Evaluation of cortical bone strength using a quantitative ultrasound measurement device in dogs.

This study was performed to evaluate cortical bone strength in dogs using a quantitative ultrasound measurement device. In this study, 16 clinically healthy dogs with no lameness underwent measurement of the ultrasound propagation velocity of cortical bone (namely, speed of sound [SOS]) at the radius and tibia. Additionally, computed tomography examination with a calibration phantom was performed in 10 dogs. We calculated the bone mineral density (BMD) and Young's modulus from the computed tomography data using bone strength evaluation software. SOS, BMD, and Young's modulus were statistically compared between the radius and tibia. In addition, we examined the correlation between SOS and BMD and between SOS and Young's modulus. We also examined the correlation between SOS and age in the 13 dogs whose age was known. BMD and Young's modulus were not significantly different between the radius and tibia, but SOS was significantly different (P<0.05). Moreover, SOS and BMD showed a positive correlation in both radius and tibia. Similarly, SOS and Young's modulus showed a positive correlation. In addition, SOS and age showed a strong positive correlation (radius: r=0.77, P<0.05, tibia: r=0.83, P<0.05). Our finding that SOS of the radius and tibia cortical bone was correlated with BMD and Young's modulus indicates that quantitative ultrasound can be useful for evaluating cortical bone strength in dogs.

Extravesicular, two-layer, side-to-side ureteroneocystostomy combined with tension-relieving techniques for feline proximal ureteral obstruction: A retrospective study.

OBJECTIVE: To describe the surgical technique for extravesicular, two-layer, side-to-side ureteroneocystostomy combined with tension-relieving techniques (ETSUTT) for feline proximal ureteral obstruction and report clinical outcomes. STUDY DESIGN: Retrospective case series. ANIMALS: Ten privately-owned cats with ureteral obstruction near the ureteropelvic junction (UPJ). METHODS: Medical records were retrospectively reviewed for cats with ureteral obstruction close to the UPJ that underwent ETSUTT (2018-2021). The ETSUTT procedure consisted of a modified extravesicular technique (two-layer, side-to-side ureteroneocystostomy) and tension-relieving techniques (renal descensus, ureterocystopexy, and nephrocystopexy). RESULTS: All cats survived through discharge. In all cats, postoperative blood urea nitrogen and creatinine concentrations were decreased, compared with preoperative concentrations. Perioperative complications included ureteral catheter dislodgement (3), transient pollakiuria (2), and dysuria (1), but no specific treatments were required. Urinary tract infection was observed postoperatively in three of the 10 cats. The median follow-up was 648 days (min-max: 86-1229 days). Seven of the 10 cats were alive without recurrent ureteral obstruction at the end of this retrospective study. CONCLUSION: The ETSUTT procedure was successfully performed without major complications in cats with ureteral obstruction occurring near the UPJ. Use of ETSUTT provided a fair-to-good, long-term prognosis in cats that were otherwise difficult to manage. CLINICAL SIGNIFICANCE: This novel procedure, ETSUTT, was feasible, safe, and could be a viable treatment option for feline proximal ureteral obstruction, including the UPJ, especially for obstructions caused by stricture.

Common bile duct perforation due to choledocholithiasis in a cat with gallbladder agenesis.

Case summary: An 8-year-old neutered male domestic shorthair cat was presented for further investigation of anorexia, vomiting and lethargy. Abdominal ultrasonography and contrast-enhanced CT revealed choledocholithiasis with suspected bacterial peritonitis and non-visualisation of the gallbladder. During surgery, the common bile duct was noted to be perforated, and a cholelith was found in the abdominal cavity. No gallbladder was confirmed during surgery. Three months postoperatively, the cat underwent CT cholangiography and absence of the gallbladder with a vestigial duplicated gallbladder was diagnosed. Relevance and novel information: Gallbladder agenesis is extremely rare in cats, with only one previous report, but several dogs have been diagnosed based on CT cholangiography and laparoscopy. This report describes gallbladder agenesis concurrent with choledocholithiasis in an adult cat and represents the first report of CT cholangiography in a cat with gallbladder agenesis.

Serum cross-linked N-telopeptide of type I collagen across the canine life span: An investigation in intact and neutered male and female dogs.

