Abstract
OBJECTIVE
Design and evaluate immune responses of neonatal foals to a mRNA vaccine expressing the virulence-associated protein A (VapA) of Rhodococcus equi.
ANIMALS
Cultured primary equine respiratory tract cells; Serum, bronchoalveolar lavage fluid (BALF), and peripheral blood mononuclear cells (PBMCs) from 30 healthy Quarter Horse foals.
METHODS
VapA expression was evaluated by western immunoblot in cultured equine bronchial cells transfected with 4 mRNA constructs encoding VapA. The mRNA construct with greatest expression was used to immunize foals at ages 2 and 21 days in 5 groups: (1) 300 μg nebulized mRNA (n = 6); (2) 600 μg nebulized mRNA (n = 4); (3) 300 μg mRNA administered intramuscularly (IM) (n = 5); (4) 300 μg VapA IM (positive controls; n = 6); or (5) nebulized water (negative controls; n = 6). Serum, BALF, and PBMCs were collected at ages 3, 22, and 35 days and tested for relative anti-VapA IgG1, IgG4/7, and IgA activities using ELISA and cell-mediated immunity by ELISpot.
RESULTS
As formulated, nebulized mRNA was not immunogenic. However, a significant increase in anti-VapA IgG4/7 activity (P < .05) was noted exclusively in foals immunized IM with VapA mRNA by age 35 days. The proportion of foals with anti-VapA IgG1 activity > 30% of positive control differed significantly (P = .0441) between negative controls (50%; 3/6), IM mRNA foals (100%; 5/5), and IM VapA (100%; 6/6) groups. Natural exposure to virulent R equi was immunogenic in some negative control foals.
CLINICAL RELEVANCE
Further evaluation of the immunogenicity and efficacy of IM mRNA encoding VapA in foals is warranted.
Abstract
OBJECTIVE
To describe the signalment, clinical findings, presumptive or definitive diagnosis, and outcome in cats with central cord syndrome (CCS).
ANIMALS
22 cats.
CLINICAL PRESENTATION
Cats evaluated for CCS at 7 referral hospitals between 2017 and 2021 were included. Information retrieved from medical records included signalment, physical and neurological examination findings, diagnostic investigations, definitive or presumptive diagnosis, treatment, and follow-up.
RESULTS
Median age at presentation was 9 years. Two neuroanatomical localizations were associated with CCS: C1-C5 spinal cord segments in 17 (77.3%) cats and C6-T2 spinal cord segments in 5 (22.7%) cats. Neuroanatomical localization did not correlate with lesion location on MRI in 8 (36.3%) cats. The most common lesion location within the vertebral column was over the C2 and C4 vertebral bodies in 6 (27.2%) and 5 (22.7%) cats, respectively. Peracute clinical signs were observed in 11 (50%) cats, acute in 1 (4.5%), subacute in 4 (18%), and chronic and progressive signs were seen in 6 (40.9%) cats. The most common peracute condition was ischemic myelopathy in 8 (36.3%) cats, whereas neoplasia was the most frequently identified chronic etiology occurring in 5 (22.7%) cats. Outcome was poor in 13 (59%) cats, consisting of 4 of 11 (36.6%) of the peracute cases, 3 of 4 (75%) of the subacute cases, and 6 of 6 of the chronic cases.
CLINICAL RELEVANCE
Central cord syndrome can occur in cats with lesions in the C1-C5 and C6-T2 spinal cord segments. Multiple etiologies can cause CCS, most commonly, ischemic myelopathy and neoplasia. Prognosis depends on the etiology and onset of clinical signs.
Abstract
OBJECTIVE
To assess the therapeutic efficacy of acupuncture in combination with Chinese herbs for treatment of horses affected with anhidrosis.
ANIMALS
44 horses affected with anhidrosis for up to 3 years’ duration were enrolled. Inclusion required both compatible clinical signs and results of a quantitative intradermal terbutaline sweat test.
