Arthroscopic verification of ultrasonographic diagnosis of meniscal pathology in dogs

OBJECTIVE: To determine the clinical usefulness of ultrasonography for diagnosis of meniscal pathology in dogs. STUDY DESIGN: Double-blind prospective study. ANIMALS: Dogs (n=10) with lameness localized to the stifle. MATERIALS AND METHODS: Sonographic examination of each affected stifle was performed by 1 ultrasonographer unaware of specific historical and clinical data for the dog. Sonographic findings were recorded, but not reviewed until study completion. Arthroscopic examination of the affected stifle was performed within 48 hours of ultrasonography by 1 surgeon unaware of ultrasonographic findings. Arthroscopic findings were recorded, but not reviewed until study completion. Two investigators compared the ultrasonographic and arthroscopic findings at study completion to determine the sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: Two of the 10 dogs had bilateral stifle evaluation. Twenty-four lateral and medial menisci, with normal and abnormal findings, were examined. The sensitivity and specificity for ultrasonographic diagnosis were 90.0% and 92.9%, respectively; positive and negative predictive values were 90.0% and 92.9%, respectively. CONCLUSIONS: Ultrasonography is highly specific and sensitive for diagnosing bucket handle tears of the medial meniscus in dogs. CLINICAL RELEVANCE: Ultrasonographic evaluation of menisci in dogs is a noninvasive method for accurately and efficiently diagnosing pathology, determining the need for surgical intervention, and providing comprehensive information to clients.     

Utility of contrast-enhanced ultrasound in differential diagnosis of adrenal tumors in dogs

This prospective case study aimed to clarify the clinical significance of contrast-enhanced ultrasound (CEUS) for the differential diagnosis of canine adrenal tumors. Forty-three client-owned dogs with adrenal tumors were included. All dogs underwent CEUS, which was evaluated qualitatively and quantitatively. The peak signal intensity (PI), time to peak signal intensity (TPI), mean transit time (MTT), upslope, and downslope were calculated for each time-intensity curve. The histopathological diagnosis of each resected mass was compared with the CEUS findings and parameters. Enhancement distribution, vascularity, tortuous nourishing vessels, enhancement pattern, and late-phase enhancement did not differ significantly between adrenal cortical adenoma (CA), adenocarcinoma (CAC), and pheochromocytoma (PHEO) in qualitative assessment. In PHEO, the TPI was significantly more rapid compared with that in CA (P=0.0287) and CAC (P=0.0404). The MTT in PHEO was significantly shorter than that in CA (P=0.0016) and CAC (P=0.0003). Upslope in PHEO was larger than that in CAC (P=0.0406). Downslope in PHEO was significantly larger than that in CA (P=0.0048) and CAC (P=0.0018). A receiver operating characteristic curve analysis demonstrated that the area under the MTT curve yielded 0.91 for distinguishing PHEO from adrenocortical tumors in dogs; an MTT cut-off value less than 6,225 msec yielded a sensitivity of 69%, specificity of 94%, and likelihood ratio of 12.46. CEUS appears to be clinically applicable for the differential diagnosis between cortical and medullary origins of primary adrenal tumors in dogs.     

Abdominal ultrasonographic findings at diagnosis of osteosarcoma in dogs and association with treatment outcome

The purpose of this study was to describe abdominal ultrasonographic findings present at diagnosis of osteosarcoma (OSA) in dogs and to investigate for associations with treatment outcome. Medical records from 118 dogs diagnosed with OSA that had abdominal ultrasonography performed as part of their initial evaluation were reviewed. Fifty‐seven percent had ultrasonographic abnormalities identified. The organ with the highest frequency of ultrasonographic changes was the spleen. While most sonographic changes were considered to be either benign or of unknown clinical consequences, metastases were identified in three dogs (2.5%), two of which (1.7%) did not have other evidence of metastasis. Dogs with any ultrasonographic abnormality were less likely to receive definitive therapy (P = 0.005) and exhibited shorter survival, although the latter observation was not statistically significant (P = 0.071). However, the identification of lesions in either the liver (P = 0.021) or the kidney (P = 0.003) was statistically associated with shorter survival.     

