Evaluation of a treatment protocol in dogs with intraspinal spirocercosis.

OBJECTIVE: To evaluate the efficiency and safety of a doramectin-based treatment protocol in dogs affected by intraspinal spirocercosis (Spirocerca lupi). ANIMALS: Client-owned dogs that were admitted to a veterinary hospital during 2021 to 2022 with acute onset of neurological signs and diagnosed with intraspinal spirocercosis. All dogs underwent complete neurological evaluation, CSF analysis, PCR confirmation of CNS S lupi infection, and follow-up evaluation of at least 6 months. PROCEDURES: Upon diagnosis, dogs were treated with doramectin at a dose of 400 µg/kg, SC, q 24 h for 3 consecutive days, followed by the same dose once a week for 6 weeks. Prednisone was administered at a dose of 1 mg/kg, PO, q 24 h and tapered every 3 days. Antimicrobial clindamycin was administered at a dose of 12.5 mg/kg, PO, q 12 h for 7 days to reduce the risk of secondary spinal cord infection. Short- and long-term outcomes (1 week to 56 months) were recorded. RESULTS: 8 dogs fulfilled the inclusion criteria, 7 of which presented with neurological deficits and 1 with cervical pain. Initiation of treatment was associated with stopping the deterioration in 7 of 8 dogs. Seven dogs improved and 6 recovered ambulation. One dog was euthanized due to lack of improvement. Six of the recovered dogs were still ataxic on the last follow-up examination at 6 to 56 months. No adverse effects of the drug were noted. CLINICAL RELEVANCE: Frequent administration of doramectin was found to be safe and effective in preventing neurological deterioration in dogs with intraspinal spirocercosis.

Spinal cord protothecosis causing paraparesis in a dog.

Protothecosis, an infectious disease caused by the green algae Prototheca zopfii and P. wickerhamii, occurs sporadically in domestic animals and humans. Diagnosis of CNS protothecosis is based on neurologic signs that indicate multifocal nervous system lesions and that follow a period of chronic diarrhea and weight loss, cytologic observation of algae in fecal culture or histopathology, and detection of the agent by PCR assay of infected tissues. Here, we report a case of a paraparetic dog with CNS protothecosis that was diagnosed definitively antemortem using CSF cytology, PCR, and DNA sequencing. A 4-y-old mixed-breed dog developed progressive paraparesis that followed weight loss and diarrhea. CSF analysis revealed marked eosinophilic pleocytosis. Prototheca organisms were detected by microscopic examination of the CSF, and speciated as P. zopfii by CSF PCR and DNA sequencing. Other possible causes of paraparesis were ruled out using computed tomography, serology, and CSF PCR. The dog's condition deteriorated despite treatment, developing forebrain and central vestibular system clinical signs, and it was euthanized at the owner's request. Postmortem examination was declined. Our findings indicate that when CNS protothecosis is suspected, antemortem diagnosis can be made using CSF analysis and a PCR assay.

Intra-Articular Administration of Autologous Micro-Fragmented Adipose Tissue in Dogs with Spontaneous Osteoarthritis: Safety, Feasibility, and Clinical Outcomes.

Similar to the disease affecting humans, osteoarthritis (OA) is a painful musculoskeletal condition affecting 20% of the adult canine population. Several solutions have been proposed, but the results achieved to date are far from being satisfactory. New approaches, such as intra-articular delivery of cells (including mesenchymal stromal cells), have been proposed. Among the many sources, the adipose tissue is considered very promising. We evaluated the safety, feasibility, and efficacy of a single intra-articular injection of autologous and micro-fragmented adipose tissue (MFAT) in 130 dogs with spontaneous OA. MFAT was obtained using a minimally invasive technique in a closed system and injected in the intra- and/or peri-articular space. Clinical outcomes were determined using orthopedic examination and owners' scores for up to 6 months. In 78% of the dogs, improvement in the orthopedic score was registered 1 month after treatment and continued gradually up to 6 months when 88% of the dogs improved, 11% did not change, and 1% worsened compared with baseline. Considering the owners' scores at 6 months, 92% of the dogs significantly improved, 6% improved only slightly, and 2% worsened compared with baseline. No local or systemic major adverse effects were recorded. The results of this study suggest that MFAT injection in dogs with OA is safe, feasible, and beneficial. The procedure is time sparing and cost-effective. Post injection cytological investigation, together with the clinical evidence, suggests a long-term pain control role of this treatment. The spontaneous OA dog model has a key role in developing successful treatments for translational medicine. Stem Cells Translational Medicine 2018;7:819-828.

