Variation of actin filament length in dogs

As the smallest functional unit of force production, the sarcomeres are important in determining muscle function. Actin filament lengths, which are important in determining optimal sarcomere length for a species, have not yet been reported in dogs. This study aims to provide a species-specific value for actin filament length in dogs, while examining intraspecies, intermuscular and intramuscular variations. Muscle samples were taken from the tibialis anterior muscle, the lateral gastrocnemius muscle head and the medial gastrocnemius muscle head in 10 dogs including a Labrador, a Belgian Malinois, a Caucasian Shepherd, German Shepherds and some mixed-breed dogs. Actin filament lengths were determined through transmission electron microscopy. Mean actin filament length across all muscle samples was 0.90 ± 0.01 μm. The low intraspecies variation, combined with a lack of important inter- and intramuscular variation found in this study, affirms the use of a species-specific optimal sarcomere length of 1.89 μm for canine muscles.

Review of the literature

Elbow incongruity is the term to describe bad alignment of the joint surfaces of the elbow. Two features illustrate incongruity of the elbow: an abnormal shape of the ulnar trochlear notch and a step between the radius and ulna, caused by either a short radius or a short ulna. It has been suggested that both an elliptical notch, and a step, can cause increased local pressure within the joint, resulting in loose fragments at different locations: ununited anconeal process (UAP), fragmented coronoid process (FCP), osteochondritis dissecans of the humeral condyle (OCD). These lesions are grouped under the term ‘elbow dysplasia’ and are the most frequent causes of front leg lameness in the dog. Although several radiographic features to diagnose incongruity have been described, the ‘scoring’ of incongruity is subjective because there is currently no objective method to measure the degree of incongruity. Because superimposition is avoided, CT is suggested as a standard technique to measure incongruity. Arthroscopy on the other hand, allows the direct visualisation of the intra-articular structures and their abnormalities. Information on both techniques are still relatively new. Several surgical techniques have been proposed to restore joint congruity; the one most frequently used is an ulnar osteotomy. But because of possible complications, other techniques are being developed. Reports evaluating the results of the different techniques are not yet available.

Osteoinductive properties of the bone marrow Myth or reality

The osteogenic potential of red bone marrow was first reported more than 100 years ago. Since then, studies have reported controversial results that do not confirm nor disprove the capacity of fresh red bone marrow to produce bone. Researches have been focused on techniques that improve the efficiency of the bone marrow, including: the increase of the concentration of the mesenchymal stem cells in the aspirated bone marrow, the combination with a ‘carrier’ that helps to maintain the mesenchymal stem cells and guides and supports the vascular ingrowth in the defect, or the combination with bone growth factors that stimulate the marrow stromal cells to differentiate into bone forming cells. Each of these techniques has its drawbacks and increases the expenses of an operation. On the other hand, the synergistic effect observed with these combinations does not resolve the problem of the osteogenic capacity of pure bone marrow, which still remains questionable.

Computerized tomography compared with radiography in the diagnosis of lateral trochlear ridge talar osteochondritis dissecans in dogs

In this retrospective study, we compared the value of radiographic and computerized tomographic (CT) imaging for the diagnosis of lateral trochlear ridge talar osteochondritis dissecans (LTRT-OCD) in 11 tarsocrural joints. The flexed dorsoplantar skyline and the plantarolateral-dorsomedial projections were the most reliable for radiographic detection of OCD fragments (in 7 of the 11 joints). Overall, radiography detected OCD fragments in 8 of 11 joints. By contrast, the OCD fragments could be visualized and exactly localized by CT in all 11 joints. Computerized tomography allowed the talar ridges to be inspected without superimposition of any bony structures. This information may be very useful when minimal invasive techniques are used to treat LTRT-OCD lesions. The findings of this study suggest that CT is superior to radiography for making a diagnosis of LTRT-OCD in the dog.

Displacement of the proximal tendon of the long digital extensor muscle

A case of bilateral displacement of the proximal tendon of the long digital extensor (LDE) muscle has been described in a 5-year-old Siberian Husky. During surgery, a prosthetic roof was created over the extensor sulcus of the proximal tibia on both legs simultaneously.

Biomechanical Properties of Ethylene Oxide Sterilized and Cryopreserved Cortical Bone Allografts

To evaluate changes during preservation, 76 femoral segments of cortical bone of dogs were tested biomechanically in order to determine their strength in compression, in bending and in torsion. These bones were wrapped in plastic-paper and they were sterilized with ethylene oxide 12%, at 30° C and 1.4 bars and preserved thereafter at 舑20° C. According to the applied loading test, three treatment groups were devised; each treatment group was subdivided into five groups: one control (fresh specimen) and four test-groups differing from each other by the preservation time; i.e. 3, 6, 9 or 12 months. Statistical analysis has demonstrated that there is not a significant difference between the test results for each test-group and its control. The conclusion of this study was that bones, treated as described above, can be stored up to one year without risks to significantly reduce their strength in compression, in bending and in torsion.

To evaluate changes during preservation, femoral segments of cortical bone of dogs were tested biomechanically in order to evaluate their resistance in compression, in bending and to twisting moments. These bones were wrapped in plastic-paper and they were sterilized with ethylene oxide 12%, at 30° C and 1.4 bars and preserved thereafter at -20 ° C. Statistical analysis has shown that there was not a significant difference between the test results for each test-group and its control. As a conclusion, bone allografts, treated as described above, can be stored up to one year without risks to reduce significantly, their resistance to compressive, bending and torsional loads.

