MOCOS-associated renal syndrome in a Brown Swiss cattle.

BACKGROUND: A recessive form of MOCOS-associated xanthinuria type II is described in Tyrolean grey cattle. A similar case was identified in a 5-month-old Brown Swiss calf with hoof overgrowth, rough coat, urine sediment, and pneumonia. HYPOTHESIS/OBJECTIVES: To characterize the disease phenotype, to evaluate its genetic etiology, and to determine the prevalence of the deleterious allele in the Brown Swiss population. ANIMALS: An affected calf, its parents, and 65 441 Swiss dairy cattle. METHODS: The affected animal was clinically examined and necropsied. Microarray genotyping was used to determine the genotypes and to assess the frequency of the MOCOS allele in a Brown Swiss control cohort. RESULTS: Ultrasonography revealed hyperechoic renal pyramids with multifocal distal shadowing and echogenic sediment in the urinary bladder. Necropsy revealed suppurative bronchopneumonia and urolithiasis. Histology revealed numerous nephroliths with multifocal chronic lymphohistiocytic interstitial infiltrates, fibrosis, tubular degeneration, chronic multifocal glomerulonephritis with sclerosis, and bilateral hydronephrosis. Dysplastic changes were observed in the corium of the claw and the cornea. Genetic testing identified the homozygous presence of a known MOCOS frameshift variant in the case. Both parents were heterozygous and the prevalence of carriers in genotyped Brown Swiss cattle was 1.4% (342/24337). CONCLUSIONS AND CLINICAL IMPORTANCE: The findings were consistent with the diagnosis of a recessive renal syndrome similar to xanthinuria type II described in Tyrolean grey cattle. The prevalence of the deleterious MOCOS allele is low in the Brown Swiss breed. However, mating of carriers should be avoided to prevent further losses.

Computer-assisted surgery for placing toggle constructs across the coxofemoral joints of small equids using a minimally invasive approach-A proof-of-concept cadaveric study.

OBJECTIVE: To develop a minimally invasive technique for placing a toggle construct across the coxofemoral joint of small equids using computer-assisted surgery. STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: Three pilot specimens: One donkey, one Shetland pony and one Warmblood foal. Six main study specimens: Three Shetland ponies, one American Miniature Horse, one Warmblood foal and one donkey. METHODS: Experimental surgeries were performed on both coxofemoral joints of each cadaver. Using a minimally invasive surgical approach, 5.5 mm bone canals were drilled through the femur and acetabulum, traversing the coxofemoral joint. Intraoperative guidance was provided by a cone-beam computed tomography (CBCT)-coupled surgical navigation system. A toggle construct was introduced through the bone canals. Surgical accuracy aberrations (SAA) were measured at the femoral entry and exit points and at the acetabular entry point on merged pre- and postoperative CBCT scans. The coxofemoral joint was assessed for articular cartilage damage by gross dissection. RESULTS: A toggle construct was placed across all 18 coxofemoral joints. The overall median SAA in the main study was 2.8 mm (range: 0.4-8.0 mm). No cartilage damage was found in the cadaveric specimens of the main study. CONCLUSION: The described technique allowed for the placement of a toggle construct across the coxofemoral joint of small equid cadaveric specimens without prior coxofemoral luxation. CLINICAL RELEVANCE: This technique may serve as an option for surgical stabilization of coxofemoral joints in small equids. Further biomechanical investigations are required to assess optimal implant positioning and toggle constructs.

CT diagnosis of occipital condyle fracture in a dog presented for severe cervical hyperesthesia.

A 9-month-old male entire Doberman Pinscher presented with acute onset of severe cervical hyperesthesia after a fall. Neurological examination revealed a normal gait with low head carriage and severe cervical hyperesthesia. A CT scan of the cervical vertebral column revealed the presence of a comminuted fracture at the dorsomedial aspect of the right occipital condyle and sclerosis of the underlying bone. Medical management was initiated consisting of an external bandage, strict rest, and pain medication. Due to the lack of clinical improvement, the dog was euthanized 2 months after diagnosis. Histopathology of the lesion was compatible with a healing fracture.

Preliminary Studies on the Intrahepatic Anatomy of the Venous Vasculature in Cats.

