Association of the FGF4L2 retrogene with fibrocartilaginous embolic myelopathy in dogs.

BACKGROUND: Fibrocartilaginous embolic myelopathy (FCE) is a well-documented condition in dogs although rarely reported in chondrodystrophic breeds. Genetic associations have not been defined. OBJECTIVES: Define the association of the chondrodystrophy-associated FGF4L2 retrogene with histopathologically confirmed cases of FCE. ANIMALS: Ninety-eight dogs with a histopathologic diagnosis of FCE. METHODS: Retrospective multicenter study. Dogs were genotyped for the FGF4L2 and FGF4L1 retrogenes using DNA extracted from formalin-fixed, paraffin-embedded tissue. Associations between breed, FCE and retrogene status were investigated with reference to a hospital population and known breed and general population allele frequencies. RESULTS: FGF4L2 genotype was defined in 89 FCE cases. Fibrocartilaginous embolic myelopathy was present in 22 dogs from FGF4L2-segregating breeds with allele frequencies of ≥5%; however, all dogs were wild type. Two Labrador retrievers with FCE carried FGF4L2 alleles. Frequency of the FGF4L2 allele was significantly (P < .001) and negatively associated with FCE relative to predicted hospital-population dogs. FCE was overrepresented in Boxer, Great Dane, Yorkshire Terrier, Bernese Mountain Dog, Miniature Schnauzer, Rottweiler, and Shetland Sheepdog breeds. CONCLUSIONS AND CLINICAL IMPORTANCE: Study data based on genotypically and histopathologically defined cases support the historical observation that FCE is uncommon in chondrodystrophic dog breeds. FGF4 plays an important role in angiogenesis and vascular integrity; anatomical studies comparing chondrodystrophic and non-chondrodystrophic dogs might provide insight into the pathogenesis of FCE.

Randomized clinical trial comparing outcomes after fentanyl or ketamine-dexmedetomidine analgesia in thoracolumbar spinal surgery in dogs.

BACKGROUND: Opioids are widely used for perioperative pain control in dogs undergoing spinal surgery, but alternatives may be required because data suggest that opioids exacerbate inflammation in the injured spinal cord and veterinary access to opioids may become more restricted in the future. OBJECTIVES: To compare recovery of ambulation and other functions between spinal cord-injured dogs receiving peri-operative fentanyl and those receiving a ketamine-dexmedetomidine combination. ANIMALS: A total of 102 client-owned dogs undergoing decompressive surgery for thoracolumbar intervertebral disc herniation. METHODS: Randomized clinical trial. Dogs were randomized 1:1 to fentanyl or a ketamine-dexmedetomidine combination for intra and postoperative analgesia. Primary outcome was time to recovery of ambulation; secondary outcomes were the postoperative Colorado Acute Pain Scale, the short-form Glasgow Composite Measure Pain Scale, time to recovery of voluntary urination and time to unassisted eating. RESULTS: No difference was found in time to recovery of ambulation between groups (adjusted sub-hazard ratio, 0.83; 95% confidence interval [CI], 0.55-1.24; P = .36) or in pain scores (Colorado: χ2  = 14.74; P = .32; Glasgow: χ2  = 6.61; P = .76). Differences in time to recovery of eating and urination were small but favored ketamine-dexmedetomidine (adjusted odds ratios, 3.31; 95% CI, 1.53-7.16; P = .002 and 2.43; 95% CI, 1.00-5.96; P = .05, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: There was no evidence that, at the doses used, fentanyl impaired ambulatory outcome after surgery for thoracolumbar intervertebral disc herniation in dogs. Pain control appeared similar between groups. Secondary outcomes suggested minor benefits associated with ketamine-dexmedetomidine. The ketamine-dexmedetomidine combination appears to be a reasonable alternative to peri-operative opioids.