Radiographic and computed tomographic assessment of the development of the antebrachia and elbow joints in Labrador Retrievers with and without medial coronoid disease.

OBJECTIVES: To compare the development, monitored by radiography and computed tomography, of the antebrachia and elbow joints in seven Labrador Retrievers with healthy elbow joints and in seven Labrador Retrievers that developed medial coronoid disease (MCD), in order to determine whether disturbances in the development of the antebrachia and elbow joints, between the age of six and 17 weeks may lead to medial coronoid disease. METHODS: A prospective study of 14 Labrador Retrievers in their active growth stage was performed. The development of the antebrachia and elbow joints was assessed between six and 17 weeks of age using radiography and computed tomography determining the development of secondary ossification centres, radioulnar length ratio, radial angulation, and inter-relationship between the humerus, ulna and radius. RESULTS: For the parameters of ossification of secondary ossification centres, radioulnar length ratio, radial angulation, and joint congruence evaluation, there was no significant difference in the development of the antebrachia and elbow joints of seven Labrador Retrievers positive and seven Labrador Retrievers negative for MCD at the age of six to 17 weeks. CLINICAL SIGNIFICANCE: These findings demonstrate that the development of MCD in the Labrador Retrievers in our study was not related to any disturbance in the development of the antebrachia and elbow joints during the rapid growth phase.

Skeletal and hepatic changes induced by chronic vitamin A supplementation in cats.

The first aim of this study was to determine whether vitamin D supplementation influenced the effects of high vitamin A intake on new bone formation in adult cats. The second aim was to determine whether high vitamin A intake in cats caused liver pathology and, if so, whether the current upper limit for the dietary intake of vitamin A for healthy adult cats would be safe. Twenty-four healthy adult cats were divided into four groups that received a control diet supplemented with peanut oil (control), or peanut oil containing a 100-fold increase in vitamin A (HA), or a 100-fold increase in vitamin A and a fivefold increase in vitamin D (HAMD), or a 100-fold increase in vitamin A and a 65-fold increase in vitamin D (HAHD) over a period of 18 months. Cats did not show abnormal locomotion or clinical signs of liver failure after 18 months of supplementation but did show subtle skeletal changes and liver pathology, suggesting that the current National Research Council (2006) safe upper limit for vitamin A for cats is too high. The addition of vitamin D did not seem to influence bone pathology. While moderately elevated dietary vitamin D levels (HAMD) seemed to protect cats against the liver pathology caused by the consumption of large amounts of vitamin A, higher dietary levels of vitamin D (HAHD) did not seem to be protective.

Assessment of articular cartilage and subchondral bone using EPIC-microCT in Labrador retrievers with incipient medial coronoid disease.

The aetiopathogenesis of medial coronoid disease (MCD) remains obscure, despite its high prevalence. The role of changes to subchondral bone or articular cartilage is much debated. Although there is evidence of micro-damage to subchondral bone, it is not known whether this is a cause or a consequence of MCD, nor is it known whether articular cartilage is modified in the early stages of the disease. The aim of the present study was to use equilibrium partitioning of an ionic contrast agent with micro-computed tomography (microCT) to investigate changes to both the articular cartilage and the subchondral bone of the medial coronoid processes (MCP) of growing Labrador retrievers at an early stage of the disease and at different bodyweights. Of 14 purpose-bred Labrador retrievers (15-27 weeks), six were diagnosed with bilateral MCD and one was diagnosed with unilateral MCD on the basis of microCT studies. The mean X-ray attenuation of articular cartilage was significantly higher in dogs with MCD than in dogs without MCD (P<0.01). In all dogs, the mean X-ray attenuation of articular cartilage was significantly higher at the lateral (P<0.001) than at the proximal aspect of the MCP, indicating decreased glycosaminoglycan content. Changes in parameters of subchondral bone micro-architecture, namely the ratio of bone volume to tissue volume (BV/TV), bone surface density (BS/TV), bone surface to volume ratio (BS/BV), trabecular thickness (Tb.Th; mm), size of marrow cavities described by trabecular spacing (Tb.Sp; mm), and structural model index (SMI), differed significantly by litter (P<0.05) due to the difference in age and weight, but not by the presence/absence of MCD (P>0.05), indicating that subchondral bone density is not affected in early MCD. This study demonstrated that cartilage matrix and not subchondral bone density is affected in the early stages of MCD.

Delayed endochondral ossification in early medial coronoid disease (MCD): a morphological and immunohistochemical evaluation in growing Labrador retrievers.