Comparison of the large muscle group widths of the pelvic limb in seven breeds of dogs

Orthopaedic diseases are common in the pelvic limbs of dogs, and reference values for large muscle groups of the pelvic limb may aid in diagnosis such diseases. As such, the objective of this study was to compare the large muscle groups of the pelvic limb in seven breeds of dogs. A total of 126 dogs from different breeds were included, and the widths of the quadriceps, hamstring and gastrocnemius muscles were measured from images of the lateral radiographies. The width of the quadriceps was not different between the breeds, but the widths of the hamstring and gastrocnemius muscles were significantly different between the breeds. The widest hamstring and gastrocnemius muscles were seen in the Rottweilers and the Boxers, respectively. The narrowest hamstring and gastrocnemius muscles were seen in the Belgian Malinois and the Golden retrievers, respectively. All ratios between the measured muscles differed significantly between the breeds. Doberman pinschers and Belgian Malinois had the highest ratio of gastrocnemius width:hamstring width. Doberman pinschers had also the highest ratio of quadriceps width:hamstring width. German shepherds had the highest ratio of gastrocnemius width:quadriceps width. The lowest ratios of quadriceps width:hamstring width were determined in the German shepherds. The ratios of the muscle widths may be used as reference values to assess muscular atrophy or hypertrophy in cases of bilateral or unilateral orthopaedic diseases of the pelvic limbs. Further studies are required to determine the widths and ratios of the large muscle groups of the pelvic limbs in other dog breeds.     

Ultrasound-guided parasternal injection in dogs: a cadaver study

ObjectivesTo describe the technique of performing an ultrasound-guided distal parasternal intercostal block and to determine the distribution of two volumes of methylene blue dye solution injected in canine cadavers.Study designProspective cadaver study.AnimalsA group of seven canine cadavers weighing 12–34 kg.MethodsThe space between the transversus thoracic and the internal intercostal muscles is a virtual cavity. Ultrasound-guided injections in the distal (parasternal) intercostal space were performed using dye solution at 0.05 mL kg^–1 in each intercostal space from the second to seventh (LV, low volume, six injections per dog) in one hemithorax, and 0.1 mL kg^–1 in the third, fifth and seventh intercostal spaces (HV, high volume, three injections in each dog) on the contralateral side. Anatomical dissection was carried out to describe dye spread characteristics and staining of intercostal nerves.ResultsThe ultrasonographic landmarks for injection were identified in each cadaver. In the LV group the solution was found in every intercostal space (36/36), whereas the HV injection stained six intercostal spaces in two dogs, five in two, and in two dogs the solution was found in four and three spaces, respectively, demonstrating multisegmental distribution. Intrapleural staining was observed after two injections.Conclusions and clinical relevanceUltrasound-guided injection of 0.05 mL kg^–1 at the distal intercostal space resulted in staining of the intercostal nerve in all dogs when performed in every space and may be an appropriate alternative to previously reported techniques. A single injection of 0.1 mL kg^–1 may anaesthetize more than one intercostal nerve, but not consistently. Clinical investigations are warranted to better characterize and to refine this locoregional technique.     

Prostate vascular flow: The effect of the ejaculation on the power doppler ultrasonographic examination

Power Doppler sonography (PD) can accurately depict tissue perfusion, recognize slow flows, and is relatively angle independent. The monitoring of local blood flow by Doppler ultrasonography is helpful in differentiating prostatic physio‐pathological conditions, but the recognizing of physiological variables that could affect it is crucial to apply this technique in clinical practice. This study aimed to evaluate if ejaculation affects blood flow to the prostate and to state how long this effect lasts. Serial PD examinations of prostate were performed in 18 dogs (1–5 years, 6–40 kg) immediately before (T0) and after (T1) the ejaculation, and repeated 6 (T2), 18 (T3) and 24 (T4) hours later. For each examination, two representative PD images were chosen and ranked by two independent observers according to the following scoring system: 0 = mild subcapsular (S) vascularization without clear evidence of parenchymal (P) vascularization; 1 = moderate P and S vascularization; 2 = severe S and moderate P vascularization; 3 = severe P and moderate S vascularization; 4 = severe P and S vascularization. Interobserver agreement was assessed using Kappa of Cohen. Ranked data, grouped according to time, were compared by ANOVA and Tukey HSD test (p < .05). Variations in the vascular flow pattern at different times were observed for all dogs. The statistical analysis evidenced a significant difference for T0 vs T1 and vs T2 and vs T3 (p < .01), with no significant difference for T0 vs T4 (p > .05). Interobserver agreement was very good (Kappa of Cohen = 0.86). This study demonstrated a definite increase in vascular flow to the prostate after ejaculation. The present results suggest a minimum of 24 hr sexual rest before the PD examination of the gland. This result should be taken into account whenever Doppler sonography is used to evaluate potential hyperaemia in dogs suspected of having prostate abnormalities.     