Diagnostic findings in a lame-free dog with complete rupture of the biceps brachii tendon

A case of a complete rupture of the biceps brachii tendon in a lame-free three-year-old Labrador Retriever is described. The dog had a history of chronic lameness following a trauma, but had become lame-free shortly before presentation. Clinical examination, biceps tendon test and shoulder instability tests under general anaesthesia were inconspicuous for shoulder instability. Routine radiographs, arthrography and ultrasound were suspicious for bicipital tendopathy. The definite diagnosis of a complete rupture of the biceps brachii tendon was made upon arthroscopic inspection of the glenohumeral joint.

Comparison of subchondral lesion size between clinical and non-clinical medial trochlear ridge talar osteochondritis dissecans in dogs

In this retrospective study of nine dogs exhibiting bilateral medial trochlear ridge talar osteochondritis dissecans (MTRT-OCD) and unilateral hind limb lameness, we compared subchondral lesion size in limbs with visible lameness, with contralateral lesions that were not associated with any visible lameness. All MTRT-OCD lesions were imaged by radiography and computed tomography (CT). The dimensions of subchondral bone lesions were measured (length, width and depth) using CT software. Similar to a method used in humans, the estimated volume (length x width x depth) and cross sectional area (length x width) were calculated and compared. We found that MTRT-OCD lesions causing visible lameness were significantly larger, and were associated with more joint thickening and degenerative joint disease than contralateral lesions that were not associated with any apparent lameness. As in the disease of shoulder osteochondritis dissecans, there is probably a correlation between the size of MTRT-OCD lesions and the symptoms of lameness.

A prospective follow up of age related changes in the subchondral bone density of the talus of healthy Labrador Retrievers

Background

During growth, the skeletal structures adapt to the increased loading conditions and mature to a fully-grown skeleton. Subchondral bone density reflects the effect of long-term joint loading and it is expected to change over time. The aim of this study was to describe the long-term changes in the density distribution of the subchondral bone of the talus of healthy Labrador Retrievers in a prospective study.

Results

The subchondral bone density distribution was evaluated using computed tomographic osteoabsorptiometry (CTOAM). Visually, all joints showed very similar density distribution patterns. No significant differences in the topography of the density maxima were found between t₁ and t₂. The mean density, maximum density, and maximum area ratio (MAR) were significantly increased with increasing age.

Conclusions

The subchondral bone density of the talus of healthy Labrador Retrievers increases with increasing age. It is likely an adaptive response of the subchondral bone due to increased joint loading during growth.

Subchondral bone density distribution of the talus in clinically normal Labrador Retrievers

BACKGROUND

Bones continually adapt their morphology to their load bearing function. At the level of the subchondral bone, the density distribution is highly correlated with the loading distribution of the joint. Therefore, subchondral bone density distribution can be used to study joint biomechanics non-invasively. In addition physiological and pathological joint loading is an important aspect of orthopaedic disease, and research focusing on joint biomechanics will benefit veterinary orthopaedics. This study was conducted to evaluate density distribution in the subchondral bone of the canine talus, as a parameter reflecting the long-term joint loading in the tarsocrural joint.

RESULTS

Two main density maxima were found, one proximally on the medial trochlear ridge and one distally on the lateral trochlear ridge. All joints showed very similar density distribution patterns and no significant differences were found in the localisation of the density maxima between left and right limbs and between dogs.

CONCLUSIONS

Based on the density distribution the lateral trochlear ridge is most likely subjected to highest loads within the tarsocrural joint. The joint loading distribution is very similar between dogs of the same breed. In addition, the joint loading distribution supports previous suggestions of the important role of biomechanics in the development of OC lesions in the tarsus. Important benefits of computed tomographic osteoabsorptiometry (CTOAM), i.e. the possibility of in vivo imaging and temporal evaluation, make this technique a valuable addition to the field of veterinary orthopaedic research.

Assessment of medial coronoid disease in 180 canine lame elbow joints: a sensitivity and specificity comparison of radiographic, computed tomographic and arthroscopic findings

Background

Diagnostic imaging is essential to assess the lame patient; lesions of the elbow joint have traditionally been evaluated radiographically, however computed tomography (CT) has been suggested as a useful technique to diagnose various elbow pathologies. The primary objective of this study was to determine the sensitivity and specificity of CT to assess medial coronoid disease (MCD), using arthroscopy as gold standard. The secondary objective was to ascertain the radiographic sensitivity and specificity for MCD compared with CT.

Methods

For this study 180 elbow joints were assessed, of which 141 had been examined with radiography, CT and arthroscopy; and 39 joints, had radiographic and CT assessment. Sensitivity and specificity were calculated for CT and radiographic findings using available statistical software.

Results

Sensitivity and specificity of CT using arthroscopy as gold standard resulted in high values for sensitivity (100 %) and specificity (93 %) for the assessment of MCD. For the radiographic evaluation, a sensitivity of 98 % and specificity of 64 - 69 % using CT as the technique of reference, were found.

Discussion

These results suggest that in case of doubt during radiographic assessment, CT could be used as a non-invasive technique to assess the presence of MCD.

Conclusion

Based on the high sensitivity and specificity obtained in this study it has been considered that CT, rather than arthroscopy, is the preferred noninvasive technique to assess MCD lesions of the canine elbow joint.

Low-Field Magnetic Resonance Imaging and Multislice Computed Tomography for the Detection of Cervical Syringomyelia in Dogs

BACKGROUND

Syringomyelia (SM) is defined as the presence of fluid-containing cavities within the parenchyma of the spinal cord. Sagittal magnetic resonance (MR) images have been described as the preferred technique for visualizing SM in dogs and humans.

