A survey of congenital reproductive abnormalities in rams in abattoirs in South west England.

Congenital abnormalities of the reproductive tract of male sheep were surveyed at three abattoirs in the south west of England during the period June 2000-January 2004. A total of 7307 rams were examined [6521 lambs (prepubescent) and hoggets (aged from their first autumn after birth until first shorn) and 786 adult rams mature rams that had been exposed to ewes]. A total of 156 congenital lesions were detected, 87 of which occurred in lambs. Testicular hypoplasia was the most common lesion occurring in 69 lambs as well as eight hoggets ('microtestes' were recognized in nine other animals in which the testis was disproportionately smaller than the epididymis). The second most common lesion found was notched scrotum occurring in 34 animals (27 young rams and seven adults). Some cases of notched scrotum were accompanied by hypospadias which was seen in a total of seven lambs and eight hoggets. Other lesions, detected in five or less animals (less than approximately 0.05% of the animals examined), included cryptorchidism and various abnormalities of the epididymis (segmental aplasia of the epididymis, blind efferent ducts and epididymal cyst) and congenital scrotal hernia. The overall prevalence of congenital lesions of 2.21% emphasizes the importance of undertaking breeding soundness examinations of young rams before they are put with the flock.

Reliability of radiological assessment of ulnar trochlear notch sclerosis in dysplastic canine elbows.

OBJECTIVES: The objectives of this study were to quantify the sensitivity and specificity of visual assessment of radiographs of the canine elbow in detecting ulnar trochlear notch sclerosis, to establish interobserver and intra-observer variation for the presence and grade of sclerosis and to quantify the effect of radiographic exposure on observer grading. METHODS: Mediolateral elbow radiographs were obtained from Labrador retrievers (n=34) aged between six and 18 months. Radiographs from dogs with an arthroscopic diagnosis of fragmented medial coronoid process (n=17) and those from a control population (n=17) were subjected to observer grading for the presence or absence of and the grade of ulnar trochlear notch sclerosis. Interobserver and intra-observer variation and observer sensitivity and specificity were calculated. Digital data from the ulnar trochlear notch were correlated with mean observer grade to quantify the effect of radiographic exposure on observer grade. RESULTS: Interobserver agreement was "fair" (kappa=0.251 to 0.369) and intra-observer agreement was "moderate" to "substantial" (kappa=0.462 to 0.667). The sensitivity of observer assessment was 72 per cent with a specificity of 22 per cent. Mean observer grade was not significantly correlated with the degree of radiographic exposure (P=0.70). CLINICAL SIGNIFICANCE: Ulnar trochlear notch sclerosis is a phenomenon associated with fragmented medial coronoid process. However, interobserver agreement in grading this feature is only fair, being identified by observers with moderate sensitivity but with relatively poor specificity. This low specificity may predispose to overdiagnosis in clinical cases. Intra-observer agreement is moderate to substantial, suggesting that individuals can reliably quantify this radiological feature on multiple occasions. The ability of observers to assess the degree of sclerotic change is not significantly affected by radiographic exposure.

Estimation of the volume of the gall bladder of 32 dogs from linear ultrasonographic measurements.

The maximum length and depth of the longitudinal section, and the maximum width and depth of the transverse section of the gall bladders of 32 dog cadavers were measured ultrasonographically; the contents of the gall bladder were then aspirated and its actual volume measured. The volume of the gall bladder was estimated from the ultrasonographic measurements by using formulae suggested for assessment of the volumes of the urinary bladder in human beings and the gall bladder of dogs, and these formulae were compared with a formula derived from the measurements made in this study. In 21 of the dogs, the measurements were repeated twice so that their reproducibility could be evaluated. All the formulae gave good estimations of the volume of the dogs' gall bladders, but the formula for the human urinary bladder volume was better than the other two. The actual volume of the gall bladder was related to the dogs' bodyweight. There were no significant differences between the repeated measurements of the maximum length and depth of the longitudinal section or the width of the transverse section of the gall bladder, but there were significant variations in the depth of the transverse section.