Neuroaxonal Dystrophy and Cavitating Leukoencephalopathy of Chihuahua Dogs.

A novel form of neuroaxonal dystrophy is described in 3 Chihuahua pups, 2 of which were from the same litter. It was characterized not only by accumulation of numerous and widely distributed axonal swellings (spheroids) but also by a severe cavitating leukoencephalopathy. The dogs presented with progressive neurological signs, including gait abnormalities and postural reaction deficits. Magnetic resonance images and gross examination at necropsy revealed dilation of lateral ventricles and cerebral atrophy, accompanied by cavitation of the subcortical white matter. Histopathologically, severe axonal degeneration with formation of large spheroids was found in the cerebral and cerebellar white matter, thalamus, and brainstem nuclei. Small-caliber spheroids were observed in the cerebral and cerebellar gray matter. The telencephalic white matter had severe myelin loss and cavitation with relative sparing of the U-fibers. Different from previously reported cases of canine neuroaxonal dystrophy, in these Chihuahuas the spheroid distribution predominantly involved the white matter with secondary severe leukoencephalopathy.

Adult autologous mesenchymal stem cells for the treatment of suspected non-infectious inflammatory diseases of the canine central nervous system: safety, feasibility and preliminary clinical findings.

BACKGROUND: Non-infectious inflammatory diseases of the canine central nervous system (CNS) are common idiopathic disorders grouped under the term meningoencephalomyelitis of unknown origin (MUO). Ante mortem diagnosis is achieved via assessment of clinical signs, magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) analysis, but the definitive diagnosis needs histopathological examination. MUO are mostly considered as autoimmune CNS disorders, so that suppressing the immune reaction is the best management method for patients. Mesenchymal stem cells (MSCs) are under investigation to treat autoimmune and degenerative disorders due to their immunomodulatory and regenerative properties. This study aims to verify the safety, feasibility, and efficacy of MSCs treatment in canine idiopathic autoimmune inflammatory disorders of the CNS. METHODS: Eight dogs presented with acute onset and rapid progression of multifocal neurological signs were selected to the study. In all patients' physical and neurological examinations, MRI and CSF analyses were performed. Clinical diagnosis in all cases was MUO. All selected dogs responded initially to immunosuppressive drugs (prednisone and a combination of prednisolone and cytosine arabinoside) but developed undesirable side effects. For all eight dogs, the owners considered euthanasia but accepted cell therapy as a last possibility. Autologous bone marrow MSCs (BMMSCs), isolated, cultured, and expanded, were administered by intrathecal (IT) injection in the cisterna magna intravenously (IV) and by intra-arterial (IA) injection in the right carotid artery. Adverse effects and clinical response were monitored for 6 months up to 2-year follow-up. RESULTS: The use of autologous BMMSCs in dogs with MUO was safe for IT, IV, and IA injections. No major short- or long-term adverse effects were registered. All the dogs presented early improvement in their general and neurological conditions, with particular effect on cervical pain. The group of dogs treated by IT+IA administration showed a shorter time of reaction to therapy compared to the group treated by IT+IV administration. CONCLUSIONS: MSCs treatment in dogs affected by MOU is safe and feasible. A larger group of dogs is needed to confirm these results as well as CNS histology in order to better understand the underlying mechanisms.