Assessment of the optimal age for a preventive ultrasonographic screening of the uterine health in bitches

Studies about prevalence of uterine pathologies in bitches are scarce. Although correlation between age and uterine disorders was documented, the most suitable age for a preventive sonographic screening has not been proposed yet. Present study aimed to estimate the eligible age for an ultrasonographic screening of uterine abnormalities in dogs. Data regarding ultrasound examination and clinical records of non‐pregnant intact females were retrospectively analysed. The age of each bitch was expressed as age ratio (actual/maximum age expected for the respective breed). The cut‐off age ratio was determined by a ROC curve for overall uterine abnormalities. Frequencies of different abnormalities below and over the cut‐off derived from the ROC curve were calculated and statistically analysed by chi‐Square and OR. Prevalence of three categories of ultrasonographic findings was as follows: cystic endometrial hyperplasia (CEH) 18%; uterine collections (UC) 10.5%; masses (M) 1.3%. By the cut‐off age ratio (0.325), derived by ROC curve (AUC = 0.91; SP 84.23%; SE 79.2%; PPV 83.4%; NPV 80%), 228 cases were divided into two subgroups: bitches over (exposed group: n.83) and below cut‐off (control group: n.145). All abnormalities resulted more frequent in exposed group: OR was 24.96 (p < 0.0001: 71.1% over vs. 9% below cut‐off) for overall abnormalities; 13.68 (p < 0.0001: 40.9% vs. 4.8%) for CEH; 6.13 (p < 0.002: 21.7% vs. 4.1%) for UC; 12.65 (p = 0.09: 3.6% vs. 0%) for M. Cystic endometrial hyperplasia represents the most common finding in adult bitches, followed by UC. A preventive sonographic screening for uterine abnormalities should start from 33% of expected longevity to preventively select animals requiring further evaluations.     

Feasibility and accuracy of ultrasound-guided sacroiliac joint injection in dogs

Frozen cadaver specimens from three dogs were used to create a sectional anatomic atlas of the sacroiliac region. Frozen/thawed cadaver specimens from 12 dogs were used to develop an ultrasound-guided sacroiliac joint injection technique. Accuracy of the technique was tested in 15 additional canine cadaver specimens, using injectate containing blue dye and iodinated contrast medium. Sonoanatomic landmarks for consistently identifying a caudodorsal window into the canine sacroiliac joint space included the L7-S1 articular process joints, ilial wing, sacral wing, sacral lamina, and median sacral crest. Accuracy of ultrasound-guided sacroiliac joint injection was not significantly affected by operator, but was affected by the tissue location targeted and the reference standard used for calculations. Accuracy of the technique was good for placing injectate into either the synchondrosis component, dorsal sacroiliac ligament or ventral sacroiliac ligament; fair to poor for placing injectate into the synovial component; and poor for placing injectate into all four sacroiliac soft tissue structures. Concurrent placement of injectate into extraarticular tissues occurred frequently. We conclude that ultrasound-guided sacroiliac joint injection is feasible for evaluation as a treatment method for lumbosacral region pain in dogs, but is not sufficiently accurate for localizing pain to the sacroiliac joint alone.     

Radiographic and computed tomographic evaluation of experimentally induced lung aspiration sites in dogs

This study was performed to radiographically examine the prevalence of aspiration sites and to evaluate their atomical correlation with the bronchial pattens. Ten healthy beagle dogs were repeatedly radiographed, at weekly intervals, in the left and right lateral, ventrodorsal (VD) and dorsoventral (DV) positions. Three mililiters of iohexol distilled with same volume of saline was infused into the tracheal inlet. Which lung lobe was aspirated was decided upon by the presence of a significant alveolar pattern due to the contrast medium. Alveolar patterns were identified at the left (100%) and right cranial lung lobes (77%) with the dogs in dependant lateral recumbency, at the right caudal lung lobe (71%) with the dogs in VD recumbency and at the right middle lung lobe (59%) with the dogs in DV recumbency, respectively. The anatomical correlation was evaluated by performing computed tomography. The right principal bronchus (165.8 ± 1.6°) was more straightly bifurcated than was the left principal bronchus (142.7 ± 1.8°, p < 0.01). In VD position, the right side lung had a greater opertunity to become aspirated. The ventrally positioned right middle lobar bronchial origin was more easily to be aspirated the other laterally positioned ones. We think that these anatomical characteristics can be one of the causes for aspiration pneumonia to occur more frequently in the right side lung.     