In this study, we conducted study to explore the association between serum cross-linked N-telopeptide of type I collagen (NTx), a marker of bone resorption, and age, body weight, and blood biochemical parameters as well as the neutered and intact status in male and female dogs. We targeted 145 healthy dogs (aged 0.33-18.33 years); 70 were males (38 intact, 32 castrated), and 75 were females (31 intact, 44 ovariohysterectomized). We found that the NTx levels were significantly higher in dogs aged ≤2 years than in older dogs. NTx concentration tended to decrease with age in dogs aged ≤2 years, but not significantly, and remained constant in dogs aged >2 years. Accordingly, we investigated sex/sterilization status in two age cohorts (juvenile-to-young-adult, ≤2 years of age; adult-to-geriatric, >2 years of age). In the adult-to-geriatric cohort, NTx concentration was highest in intact males, followed by neutered males, neutered females, and intact females. The intact vs. neutered difference was significant in males, but not in females. Our results suggested that estradiol deficiency may not affect bone metabolism in female dogs, but androgen deficiency may affect bone metabolism in male dogs. Furthermore, age did not affect bone metabolism after 2 years. NTx concentrations were significantly higher in the juvenile-to-young-adult cohort than in the adult-to-geriatric cohort and tended to decrease with age, similar to young humans. This study unveils novel sex differences in canine serum NTx concentrations and suggests the effect of neutering on bone metabolism, showing that serum NTx concentrations change with age.

Relationship between serum estradiol, cathepsin K, and N-telopeptide of type I collagen in female dogs.

Ovariohysterectomized (OHE) female dogs do not develop the osteopenia and osteoporosis associated with decreasing estrogen in post-menopausal women, possibly due to post-OHE bone mineral density retention through a mechanism that remains unclear. In this study, we aimed to elucidate this mechanism by investigating estradiol (E2) and bone markers. Samples were collected from 56 OHE and 43 intact bitches (0.33 to 17.58 years old) and analyzed for serum E2, osteoclast-secreted cysteine protease cathepsin K (CTK), and N-telopeptide of type I collagen (NTx) by ELISA. OHE and intact bitches showed no significant difference in serum E2 or NTx, and there was no correlation between serum E2 and NTx and age and time since OHE. Intact bitches showed a very low correlation between E2 and NTx, but OHE bitches showed no correlation, and serum CTK was generally undetectable in both groups. Our findings suggest the influence of gonadal hormones on bone metabolism does not work effectively in dogs; this is consistent with a shorter duration of exposure to E2 in bitches (through the 4-to-8-month anestrus phase) than women.

Long-term outcomes of 54 dogs with tracheal collapse treated with a continuous extraluminal tracheal prosthesis.

OBJECTIVE: To describe the surgical placement of a continuous extraluminal tracheal prosthesis (CETP) and report the subsequent postoperative clinical outcomes in dogs with tracheal collapse. STUDY DESIGN: Retrospective case series. ANIMALS: Fifty-four dogs. METHODS: Medical records of dogs in which cervical and/or thoracic inlet tracheal collapse was diagnosed and treated by placement of a CETP between 2010 and 2017 were reviewed to evaluate postoperative complications, changes in respiratory function, and survival. Histological examinations of tracheal tissues performed in 2 dogs at 51 and 57 months after surgery were also reviewed. RESULTS: Fifty-three (98%) dogs survived to discharge. Postoperative complications included laryngeal paralysis (1 dog), disseminated intravascular coagulation (1 dog), and recurrent tracheal collapse (2 dogs). None of the dogs exhibited clinical evidence of tracheal necrosis. Preoperative dry, harsh cough resolved in 87% of the dogs after surgery. Goose honking cough was resolved in 25 of 26 (96%) dogs. Median follow-up time was 30 months (range, 16 days to 76 months). The survival rate at 36 months was 86% (CI: 75%-96%). On histological examination in 2 dogs, the tracheal tissue surrounding the prosthesis was well preserved and without evidence of chronic inflammation. CONCLUSION: Continuous extraluminal tracheal prosthesis placement in dogs with tracheal collapse resulted in low postoperative complication rates and good long-term outcomes. CLINICAL SIGNIFICANCE: Continuous extraluminal tracheal prosthesis placement provides a viable alternative surgical option for managing dogs with tracheal collapse.