Hepatic surgeries are often performed in cats to obtain a disease diagnosis, for the removal of masses, or for the treatment of shunts. Whereas the vascular anatomy of the liver has been studied in dogs, such evidence is lacking in cats. The current study used corrosion casts of portal and hepatic veins and computed tomography (CT) analysis of the casts to identify and describe the intrahepatic anatomy in healthy cat livers (n = 7). The results showed that feline livers had a consistent intrahepatic portal and venous anatomy, with only minor disparities in the numbers of secondary and tertiary branches. The feline portal vein consistently divided into two major branches and not three, as previously described in the literature for cats. The finding of a portal vein originating from the right medial lobe branch leading to the quadrate lobe in 4/7 specimens is a novelty of the feline anatomy that was not previously described in dogs. Partial to complete fusion of the caudate process of the caudate and the right lateral lobe, with a lack of clear venous separation between the lobes, was present in two specimens. These findings allowed a detailed description of the most common intrahepatic venous patterns in cats. Further anatomical studies should be encouraged to confirm the present findings and to investigate the utility of this information in surgical settings.

Post-mortem Computed Tomographic Angiography in Equine Distal Forelimbs: A Feasibility Study.

In-depth understanding of pathophysiological processes occurring in the vasculature of the equine distal limb is of great importance to improve both diagnostic and therapeutic approaches to diseases. To gain further insights, a model allowing high-resolution 3D-visualization of the vasculature is necessary. This pilot study evaluated the feasibility of restoring vascular perfusion in frozen-thawed distal equine cadaver limbs without prior preparation using computer tomographic imaging (CT). Five frozen-thawed, radiographically normal forelimbs were perfused with a lipophilic contrast agent through the median artery and radial vein in three phases (arterial, venous, and arterial-venous combined (AVC) dynamic). For comparison, one additional limb was perfused with a hydrosoluble contrast agent. The CT-studies (16-slice MDCT, 140 kV, 200 mA, 2 mm slice thickness, 1 mm increment, pitch 0.688) were evaluated at 11 specified regions for visualization of the vasculature and presence of artifacts or anatomic variations. The protocol used in this study proved to be feasible and provided good visualization (93.1%) of vasculature with low rates of artifacts. During the different phases, vascular visualization was similar, but while filling defects decreased in the later phases, extravasation worsened in the 2 limbs where it was observed. Subjectively, the best quality of angiographic images was achieved during the AVC dynamic phase. Perfusion with hydrosoluble contrast resulted in significantly lower vascular visualization (74.0%) and higher artifact rates. This study shows that reperfusion of frozen-thawed equine distal limbs with a lipophilic contrast agent allows for high-quality 3D-visualization of the vasculature and may serve as a model for in situ vascular evaluation in the future.

Increased teat wall thickness in response to machine milking.

Transiently increased teat wall thickness in response to machine milking has been documented by various methods, including ultrasound. However, correlative ultrasonography and histology to detect the origin of this phenomenon is lacking. The first goal of the present study was to evaluate and compare milking-related changes of the teat tissue in 2 breeds of dairy cows (11 Simmental and 3 Holstein) using B-mode ultrasonography. Additionally, the observed changes were compared with ultrasonographic findings in a Holstein cow with periparturient udder edema. Finally, corresponding histological sections of the Simmental teats were analyzed and compared with those from a lactating nonmilked Angus cow. We hypothesized that the mechanical load of both stretching by the vacuum during phases of open teat cup liner and compression by the closed liner during machine milking results in a transient congestion of blood vessels in the teat wall. The barrel of 1 front teat of each cow was scanned immediately before and after machine milking (system vacuum: 42 kPa; pulsation rate: 60 cycles/min; pulsation ratio: 65:35). Shortly after milking (33 ± 6 min), the Simmentals were slaughtered, and their scanned teat was immediately removed and processed for investigation by light microscopy. Ultrasonography after milking revealed anechoic tubular structures mainly in the inner half of the teat wall. Histological examination revealed these structures to be thick-walled veins. The left front and hind teats of the nonmilked lactating cow, collected and prepared identically to those from the Simmental cows, showed the same histological features. Ultrasonographic measurements showed that the diameter of these veins significantly increased after milking compared with matching images before milking. This effect was most pronounced in the Holstein cows. Similarly, these veins were very prominent in the periparturient cow. However, neither the milked cows, including the periparturient cow, nor the lactating nonmilked cow provided any evidence of edematous extravasation on ultrasonography or histology. These findings corroborated our hypothesis that the increase in size of thick-walled veins in the teat tissue is the main reason for the thickening of the teat walls in response to machine milking.

