually nonfunctional in dogs. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is an imaging modality that detects intracellular accumulation of radioactive deoxyglucose administered in the body and is used in combination with computed tomography to provide functional information with exact anatomical localization. It is used in human medicine to detect residual or recurrent head and neck neoplasm after treatments, such as surgical resection. This report describes the first case of diagnosing recurrent thyroid carcinoma (TC) through FDG-PET in a dog. Case: A 9-year-old castrated male Maltese dog presented with a palpable mobile mass in the right ventral cervical region. Radiography and ultrasonography (US) showed a radiopaque mass adjacent to the trachea, and the right thyroid gland was enlarged on computed tomography. The surgically excised mass was encapsulated and measured to be 2.3 × 1.0 × 3.4 cm (width x length x height) in size. Histopathologically, the mass was diagnosed as differentiated follicular TC, and gross and vascular invasions were observed. To prevent recurrence, postoperative carboplatin chemotherapy was performed for 5 months. Two months after completion of chemotherapy, a nodule of approximately 7 mm in diameter was detected in the thyroidectomy bed by US. FDG-PET scanning was performed as an effective means of evaluating the malignancy, local recurrence, and metastasis of differentiated follicular TC. The nodule had the dimensions of 2.8 × 5.9 × 8.6 mm, a maximum standardized uptake value (SUV) of 8.49, and a mean SUV of 5.6. The results of FDG-PET suggested the recurrence of TC; therefore, the second chemotherapy protocol using toceranib was applied for 16 months. After initiation of the 2nd chemotherapy, follow-up examinations were conducted approximately every 4 months. On the 134th day, although the nodule was not palpated, its size was observed to have increased to 5.0 × 3.8 × 13.6 mm on cervical US on the 232nd day, showing heterogeneous and hypoechoic parenchyma. On the 405th day, the tumor was enlarged to a size of 13.4 × 12.9 × 22 mm and identified as a lobular, amorphous shape, and its heterogeneity was increased. Moreover, 2 pulmonary nodules with well-defined margins were found on radiography in the left caudal lung lobe (9 × 10 mm and 12 × 12 mm [width × length]); thus, lung metastasis was suspected. On the 536th day, anorexia and lethargy occurred, and the dog was lost to follow-up. Discussion: In the present case, local recurrence of TC was suspected based on cervical US. Although US was useful as a screening tool, additional examinations were necessary for evaluating local invasiveness, malignancy, and nodal/distant metastasis. FDG-PET can detect recurrence at an early stage because it can sense increased tumor metabolism through physiologic absorption of FDG, even before the beginning of anatomic change in the lesion. Therefore, FDG-PET can assist in treatment planning and provide better prognosis. In humans, focal FDG uptake and a high maximum SUV in the thyroid gland on FDG-PET were associated with a higher risk of cancer. Because there was no evidence of neoplasia except the thyroid lesion during the FDG-PET examination, the tumor showed an increasingly malignant pattern of the thyroid gland on US during the follow-up period, and the metastatic pulmonary nodules were identified on the 650th day after the thyroidectomy, the present case was diagnosed as recurrent TC. This report describes the use of FDG-PET for diagnosing local recurrence of TC, pointing to FDG-PET as a potential strategy to evaluate loco-regional recurrence and distant metastasis of TC.

Cystitis in a bitch with chronic kidney disease caused by multidrug-resistant Escherichia coli

Background: In dogs with bacterial cystitis that is resistant to multiple antibiotics, resulting from repeated infections andantimicrobial administration, especially if the dog has impaired renal function and the induction of systemic side effectsby intravenous or oral administration is a concern, intravesical instillation of antibiotics might represent an alternativetreatment option. In human and veterinary medicine, a number of studies showed intravesical instillation of antibiotics iseffective for the therapy multidrug-resistant bacterial urinary tract infection (UTI). This report firstly illustrates successfulintravesical meropenem treatment of a UTI caused by multidrug-resistant Escherichia coli with no systemic side effectsin dog with chronic kidney disease (CKD).Case: A 15-year-old spayed female Maltese was presented with recurrent bacterial cystitis. The risk factors for the recurrent UTI were spinal cord injury and CKD which had been managed for 1 year. Ultrasound-guided cystocentesis wasperformed to obtain a urine sample for urinalysis, bacteriologic culture, and antibiotic susceptibility testing. Bacterialcystitis caused by multidrug-resistant Escherichia coli was diagnosed on the basis of bacterial culture, and antimicrobialsusceptibility testing. Because the dog had CKD, reducing the clearance of meropenem, intravesical instillation of antibiotics was initiated. The intravesical instillation process consisted of the emptying of the urinary bladder, infusion of adiluted meropenem solution (8.5 mg/kg diluted in 20 mL of saline solution) into the bladder through a urethral catheter,and retention of the meropenem solution in the bladder for 1 h, and its removal. The procedure was repeated every 8 h. Onday 8 of the intravesical instillation therapy, bactereologic culture yielded a growth of E. coli (50,000 CFUs/mL), whichwas less than previously obtained. the concentration of the meropenem solution...(AU)