A technique for pelvic radiography in the standing horse.

REASONS FOR PERFORMING STUDY: An alternative technique of radiographing the pelvis in the standing horse is required, to avoid the risks associated with general anaesthesia. HYPOTHESIS: That lateral oblique radiography in the standing horse would be a useful technique in the investigation of pelvic injury. OBJECTIVES: To describe the technique of lateral oblique pelvic radiography in the standing horse and demonstrate the feasibility and usefulness of this technique. METHODS: A technique for lateral oblique radiography in the standing horse was devised and retrospective review made of radiographic findings in 18 clinical cases. RESULTS: The caudal iliac shaft, greater trochanter of the femur, femoral head, acetabulum and coxofemoral articulation on the side under investigation were visualised consistently using this technique. Of the 18 cases, 3 iliac shaft fractures, 1 acetabular fracture, 2 coxofemoral luxations and 4 horses with new bone formation around the coxofemoral joint and/or proximal femur were identified. CONCLUSIONS: Lateral oblique radiography in the standing, conscious horse can be used to investigate conditions affecting the caudal iliac shaft, coxofemoral articulation and proximal femur in the horse. POTENTIAL RELEVANCE: The technique is straightforward, noninvasive and useful in the investigation of horses with suspected pelvic injury. However, not all pelvic injuries would be identified, and normal radiographic findings do not rule out injury or fractures elsewhere in the pelvis.

Bacterial cholangitis/cholangiohepatitis with or without concurrent cholecystitis in four dogs.

OBJECTIVES: To evaluate the clinical, clinical pathology, diagnostic imaging, microbiological and pathological features of cholangitis/cholangiohepatitis in the dog. METHODS: The study design was a retrospective review of cases of bacterial cholangitis/cholangiohepatitis presented to the University of Bristol during the period 1995 to 2000. The diagnosis was made based on hepatic histopathological findings and positive bile culture results. RESULTS: Four dogs met the inclusion criteria. Common presenting signs included anorexia (n=4), jaundice (n=4), vomiting (n=4) and pyrexia (n=2). All four dogs had a leucocytosis or neutrophilia reported at some time in their history along with serum bilirubin elevation. In addition, serum alkaline phosphatase and alanine transaminase activity was increased in all of the dogs in which it was measured both before and at the time of referral. In general, the diagnostic imaging findings were non-specific. Organisms cultured from bile aspirates were Escherichia coli (n=3), Clostridium species (n=2) and a faecal Streptococcus species (n=1). Two cases resolved with medical treatment alone; two with concurrent cholecystitis required cholecystectomy. Following surgery, both of these cases showed a resolution of clinical signs. CLINICAL SIGNIFICANCE: This report highlights the fact that bacterial cholangitis/cholangiohepatitis with or without concurrent cholecystitis should be considered as a potential differential in dogs presenting with signs referable to biliary tract disease.

Ultrasonographic evaluation of the thickness of the small intestinal wall in dogs with inflammatory bowel disease.

OBJECTIVES: To establish whether the intestinal wall thickness, as measured ultrasonographically, is significantly increased in dogs with inflammatory bowel disease (IBD). The results would provide the information necessary to decide whether measurement of ultrasonographic wall thickness can predict IBD in dogs. METHODS: The intestinal wall thickness of 75 dogs with idiopathic IBD, as measured by ultrasonography, was compared with recently published normal values. IBD was either confirmed histologically (n = 54) or suspected (n = 21). In all cases there was a positive response to immunosuppressive treatment. RESULTS: A positive association between intestinal wall thickness in dogs and either the histological diagnosis or the response to treatment was not found. Ultrasonographic intestinal wall measurements do not appear to be able to establish a diagnosis of intestinal inflammation and may result in a false negative diagnosis in cases of IBD. CLINICAL SIGNIFICANCE: The same 'grey zone' of between 4 and 6 mm used in humans can be used in the canine duodenum to distinguish the normal range, reserving the term 'abnormal' for an intestinal measurement greater than 6 mm in the duodenum and greater than 4.7 mm in the jejunum.