Feasibility, indications, and radiographically confirmed diagnoses of standing extremity cone beam computed tomography in the horse.

OBJECTIVE: To report on the feasibility, indications, and diagnostic yield of cone beam computed tomography (CBCT) of horses' extremities performed under standing sedation. STUDY DESIGN: Retrospective clinical case series. SAMPLE POPULATION: Fifty-nine CBCT examinations in 58 horses. METHODS: Examinations were categorized for indications for CBCT dependent on a suspicion, presence, or absence of a diagnosis prior to CBCT. The number of acquisitions per examination, total time for the examination, diagnostic score of each acquisition (diagnostic, diagnostic-compromised, nondiagnostic), and additional diagnostic information regarding preexisting diagnostic information were recorded. RESULTS: Three (median) acquisitions were performed per examination in a median study time of 14 minutes. In 24 of 33 cases with a suspected diagnosis, this diagnosis was confirmed or definitively refuted; in seven of 33 cases, the suspected diagnosis was refuted without a new diagnosis; and, in two of 33 cases, the suspected diagnosis could not be confirmed nor could a new diagnosis be made. In five of nine cases without a preexisting diagnosis, a diagnosis was established. In 16 cases with a diagnosis prior to CBCT, additional information was recorded, or a surgical plan was prepared. In 14 of 18 cases in which additional contrast techniques were used, additional information was gained. CONCLUSION: Standing CBCT of the horses' extremities is feasible and can produce diagnostic information in a timely fashion. CLINICAL SIGNIFICANCE: The results provide evidence of the practicality and diagnostic potential of standing CBCT of horses' extremities.

Analysis of a Laxity Index Database and Comparison with the Fédération Cynologique Internationale Grades of This Population.

OBJECTIVE: This study aimed to analyse the distribution of the laxity indices (LI) in a dog population, to compare the LI with the Fédération Cynologique Internationale (FCI) grades and to search for differences of LI between breeds. STUDY DESIGN: The database was composed of all dogs presented to the University Hospital of the Faculty of Veterinary Medicine in Ghent for obligatory hip screening between January 2016 and February 2019, and all patients presented to orthopaedic consultation between January 2017 and January 2019 for a complaint of hindlimb lameness, which underwent both a standard extended ventrodorsal radiograph of the hips and a stress radiograph revealing hip joint laxity. The latter was obtained by means of the Vezzoni-modified Badertscher distension device and the LI was calculated. For each dog of the population, the LI was then compared with the FCI grade. RESULTS: The LI values ranged between 0.15 and 1.04, with a mean of 0.46. The LI and the FCI grade increased together, and showed a moderate-to-good correlation. There was a highly significant overall difference in the mean value of LI per FCI grade group (p < 0.001). The mean LI of the Labrador Retrievers was slightly but significantly lower than the mean LI of the Golden Retrievers (p < 0.01). CONCLUSION: The LI calculated on a stress radiograph taken with the Vezzoni-modified Badertscher distension device shows a good correlation with the FCI grade assigned on a standard extended ventrodorsal projection. A wide range of passive hip joint laxity exists in dogs considered to be phenotypically normal based on the FCI grading method.

Solitary tracheal B-cell lymphoma in an adult alpaca (Vicugna pacos).

BACKGROUND: This report describes a case of solitary tracheal lymphoma in a 14-year-old alpaca mare. CASE PRESENTATION: The alpaca was referred for dyspnea and inspiratory noise. The clinical examination included complete blood cell count, blood chemistry, endoscopy, ultrasound, radiographs, and computed tomography (CT). A solitary tracheal intraluminal and juxtatracheal lymphoma was diagnosed by fine needle aspiration (FNA). The owner requested euthanasia due to the uncertain prognosis. At postmortem examination, the presence of solitary lymphoma without involvement of other organs was confirmed. Immunohistochemical analysis confirmed a B-cell origin. CONCLUSIONS: Although multicentric lymphoma is the most commonly described neoplasia affecting South American camelids (SAC), solitary forms of the disease may occur.

Radiography and Standing Computed Tomography of an Osteochondritis Dissecans Lesion Found at the Dorsodistolateral Aspect of the Calcaneus in a 3-Year-Old Horse.

