OBJECTIVE To identify the genetic cause for congenital photosensitivity and hyperbilirubinemia (CPH) in Southdown sheep. ANIMALS 73 Southdown sheep from a CPH research flock and 48 sheep of various breeds from commercial flocks without CPH. PROCEDURES Whole-genome sequencing was performed for a phenotypically normal Southdown sheep heterozygous for CPH. Heterozygous variants within Slco1b3 coding exons were identified, and exons that contained candidate mutations were amplified by PCR assay methods for Sanger sequencing. Blood samples from the other 72 Southdown sheep of the CPH research flock were used to determine plasma direct and indirect bilirubin concentrations. Southdown sheep with a plasma total bilirubin concentration < 0.3 mg/dL were classified as controls, and those with a total bilirubin concentration ≥ 0.3 mg/dL and signs of photosensitivity were classified as mutants. Sanger sequencing was used to determine the Slco1b3 genotype for all sheep. Genotypes were compared between mutants and controls of the CPH research flock and among all sheep. Protein homology was measured across 8 species to detect evolutionary conservation of Slco1b. RESULTS A nonsynonymous mutation at ovine Chr3:193,691,195, which generated a glycine-to-arginine amino acid change within the predicted Slco1b3 protein, was significantly associated with hyperbilirubinemia and predicted to be deleterious. That amino acid was conserved across 7 other mammalian species. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested a nonsynonymous mutation in Slco1b3 causes CPH in Southdown sheep. This disease appears to be similar to Rotor syndrome in humans. Sheep with CPH might be useful animals for Rotor syndrome research.

OBJECTIVE To evaluate the coding regions of ADAMTS17 for potential mutations in Chinese Shar-Pei with a diagnosis of primary open-angle glaucoma (POAG), primary lens luxation (PLL), or both. ANIMALS 63 Shar-Pei and 96 dogs of other breeds. PROCEDURES ADAMTS17 exon resequencing was performed on buccal mucosal DNA from 10 Shar-Pei with a diagnosis of POAG, PLL, or both (affected dogs). A candidate causal variant sequence was identified, and additional dogs (53 Shar-Pei [11 affected and 42 unaffected] and 95 dogs of other breeds) were genotyped for the variant sequence by amplified fragment length polymorphism analysis. Total RNA was extracted from ocular tissues of 1 affected Shar-Pei and 1 ophthalmologically normal Golden Retriever; ADAMTS17 cDNA was reverse transcribed and sequenced, and ADAMTS17 expression was evaluated by quantitative reverse-transcription PCR assay. RESULTS All affected Shar-Pei were homozygous for a 6-bp deletion in exon 22 of ADAMTS17 predicted to affect the resultant protein. All unaffected Shar-Pei were heterozygous or homozygous for the wild-type allele. The variant sequence was significantly associated with affected status (diagnosis of POAG, PLL, or both). All dogs of other breeds were homozygous for the wild-type allele. The cDNA sequencing confirmed presence of the expected variant mRNA sequence in ocular tissue from the affected dog only. Gene expression analysis revealed a 4.24-fold decrease in the expression of ADAMTS17 in ocular tissue from the affected dog. CONCLUSIONS AND CLINICAL RELEVANCE Results supported that the phenotype (diagnosis of POAG, PLL, or both) is an autosomal recessive trait in Shar-Pei significantly associated with the identified mutation in ADAMTS17.

The objective of this study was to characterize arterial blood pressure (BP) measurements obtained by using 2 indirect methods, oscillometry and Doppler ultrasonic sphygmomanometry, in conscious goats. Agreement between systolic BP yielded by these 2 methods was then assessed. Sixty female dairy goats aged from 1.5 to 11.8 y (median: 5.5 y) were examined in a standing position with a cuff placed on the tail. All goats had a severe arthritic form of caprine arthritis-encephalitis. Three to 5 repeated measurements of each BP type were averaged for each goat and considered as a final measurement. With oscillometry, systolic blood pressure (O-SBP), diastolic blood pressure, and mean blood pressure, as well as heart rate (HR) were measured, while only systolic blood pressure was measured with Doppler (D-SBP). The O-SBP did not correlate with D-SBP [correlation coefficient (r) = 0.24, P = 0.067]; the mean difference (± standard deviation) was 24.5 ± 26.3 mmHg and limits of agreement were from -27.2 mmHg [95% confidence interval (CI): -39.0, -15.4 mmHg] to 76.1 mmHg (95% CI: 64.3, 87.9 mmHg). No significant linear correlation was found between any BPs and HR (r: -0.10 to 0.22) or age (r: -0.26 to 0.07) of the goats. The study showed that, while BP could be measured in conscious goats using both oscillometry and Doppler ultrasonic sphygmomanometry, the results obtained were so inconsistent that these methods could not be used interchangeably.