Medial coronoid disease (MCD) is a common joint disease of dogs. It has a multifactorial aetiology, but the relationship between known causal factors and the disease has yet to be elucidated. As most of the published literature is clinical and it reports changes associated with advanced disease, it is not known whether the changes reflect the cause or consequences of the condition. The aim of this study was to investigate early micromorphological changes occurring in articular cartilage and to describe the postnatal development of the medial coronoid process (MCP) before MCD develops. Three litters of MCD-prone young Labrador retrievers were purpose-bred from a dam and two sires with MCD. Comparisons of the micromorphological appearance of the MCP in MCD-negative and MCD-positive joints demonstrated that MCD was initially associated with a disturbance of endochondral ossification, namely a delay in the calcification of the calcifying zone, without concurrent abnormalities in the superficial layers of the joint cartilage. Cartilage canals containing patent blood vessels were only detected in dogs <12 weeks old, but the role of these channels in impaired ossification requires further investigation. Retained hyaline cartilage might ossify as the disease progresses, but weak areas can develop into cracks between the retained cartilage and the subchondral bone, leading to cleft formation and fragmentation of the MCP.

Phenotypic characteristics of hydrocephalus in stillborn Friesian foals.

Hydrocephalus is uncommon in horses. However, in recent years, it has become clear that the prevalence of hydrocephalus is greater in Friesian horses than in other breeds probably due to their limited gene pool. Before identification of candidate genes that predispose to the development of hydrocephalus in Friesian horses can be pursued, an in-depth, phenotypic, pathological description of the condition in Friesians would be of great benefit. Our study aimed to characterize the morphology of hydrocephalus in Friesian horses, to support further investigation of the genetic background of this condition. Four stillborn Friesian foals with hydrocephalus were examined macroscopically and microscopically and compared with 2 normal stillborn Friesian foals without hydrocephalus. In all clinical cases, tetraventricular and venous dilatations were observed, together with malformation of the petrosal bone and, as a result, narrowing of the jugular foramen. These observations suggest a communicative hydrocephalus with a diminished absorption of cerebrospinal fluid into the systemic circulation at the venous sinuses due to a distorted, nonfunctional jugular foramen. This type of hydrocephalus is also recognized in humans and dogs and has been linked genetically to chondrodysplasia; this has already been recognized in dwarfism, which is another monogenetic defect in Friesian horses.

The early development of medial coronoid disease in growing Labrador retrievers: radiographic, computed tomographic, necropsy and micro-computed tomographic findings.

Medial coronoid disease (MCD) encompasses lesions of the entire medial coronoid process (MCP), both of the articular cartilage and the subchondral bone. To detect the earliest signs of MCD, radiography and computed tomography were used to monitor the development of MCD in 14 Labrador retrievers, from 6 to 7 weeks of age until euthanasia. The definitive diagnosis of MCD was based on necropsy and micro-computed tomography findings. The frequency of MCD in the dogs studied was 50%. Radiographic findings did not provide evidence of MCD, ulnar subtrochlear sclerosis or blunting of the cranial edge of the MCP. Computed tomography was more sensitive (30.8%) than radiography (0%) in detecting early MCD, with the earliest signs detectable at 14 weeks of age. A combination of the necropsy and micro-computed tomography findings of the MCP showed that MCD was manifested as a lesion of only the subchondral bone in dogs <18 weeks of age. In all dogs (affected and unaffected), there was close contact between the base of the MCP and the proximal radial head in the congruent joints. Computed tomography and micro-computed tomography findings indicated that the lesions of MCD probably originated at the base of the MCP.

Lymphocytic hypophysitis in a dog with diabetes insipidus.

An 8-year-old male German longhaired pointer was referred for diabetes insipidus responsive to treatment with desmopressin. The dog had polyuria and polydipsia, exercise intolerance and a dull hair coat. Plasma concentrations of thyroid-stimulating hormone, thyroxine, growth hormone (GH) and insulin-like growth factor-1 were decreased; plasma adrenocorticotropic hormone (ACTH) was slightly elevated and plasma α-melanocyte-stimulating hormone (MSH) was within the reference range. Computed tomography revealed a heterogeneously contrast-enhancing pituitary mass compressing the hypothalamus. Transsphenoidal hypophysectomy was performed and microscopical examination of the surgical biopsy samples revealed hypophysitis without evidence of pituitary adenoma. The hypophysitis was characterized by marked lymphocytic infiltration of the adenohypophysis that contained a mixed population of neuroendocrine cells expressing GH, ACTH or α-MSH. The lymphocytes were identified as T cells, resulting in a final diagnosis of lymphocytic hypophysitis strongly resembling human primary lymphocytic hypophysitis.