Cystitis in a bitch with chronic kidney disease caused by multidrug-resistant Escherichia coli

Background: In dogs with bacterial cystitis that is resistant to multiple antibiotics, resulting from repeated infections andantimicrobial administration, especially if the dog has impaired renal function and the induction of systemic side effectsby intravenous or oral administration is a concern, intravesical instillation of antibiotics might represent an alternativetreatment option. In human and veterinary medicine, a number of studies showed intravesical instillation of antibiotics iseffective for the therapy multidrug-resistant bacterial urinary tract infection (UTI). This report firstly illustrates successfulintravesical meropenem treatment of a UTI caused by multidrug-resistant Escherichia coli with no systemic side effectsin dog with chronic kidney disease (CKD).Case: A 15-year-old spayed female Maltese was presented with recurrent bacterial cystitis. The risk factors for the recurrent UTI were spinal cord injury and CKD which had been managed for 1 year. Ultrasound-guided cystocentesis wasperformed to obtain a urine sample for urinalysis, bacteriologic culture, and antibiotic susceptibility testing. Bacterialcystitis caused by multidrug-resistant Escherichia coli was diagnosed on the basis of bacterial culture, and antimicrobialsusceptibility testing. Because the dog had CKD, reducing the clearance of meropenem, intravesical instillation of antibiotics was initiated. The intravesical instillation process consisted of the emptying of the urinary bladder, infusion of adiluted meropenem solution (8.5 mg/kg diluted in 20 mL of saline solution) into the bladder through a urethral catheter,and retention of the meropenem solution in the bladder for 1 h, and its removal. The procedure was repeated every 8 h. Onday 8 of the intravesical instillation therapy, bactereologic culture yielded a growth of E. coli (50,000 CFUs/mL), whichwas less than previously obtained. the concentration of the meropenem solution...

Treatment of discoid lupus erythematosus in a dog with human intravenous immunoglobulin

Background: Discoid lupus erythematosus (DLE) is a common canine autoimmune skin disease, in which systemic manifestations are absent. Skin Lesions are usually present on the nasal planum, and characterised by erythema, depigmentation, erosion, ulceration, and crusting. The diagnosis is based on histopathological results, which should demonstrate lymphoplasmacytic lichenoid-interface dermatitis. Human intravenous immunoglobulin (hIVIg) has been used in veterinary medicine to treat cutaneous diseases including erythema multiforme, PF, and severe adverse cutaneous drug reactions. In human medicine, it has been effective to treat DLE. This report firstly describes the clinical response to hIVIg in a dog with DLE resistant to common immunosuppressive drugs. Case: A 5-year-old, intact female Shih Tzu presented with a 1-month history of slowly progressive black crusting on the nasal planum, chin, and claw. Based on the results of a dermatologic examination, superficial pyoderma was diagnosed. The skin lesions did not improve during and after anti-infective treatment. After removing the crusts, a skin biopsy was obtained from the muzzle. Histopathology of lesional skin biopsy specimens revealed lymphoplasmacytic interface dermatitis at the dermoepidermal junction. Microscopic examination also revealed vacuolar changes and pigmentary incontinence of the basal layer as a lichenoid tissue reaction. No mites or fungi were detected on the skin section. The absence of acantholytic cells excluded pemphigus foliaceus, which is also characterised by the lesions of the nasal planum. Based on the distribution of the lesions, histopathology and exclusion of other dermatoses, the dog was diagnosed with DLE. The skin lesions temporarily improved after treatment with prednisolone (2 mg/kg PO q12h). However, after tapering the dose of prednisolone, new black crusts developed on the nasal planum and claw. Although the dog was successively treated with other immunosuppressive drugs, including azathioprine, cyclosporin with dexamethasone, and mycophenolate mofetil, black crusts still remained. Due to the low efficacy of these immunosuppressive drugs, hIVIg was administered at 0.5 g/kg once daily for 4 days, for a total dose of 2 g/kg. During hIVIg administration, the crusted lesions gradually improved. After the hIVIg administration, the dog was treated with prednisolone (1 mg/kg PO q12h). The lesions were almost in complete remission at 21 days after an additional application of prednisolone. The skin lesions did not recur, and the treatment was eventually discontinued after 6 weeks of additional prednisolone application. Discussion: The standard treatment of canine DLE includes glucocorticoids, and second-line immunosuppressive drugs, such as azathioprine and cyclosporine, are usually added in cases resistant to steroids. This case suggests that hIVIg may be beneficial as an adjunctive treatment option for canine DLE, especially when the application of standard immunosuppressive drugs is limited due to adverse effects or low efficacy. There is evidence from several studies that the steroid-sparing effect of hIVIg is significant in human patients. In the current case, the effective dose of prednisolone was reduced to 2 mg/kg/day after hIVIg administration, and prednisolone therapy was finally discontinued completely. The hIVIg appears to lower the daily steroid dose requirement in this dog.