Characteristics and multipotency of equine dedifferentiated fat cells.

Dedifferentiated fat (DFAT) cells have been shown to be multipotent, similar to mesenchymal stem cells (MSCs). In this study, we aimed to establish and characterize equine DFAT cells. Equine adipocytes were ceiling cultured, and then dedifferentiated into DFAT cells by the seventh day of culture. The number of DFAT cells was increased to over 10 million by the fourth passage. Flow cytometry of DFAT cells showed that the cells were strongly positive for CD44, CD90, and major histocompatibility complex (MHC) class I; moderately positive for CD11a/18, CD105, and MHC class II; and negative for CD34 and CD45. Moreover, DFAT cells were positive for the expression of sex determining region Y-box 2 as a marker of multipotency. Finally, we found that DFAT cells could differentiate into osteogenic, chondrogenic, and adipogenic lineages under specific nutrient conditions. Thus, DFAT cells could have clinical applications in tissue regeneration, similar to MSCs derived from adipose tissue.

A preliminary study of osteochondral regeneration using a scaffold-free three-dimensional construct of porcine adipose tissue-derived mesenchymal stem cells.

BACKGROUND: Osteoarthritis (OA) is a major joint disease in humans and many other animals. Consequently, medical countermeasures for OA have been investigated diligently. This study was designed to examine the regeneration of articular cartilage and subchondral bone using three-dimensional (3D) constructs of adipose tissue-derived mesenchymal stem cells (AT-MSCs). METHODS: AT-MSCs were isolated and expanded until required for genetical and immunological analysis and construct creation. A construct consisting of about 760 spheroids that each contained 5.0 × 10(4) autologous AT-MSCs was implanted into an osteochondral defect (diameter: 4 mm; depth: 6 mm) created in the femoral trochlear groove of two adult microminipigs. After implantation, the defects were monitored by computed tomography every month for 6 months in animal no. 1 and 12 months in animal no. 2. RESULTS: AT-MSCs were confirmed to express the premature genes and to be positive for CD90 and CD105 and negative for CD34 and CD45. Under specific nutrient conditions, the AT-MSCs differentiated into osteogenic, chondrogenic, and adipogenic lineages, as evidenced by the expressions of related marker genes and the production of appropriate matrix molecules. A radiopaque area emerged from the boundary between the bone and the implant and increased more steadily upward and inward for the implants in both animal no. 1 and animal no. 2. The histopathology of the implants after 6 months revealed active endochondral ossification underneath the plump fibrocartilage in animal no. 1. The histopathology after 12 months in animal no. 2 showed not only that the diminishing fibrocartilage was as thick as the surrounding normal cartilage but also that massive subchondral bone was present. CONCLUSIONS: The present results suggest that implantation of a scaffold-free 3D construct of AT-MSCs into an osteochondral defect may induce regeneration of the original structure of the cartilage and subchondral bone over the course of 1 year, although more experimental cases are needed.

Ganglion cysts arising from a canine stifle joint.

A 10-year-old, neutered male Labrador retriever presented with progressive left hind lameness. Ultrasonography revealed large, subcutaneous, ovoid cysts around the stifle joint. Radiographic and computed tomographic images revealed periosteal reaction of the distal femur. Magnetic resonance (MR) imaging showed a large cyst that was hypointense in T1-weighted images, hyperintense in T2-weighted images and had a thin lining that was enhanced by intravenous gadonium injection. The cyst communicated with the joint cavity and other small cysts around the joint. Histopathology of an excisional biopsy specimen led to diagnosis of ganglion cyst. This report provides MR images of a ganglion cyst in a canine stifle.

A preliminary study of diagnostic color Doppler ultrasonography in equine superficial digital flexor tendonitis.

We hypothesized that semi-quantitative determinations of changeable blood flows in granulation and scar tissues during tendon healing could be helpful for differentiation between the acute phase rich in blood vessels and the remodeling phase with fewer vessels. Ten Thoroughbreds with injured superficial digital flexor tendon (SDFT) in a forelimb were used for evaluation of blood flows in the injured tendons of racehorses using color Doppler (CD) ultrasonography. Using longitudinal CD images, features of maximum color activities were defined. These were rhythmically blinking, tiny to small signals (grade 1), pulsatile expanded dots (grade 2), and dynamic streams (grade 3). Grade of color activity in CD ultrasonography could be useful for quantitative assessment of equine SDFT repair.