Phenotypic and genetic evaluation of elbow dysplasia in Dutch Labrador Retrievers, Golden Retrievers, and Bernese Mountain dogs.

Canine elbow dysplasia encompasses four developmental diseases: ununited anconeal process, osteochondrosis of the medial part of the humeral condyle, fragmented medial coronoid process (FCP), and incongruity of the elbow joint. Four radiographic views per joint were used to evaluate 2693 Labrador Retrievers (LRs), 1213 Golden Retrievers (GRs), and 974 Bernese Mountain Dogs (BMDs) for the presence of elbow dysplasia between 2002 and 2009 in the Netherlands. The views were also graded for signs of osteoarthritis and sclerosis. FCP was diagnosed most frequently in LRs, GRs and BMDs, with an incidence of 6%, 5%, and 15%, and a heritability of 0.17, 0.24, and 0.06, respectively. Heritabilities were estimated using a sire model and all available ancestors. Sclerosis at the base of the medial coronoid process was the radiographic sign most strongly correlated with FCP (r=0.95, 0.92, and 0.95 in LRs, GRs and BMDs, respectively). The sex of the dog was significantly correlated with the presence of osteoarthritis in LRs, but not in GRs and BMDs. Male LRs were 1.7-fold more frequently, but not more severely, affected by osteoarthritis than female dogs. Age at radiographic examination was significantly associated with osteoarthritis in all three breeds. The heritability estimates in Retrievers were high enough to warrant including FCP findings in the breeding policy, but until the biomechanical and genetic background of elbow dysplasia are better understood, correct phenotyping with a sensitive technique is essential.

Prevalence of spondylosis deformans in the feline spine and correlation with owner-perceived behavioural changes.

OBJECTIVES: The primary objective was to determine the prevalence, spinal distribution, and association with the signalment of cats suffering from different grades of feline spondylosis deformans (spondylosis). The secondary objective was to document behavioural changes associated with spondylosis by owner observation. METHODS: A cross-sectional study was performed to determine the prevalence of feline spondylosis (group 1). A prospective study was performed to determine the association between radiographic abnormalities of the lumbosacral region (L3-S1) and owner perceived behavioural changes based on a completed questionnaire (group 2). The radiographs were reviewed using a grading system (0-3) for spondylosis. RESULTS: The prevalence of spondylosis in group 1 was 39.4% (158/402). Cats with spondylosis were significantly older than cats without spondylosis (p <0.001). The thoracic (T) vertebrae T4-T10 were most often affected by spondylosis, but spondylosis was most severe in the T10-S1 vertebrae. In group 2, spondylosis of the lumbosacral region was significantly correlated with owner-reported behavioural changes, such as a decreased willingness to greet people and to being petted, increased aggressiveness, and a poor perceived quality of life (p = 0.037). CLINICAL SIGNIFICANCE: This study found that feline spondylosis is common and that spondylosis of the lumbosacral region may be accompanied by behavioural changes.

Cross-sectional study of the prevalence and clinical features of osteoarthritis in 100 cats.

To assess clinical signs and relevance of osteoarthritis (OA) in cats, the radiographic prevalence of OA in the appendicular skeleton of 100 client-owned cats (≥ 6 years old) was assessed. Possible associations between radiographic OA, clinical locomotor system examination, and owner-perceived behavioural changes were evaluated. OA was most prevalent in the shoulders, elbows, hips and tarsal joints with 61% of cats having OA in at least one joint and 48% in more than one joint. Overall, clinical examination of the larger peripheral joints had the highest sensitivity and specificity for radiographic OA. Regression analysis showed age to be related to OA (P = 0.002), as were decreased mobility and grooming (P = 0.008), although there was a correlation with age. Finally, increased inappropriate elimination was associated with OA (P = 0.046). It was concluded that the prevalence of OA in cats is strikingly high and increases with age. OA in cats seems to be associated with behavioural changes.

The effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine.