OBJECTIVE

To investigate whether computed tomography (CT) can be used to diagnose SM.

ANIMALS

Thirty-two client-owned dogs referred for investigation of the cervical spine on magnetic resonance imaging (MRI) and CT.

METHODS

Two reviewers retrospectively analyzed sagittal and transverse T1-weighted spin echo (T1WSE) MR images and CT images from each dog for the presence of SM and, if SM was present, the width (mm, syrinx width [SW]) was measured. The results were analyzed statistically.

RESULTS

For the presence of SM there was a moderate interobserver agreement for MR (81%, κ = 0.54) and almost perfect agreement for CT (94%, κ = 0.87). There was a moderate intramodality agreement for both observers (observer 1 81%, κ = 0.59; observer 2 81%, κ = 0.57). For measurement of SW the repeatability was the best on the midsagittal T1WSE images (95% repeatability coefficient <0.52 mm) and the reproducibility was the best on midsagittal images in both modalities (95% limits of agreement -0.55-0.45; P = 0.002).

CONCLUSION AND CLINICAL IMPORTANCE

Both techniques can be used to detect SM. Midsagittal MR and CT images are best used for measuring SW. Computed tomography can be used as a diagnostic tool for SM when MRI is not available, but CT cannot replace MRI as the standard screening technique for the detection of SM in Cavalier King Charles Spaniel for breeding purposes.

Low-field MRI and multislice CT for the detection of cerebellar (foramen magnum) herniation in Cavalier King Charles Spaniels

Background

Cavalier King Charles Spaniels (CKCS) have a high prevalence of Chiari‐like malformation (CM). Herniation of the cerebellum into the foramen magnum is a key diagnostic feature for CM. Midsagittal MR images are the preferred technique for visualizing cerebellar herniation (CH).

Objective

To investigate whether CT can be used to diagnose CH.

Animals

Fifteen client‐owned CKCS dogs referred for investigation of the brain and cranial cervical spine on MRI and CT.

Methods

Two reviewers retrospectively analyzed midsagittal T1WSE and T2WSE MR images and midsagittal pre‐ and postcontrast 2D multiplanar reformatted CT images from each dog for the presence of CH. And, if present, the length (mm, CHL) of the herniation was measured. The results were analyzed statistically.

Results

There was no significant difference between the different observers and techniques for the detection of CH and measurement of CHL. Overall, the CHL was longer on the CT images.

Conclusion and Clinical Importance

Both techniques are useful for detecting CH and measuring CHL. Because CHL does not have a known direct impact on the clinical presentation of CM, CT can be used as a diagnostic tool in a routine clinical practice for CM in CKCS when MRI is not available. We emphasize that MRI is the standard screening technique in CKCS for breeding purposes to detect the presence of CM and SM and, at the current time, CT cannot replace MRI.

Prevalence of hip dysplasia, elbow dysplasia and humeral head osteochondrosis in dog breeds in Belgium

The official screening results of the Belgian National Committee for Inherited Skeletal Disorders, an affiliate of the Belgian Kennel Club, have been used to estimate the prevalence of hip dysplasia, elbow dysplasia and humeral head osteochondrosis in the dog breeds in Belgium, and these have been compared with reported prevalence data from other countries. In some breeds, the prevalence of hip and elbow dysplasia is very high, both in Belgium and in other countries. Comparisons of the prevalence of hip dysplasia are not always feasible because different systems are used to evaluate the quality of the hips and because there is no strict consensus on what should be considered a diseased hip joint.

Correlation of histology of healed fractures and tissue surrounding implants with ultrasonographic and radiographic appearance

OBJECTIVES

To determine if there was histological correlation with ultrasonographic images of healed fractures and implant-associated tissue after fracture treatment by plate osteotomy.

METHODS

Eight adult dogs were included in this retrospective study. Ultrasonography (B-mode and power Doppler) and radiography were performed before plate removal. Surgical biopsies were taken of the fracture site and the tissue adjacent to the plate. These were stained with haematoxylin and eosin to assess histomorphology and bone content and immunolabelled with CD31 to assess vascularity.

RESULTS

Ultrasound and radiographic diagnoses of a healed fracture correlated with histological finding of bone healing. Ultrasonography and histology findings of vascularity were also highly correlated. The tissue surrounding the surgical implants was significantly more vascularised on both ultrasonography and histology than that at the fracture site itself.

CLINICAL RELEVANCE

Ultrasonography can be used to diagnose fracture healing in plated fractures. Power Doppler ultrasonography examination of fracture healing should be performed away from surgical implants to avoid false-positive results of vascularisation.

Radiographic assessment of the progression of osteoarthrosis in the contralateral stifle joint of dogs with a ruptured cranial cruciate ligament

The formation and progression of osteoarthrosis in the unaffected contralateral stifle joints of 14 dogs with a unilateral cranial cruciate ligament rupture were monitored radiographically in terms of a global score and the scores for 10 parameters specific for the stifle joint. The dogs were examined initially and six and 12 months later by three observers, and the variability between the observers' scores was also assessed. The score for osteophytes at the tibial attachment site of the ligament was the most reliable parameter, and that for the increase in femoropatellar joint space was the least reliable. In the contralateral stifle joints there were significant increases after six and 12 months in osteophyte formation caudal to the tibial plateau, and in subchondral sclerosis of the tibial plateau and of the long digital extensor muscle groove. These three parameters progressed more regularly during the disease process than the other parameters. The global osteoarthrosis score of the contralateral stifle joint was an important risk factor for sustaining a rupture of the cranial cruciate ligament in that joint during the next six months.