The aim of this study was to look for mutations in the equine ACTN3 gene and to identify sequence variants that might be associated with the phenotype and performance of Brazilian sport horses training for events in a tropical climate. Among 17 such horses direct DNA sequencing and mutation analysis of the exon 15 and the intron-exon boundaries of ACTN3 revealed 2 new sequence variants in the ACTN3 intron 14-15, designated c.1681-86G > A and c.1681-129delA. Wild-type/deletion heterozygotes (A/del) had a lower mean subcutaneous fat layer in the region of the gluteus medius, as measured by ultrasonography, than the del/del homozygotes; the correlation was significant (P = 0.017). This single base-pair deletion in ACTN3 intron 14-15 may have resulted in metabolic changes that led to increased deposition of body fat in the homozygous state. However, neither sequence variant was correlated with the time to fatigue in a test on a high-speed treadmill with an incremental-speed protocol.

OBJECTIVE To determine the effects of grape seed extract (GSE), lutein, and fish oil containing omega-3 fatty acids on oxidative stress, migration, proliferation, and viability of lens epithelial cells (LECs). SAMPLE Lens capsules or cultured LECs obtained from canine cadavers. PROCEDURES An antioxidant reductive capacity assay was used to determine reducing capability of each substance. The LECs were cultured and incubated with various substances, including N-acetyl cysteine (NAC), when appropriate, and dimethyl sulfoxide (DMSO) as positive and vehicle control substances, respectively. A dichlorofluorescein assay was used to evaluate reactive oxygen species (ROS) production, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell viability. Ex vivo posterior capsule opacification (PCO) was used to evaluate LEC migration and proliferation. RESULTS Antioxidant reductive effects of GSE surpassed those of NAC, lutein, and fish oil containing omega-3 fatty acids. The GSE reduced ROS production in LECs, compared with the DMSO vehicle control, whereas lutein was pro-oxidative. All test substances reduced cell viability. Ex vivo PCO was not altered by GSE, was decreased by lutein, and was increased by fish oil containing omega-3 fatty acids, compared with results for the DMSO vehicle control. CONCLUSIONS AND CLINICAL RELEVANCE Only GSE had significant antioxidant capabilities and reduced ROS production; however, no effect on ex vivo PCO was detected. Fish oil containing omega-3 fatty acids increased ex vivo PCO. No conclusions could be made regarding antioxidant effects of these substances on LECs. These findings suggested that the substances will not decrease PCO.

OBJECTIVE To evaluate effects of pneumoperitoneum created with warmed humidified CO2 (WHCO2) during laparoscopy on core body temperature, cardiorespiratory and thromboelastography variables, systemic inflammation, peritoneal response, and signs of postoperative pain in healthy mature dogs. ANIMALS 6 mature purpose-bred dogs. PROCEDURES In a randomized crossover study, each dog was anesthetized twice, and pneumoperitoneum was created with standard-temperature CO2 (STCO2; 22°C and 0% relative humidity) and WHCO2 (37°C and 98% relative humidity). Data were collected during each procedure, including core body temperature, cardiorespiratory and thromboelastography variables, and inflammatory biomarkers. Peritoneal biopsy specimens were collected and evaluated with scanning electron microscopy. Dogs were assessed for signs of postoperative pain. RESULTS Mean core body temperature was significantly lower (35.2°C; 95% confidence interval, 34.5° to 35.8°C) with WHCO2 than with STCO2 (35.9°C; 95% confidence interval, 35.3° to 36.6°C) across all time points. Cardiac index increased during the procedure for both treatments but was not significantly different between treatments. Thromboelastography variables did not differ significantly between treatments as indicated by the coagulation index. Subjective evaluation of peritoneal biopsy specimens revealed mesothelial cell loss with STCO2. There was no significant difference in circulating C-reactive protein or interleukin-6 concentrations. There was a significant increase in the number of postoperative pain scores > 0 for the WHCO2 treatment versus the STCO2 treatment. CONCLUSIONS AND CLINICAL RELEVANCE Analysis of these data suggested that effects on evaluated variables attributable to the use of WHCO2 for creating pneumoperitoneum in healthy mature dogs undergoing laparoscopy did not differ from effects for the use of STCO2.

OBJECTIVE To characterize the fecal microbiota of horses and to investigate alterations in that microbiota on the basis of sample collection site (rectum vs stall floor), sample location within the fecal ball (center vs surface), and duration of environmental exposure (collection time). ANIMALS 6 healthy adult mixed-breed mares. PROCEDURES From each horse, feces were collected from the rectum and placed on a straw-bedded stall floor. A fecal ball was selected for analysis immediately after removal from the rectum and at 0 (immediately), 2, 6, 12, and 24 hours after placement on the stall floor. Approximately 250 mg of feces was extracted from the surface and center of each fecal ball, and genomic DNA was extracted, purified, amplified for the V1-V2 hypervariable region of the 16S rDNA gene, and analyzed with a bioinformatics pipeline. RESULTS The fecal microbiota was unique for each horse. Bacterial community composition varied significantly between center and surface fecal samples but was not affected by collection time. Bacterial community composition varied rapidly for surface fecal samples. Individual bacterial taxa were significantly associated with both sample location and collection time but remained fairly stable for up to 6 hours for center fecal samples. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, for horses, fecal samples for microbiota analysis should be extracted from the center of fecal balls collected within 6 hours after defecation. Samples obtained up to 24 hours after defecation can be analyzed with the realization that some bacterial populations may deviate from those immediately after defecation.