REASONS FOR PERFORMING STUDY: In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown. OBJECTIVES: To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine. METHODS: Computed tomography was performed on 6 cadaver cervical spines from adult Warmblood horses subjected to euthanasia for reasons unrelated to cervical spine abnormalities, in a neutral position, in 20 and 40° extension, and in 20 and 40° flexion. Multiplanar reconstructions were made to obtain transverse images perpendicular to the long axis of each pair of intervertebral foramina from C2-T1. Intervertebral foramina dimensions were measured in the 5 positions. RESULTS: Compared to the neutral position, 40° extension caused a decrease in foramina dimensions at segments C4-C5, C5-C6, C6-C7 (P < 0.001) and C7-T1 (P < 0.002); 20° extension caused a decrease in foramina dimensions at segments C5-C6 (P < 0.02), C6-C7 (P < 0.001) and C7-T1 (P < 0.01); 20° flexion caused an increase in foramen length at segment C6-C7 (P < 0.01). CONCLUSIONS: Ex vivo extension of the cervical spine causes a decrease in intervertebral foramina dimensions at segments C4-T1, similar to that found in man. POTENTIAL RELEVANCE: In vivo extension of the cervical spine could possibly interfere with peripheral nerve functioning at segments C4-T1. This effect may be even more profound in patients with a reduced intervertebral foramina space, for example in the presence of facet joint arthrosis.

The dog as an animal model for DISH?

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic disorder of the axial and peripheral skeleton in humans and has incidentally been described in dogs. The aims of this retrospective radiographic cohort study were to determine the prevalence of DISH in an outpatient population of skeletally mature dogs and to investigate if dogs can be used as an animal model for DISH. The overall prevalence of canine DISH was 3.8% (78/2041). The prevalence of DISH increased with age and was more frequent in male dogs, similar to findings in human studies. In the Boxer breed the prevalence of DISH was 40.6% (28/69). Dog breeds represent closed gene pools with a high degree of familiar relationship and the high prevalence in the Boxer may be indicative of a genetic origin of DISH. It is concluded that the Boxer breed may serve as an animal model for DISH in humans.

Computed tomography of the upper cheek teeth in horses with infundibular changes and apical infection.

REASONS FOR PERFORMING STUDY: Infundibular changes are frequently encountered computed tomographic studies of the equine maxillary cheek teeth but the possible importance of this finding is not known. Infundibular caries is a possible cause for pulpitis and apical infection in some horses. OBJECTIVES: To study the relationship between the 2 pathologies and the frequency of changes. METHODS: The maxillary cheek teeth 108-208, 109-209 and 110-210 of 25 horses were evaluated using computed tomography and both the prevalence of infundibular and apical infection changes as the possible link with apical infection evaluated statistically. RESULTS: The prevalence of infundibular changes was high in both normal and diseased teeth. Both apical infection and the occurrence of infundibular changes were more prevalent in 109-209 and 110-210. In spite of this, the 2 processes could not be linked to one another. No differences were noted between the left and right sides. CONCLUSIONS: A direct relationship between the 2 processes was not established statistically and other underlying causes for the high occurrence of both apical infection and infundibular changes in diseased and normal 108-208, 109-209 and 110-210 are considered.

Growth hormone excess and the effect of octreotide in cats with diabetes mellitus.

In this prospective study 16 cats with diabetes mellitus were examined for concurrent acromegaly by measuring plasma growth hormone (GH) and insulin-like growth factor-I concentrations, and magnetic resonance imaging (MRI) of the pituitary fossa. Additionally, the effects of octreotide administration on the plasma concentrations of glucose, GH, alpha-melanocyte-stimulating hormone (alpha-MSH), adrenocorticotrophic hormone (ACTH), and cortisol were measured. Five cats were diagnosed with hypersomatotropism. The pituitary was enlarged in these 5 cats and in 2 other cats. Six cats that required a maximum lente insulin dosage >or=1.5 IU/kg body weight per injection had pituitary enlargement and 5 of these cats had acromegaly. Plasma concentrations of GH, ACTH, and cortisol decreased significantly after single intravenous administration of the somatostatin analogue octreotide in the acromegalic cats. The effect on GH concentrations was more pronounced in some of the acromegalic cats than in others. In the non-acromegalic cats only ACTH concentrations decreased significantly. In both groups plasma glucose concentrations increased slightly but significantly, whereas alpha-MSH concentrations were not significantly affected. In conclusion, the incidence of hypersomatotropism with concomitant pituitary enlargement appears to be high among diabetic cats with severe insulin resistance. Some of these cats responded to octreotide administration with a pronounced decrease in the plasma GH concentration, which suggests that octreotide administration could be used as a pre-entry test for treatment with somatostatin analogues.

