The use of a minimally invasive integrated endoscopic system to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions.

Introduction: The objective was to evaluate the use of a minimally invasive surgical (MIS) approach to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions (IVDE). Additionally, we aimed to evaluate the degree of soft tissue trauma using the endoscopic procedure compared to the standard open approach. Methods: Eight client-owned dogs presented to the Colorado State University Veterinary Teaching Hospital with acute onset thoracolumbar IVDE were included in this study. This was a prospective, randomized case-series. Patients were assigned to undergo an endoscopic (group 1; n = 4) or a standard open approach (group 2; n = 4) for a hemilaminectomy. A post-operative MRI was performed in all cases. Results: Conversion to an open approach was not necessary for any case in group 1. All cases had adequate spinal cord decompression on post-operative MRI. There was no significant difference in soft tissue changes noted on post-operative MRI between the two groups. Discussion: The MIS approach to hemilaminectomies in chondrodystrophic dogs with thoracolumbar IVDE can successfully be performed to decompress the neural tissue and appears to lead to similar clinical outcomes in the early postoperative period compared to the standard open approach. Larger studies are needed to determine the potential advantages of the MIS technique compared to the standard open approach in veterinary medicine.

Assessment of risk factors in dogs with presumptive advanced canine cognitive dysfunction.

Objectives: The aim of this study was to investigate the potential risk factors involved in the development of presumptive advanced canine cognitive dysfunction (pACCD). Materials and methods: A questionnaire was developed to identify dogs with presumptive canine cognitive dysfunction (CCD) based on an adapted Canine Dementia Scale and to evaluate for potential risk factors among the presumptive advanced cognitive dysfunction group. The questionnaire was distributed to 7,574 owners of dogs (≥8 years of age) who presented to the CSU VTH between 2017 and 2020. Dogs were classified into four groups based on the Canine Dementia Scale score (normal, mild, moderate, and severe cognitive impairment) and two subgroups for the cognitively impaired groups based on the presence or absence of underlying medical conditions. Comparisons between normal and presumptive advanced cognitively impaired groups, with and without underlying medical conditions, were made against various risk factors. Chi-square tests and logistic regression analysis were used to determine associations between categorical variables and a p-value of <0.05 was considered indicative of evidence of association. Results: The completed response rate for the questionnaire was 14.2% (1,079/7,574). Among those, 231 dogs were classified as having presumptive advanced cognitive dysfunction. The prevalence of presumptive advanced cognitive dysfunction in the included age groups was 8.1% in ages 8 to <11 years, 18.8% in ages 11 to <13 years, 45.3% in ages 13 to <15 years, 67.3% in ages 15 to <17 years, and 80% in ages >17 years. Dogs with a thin body condition score had the largest contribution to the chi-square statistic. Based on the logistic regression model, both age (p < 0.001) and BCS (p = 0.0057) are associated with presumptive ACCD. Conclusion and relevance: The chi-square test and logistic regression analysis both suggested an association between a thin body condition and an increased chance of cognitive decline. However, it is difficult to determine if the thin BCS in this group could be secondary to another confounding factor. The prevalence of cognitive dysfunction rapidly increased with age in this study. These findings warrant continued studies including veterinary evaluations to explore risk factors of canine dementia.

Survey of risk factors and frequency of clinical signs observed with feline cognitive dysfunction syndrome.

OBJECTIVES: The aims of this study were to distribute a survey to cat owners to identify common clinical signs of feline cognitive dysfunction (FCD) and to evaluate for potential risk factors. METHODS: A questionnaire was developed and adapted based on previously validated canine cognitive dysfunction questionnaires. This questionnaire was distributed to 4342 cat owners who had presented to Colorado State University Veterinary Teaching Hospital between 2015 and 2020. Cats aged ⩾8 years with signs of cognitive dysfunction and no underlying medical conditions were classified as the FCD-positive group. Cats aged ⩾8 years with no signs of cognitive dysfunction were classified as the FCD-negative control group. Chi-square or Fisher's exact tests were used to determine associations between categorical variables and a P value <0.05 was considered indicative of evidence of association. RESULTS: A total of 615 completed survey responses were recorded, which was a response rate of 14.2%. Among those, 80 (13%) cats were identified as the FCD-positive group and 114 (18.5%) were identified as the FCD-negative control group. The most common clinical sign in the FCD-positive group was inappropriate vocalization (32/80, 40.0%). The only variable determined to have an association with the FCD group (positive or negative), with a P value of 0.033, was the environmental setting. Cats living in a rural environment (FCD-positive or -negative) had the largest contribution to the χ2 statistic. CONCLUSION AND RELEVANCE: The observed number of FCD-positive cats living in a rural community was less than the expected value based on the χ2 tests. This is suggestive of an association between living in a rural environment and a reduced chance of cognitive dysfunction. There are many factors such as air pollution, social interactions and environmental enrichment that need to be studied further to determine how they relate to FCD as this could not be concluded from this study.

Reprogramming the Canine Glioma Microenvironment with Tumor Vaccination plus Oral Losartan and Propranolol Induces Objective Responses.

Purpose: Malignant gliomas have a highly immune suppressive tumor microenvironment (TME) which renders them largely unresponsive to conventional therapeutics. Therefore, the present study evaluated a therapeutic protocol designed overcome the immune barrier by combining myeloid cell targeted immunotherapy with tumor vaccination. Experimental Design: We utilized a spontaneously occurring canine glioma model to investigate an oral TME modifying immunotherapy in conjunction with cancer stem cell (CSC) vaccination. Dogs were treated daily with losartan (monocyte migration inhibitor) and propranolol (myeloid-derived suppressor cell depleting agent) plus anti-CSC vaccination on a bi-weekly then monthly schedule. Tumor volume was monitored by MRI and correlated with patient immune responses. Results: Ten dogs with histologically confirmed gliomas were enrolled into a prospective, open-label clinical trial to evaluate the immunotherapy protocol. Partial tumor regression was observed in 2 dogs, while 6 dogs experienced stable disease, for an overall clinical benefit rate of 80%. Overall survival times (median = 351 days) and progression-free intervals (median = 163 days) were comparable to prior studies evaluating surgical debulking followed by immunotherapy. Dogs with detectable anti-CSC antibody responses had an increased overall survival time relative to dogs that did not generate antibody responses (vaccine responder MST = 500 days; vaccine non-responder MST = 218 days; p = 0.02). Conclusions: These findings suggest that combining myeloid cell targeted oral immunotherapy with tumor vaccination can generate objective tumor responses, even in the absence of conventional therapy. Overall, this approach has promise as a readily implemented therapeutic strategy for use in brain cancer patients.