METHODS
Study horses were randomly allocated into 2 groups. Group 1 (n = 19) was treated with daily Chinese herbs and 4 weekly acupuncture sessions. Group 2 (n = 25) was given daily hay powder as a placebo and 4 weekly sham acupuncture sessions. Horses were tested by quantitative intradermal terbutaline sweat test within 2 days after treatment completion and again 4 weeks following treatment.
RESULTS
Terbutaline-induced sweat responses (mg) were not different between groups within 2 days and 4 weeks after treatment. Two days after treatment, ratios of sweat responses (compared to baseline) were higher (P < .05) in the treatment group compared to the placebo group at terbutaline concentrations of 1.0, 100, and 1,000 µg/mL. The number of horses responding to treatment was higher in the treatment group (5/19 [26%]), compared to horses in the placebo group (1/25 [4%]) for 1 of 5 terbutaline concentrations 2 days (10 µg/mL) or 4 weeks (0.1 µg/mL) after treatment.
CLINICAL RELEVANCE
Ratios of sweat responses were higher in treatment horses 2 days after treatment, compared to baseline, but not 4 weeks later. The efficacy of a traditional Chinese veterinary medicine protocol for anhidrosis treatment with acupuncture and Chinese herbs was low but higher in treated horses compared with placebo.
Abstract
OBJECTIVE
Perform a cadaveric experimental pilot study to measure and compare potential radiation exposure to an orthopedic surgeon from 2 different-generation mini C-arm models during a simulated orthopedic surgery.
SAMPLE
16 radiation dosimeters.
METHODS
Mock surgery setups were constructed with a canine cadaver thoracic limb and 2 different-generation mini C-arm models. Four radiation dosimeters were placed near the mini C-arm to mimic common locations of radiation exposure during image acquisition. One mini C-arm was placed in auto technique mode, and 100 static images were acquired. The dosimeters were replaced, and a 5-minute-long dynamic image was acquired. The same protocols were repeated for the second mini C-arm. The dosimetry badges were then submitted for radiation exposure quantification.
RESULTS
All but 1 dosimeter had radiation exposure levels below the detectable limits of the dosimeter. The dosimeter closest to the primary x-ray beam of 1 mini C-arm during dynamic image acquisition had a reading of 1 mrem.
CLINICAL RELEVANCE
Intraoperative radiation exposure from the mini C-arm is low, specifically to areas not protected by lead and in close proximity to the primary x-ray beam. That being said, surgeons should always practice the principles of ALARA (ie, as low as reasonably achievable) to minimize radiation exposure in the workplace.
Abstract
OBJECTIVE
To describe a case of caudal duplication successfully operated with long-term follow-up.
ANIMAL
A 12-week-old female Chihuahua mix.
CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES
The dog of this report presented for evaluation of duplicate external organs, including 2 anuses, 2 vulvas, and 2 tails. The dog was clinically normal except for signs of cystitis. Contrast CT identified complete urogenital and anorectal duplication, characterized by duplication of the cecum, descending colon/rectum, urinary bladder, urethra, uterus, and ovaries, with left-sided rectovestibular fistula.
TREATMENT AND OUTCOME
Exploratory laparotomy was performed to remove the left cecum and colon, the left ureter was transected and implanted into the right urinary bladder, the left bladder and urethra were removed, and bilateral ovariohysterectomy removed 4 ovaries and 2 uteruses. Following abdominal closure, the left anus and vulva with remaining portions of distal rectum and urethra, respectively, were removed en bloc with both tails. Long-term follow-up at 5 years showed the dog to be clinically normal.
CLINICAL RELEVANCE
Caudal duplication is extremely rare in veterinary medicine, and this report details successful surgical correction with good long-term follow-up.