Penetrating injuries in dogs and cats. A study of 16 cases

The objective of this retrospective study was to assess radiographical and surgical findings, surgical management and outcome of penetrating injuries in dogs and cats by evaluating patient records. Sixteen patients were identified (15 dogs and one cat), four with gunshot wounds, and 12 with fight wounds (11 with bite wounds, one struck by a claw). The thoracic cavity was affected in six patients, the abdominal cavity in three cases. Both cavities were affected in five dogs and the trachea in two cases. All of the patients with fight wounds were small breed dogs. Multiple injuries to internal organs that required intervention were found surgically after gunshot wounds and a high amount of soft tissue trauma requiring reconstruction was present after fight wounds. Radiography diagnosed body wall disruption in two cases. All of the affected thoracic body walls in the fight group had intercostal muscle disruptions which was diagnosed surgically. Fourteen patients survived until discharge and had a good outcome. In conclusion, penetrating injuries should be explored as they are usually accompanied by severe damage to either the internal organs or to the body wall. A high level of awareness is required to properly determine the degree of trauma of intercostal muscle disruption in thoracic fight wounds.

Ultrasonographic assessment of fracture healing after plate osteosynthesis

The goals of this study were to assess the ability of ultrasonography (US) to assess uncomplicated fracture healing and to establish normal images. Twenty-two dogs, ranging in age from 6 to 180 months were studied. Body weight ranged from 2.2 to 60 kg. All fractures were treated by plate osteosynthesis. US (B-mode and power Doppler) and radiography were performed until both were consistent with complete healing. B-mode US was performed in all dogs, and power Doppler US in 14. Fracture healing was judged to be complete based on US earlier than when based on radiography. The tissue immediately adjacent to the plate appeared vascularized on power Doppler images at a time when the tissue at the fracture site had a negative power Doppler exam. US appears useful for assessment of primary fracture healing and power Doppler was useful for detecting vascularization at the fracture site in nonhealed fractures. Power Doppler interrogation should be performed away from any metal implant, as a result from an interrogation adjacent to an implant will not reflect actual vascularization at the fracture site.

Lymphocyte Proliferation to Collagen Type I in Dogs

The objective of this study was to investigate if cellular reactivity to collagen type I exists in dogs with unilateral cranial cruciate ligament (CrCL) rupture and if it relates to disease progression. The patient group consisted of 10 dogs with unilateral CrCL rupture. The control dogs consisted of three healthy control dogs, and two healthy dogs with unilateral sham operations of the stifle joint. All dogs were assayed repeatedly every 6 months for 12-24 months. Peripheral blood mononuclear cells were isolated from whole blood and were cultured with human collagen type I at concentrations of 5, 20 and 40 microg/ml for 6 and 7 days. Lymphocyte reactivity to collagen type I occurred not only in dogs with CrCL rupture, but also in sham-operated dogs and healthy dogs. Five of the eight assays (63%) performed at the time of operation or at the time of diagnosis of CrCL rupture had a stimulation index (SI) >or=3.0. This was not significantly different compared to healthy control dogs, not to the sham-operated control dogs. The CrCL rupture was assessed intraoperatively in six cases. Three cases had partial rupture and three had complete rupture. Only one dog with partial rupture, and two dogs with complete rupture had a positive SI. An increase in proliferation to collagen type I was seen in dogs with CrCL rupture, whereas it either remained stable or decreased in the control dogs. No distinct pattern in lymphocyte reactivity to collagen type I could be established from the dogs that sustained a CrCL rupture in the contralateral stifle joint, although most dogs that did not sustain a CrCL rupture in the contralateral stifle joint remained negative during this study with exception of one dog. Further research is required to determine whether cellular reactivity to collagen type I may play an initiating role in cruciate degradation.

Interobserver agreement in the diagnosis of canine hip dysplasia using the standard ventrodorsal hip-extended radiographic method

OBJECTIVES

To determine the agreement between observers and to investigate the effect of observer experience in diagnosing canine hip dysplasia and providing final scoring of hips using the standard ventrodorsal hip-extended radiographic method. The agreement of the final scoring, with a presumed correct assessment based on the Norberg angle, is also investigated.

METHODS

Thirty observers were requested to read 50 ventrodorsal hip-extended radiographs of 25 dogs according to Federation Cynologique International criteria. Groups of experienced (nine members) and inexperienced (21 members) observers were used.

RESULTS

For providing the distinction between dysplastic versus non-dysplastic dogs, the average interobserver agreement was 72 per cent and was significantly higher (P<0.0001) than the score that could be expected by chance without any agreement between observers. For providing the final score (A, B, C, D or E), an average interobserver agreement of 43.6 per cent was found. In the experienced group, an agreement score of 76 per cent was found for the distinction between AB versus non-AB and an agreement score of 81 per cent was found for the distinction between C versus non-C. The agreement score was significantly higher (P<0.0001) for the experienced group than for the inexperienced group in all cases. Agreement between the presumed correct assessment based on the Norberg angle and the observer's evaluation was low (P=0.35), irrespective of whether the observers were experienced (71.8 per cent correct assessments) or inexperienced (69 per cent correct assessments).

CLINICAL SIGNIFICANCE

Although interobserver agreement is low, observer experience increases agreement.