Review and retrospective analysis of degenerative lumbosacral stenosis in 156 dogs treated by dorsal laminectomy.

The medical records of 156 dogs with degenerative lumbosacral stenosis (DLS) that underwent decompressive surgery were reviewed for signalment, history, clinical signs, imaging and surgical findings. The German Shepherd Dog (GSD) was most commonly affected (40/156, 25.6%). Pelvic limb lameness, caudal lumbar pain and pain evoked by lumbosacral pressure were the most frequent clinical findings. Radiography showed lumbosacral step formation in 78.8% (93/118) of the dogs which was associated with elongation of the sacral lamina in 18.6% (22/118). Compression of the cauda equina was diagnosed by imaging (epidurography, CT, or MRI) in 94.2% (147/156) of the dogs. Loss of the bright nucleus pulposus signal of the L7-S1 disc was found on T2-weighted MR images in 73.5% (25/34) of the dogs. The facet joint angle at L7-S1 was significantly smaller, and the tropism greater in GSD than in the other dog breeds. The smaller facet joint angle and higher incidence of tropism seen in the GSD may predispose this breed to DLS. Epidurography, CT, and MRI allow adequate visualization of cauda equina compression. During surgery, disc protrusion was found in 70.5% (110/156) of the dogs. Overall improvement after surgery was recorded in the medical records in 79.0% (83/105) of the dogs. Of the 38 owners that responded to questionnaires up to five years after surgery, 29 (76%) perceived an improvement.

Degeneration, inflammation, regeneration, and pain/disability in dogs following destabilization or articular cartilage grooving of the stifle joint.

OBJECTIVE: The most used model for joint instability is the canine anterior cruciate ligament transection (ACLT)-model. The ACLT-model can be extended with a medial meniscectomy (MX) (i.e., ACLT-MX-model) to avoid unintentional, and with that variable, meniscal damage. The present study compares the ACLT-MX-model with the more recently introduced Groove-model on longitudinal measurements of osteophyte formation and gait as a surrogate marker of pain and disability, in addition to structural endpoint parameters. METHODS: Degenerative joint damage was induced Labrador dogs according to the ACLT-MX-model (n=7) or Groove-model (n=7). Every 4 weeks radiographs were taken to analyze osteophyte formation. Every 2 weeks gait was recorded using force-plate analysis. Joints were analyzed for features of degeneration 12 weeks after surgery. RESULTS: Both models showed similar osteophyte formation and gait changes for both experimental and contra-lateral control joints, although more pronounced for the ACLT-MX-model. This was supported by the structural endpoint measurements. Cartilage integrity, chondrocyte activity and synovial inflammation revealed similar characteristics of degenerative joint disease in both groups, again more pronounced in the ACLT-MX-model. CONCLUSIONS: The ACLT-MX-model demonstrates characteristics of joint degeneration that are related to moderate to severe osteoarthritis with clear synovial inflammatory activity. The Groove-model is a less painful and a significantly milder model of joint degeneration. The latter model might be more suitable to study subtle changes as a result of intervention than the more robust ACLT-MX-model.

ACTH-independent hyperadrenocorticism due to food-dependent hypercortisolemia in a dog: a case report.

In addition to adrenocortical tumours, aberrant expression of functional hormone receptors in the adrenal cortex may cause adrenocorticotrophic hormone (ACTH)-independent hyperadrenocorticism. Here we report on a 6 year old Vizsla dog in which ACTH-independent hyperadrenocorticism was associated with meal-induced hypercortisolemia. Diagnosis was based on history, physical findings, biochemical changes, and elevation of the urinary corticoid/creatinine ratio (UCCR) on two consecutive days (11 and 8.3 x 10(-6), reference range <8.3 x 10(-6)). Basal plasma ACTH concentration was found by repeated measurements to be suppressed (<1 ng/L, reference range 5-85 ng/L) and administration of corticotrophin releasing hormone (CRH) resulted in a minor increase (to 6 ng/L), consistent with ACTH-independent hyperadrenocorticism. Ultrasonography and computed tomography revealed two uniformly enlarged adrenal glands. Magnetic resonance imaging of the pituitary area showed a non-enlarged, normally enhancing pituitary gland. Based on these results, expression of functional aberrant adrenocortical receptors was suspected and the possibility of food-dependent hyperadrenocorticism was explored. The UCCR on two separate occasions rose from 11 and 8 x 10(-6) before a meal to 25 and 23 x 10(-6) at 3 h after ingestion of a meal, respectively. There was a corresponding increase in plasma cortisol concentration (from 90 to 150 nmol/L), while plasma ACTH concentration remained low or undetectable. Consistent with the diagnostic criteria for food-dependent hyperadrenocorticism in humans, administration of octreotide completely prevented meal-induced hypercortisolemia. The dog was treated successfully with the cortisol-synthesis-inhibitor trilostane (2h before meal), and at 26 months after the final diagnosis the dog is still in good condition. The combination of (1) low plasma ACTH concentration in the absence of an adrenocortical tumour, (2) an increase of >100% in UCCR after ingestion of a meal, (3) prevention of the meal-induced increase in plasma cortisol concentration by octreotide, and (4) reversal of signs of hypercortisolism by administration of trilostane a few hours before the meal led to the diagnosis of food-dependent hyperadrenocorticism in this dog.