An incidental osteochondritis dissecans (OCD) lesion was found in a left tarsus of a 3-year-old Freiberger stallion presented for a prepurchase examination. The lesion was best visualized on the dorsomedial-plantarolateral oblique and dorsoplantar projections. A standing computed tomographic examination confirmed a fragmentation of the dorsodistolateral aspect of the calcaneus. In suspected OCD lesions at the distal aspect of the talus or calcaneus, a dorsoplantar projection of the tarsus improves lesion localization and could be added to the standard radiographic protocol during OCD screenings. Computed tomography allowed more detailed evaluation of a not previously described calcaneal origin of this uncommon presumed OCD lesion in the equine tarsus.

Clinical use of computer-assisted orthopedic surgery in horses.

OBJECTIVE: To describe clinical applications of computer-assisted orthopedic surgery (CAOS) in horses with a navigation system coupled with a cone beam computed tomography unit. STUDY DESIGN: Retrospective clinical case series. ANIMALS: Thirteen adult horses surgically treated with CAOS. METHODS: Medical records were searched for horses that underwent CAOS between 2016 and 2019. Data retrieved included signalment, diagnosis, lameness grade prior to surgery, surgical technique and complications, anesthesia and surgery time, and information pertaining to the perioperative case management and outcome. RESULTS: In 10 cases, surgical implants were placed in the proximal phalanx, third metatarsal bone, ulna, or medial femoral condyle. In one case, navigated transarticular drilling was performed to promote ankylosis of the distal tarsal joints. In another case, an articular fragment of the middle phalanx was removed with the help of CAOS guidance. In the final case, a focal osteolytic lesion of the calcaneal tuber was curetted with the aid of CAOS. In seven cases, a purpose-built frame was used for the surgical procedure. All surgeries were performed successfully and according to the preoperative plan. CONCLUSION: Computer-assisted orthopedic surgery can be an integral part of the clinical case management in equine surgery. To optimize workflow and time-efficiency, the authors recommend designating one team for operative planning and another for the execution of the surgical plan. Specialized equipment, such as the purpose-built frame, will further improve CAOS applications in equine surgery. CLINICAL SIGNIFICANCE: After they have become familiar with the operational principles, equine surgeons can readily apply CAOS for a broad spectrum of indications.

High-frequency ultrasound, computed tomography and computed tomography arthrography of the cranial cruciate ligament, menisci and cranial meniscotibial ligaments in 10 radiographically normal canine cadaver stifles.

BACKGROUND: Bilateral non-traumatic cranial cruciate disease is frequently seen in originally unilateral cruciate pathology. Untreated cranial cruciate ligament disease and concurrent meniscal lesions cause progressive osteoarthritis and pain of the stifle joint. Early presurgical diagnosis is important, but remains difficult. The purpose of this ex vivo study was (1) to describe the ultrasonographic appearance of the canine cranial cruciate ligament (CrCrL), menisci and meniscal ligaments using a high-frequency linear transducer, (2) to determine the length of the CrCrL seen on ultrasonography (US) and (3) to describe and compare the appearance of the CrCrL, menisci and meniscal ligaments on US, computed tomography (CT) and computed tomography arthrography (CTA). RESULTS: US and CT examinations were performed on 10 radiographically normal cadaveric stifles of adult dogs weighing more than 15 kg, followed by macroscopic and histologic evaluations. The CrCrL had a parallel hyperechoic fibrillar pattern at the insertion on the tibia and a hypoechoic structure more proximally in all stifles. This pattern was visible over 35% (median) of the total length of the ligament, with 50% (median) of the total length CrCrL that could be outlined. All medial menisci and 8 out of 10 of the lateral menisci showed hypoechoic lines within their bodies oriented obliquely to the direction of the ultrasound beam. Fifteen of the 20 cranial meniscotibial ligaments were detected, showing a hyperechoic fibrillar pattern. Normal macro- and microscopic appearance was observed in all menisci, with the radial bundles of collagen fibers at the level of and with similar orientation as the intrameniscal hypoechoic lines on US. The CrCrL, menisci and meniscal ligaments were of intermediate density on CT, but marked improvement of the border detection was obtained using CTA. Contrast within the CrCrL was observed in 4/10 stifles using CT and confirmed in 3/4 stifles on histology. One of these ligaments had a partial tear (5-10%) on macroscopic evaluation. None of the menisci showed any abnormalities on CTA. CONCLUSIONS: Normal canine menisci are heterogeneous on high-frequency US and a fibrillar pattern may be observed in the cranial meniscotibial ligaments and the distal portion of the CrCrL. Linear areas of contrast may be detected within the cranial cruciate ligament of radiographically normal stifles.