The use of an external skeletal traction device for distal fractures in the dog. A clinical case series of 11 patients

Metacarpal and metatarsal fractures in 11 patients were treated 'closed' with a specially designed External Skeletal Fixation (ESF) frame with a walking bar and traction applied to the digits. Mediolateral angulation had improved postoperatively in 10 of the 11 patients. Craniocaudal angulation had improved in eight patients and could not be evaluated in three due to ESF frame superimposition. At follow-up, eight patients had a good clinical function, whereas three patients were still slightly lame. Only minor ESF-related complications were seen (pin loosening, pin tract infection, cerclage wire breakage and bending of the frame), which resolved without intervention after frame removal.

Excision arthroplasty of the interphalangeal joint as an alternative to digit amputation in two dogs

Excision arthroplasty of the interphalangeal joint was used as an alternative to digit amputation for comminuted fractures of the phalangeal bones in two dogs. Both patients had return of pain-free use of the affected limb, even though both weight-bearing digits were involved in one case. This type of surgery might prove to be superior to the more invasive digit amputation, salvaging the digits and providing a better functional outcome.

Diagnostic findings in a lame-free dog with complete rupture of the biceps brachii tendon. A case report in a unilaterally affected working Labrador Retriever

A case of a complete rupture of the biceps brachii tendon in a lame-free three-year-old Labrador Retriever is described. The dog had a history of chronic lameness following a trauma, but had become lame-free shortly before presentation. Clinical examination, biceps tendon test and shoulder instability tests under general anaesthesia were inconspicuous for shoulder instability. Routine radiographs, arthrography and ultrasound were suspicious for bicipital tendopathy. The definite diagnosis of a complete rupture of the biceps brachii tendon was made upon arthroscopic inspection of the glenohumeral joint.

Comparison of subchondral lesion size between clinical and non-clinical medial trochlear ridge talar osteochondritis dissecans in dogs

In this retrospective study of nine dogs exhibiting bilateral medial trochlear ridge talar osteochondritis dissecans (MTRT-OCD) and unilateral hind limb lameness, we compared subchondral lesion size in limbs with visible lameness, with contralateral lesions that were not associated with any visible lameness. All MTRT-OCD lesions were imaged by radiography and computed tomography (CT). The dimensions of subchondral bone lesions were measured (length, width and depth) using CT software. Similar to a method used in humans, the estimated volume (length x width x depth) and cross sectional area (length x width) were calculated and compared. We found that MTRT-OCD lesions causing visible lameness were significantly larger, and were associated with more joint thickening and degenerative joint disease than contralateral lesions that were not associated with any apparent lameness. As in the disease of shoulder osteochondritis dissecans, there is probably a correlation between the size of MTRT-OCD lesions and the symptoms of lameness.

Swimmer syndrome in a Devon rex kitten and an English bulldog puppy

A three-week-old Devon rex kitten and a four-week-old English bulldog puppy were presented with "swimmer syndrome". The owners consulted several veterinarians who suggested euthanasia as the only possible solution for this condition. Physiotherapy in the puppy, and physiotherapy and bandaging in the kitten led to the resolution of the clinical signs and resulted in normal ambulation after several weeks. The authors concluded that intensive physiotherapy and dedication of the owner can lead to success.

Endoscopic Examination and Tissue Sampling of the Bovine Teat and Udder Cistern

The aim of this study was to evaluate the application of an endoscopic technique to investigate the teat and udder cisterns of the bovine mammary gland, and to biopsy tissues within the cisterns. An anesthetic protocol for application in standing animals was designed, using a combination of general and local anesthesia. Individual quarter milk production (QMP), quarter somatic cell count (SCC), and occurrence of new intramammary infection were assessed after application of the technique, and possible applications for biopsies collected were investigated. Bovine teat and gland cistern lining could be visualized and small biopsy samples could be collected. The collected biopsy samples were successfully used in histological-histopathological examination and PCR analysis. To study the impact of endoscopy on QMP, milk SCC, and bacteriology, endoscopic examination of 12 low SCC (<200,000 cells/ mL) quarters was performed in 8 different first- and second-lactation cows. Immediately following endoscopy, 8 quarters received antibiotic treatment, whereas 4 quarters remained untreated. During a 15-d follow-up, no new intramammary infection could be observed in the endoscopically treated quarters. For QMP, no significant interaction between time and treatment could be observed throughout the 15-d follow-up period. Quarter SCC did not differ among treatments (control, endoscopy with antibiotics, and endoscopy without antibiotics). In conclusion, the endoscopic technique is suitable for examination and tissue biopsy collection of the bovine mammary gland cisterns without major interference with QMP and quarter SCC.

Review of the literature: elbow incongruity in the dog

Elbow incongruity is the term to describe bad alignment of the joint surfaces of the elbow. Two features illustrate incongruity of the elbow: an abnormal shape of the ulnar trochlear notch and a step between the radius and ulna, caused by either a short radius or a short ulna. It has been suggested that both an elliptical notch, and a step, can cause increased local pressure within the joint, resulting in loose fragments at different locations: ununited anconeal process (UAP), fragmented coronoid process (FCP), osteochondritis dissecans of the humeral condyle (OCD). These lesions are grouped under the term 'elbow dysplasia' and are the most frequent causes of front leg lameness in the dog. Although several radiographic features to diagnose incongruity have been described, the 'scoring' of incongruity is subjective because there is currently no objective method to measure the degree of incongruity. Because superimposition is avoided, CT is suggested as a standard technique to measure incongruity. Arthroscopy on the other hand, allows the direct visualisation of the intra-articular structures and their abnormalities. Information on both techniques are still relatively new. Several surgical techniques have been proposed to restore joint congruity; the one most frequently used is an ulnar osteotomy. But because of possible complications, other techniques are being developed. Reports evaluating the results of the different techniques are not yet available.