Quantitative assessment of muscle mass and gene expression analysis in dogs with glucocorticoid-induced muscle atrophy

The present study aimed to quantitatively evaluate muscle mass and gene expression in dogs with glucocorticoid-induced muscle atrophy. Five healthy beagles received oral prednisolone for 4 weeks (1 mg/kg/day), and muscle mass was then evaluated via computed tomography. Histological and gene expression analyses were performed using biopsy samples from the biceps femoris before and after prednisolone administration. The cross-sectional area of the third lumbar paraspinal and mid-femoral muscles significantly decreased after glucocorticoid administration (from 27.5 ± 1.9 to 22.6 ± 2.0 cm² and from 55.1 ± 4.7 to 50.7 ± 4.1 cm², respectively; P<0.01). The fast- and slow-twitch muscle fibers were both atrophied (from 2,779 ± 369 to 1,581 ± 207 μm² and from 2,871 ± 211 to 1,971 ± 169 μm², respectively; P<0.05). The expression of the growth factor receptor-bound protein 10 (GRB10) significantly increased after prednisolone administration (P<0.05). Because GRB10 suppresses insulin signaling and the subsequent mammalian target of rapamycin complex 1 activity, increased expression of GRB10 may have resulted in a decrease in protein anabolism. Taken together, 1 mg/kg/day oral prednisolone for 4 weeks induced significant muscle atrophy in dogs, and GRB10 might participate in the pathology of glucocorticoid-induced muscle atrophy in canines.     

Qualitative and quantitative comparison of renal vs. hepatic ultrasonographic intensity in healthy dogs

A prospective, cross-sectional study was performed to qualitatively and quantitatively compare the echogenicity of the renal cortex relative to the liver in healthy dogs. Twenty-five normal adult dogs were examined ultrasonographically. Three standard B-mode images (8.0 MHz) and three tissue harmonic images of the cranial pole of the right kidney adjacent to the caudate lobe of the liver were obtained. Renal and hepatic echogenicities were qualitatively compared by two observers. Subsequently, regions of interest (ROIs) were drawn in the renal cortex and the adjacent liver parenchyma at equal depths on each image, using two different ROI geometries: deep adjacent half-annular ROIs centered at the focal zone and small superficial adjacent squares placed in the near field. Renal and hepatic mean pixel intensities were quantified and averaged for individual subjects. Qualitatively, the right renal cortex was more commonly hyperechoic to liver. Quantitatively, the renal cortical mean pixel intensity was significantly higher than that of liver using deep half-annular ROIs, but not superficial square ROIs, for both standard (P = 0.0007) and harmonic (P = 0.0107) tissue imaging. These findings suggest that the renal cortex can be slightly hyperechoic to adjacent liver. The framework within which the canine renal cortical parenchyma is routinely evaluated in abdominal ultrasonography should be reconsidered, and mild hyperechogenicity relative to the liver (at 8.0 MHz) interpreted as a normal finding.     

Ultrasonographic identification of vascular invasion by adrenal tumors in dogs

Adrenalectomy is the treatment of choice for adrenal tumors that are producing adverse clinical signs. Surgical planning prior to adrenalectomy is aided by identifying tumors with invasion into adjacent vessels or the presence of a tumor thrombus extending into the caudal vena cava. In this paper, we evaluated the sensitivity and specificity of ultrasound in determining if vascular invasion or tumor thrombus is present. Thirty-four dogs with 36 adrenal tumors were reviewed retrospectively. Overall, 36% of tumors had vascular invasion. Abdominal ultrasound was 100% sensitive and 96% specific in identifying the presence of a tumor thrombus in the caudal vena cava. The sensitivity and specificity was 76% and 96%, respectively, when all forms of vascular invasion were evaluated and included patients with vascular wall invasion without concurrent thrombus. Abdominal ultrasound is a good screening tool for identifying vascular invasion or tumor thrombus associated with adrenal tumors in dogs.     