B-mode and contrast-enhanced ultrasonography of the mammary gland during the estrous cycle of dogs.

Pathology of the mammary gland is a common health issue in dogs and includes neoplasia, cysts, inflammation and infection. The use of the B-mode (US) and contrast-enhanced (CEUS) ultrasonography may aid in the diagnosis. Previous studies are currently lacking of the ultrasonic images of the mammary gland of healthy bitches in different stages of the estrous cycle and associated normal blood perfusion patterns. The purpose, therefore, was to describe the normal B-mode US and CEUS images of the mammary gland and inguinal lymph node, in six intact female beagles during five different stages of the estrous cycle (proestrus, estrus, early and late diestrus and anestrus). Within the same stage of the estrous cycle, the size (thickness) of the caudal mammary glands increased. During early and late diestrus, all mammary glands increased in thickness and had an increased heterogeneous B-mode ultrasonic appearance. The mammary glands had a heterogeneous, disorganized perfusion pattern when assessed using CEUS. For the cranial abdominal mammary gland, the area under the curve and the mean transit time increased between estrus and late diestrus and decreased between late diestrus and anestrus. For the inguinal mammary gland, only the time to peak was longer during the periods of anestrus compared to estrus whereas all the other contrast parameters did not change during the estrous cycle. In conclusion, hormonal influences cause major changes in the size, appearance and blood perfusion of mammary glands during the estrous cycle and should be considered when evaluating pathological changes of mammary glands.

Intraobserver and interobserver agreement on the radiographical diagnosis of canine cranial cruciate ligament rupture.

Even though radiography is one of the most frequently used imaging techniques for orthopaedic disorders, it has been demonstrated that the interpretation can vary between assessors. As such, the purpose of this study was to examine the intraobserver and interobserver agreement and the influence of level of expertise on the interpretation of radiographs of the stifle in dogs with and without cranial cruciate ligament rupture (CCLR). Sixteen observers, divided in four groups according to their level of experience, evaluated 30 radiographs (15 cases with CCLR and 15 control stifles) twice. Each observer was asked to evaluate joint effusion, presence and location of degenerative joint disease, joint instability and whether CCLR was present or absent. Overall, intraobserver and interobserver agreement ranged from fair to almost perfect with a trend towards increased agreement for more experienced observers. Additionally, it was found that stifles that were classified with high agreement have either overt disease characteristics or no disease characteristics at all, in comparison to the ones that are classified with a low agreement. Overall, the agreement on radiographic interpretation of CCLR was high, which is important, as it is the basis of a correct diagnosis and treatment.

TTA Rapid: Description of the Technique and Short Term Clinical Trial Results of the First 50 Cases.

OBJECTIVE: To (1) describe a modified technique for tibial tuberosity advancement (TTA) in dogs with cranial cruciate ligament (CCL) rupture and (2) report short term outcome and complications. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs with unilateral CCL rupture (n = 50). METHODS: TTA was performed with a novel implant to achieve advancement of the tibial crest. The technical protocol, specific implants and instrumentation, and the short term outcome are described. RESULTS: Various breeds (mean ± SD weight, 31.9 ± 13.3 kg) were included. Mean age at treatment was 64 ± 30.6 months. Minor complications occurred in 30% and major complications in 4% of the cases. Forty-eight (96%) dogs had a good to excellent outcome 3 months after surgery. CONCLUSION: The modified technique is a viable alternative to other osteotomy techniques.

The effect of anesthesia with propofol and sedation with butorphanol on quantitative contrast-enhanced ultrasonography of the healthy feline kidney.

Contrast-enhanced ultrasonography of the left kidney was performed using a commercial contrast agent in six healthy adult purpose-bred cats. A cross-over design was used to compare three protocols: (1) awake, (2) butorphanol (0.4 mg/kg IM), and (3) propofol (3.5-7.7 mg/kg IV boluses to effect). Time-intensity curves were created from two regions-of-interest drawn in the renal cortex. The curves were analyzed for blood flow parameters representing blood volume (base intensity, peak intensity, area-under-curve) and blood velocity (arrival time, time-to-peak, wash-in/out). There was no difference in the subjective enhancement pattern between the three protocols. No significant effect of butorphanol was observed in any of the perfusion parameters (P > 0.05). Propofol did not influence the most important perfusion parameter, area-under-the-curve, and is adequate for use in contrast-enhanced ultrasound studies.