Osteoinductive properties of the bone marrow--myth or reality

The osteogenic potential of red bone marrow was first reported more than 100 years ago. Since then, studies have reported controversial results that do not confirm nor disprove the capacity of fresh red bone marrow to produce bone. Researches have been focused on techniques that improve the efficiency of the bone marrow, including: the increase of the concentration of the mesenchymal stem cells in the aspirated bone marrow, the combination with a 'carrier' that helps to maintain the mesenchymal stem cells and guides and supports the vascular ingrowth in the defect, or the combination with bone growth factors that stimulate the marrow stromal cells to differentiate into bone forming cells. Each of these techniques has its drawbacks and increases the expenses of an operation. On the other hand, the synergistic effect observed with these combinations does not resolve the problem of the osteogenic capacity of pure bone marrow, which still remains questionable.

The Effect of Different Isolation Procedures on Canine Leucocyte Populations and on Lectin-induced Lymphocyte Proliferation

Proliferation assays performed on peripheral blood mononuclear cells (PBMC) are commonly used in experimental and clinical immunology. A prerequisite for an in vitro assay is the ability to obtain relatively pure populations of mononuclear cells from whole blood, as contaminating polymorphonuclear cells may affect the proliferation of lymphocytes. Purification of canine leucocytes from whole blood is associated with difficulties in obtaining pure lymphocytes in high yields. The aim of this study was to optimize the lymphocyte purification from canine whole blood in terms of total cell recovery and purity, while not influencing the proliferation capacity of the isolated cells. To acquire optimal isolation of canine lymphocytes several density gradient media of different densities and osmolalities were examined. For optimal phagocyte removal, pre-treatment of whole blood with carbonyl iron/arabic gum and/or adherence to fibrinogen pre-coated polystyrene tissue flasks were examined. Lectin-induced proliferation was used as measurement of cell activity of the obtained cell fractions after the different separation procedures. Canine blood pre-treated with carbonyl iron/arabic gum followed by density gradient centrifugation with medium 'G' (density: 1.079 g/cm(3), osmolality: 256 mOsm) and adherence to pre-coated polystyrene tissue flask obtained the best PBMC cultures with a median lymphocyte purity of 88% and a median yield of recovered lymphocytes of 54%. This culture also resulted in the highest proliferation and subsequently the highest stimulation index upon lectin stimulation.

Interleukin-8 mRNA expression in synovial fluid of canine stifle joints with osteoarthritis

The objective of this study was to examine and compare the presence of interleukin (IL)-8 mRNA in canine stifle osteoarthritis (OA) differing in etiopathogenesis. Synovial fluid (SF) samples were collected from 24 clinically normal stifle joints and 46 diseased stifle joints (32 stifle joints with cranial cruciate ligament rupture (CCLR), 2 joints with CCLR and patella luxation (PL), 7 joints with medial PL and 5 joints with primary OA). The samples were centrifuged to collect synovial fluid cells for RNA extraction. Reverse transcription polymerase chain reaction (RT-PCR) was performed to obtain cDNA from all samples. Canine IL-8 mRNA expression was determined using real time PCR. Synovial fluid glass smears were made of all samples and coloured with H&E for differential cell counts. All stifle joints were radiographed and graded for the severity of OA. Sixty-one percent (28/46) of the samples from canine stifle OA had IL-8 mRNA expression in contrast to 4% (1/24) in the control stifle joints. This difference in prevalence is highly significant. There were no statistically significant pairwise differences among the mean ranks of the various OA groups for the absolute amount of IL-8 mRNA expression. Neither was there a link between the severity of OA (determined by radiographic evaluation) and the presence of IL-8 in the SF nor any significant difference in the absolute amount of IL-8 between the different OA grades. No statistical difference was found in differential cell counts between IL-8-positive and -negative SF samples. IL-8 cannot be used as a specific joint disease marker since IL-8 expression is found in OA differing in etiopathogenesis. It might, however, relate to the ongoing inflammation within the joint.

Computerized tomography compared with radiography in the diagnosis of lateral trochlear ridge talar osteochondritis dissecans in dogs

In this retrospective study, we compared the value of radiographic and computerized tomographic (CT) imaging for the diagnosis of lateral trochlear ridge talar osteochondritis dissecans (LTRT-OCD) in 11 tarsocrural joints. The flexed dorsoplantar skyline and the planta-rolateral-dorsomedial projections were the most reliable for radiographic detection of OCD fragments (in 7 of the 11 joints). Overall, radiography detected OCD fragments in 8 of 11 joints. By contrast, the OCD fragments could be visualized and exactly localized by CT in all 11 joints. Computerized tomography allowed the talar ridges to be inspected without superimposition of any bony structures. This information may be very useful when minimal invasive techniques are used to treat LTRT-OCD lesions. The findings of this study suggest that CT is superior to radiography for making a diagnosis of LTRT-OCD in the dog.