Abstract
OBJECTIVE
To compare dexmedetomidine-ketamine (DK; 0.1 and 10 mg/kg, respectively) with midazolam (M; 1.0 mg/kg) or 0.9% sodium chloride (S; 0.2 mL/kg) administered IM in the forelimb (F) or hindlimb (H) in eastern box turtles (Terrapene carolina carolina).
ANIMALS
20 clinically healthy, captive adult eastern box turtles.
METHODS
In a randomized, blinded, complete crossover study with 1-week washout periods, turtles were administered each of 3 treatments: F-DKS, F-DKM, or H-DKM. Palpebral reflex, muscle tone, and withdrawal responses were serially assessed and used to calculate cumulative sedation scores at each 5-minute time point. The ability to intubate was evaluated. At 60 minutes, atipamezole (1.0 mg/kg) and either flumazenil (F-DKM, H-DKM; 0.05 mg/kg) or 0.9% sodium chloride (F-DKS; 0.5 mL/kg) were administered IM.
RESULTS
All treatments resulted in clinically relevant anesthetic effects. F-DKM produced significantly higher sedation scores than H-DKM or F-DKS at all time points between 10 and 60 minutes (P < .05). Sedation score variability was observed with all treatments with significantly higher variability for H-DKM (P < .05). Intubation was successful in 32, 89, and 11% of turtles in F-DKS, F-DKM, and H-DKM, respectively. Median (range) recovery time was 10 (5–22), 16 (7–45), and 12 (4–28) minutes for F-DKS, F-DKM, and H-DKM, respectively.
CLINICAL RELEVANCE
In eastern box turtles, forelimb dexmedetomidine-ketamine resulted in clinically relevant anesthetic effects that were heightened with the addition of midazolam. Hindlimb administration of midazolam-dexmedetomidine-ketamine resulted in reduced and more variable anesthetic effects compared to forelimb administration, supporting a hepatic first-pass effect.
Abstract
OBJECTIVE
Effect of photobiomodulation therapy (PBMT) in patients with CCLR after TPLO surgery by measuring C-reactive protein (CRP), percentage weight bearing, lameness using a short form of a composite measure pain scale, evaluated by the clinician and owners, and surgical site infection.
SAMPLE
54 client-owned dogs with CCLR undergoing unilateral TPLO surgery were enrolled in this study between April 5, 2021, through April 10, 2022.
METHODS
The study population was randomly assigned to either a treatment group receiving PMBT (24 dogs) or a control group (30 dogs). PMBT was performed on the treatment group immediately after induction, and 6 hours, 24 hours, 48 hours, and 8 weeks postoperatively. The control group received sham PMBT (device turned off) at the same time. Evaluation of CRP, CMPS-SF, evidence of SSI, and %WB were evaluated for all dogs 24 hours preoperatively, and then 24 hours, 48 hours, and 8 weeks postoperatively. Owners completed CMPS-SF and subjective evaluations weekly for 8 weeks postoperatively.
RESULTS
No statistically significant differences were found between treatment groups when evaluating CRP, %WB, and CMPS-SF by the clinician and weekly evaluation of the CMPS-SF by owners. Although no statistically significant differences were found in patients developing surgical site infections between treatment groups, SSI was only observed in patients in the control group (5/30, 16.6%). Most were minor/superficial infections (4/30 13.3%), and a single dog (1/30, 3.3%) had a major/deep surgical site infection.
CLINICAL RELEVANCE
Although with promising but not statistically significant differences between groups, surgical site infections may be reduced after PBMT application.
Abstract
OBJECTIVE
To determine the K-constant for body surface area calculation from body weight in corn snakes (Pantherophis guttatus) through the use of computed tomography (CT) measurements.
ANIMALS
12 adult corn snakes held by North Carolina State University for research purposes underwent CT between November 2022 and January 2023.
METHODS
Each snake had a CT scan, physical examination, and body weight measurement. CT images were uploaded into software able to perform 3-D reconstruction and measure body surface area. The species-specific K-constant was determined using nonlinear regression analysis between body surface area and (body weight in grams)2/3.