OBJECTIVE To identify clinical or clinicopathologic variables that can be used to predict a positive PCR assay result for Anaplasma phagocytophilum infection in equids. ANIMALS 162 equids. PROCEDURES Medical records were reviewed to identify equids that underwent testing for evidence of A phagocytophilum infection by PCR assay between June 1, 2007, and December 31, 2015. For each equid that tested positive (case equid), 2 time-matched equids that tested negative for the organism (control equids) were identified. Data collected included age, sex, breed, geographic location (residence at the time of testing), physical examination findings, and CBC and plasma biochemical analysis results. Potential predictor variables were analyzed by stepwise logistic regression followed by classification and regression tree analysis. Generalized additive models were used to evaluate identified predictors of a positive test result for A phagocytophilum. RESULTS Total lymphocyte count, plasma total bilirubin concentration, plasma sodium concentration, and geographic latitude were linear predictors of a positive PCR assay result for A phagocytophilum. Plasma creatine kinase activity was a nonlinear predictor of a positive result. CONCLUSIONS AND CLINICAL RELEVANCE Assessment of predictors identified in this study may help veterinarians identify equids that could benefit from early treatment for anaplasmosis while definitive test results are pending. This information may also help to prevent unnecessary administration of oxytetracycline to equids that are unlikely to test positive for the disease.

OBJECTIVE To assess differences in skin shrinkage between grossly visible tumor and grossly normal marginal skin of dogs for cutaneous mast cell tumors (MCTs) excised with curative intent and to determine an equation to estimate postexcisional gross tumor margins from preexcisional measurements and vice versa. SAMPLE 19 cytologically confirmed and surgically excised cutaneous MCTs obtained from dogs. PROCEDURES Tumors were measured in craniocaudal and dorsoventral directions before excision, immediately after excision, and after fixation in formalin. Both grossly visible tumor and surrounding grossly normal skin that comprised the surgical margin were measured at each time point. Percentage of shrinkage was compared among time points and between the tumor and surrounding grossly normal skin. Patient and histopathologic variables were correlated to skin shrinkage. RESULTS Overall shrinkage was 17.70%. The amount of shrinkage within the grossly visible tumor (4.45%) was less than that within the surrounding grossly normal skin (24.42%). Most of the shrinkage occurred immediately after excision. There was no effect of age, sex, completeness of excision, or degree of edema. Accuracy of an equation to estimate postexcisional margins from preexcisional measurements was only 18.4%. CONCLUSIONS AND CLINICAL RELEVANCE Grossly evident MCTs of dogs shrunk less than did the grossly normal surrounding skin. Although an equation to estimate postexcisional margins from preexcisional measurements could be derived, it likely would need to contain additional variables not included in the study reported here. Until such an equation exists, care must be used when extrapolating surgical margins from histologic margins and vice versa.

OBJECTIVE To determine the pharmacokinetics and sedative effects of 2 doses of a concentrated buprenorphine formulation after SC administration to red-tailed hawks (Buteo jamaicensis). ANIMALS 6 adult red-tailed hawks. PROCEDURES Concentrated buprenorphine (0.3 mg/kg, SC) was administered to all birds. Blood samples were collected at 10 time points over 24 hours after drug administration to determine plasma buprenorphine concentrations. After a 4-week washout period, the same birds received the same formulation at a higher dose (1.8 mg/kg, SC), and blood samples were collected at 13 time points over 96 hours. Hawks were monitored for adverse effects and assigned agitation-sedation scores at each sample collection time. Plasma buprenorphine concentrations were quantified by liquid chromatography–tandem mass spectrometry. RESULTS Mean time to maximum plasma buprenorphine concentration was 7.2 minutes and 26.1 minutes after administration of the 0.3-mg/kg and 1.8-mg/kg doses, respectively. Plasma buprenorphine concentrations were > 1 ng/mL for mean durations of 24 and 48 hours after low- and high-dose administration, respectively. Mean elimination half-life was 6.23 hours for the low dose and 7.84 hours for the high dose. Mean agitation-sedation scores were higher (indicating some degree of sedation) than the baseline values for 24 hours at both doses. No clinically important adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Concentrated buprenorphine was rapidly absorbed, and plasma drug concentrations considered to have analgesic effects in other raptor species were maintained for extended periods. Most birds had mild to moderate sedation. Additional studies are needed to evaluate the pharmacodynamics of these doses of concentrated buprenorphine in red-tailed hawks.