Analysis of cartilage oligomeric matrix protein and matrix metalloproteinase-9 in cerebrospinal fluid of miniature dachshund with intervertebral disc herniation.

We evaluated whether the cerebrospinal fluid (CSF) concentration of cartilage oligomeric matrix protein (COMP) is related to disease severity, prognosis and matrix metalloproteinase (MMP)-9 activity of the CSF in miniature dachshund with intervertebral disc herniation. Samples were obtained from 23 patients and 6 normal dogs, and all patients received hemilaminectomy. Twenty dogs recovered successfully and 3 of 11 dogs without deep nociception had MMP-9 activity in the CSF and an unsuccessful outcome. The COMP levels from patients were significantly higher than those from normal dogs. MMP-9 activity and neurological severity were not related to the COMP levels. However, the COMP levels from 3 unsuccessful cases that had MMP-9 activity were significantly lower than those from all recovered cases and/or successful cases without deep nociception. Concerning severe cases, increased proteolytic activity might affect the COMP concentration and prognosis due to MMP-9 associated deleterious effects.

CT and MRI imaging diagnosis of epidural idiopathic sterile pyogranulomatous inflammation in a dog spinal canal.

A 12-year-old neutered male shih tzu developed progressive pelvic limb paraparesis. Computed tomography showed a radiolucent mass lesion in the spinal canal at the left side of the 11th thoracic vertebra. The mass was not enhanced by intravenous contrast medium injection. It was hyperintense on both T1- and T2-weighted magnetic resonance images. The signal intensity of the mass was decreased with a fat suppression technique, indicating a fatty origin. After removal of the mass via T11-T12 hemilaminectomy, chronic panniculitis was confirmed by histopathological examination. This case demonstrates the utility of computed tomography and magnetic resonance imaging for the diagnosis of spinal canal pyogranulomatous inflammation.

A comparative study of chronic kidney disease in dogs and cats: induction of cyclooxygenases.

The present study investigated whether renal cyclooxygenase (COX) induction is associated with the severity of chronic kidney disease (CKD) in dogs and cats. The collected kidneys were examined histopathologically and immunohistochemically. The immunoreactivities of COX-1 and COX-2 were evaluated quantitatively, and the correlations to the plasma creatinine concentrations, glomerular size, glomerulosclerosis, interstitial fibrosis, and interstitial cell infiltration were evaluated statistically. Immunoreactivities for COX-1 were heterogeneously observed in the medullary distal tubules and collecting ducts; no correlations with the severity of renal damage were detected. Immunoreactivities for COX-2 were heterogeneously observed in the macula densa (MD) regions. In dogs, the percentage of COX-2-positive MD was significantly correlated with the glomerular size. In cats, glomeruli with COX-2-positive MD had significantly higher sclerosis scores than those with COX-2-negative MD. In conclusion, renal COX-2 is induced in canine and feline CKD, especially in relation to the glomerular changes.

Mating behavior increases workload of the heart in Thoroughbred stallions.

To evaluate the influence of mating behavior on cardiac function, changes in heart rate (HR), electrocardiogram (ECG), hematocrit (Hct) and serum concentration of alpha-atrial natriuretic peptide (alpha-ANP) were evaluated in 10 clinically sound Thoroughbred stallions before and after mating behavior. The stallions were submitted twice to experimental pseudomating in the same month in 2009 and 2010. Measurements and blood samples were collected at a stable before mating (baseline) and at a covering yard before and after mating. ECG was recorded by a Holter-ECG system. Arrhythmias were detected in 5 stallions before or after mating behavior. Minimum HR (HRmin), maximum HR (HRmax) and HR recorded when the stallions entered into yard (HRent) and ejaculated (HRejc) were 34.2 ± 3.7, 168.9 ± 14.2, 141.8 ± 35.3 and 142.6 ± 27.3 beats/min, respectively. Time from entrance into the yard to ejaculation (mating time; MT) ranged from 30 to 2,103 sec and was highly correlated with HRent (r=-0.82) and the time required for attaining HRmax after entrance into the yard (dT HRmax) (r=0.87). Hct and serum alpha-ANP concentration significantly increased after ejaculation (60.0 ± 3.2%, P<0.0001, and 1.54 ± 0.61 ng/ml, P=0.0353) compared with the baselines values (46.9 ± 4.4%, 1.40 ± 0.60 ng/ml). HRent and Hct were significantly higher in the stallions with an MT of less than 5 min (n=5) compared with those (n=5) with an MT of more than 5 min (P=0.0324 and P=0.0082). Mating behavior increases the workload of the heart in Thoroughbred stallions.