Influence of acetylsalicylic acid and ketoprofen on canine thyroid function tests

Many factors including drugs can influence thyroid function in humans, rats and dogs. Studies in humans report significant effects of non-steroidal anti-inflammatory agents (NSAIDs) on thyroid function tests, which can lead to misinterpretation of the results and inappropriate therapeutic decisions. As NSAIDs are used more and more frequently in dogs, it is important to know to what extent they can influence results. Eighteen spayed female beagle dogs were randomly assigned to three treatment sequences in a 3 x 3 crossover study design with treatments consisting of acetylsalicylic acid (ASA) (25 mg/kg BW q 12 h), ketoprofen (Keto) (1 mg/kg BW q 24 h) or placebo administered for a 1-week period with a 3-week washout period between treatment periods. Blood samples for determination of total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), thyrotropin (TSH), reverse triiodothyronine (rT3), Keto and ASA concentrations were taken during each treatment period on days 0, 1, 3 and 7. During the washout period samples were taken weekly. A significant decrease in TT4 was observed as soon as 24 h after ASA administration, whereas the decrease in TT3 was less pronounced and differed significantly from the placebo only after 1 week of administration. No significant effects were found for free T4 and TSH with ASA administration. No significant effects on thyroid results were found following Keto administration. The results indicate that TT4 can be markedly decreased by ASA therapy and until the results of further studies are available, thyroid function test results should be interpreted cautiously in dogs on NSAIDs therapy.

Regional binding index of the radiolabeled selective 5-HT2A antagonist 123I-5-I-R91150 in the normal canine brain imaged with single photon emission computed tomography

The pattern of the specific 5-HT2A (5-hydroxytryptamine 2A receptor) antagonist 123I-5-I-R91150 was measured in 10 healthy dogs without neurologic and behavior abnormalities. Eight cortical regions (left and right fronto-, temporo-, parieto-, and occipitocortical area), one global subcortical region (including the thalamic system) were compared with a reference region lacking receptors; that is, the cerebellum. The 123I labeled radioligand was injected intravenously 100-200 minutes before acquisition. Both transmission and emission data were obtained with a triple head gamma camera equipped with high-resolution fanbeam collimators. The emission data were corrected for scatter and attenuation. To delineate different cerebral regions more accurately, the regions of interest (ROI) defined in a former study on brain perfusion measured with 99mTc-ethyl cysteinate dimer (ECD) in the same dogs were used. The co-registration of the 99mTc-ECD and the 123I-5-I-R91150, obtained from each dog, was realized with the help of corresponding transmission maps. By normalizing each regional cerebral activity to the activity observed in the cerebellum, the regional radioactivity (binding index) could be relatively quantified. Highest brain uptake was noted in the frontocortical brain areas (right: 1.85, left: 1.89), followed by the temporocortical region (right: 1.58, left: 1.56). Least uptake was noted in the more caudal and middle brain regions [occipito- (right: 1.46, left: 1.41), parietocortical (right: 1.30, left: 1.26), and striatal region (1.19)]. No gender nor age influence was noted in this series. The 123I labeled serotonin-2A receptor ligand seems to have similar cortical binding in the normal canine brain, as shown in humans and other animal species. A frontocortical to occipitocortical (rostrocaudal) binding index gradient was identified within the dog, which has not been seen in imaging studies from humans and other animal species. The significance of these results will need further investigation. This normative data can be used to compare regional brain uptake of the 123I-radioligand to dogs with behavioral disorders related to the serotonergic system, in future studies.

Approaches for ultrasonographic evaluation of long bones in the dog

The objective of this study was to identify access portals for ultrasonographic evaluation of canine long bones (humerus, radius, ulna, femur, and tibia). A 7.5 MHz linear transducer was used in five medium-sized dogs (range of 25-35 kg body weight). Good approaches could be identified for all long bones. For the proximal humerus, a cranial portal, and the distal humerus, a lateral portal is suggested. For the radius and ulna, a craniolateral approach seemed to be the best. In the hindlimb, a medial approach for the femur and a craniolateral approach for the tibia were the most effective approaches.

Radiographic, computed tomographic and arthroscopic findings in 23 dogs with osteochondrosis of the tarsocrural joint

Twenty-three dogs with osteochondrosis of the tarsocrural joint were evaluated by radiography, computed tomography (CT) and arthroscopy. The radiographic examination included an extended and flexed mediolateral, a plantarodorsal, a flexed dorsoplantar skyline view, and a plantaromedial-dorsolateral and a plantarolateral-dorsomedial view (two oblique views). The CT examination was carried out in ventral recumbency and 1 mm slices were taken with a bone window setting; 31 lesions were identified in the 46 joints examined. The arthroscopic exploration used either a plantar or a dorsal puncture, depending on the site of the lesion. In six cases the lateral, and in 17 cases the medial trochlear ridge was involved. Although the survey radiographs were sufficient to make a diagnosis, the CT examination helped to determine the exact site, and the number and size of the fragments of bone. A four-stage classification system comparable to the one used in man was established. Arthroscopy provided information about synovial inflammation and damage to the joint cartilage, and made it possible to remove fragments of bone from one-third of the cases.

Biomechanical properties of braided polyester tapes intended for use as intra-articular cranial cruciate ligament prostheses in dogs

OBJECTIVE

To determine the in vitro structural and material properties of braided, multifilament, nonabsorbable polyester tapes, used for intra-articular stabilization of cranial cruciate ligament- (CCL-) deficient stifle joints in dogs, and compare those with properties of multifilament polyamide tapes.

SAMPLE POPULATION

30 polyester tapes (width, 4 mm), 10 polyester tapes (width, 7 mm), and 30 polyamide tapes (width, 4 mm) were tested to failure. Cyclic loading experiments were also performed, using 3 polyester tapes of each width.

PROCEDURE

Tapes were mounted in a tensile tester as single loops, simulating intra-operative conditions, and elongated to failure at 1,000 mm/min. Additionally, the behavior of polyester tapes was tested at different elongation rates. In a second series of experiments, biomechanical variables of the polyester tapes were measured after 25 sets of 2,000 cycles between physiologic force limits.