Hyperthyroidism due to an intrathoracic tumour in a dog with test results suggesting hyperadrenocorticism.

The elevated urinary corticoid/creatinine ratios of an 11-year-old Jack Russell terrier with polyuria were suppressible in a high-dose dexamethasone suppression test, which was suggestive of pituitary-dependent hyperadrenocorticism. The absence of physical and routine-laboratory changes compatible with hyperadrenocorticism and the relatively high plasma thyroxine concentration were the impetus for additional studies of thyroid and adrenocortical functions. A high plasma thyroxine concentration (62 nmol/l; 5.0 microg/100 ml) suggested the presence of hyperthyroidism. Radiography, (99m)TcO(4) (-) scintigraphy, ultrasonography, computed tomography and cytology revealed a hyperfunctioning intrathoracic thyroid tumour. In the low-dose dexamethasone suppression test, the plasma cortisol concentration exceeded the reference value of 40 nmol/l (1.4 microg/100 ml) at eight hours after dexamethasone administration (0.01 mg/kg intravenously), a test result compatible with hyperadrenocorticism. In conclusion, this report represents the first case of a dog with an autonomously hyperfunctioning thyroid tumour in the thorax. The elevated urinary corticoid excretion and the positive low-dose dexamethasone suppression test may be explained by alterations in cortisol metabolism, the stress of the hyperthyroid state or both.

Determination of optimal window width and level for measurement of the canine pituitary gland height on computed tomographic images using a phantom.

The purpose of this study was to determine the optimal window level and width for accurate measurement of pituitary gland height in a phantom. A phantom, mimicking the appearance of the pituitary gland, was made by using the base of a canine skull immersed in buttermilk. Seven different-sized cylindrical pieces of cheese were made and the real diameter of each sample was measured by using a caliper. The cheese was then placed in the pituitary fossa, and 2-mm thick contiguous computed tomography (CT) slices were acquired. The height of the cheese was measured using electronic calipers with different window width and level (WW-WL) settings. The mean difference between CT and manual caliper measurements and concordance correlation coefficients were calculated for all settings. CT measurements underestimated manual caliper measurements with all settings, but the smallest difference (0.5 mm) was obtained with a 250-80 window. Concordance coefficients ranged from 0.699 to 0.820, with the maximum concordance coefficient obtained with a 250-80 window. A second series of measurements using a different window setting for the brain-pituitary gland edge (WW-WL: 250-80) and for the bone-pituitary gland edge (WW-WL: 250-240) resulted in a reduction in the mean difference (0.1 mm) and an increase in the concordance coefficient (0.836). It was concluded that underestimation of the height of the pituitary gland on CT images is most likely due to erroneous placement of the edge of the basisphenoid bone using a low level and a narrow window.

[Cerebellar cortical degeneration in an American Staffordshire terrier]. / Cerebellaire corticale degeneratie bij een Amerikaanse Staffordshire terriër.

Most diseases affecting the cerebellum are congenital and three groups can be distinguished on pathogenetic grounds. In the first group, diseases are caused by intrauterine or neonatal viral infections, in the second group by malformations of genetic or unknown origin, and in the third group by degenerative disease, or abiotrophies. Familial late-onset cerebellar abiotrophy has been reported in the Gordon Setter the Old English Sheepdog, the Brittany Spaniel and more recently the American Staffordshire Terrier. This case report describes the clinical, diagnostic and pathological changes in an American Staffordshire Terrier with cerebellar cortical degeneration. This is the first case diagnosed in the Netherlands.