Immunohistochemical analysis of cartilage-derived retinoic acid-sensitive protein (CD-RAP)/melanoma inhibitory activity (MIA) in murine, canine, bovine and equine cerebrospinal tissues.

Cartilage-derived retinoic acid-sensitive protein (CD-RAP)/melanoma inhibitory activity (MIA), which appears abundantly in hypertrophic cartilage at the stage of endochondral ossification, is also detected in cerebrospinal fluid (CSF) following spinal cord injury. In this study, the localization of the CD-RAP/MIA molecule in normal tissues of the spine and brain obtained from mice, rats, dogs, cattle and horses was examined using immunohistochemistry with a specific antibody. The positive signals of CD-RAP/MIA were found at nerve cells in the spinal cords of all species and were especially strong at cerebellar Purkinje cells. The results suggested that CD-RAP/MIA included in normal cerebrospinal tissues could be a biomarker associated with tissue injuries, as the molecules might flow into the CSF.

Microminipig, a non-rodent experimental animal optimized for life science research:novel atherosclerosis model induced by high fat and cholesterol diet.

Atherosclerotic lesions were observed in male and ovariectomized female Microminipig (MMP) fed a high fat and cholesterol diet with sodium cholate (HFCD/SC) for 3 months. HFCD/SC induced hypercholesterolemia accompanied by an increase in serum total cholesterol (T-Cho), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and cholesterol ester (CE). Unlike the mouse or rabbit, a dominant LDL-C fraction in the intact MMP, similar to that in humans, was observed by serum lipoprotein analysis. HFCD/SC increased body weight gain. At the end of the experiment, computed tomography scans of conscious animals showed that HFCD/SC had decreased liver attenuation values (Hounsfield unit) and increased subcutaneous and abdominal fat, suggesting the induction of fatty liver and obesity. HFCD/SC induced atherosclerotic lesions in systemic arteries, including the external and internal iliac arteries, abdominal aorta, coronary artery, and cerebral arterial circle. Atherosclerosis and pathological findings induced by HFCD/SC in MMP were similar to those in humans. The MMP is a potentially suitable tool for investigating human atherosclerosis.

Microminipig, a Non-rodent Experimental Animal Optimized for Life Science Research: Novel Atherosclerosis Model Induced by High Fat and Cholesterol Diet.

Atherosclerotic lesions were observed in male and ovariectomized female Microminipig (MMP) fed a high fat and cholesterol diet with sodium cholate (HFCD/SC) for 3 months. HFCD/SC induced hypercholesterolemia accompanied by an increase in serum total cholesterol (T-Cho), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and cholesterol ester (CE). Unlike the mouse or rabbit, a dominant LDL-C fraction in the intact MMP, similar to that in humans, was observed by serum lipoprotein analysis. HFCD/SC increased body weight gain. At the end of the experiment, computed tomography scans of conscious animals showed that HFCD/SC had decreased liver attenuation values (Hounsfield unit) and increased subcutaneous and abdominal fat, suggesting the induction of fatty liver and obesity. HFCD/SC induced atherosclerotic lesions in systemic arteries, including the external and internal iliac arteries, abdominal aorta, coronary artery, and cerebral arterial circle. Atherosclerosis and pathological findings induced by HFCD/SC in MMP were similar to those in humans. The MMP is a potentially suitable tool for investigating human atherosclerosis.

Novel microminipig model of atherosclerosis by high fat and high cholesterol diet, established in Japan.