RESULTS
The mean body weight of the 12 adult corn snakes was 228 g, with a mean body surface area of 505.1 cm2. The calculated K-constant was 13.6 (P < .001). The resulting formula for body surface area in corn snakes is BSA in cm2 = 13.6 X (body weight in grams)2/3.
CLINICAL RELEVANCE
The body surface area formula developed for corn snakes will allow for improved dosing accuracy for medications with low therapeutic safety margins. Additional pharmacokinetic and pharmacodynamic studies are necessary to determine the safety and efficacy of individual medications.
Abstract
OBJECTIVE
Compare 3 methods of nucleus pulposus (NP) volume measurement using the rabbit lumbar spines as a preclinical model to determine the effectiveness of prophylactic intervertebral disk fenestration in dogs.
ANIMALS
Twelve 9-month-old, skeletally mature female entire New Zealand White rabbits weighing between 3.5 to 4.5 kg.
METHODS
NP volume measurements of dissected rabbit lumber spines between L1 and L6 were made and compared using gross measurements, reconstructed MRI images, and water volumetry based on Archimedes’ principle. Water volumetry was used as the true gold standard volume measurement in this study.
RESULTS
The true volume (mean ± SD) of the nucleus pulposus NP as measured by water volumetry increased caudally from L1/L2 (16.26 ± 3.32 mm3) to L5/L6 (22.73 ± 6.09 mm3). Volume estimates made by MRI were significantly higher than those made using water volumetry at all sites (L1/L2 [P = .044], L2/L3 [P = .012], L3/L4 [P = .015], L4/L5 [P < .001], and L5/L6 [P < .001]). Gross measurements also significantly overestimated volume when compared to water volumetry at all sites; L1/L2 (P = .021), L2/L3 (P = .025), L3/L4 (P = .001), L4/L5 (P < .001), and L5/L6 (P < .001). MRI and gross volume estimates were significantly different at L4/L5 (P = .035) and L5/L6 (P = .030).
CLINICAL RELEVANCE
The findings of this preclinical model might be relevant to veterinary surgeons who perform prophylactic fenestration for which there is no reliable method to determine the amount of NP to be removed. Preclinical ex vivo and in vivo fenestration studies with pre- and postoperative NP volume assessment are required.
Abstract
OBJECTIVE
To determine if plasma concentrations of symmetric dimethylarginine (SDMA), N-acetyl-beta-d-glucosaminidase (NAG), GGT, ALT, AST, lactate, total calcium, and ionized calcium (iCa) and the calcium:phosphorus ratio are clinically relevant biomarkers to detect early stages of tubular lesions in snakes.
ANIMALS
6 adult corn snakes (Pantherophis guttatus).
METHODS
Corn snakes were administered 11 injections of gentamicin at 50 mg/kg, SC, q 24 h in an experimental model of induced tubular necrosis. Plasma biochemistry and blood gas analyses were performed at baseline and after the 3rd and 11th injections. Parameters were compared between time points using a paired Wilcoxon test. In 3 individuals, renal biopsies were collected at baseline before starting injections and at the 3rd and 11th injections, while renal tissue samples were procured after euthanasia in all individuals.
RESULTS
Renal proximal and distal tubular necrosis and hepatic steatosis were present in all individuals at necropsy. Compared to baseline, decreased blood concentrations of lactate, ionized calcium, and total calcium and a decreased calcium:phosphorus ratio were noted. A significant decrease of lactate and ionized calcium was observed after 3 days. Conversely, no changes in SDMA, NAG, ALT, AST, GGT, and sodium were detected.
CLINICAL RELEVANCE
Ionized calcium and lactate concentrations were the earliest parameters to decrease compared to baseline values in this experimental model. While SDMA is a sensitive indicator of renal disease in mammals, this biomarker did not increase in a model of induced acute tubular necrosis in corn snakes.