Ultrasonographical examination of feline adrenal glands: intra- and inter-observer variability.

Interpretation of ultrasonographical measurements requires an understanding of the source and the magnitude of variation. A substantial part of the variation can be attributed to the observer, the equipment or the animal. The aim of this study was to evaluate which adrenal gland measurement is the least variable within and between observers. Three experienced ultrasonographers examined six cats at three different times on the same day, more than 1 h apart, according to a strict scanning protocol. Seven ultrasonographical measurements were performed on each adrenal gland (maximal length on sagittal images, maximal height at the cranial and caudal poles on sagittal and transverse images, and maximal width of the cranial and caudal poles on transverse images). Height measurements in both planes showed the lowest variability within and between observers compared with length and width measurements. Descriptive ultrasonographical features, such as echogenicity of the gland, presence of hyperechoic spots or layering assessment, demonstrated satisfactory-to-good intra- and inter-observer agreement, whereas the shape assessment showed very poor inter-observer agreement. The results of this study describe a reliable scanning protocol that can be the basis for future adrenal ultrasonographical examinations for cats suspected of adrenal disease (eg, hyperaldosteronism, hyperadrenocorticism, sex hormone-producing tumours).

Comparison of cross-sectional anatomy and computed tomography of the tarsus in horses.

OBJECTIVE: To compare computed tomography (CT) images of equine tarsi with cross-sectional anatomic slices and evaluate the potential of CT for imaging pathological tarsal changes in horses. SAMPLE: 6 anatomically normal equine cadaveric hind limbs and 4 tarsi with pathological changes. PROCEDURES: Precontrast CT was performed on 3 equine tarsi; sagittal and dorsal reconstructions were made. In all limbs, postcontrast CT was performed after intra-articular contrast medium injection of the tarsocrural, centrodistal, and tarsometatarsal joints. Images were matched with corresponding anatomic slices. Four tarsi with pathological changes underwent CT examination. RESULTS: The tibia, talus, calcaneus, and central, fused first and second, third, and fourth tarsal bones were clearly visualized as well as the long digital extensor, superficial digital flexor, lateral digital flexor (with tarsal flexor retinaculum), gastrocnemius, peroneus tertius, and tibialis cranialis tendons and the long plantar ligament. The lateral digital extensor, medial digital flexor, split peroneus tertius, and tibialis cranialis tendons and collateral ligaments could be located but not always clearly identified. Some small tarsal ligaments were identifiable, including plantar, medial, interosseus, and lateral talocalcaneal ligaments; interosseus talocentral, centrodistal, and tarsometatarsal ligaments; proximal and distal plantar ligaments; and talometatarsal ligament. Parts of the articular cartilage could be assessed on postcontrast images. Lesions were detected in the 4 tarsi with pathological changes. CONCLUSIONS AND CLINICAL RELEVANCE: CT of the tarsus is recommended when radiography and ultrasonography are inconclusive and during preoperative planning for treatment of complex fractures. Images from this study can serve as a CT reference, and CT of pathological changes was useful.

Short-term effect of recombinant human thyroid-stimulating hormone on thyroid volume and echogenicity in healthy beagles.

In humans, administration of recombinant human thyroid stimulating hormone (rhTSH) allows radioactive iodine dose reduction and higher efficacy in the treatment of multinodular goiter and thyroid cancer. A similar effect might be expected in dogs with thyroid carcinoma. However, if rhTSH leads to an increase in thyroid volume, it must be used carefully in dogs with large thyroid tumors to avoid compression of key anatomical structures. The aim of this study was to determine the short-term effect of rhTSH on thyroid volume and echogenicity, measured by ultrasonography, in healthy Beagles. Seven beagles were divided randomly in two groups in a prospective placebo-controlled blinded cross-over study. On day 1, one group received 100 microg of rhTSH intravenously and the other group received placebo. After a wash-out period of 3 weeks, the groups were crossed over. Evaluation of thyroid echogenicity, homogeneity, shape, capsule delineation, and measurement of thyroid length, width, and height were performed by the same observer at baseline, and at 6, 24, and 48h after injection of rhTSH and placebo. There was no significant difference between the effect of rhTSH and placebo on thyroid volume (P = 0.397), echogenicity, homogeneity, or capsule delineation. Time had a significant effect on thyroid volume (P = 0.027). No adverse effects after rhTSH administration were noticed. The effect of rhTSH on thyroid volume in dogs with thyroid carcinoma needs to be assessed.