Novel atherosclerotic lesions were induced in the Microminipig (MMP, registered with the Japanese Ministry of Agriculture, Forestry and Fisheries as a novel variety of swine), the smallest pig available for experimental use, by feeding a high fat (12%) and high cholesterol (5%) diet (HFCD) with sodium cholate (SC, 0.7%) (HFCD/SC) for three months. Three MMPs were used: a male fed with normal diet (M-ND), and a male and an ovariectomized female fed with HFCD/SC (M-HFCD/SC and Fx-HFCD/SC). HFCD/SC induced hypercholesterolemia accompanied by an increase in serum total cholesterol (T-Cho), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and cholesterol ester (CE) from the first week. Serum levels of T-Cho, LDL-C and CE reached a maximum in two to three weeks, and HDL-C gradually increased during the experimental period (duration). Serum lipoprotein analysis showed a dominant LDL-C fraction, as seen in humans, in all three MMPs. Body weight gain in the MMPs fed with HFCD/SC was greater than in the animal fed with M-ND. At the end of the experiment, computed tomography scans of conscious animals showed increases in subcutaneous and abdominal fat in those fed with HFCD/SC, suggesting the induction of obesity. Atherosclerotic lesions in systemic arteries (including external and internal iliac arteries, abdominal aorta, coronary artery, cerebral arterial circle), fatty changes, and foamy cell infiltration in the liver and spleen were histopathologically observed in the MMPs fed with HFCD/SC. Atherosclerosis and the pathological findings induced by HFCD/SC in MMPs were similar to the pathological changes associated with human atherosclerosis, suggesting that the MMP has the potential to be a suitable animal model for human atherosclerosis.

Cartilage oligomeric matrix protein in canine spinal cord appears in the cerebrospinal fluid associated with intervertebral disc herniation.

STUDY DESIGN: Cerebrospinal fluid (CSF) from dogs with intervertebral disc herniation (IVDH) were analyzed using a specific antibody against cartilage oligomeric matrix protein (COMP). Immunolocalization and genetic expression of COMP were also examined in the spinal cords of mouse, rat, and dog. OBJECTIVE: To investigate the hypothesis that COMP is present in CSF of dogs with IVDH, and the clinical relevance of COMP expression in CSF as a potential biomarker of spinal cord injury. SUMMARY OF BACKGROUND DATA: In dog IVDH, diagnostic imaging is useful for determining the spinal cord compression, but less useful for assessment of traumatic degeneration. Aggrecan, a well-known component of cartilage matrix, is increased in CSF from cases of neural damage and inflammation of the spinal cord. METHODS: CSF from the cisterna magna (C-CSF) and the lumbar spine (L-CSF) of 19 dogs with IVDH and 5 normal dogs were analyzed using inhibition enzyme-linked immunosorbent assay (ELISA) and immunoblotting with an antibody cross-reactive with dog COMP. Samples of normal spinal cord from mouse, rat, and dog were also prepared for immunohistochemistry and in situ hybridization. RESULTS: ELISA values were significantly higher for L-CSF than for C-CSF in dogs with IVDH, whereas there was no significant difference between them in normal dogs. Immunoblots of L-CSF samples revealed positive bands of approximately 500 kDa in 6 cases of IVDH (positive cases), but no signal in negative cases. ELISA values were significantly higher in the positive cases than in the negative cases. Both COMP protein and mRNA were present at high levels in the gray matter of the spinal cord in all species. CONCLUSION: In dog IVDH, release of COMP from the spinal cord in association with injury may lead to COMP accumulation in L-CSF posterior to the site of disc extrusion, and therefore might be a predictive marker of spinal cord injury.

Gene and protein expression of cartilage oligomeric matrix protein associated with oncogenesis in canine tumors.

To investigate the expression of cartilage oligomeric matrix protein (COMP) associated with oncogenesis, samples of serum and tumor tissue were obtained from 25 dogs with tumors. The serum levels of COMP in dogs with tumors were significantly higher than in 38 normal controls and correlated with the concentrations of tumor tissue extracts. Positive bands to COMP antibody were detected on immunoblots of tumor extracts. Immunohistochemistry and in situ hybridization demonstrated positive signals of COMP and its mRNA in the cytoplasm of tumor cells from mammary gland tumors, but not in the normal mammary gland. Positive immunohistochemistry results were also obtained for COMP in mast cell tumor and melanoma cells. Oncogenesis might augment production of COMP and the serum level of COMP in dogs.