Clinical and ultrasonographic findings of a tear of the gastrocnemius muscle and enthesopathy of the origin of the superficial digital flexor muscle in a reining Quarter Horse mare

Proximal gastrocnemius and superficial digital flexor (SDF) muscle injuries are reported in the horse but are uncommon. In adult horses, the definitive diagnosis is more commonly based on clinical signs with or without the use of radiographic examination and/or nuclear scintigraphy. This case report describes the clinical and ultrasonographic findings of a tear of the gastrocnemius muscle in a 6-year-old reining mare. At standing physical examination, there was a sickled hock appearance, with the point of the hock of the left hindlimb lower (dropped hock) than that of the right hindlimb. At dynamic examination at walk, the mare had instability of the left hock characterised by medial rotation of the hoof and lateral rotation of the point of the hock (twisting motion); at trot, the horse showed mild/moderate left hindlimb lameness characterised by more downward movement of the pelvis during weightbearing of the lame limb compared with that of the sound limb. Ultrasonographic examination of the left thigh and crus showed a large irregular hypoechogenic area and irregularly shaped, retracted muscle stumps on the lateral aspect of the gastrocnemius muscles; the proximal insertion of the SDF muscle on the supracondylar fossa of the femur was irregular in its outline, hypoechogenic and thickened compared with that of the right side. Characteristic muscle fibre pattern was not identified in the left gastrocnemius muscle. On the radiography, a mild irregularity of the bone margin of the lateral supracondylar tuberosity was detected on the caudo 45° medial-craniolateral oblique view of the distal femur. Clinical and diagnostic imaging findings were consistent with partial failure of the caudal part of the reciprocal apparatus and injury of the gastrocnemius and SDF muscles/origin. The horse was managed conservatively by corrective shoeing, muscle relaxing drugs, controlled exercise and manual stretching.     

Extraocular muscle myositis and restrictive strabismus in 10 dogs

Ten cases of uni- or bilateral restrictive ventromedial strabismus in young dogs of different breeds are reported. Clinically, abnormalities were restricted to the extraocular muscles with sparing of the masticatory muscles and limb muscles. This was supported in some cases by imaging studies, electrophysiology, and immunocytochemical assay for antibodies against type 2M fibers. Histologically, there was variable lymphocytic plasmacytic mononuclear cell infiltration and fibrosis. This disorder is similar in many aspects to chronic masticatory myositis with focal myositis and subsequent fibrosis. Surgical correction may restore eye position and vision.     

Diabetes mellitus affects the duration of action of vecuronium in dogs

ObjectiveTo compare the duration of action of vecuronium in diabetic dogs with a control group.Study designProspective clinical study.AnimalsForty client-owned diabetic (n = 20) and non-diabetic dogs.MethodsDogs were considered free from other concurrent disease based on clinical examination and laboratory data. After pre-anaesthetic medication with acepromazine and methadone, anaesthesia was induced with intravenous (IV) propofol and maintained with isoflurane-nitrous oxide in oxygen. Neuromuscular blockade (NMB) was achieved with vecuronium, 0.1 mg kg^?1 IV and its effects recorded by palpation (pelvic limb digital extension) and electromyography (m. tibialis cranialis) of responses (twitches; T) to repeated train-of-four (TOF) nerve stimulation. Time to onset of NMB was the period between vecuronium injection and loss of fourth twitch (T4) in the TOF pattern recorded by EMG and palpation. Duration of NMB was defined as the time from drug administration to return of T1 by palpation (T1_tactile) and EMG (T1_EMG). Times to return of T2-4 were also recorded. Time from induction of anaesthesia to vecuronium injection was recorded. Heart rate, non-invasive mean arterial pressure, body temperature, end-tidal isoflurane and end-tidal CO₂ concentrations were recorded at onset of NMB and when T1_EMG returned. Loss and return of palpable and EMG responses for diabetic and non-diabetic dogs were compared using t-tests and Mann Whitney U-tests.ResultsThere were significant (p < 0.05) differences between diabetic and non-diabetic dogs for the return of all four palpable and EMG responses. Times (mean ± SD) for return of T1_tactile were 13.2 ± 3.5 and 16.9 ± 4.2 minutes in diabetic and non-diabetic dogs respectively. There were no differences between diabetic and non-diabetic dogs in the time to onset of vecuronium with EMG or tactile monitoring.Conclusions and clinical relevanceThe duration of action of vecuronium was shorter in diabetic dogs as indicated by both tactile and EMG monitoring.