RESULTS

Mean (+/- SD) ultimate loads of the 4-mm wide polyamide tapes, 4-mm wide polyester tapes, and 7-mm wide polyester tapes were 266.48 +/- 13.19 301.78 +/- 16.92, and 726.40 +/- 37.74 N, respectively. Corresponding stiffnesses were 15.57 +/- 0.49, 21.63 +/- 2.19, and 34.85 +/- 2.66 N/mm, respectively. Failure properties of polyester tapes were affected by previous cyclic loading.

CONCLUSIONS AND CLINICAL RELEVANCE

Polyester tapes of 4- or 7-mm widths should be able to resist forces resulting from weight bearing in dogs, suggesting that these tapes will be effective for stabilization of the stifle joint in dogs with a ruptured CCL.

Prevalence and relevance of antibodies to type-I and -II collagen in synovial fluid of dogs with cranial cruciate ligament damage

OBJECTIVE

To measure and compare synovial fluid antibody titers to type-I and -II collagen in stifle joints with instability caused by complete or partial cranial cruciate ligament (CCL) rupture and joints with osteoarthrosis secondary to other pathologic changes in dogs.

ANIMALS

82 dogs with diseased stifle joints.

PROCEDURE

Synovial fluid samples were collected from 7 dogs with clinically normal stifles (control group) and 82 dogs with diseased joints (50 stifle joints with complete rupture of the CCL, 20 with partial damage of the CCL, and 12 joints with radiographic signs of osteoarthritis secondary to other arthropathies). Synovial fluid samples were tested for autoantibodies to type-I and -II collagen by an ELISA.

RESULTS

In dogs with complete and partial CCL rupture, synovial fluid antibody titers to type-I and -II collagen were significantly increased, compared with control dogs. Forty-eight percent (24/50) of samples from dogs with complete CCL rupture and 35% (7/20) of samples from dogs with partial CCL rupture had antibody titers to type-I collagen that were greater than the mean plus 2 standard deviations of the control group titers. Synovial fluid antibody titers to type-II collagen were high in 40% of the dogs with partial or (8/20) complete (20/50) CCL rupture. Dogs with osteoarthrosis secondary to other pathologic changes had significantly increased synovial fluid antibodies to type-I and -II collagen, compared with control dogs.

CONCLUSION

Increases in autoantibodies to collagen in synovial fluid are not specific for the type of joint disorder. It is unlikely that the anticollagen antibodies play an active role in the initiation of weakening of the CCL.

Use of compression stress radiography for the detection of partial tears of the canine cranial cruciate ligament

Twenty-three cases of partial rupture of the cranial cruciate ligament (CCL) were reviewed. All of these patients were evaluated for clinical and radiographic signs of instability. Nine cases showed a negative drawer sign on manual assessment. A positive radiographic tibial compression test was obtained for all stifle joints with a partially ruptured cruciate. In 13 cases, the site of injury and the appearance of the torn ends were evaluated. The final diagnosis of partial CCL rupture was made by direct visualisation and probing of the CCL during arthrotomy (22 cases) or arthroscopy (one case).

Radiographic measurement of craniocaudal instability in stifle joints of clinically normal dogs and dogs with injury of a cranial cruciate ligament

OBJECTIVE

To determine craniocaudal laxity of the stifle joint of dogs when joints were positioned in tibial compression or neutral position.

SAMPLE POPULATION

19 normal stifle joints in 10 clinically normal dogs, 29 stifle joints with varying injury to the cranial cruciate ligament (10 complete ruptures alone, 10 complete ruptures with concomitant damage to the medial meniscus, 6 partial ruptures alone, and 3 partial ruptures with concomitant meniscal tearing), and 19 unaffected contralateral stifle joints in those 29 dogs.

PROCEDURE

Relative displacement of bony landmarks was measured on paired lateral radiographs (neutral and tibial compression positions). Two measuring techniques were customized for use in dogs.

RESULTS

The first technique failed to distinguish results in normal stifle joints from those in stifle joints with partial deficiency of cranial cruciate ligaments. Significant differences were found for joints with complete rupture, compared with stifle joints in clinically normal dogs. The second technique detected differences between normal stifle joints and injured joints with partial or complete rupture of the cranial cruciate ligament. Significant differences were not detected between joints with partial versus complete rupture. Adjusting data to account for size of dog did not improve results.

CONCLUSIONS AND CLINICAL RELEVANCE

A wide range in measurements of laxity was found for stifle joints with intact cranial cruciate ligaments. Differences in degree of damage to the ligament and medial meniscus cannot be deduced from the amount of relative displacement measured on radiographs. Pathologic changes to the cranial cruciate ligament will not necessarily induce detectable changes in laxity of stifle joints in dogs.

Popliteal sesamoid displacement associated with cruciate rupture in the dog

Distal displacement of the popliteal sesamoid is a useful parameter in the interpretation of tibial compression radiographs in cases of cranial cruciate ligament rupture in the dog. An accuracy of 99 per cent and a specificity of 100 per cent were achieved by assessing the localisation of the sesamoid bone in the diagnosis of cruciate disease.

Diagnosis of cranial cruciate ligament injury in dogs by tibial compression radiography

Stress radiographs were taken of 42 sound stifle joints, of five stifles with injuries other than cruciate disease, and of 72 stifles with surgically confirmed cranial cruciate damage. The stifles were also examined by the cranial drawer test. No false positive compression radiographs were obtained. In the 72 stifles with cranial cruciate damage, instability was diagnosed on the stressed view in all but two cases. The sensitivity of the radiographic tibial compression test was 97 per cent, compared with 86 per cent for the cranial drawer test; the specificities of the tests were 100 per cent and nearly 98 per cent, respectively.