Comparison of ultrasonographic and radiographic measurements of bladder dimensions and volume determinations.

The purpose of this study was to compare the linear dimensions of the bladder measured by ultrasonographic and radiographic methods and the accuracy of these methods for evaluation of bladder volume. Forty dogs were included in this study. Each dog was placed in right lateral recumbency and a plain lateral caudal abdominal radiograph was made. The bladder length and depth were measured in centimetres from the radiograph, taking into account magnification errors. Immediately after radiography was completed, ultrasonographic measurements of bladder length and depth on longitudinal section were measured in centimetres. The bladder was then emptied by catheterisation and the actual urine volume measured. 'Best subsets' analysis indicated that radiographic and ultrasonographic bladder lengths were the best predictors of actual bladder volume. Formulae were derived from radiographic and ultrasonographic bladder dimensions for estimating bladder volume. The formula using radiographic measurements was found to be a better predictor of actual bladder volume than the formula derived from ultrasonographic measurements, since it had higher F and lower error mean square values.

Frequency of urination and ultrasonographic estimation of residual urine in normal and dysuric dogs.

The aim of this study was to determine residual urine and frequency of urination in normal male and female dogs and to compare these with dogs with neurogenic and obstructive dysuria. The bladder volume before urination was estimated ultrasonographically in 99 dogs (48 normal and 51 abnormal dogs). Each animal was then taken outdoors and walked on grass for 10 minutes. The number of attempts to urinate (successful or not) was recorded. Bladder urine volume after urination was then calculated. Normal females made only one or two (100 per cent successful) attempts to urinate while males a mean of 6.9 attempts (mean 75.4 per cent successful) within 10 minutes. The residual urine per kg body weight of normal dogs varied from 0.1 to 3.4 ml kg(-1)(median 0.2 ml kg(-1)). The residual urine volumes of normal dogs were significantly less (P<0.0001) than those of dogs with neurological disorders or obstructive disease. Ultrasonographic estimation of residual urine volumes could be valuable in diagnosing suspected neurological or obstructive bladder disease and in monitoring the response to treatment.

Ultrasonographic estimation of prostatic size in canine cadavers.

The purpose of this study was to determine the accuracy of transabdominal ultrasound in estimating the volume and weight of the canine prostate gland, to derive a simple formula from actual and ultrasonographic prostate measurements for estimating prostate volume and weight, and to evaluate the reproducibility of ultrasonographic measurements of linear prostate dimensions. The prostate volume and weight were measured and also calculated in 77 male canine cadavers (60 entire and 17 neutered) with the aid of statistical computer programmes using actual linear dimensions of the prostate ('actual') and those measured ultrasonographically before ('in vivo') and after ('in vitro') removal of the prostate gland. Therefore, 'in vivo', 'in vitro' and 'actual' estimations of prostate size were obtained and compared with prostatic volume and weight. The evaluation of the reproducibility of the ultrasonographic measurements made was performed in 59 of the dogs in which the prostate was imaged three times in longitudinal and three times in transverse sections. This study demonstrated that prostatic weight and volume are related to body weight and age in entire dogs but not in neutered dogs. Formulae were derived to estimate prostate weight and volume from physical and ultrasonographic measurements. There were good correlations between the ultrasonographic and physical measurements and prostate size derived from these measurements provided a good estimate of actual prostate size. 'Best subsets' analyses indicated that prostate width and length (measured physically or ultrasonographically) were the best predictors of prostatic volume and weight, both when all dogs were considered together and in entire dogs only. Statistical analyses indicated that there were no significant differences between the repeated measurements of length and depth (P>0.05). However, there was a significant difference between repeated measurements of width (P= 0.0357).

Tendonitis of the deep digital flexor tendon in the distal metacarpal/metatarsal region associated with tenosynovitis of the digital sheath in the horse.

Twenty-four horses with ultrasonographic evidence of tendonitis of the deep digital flexor tendon in the metacarpal/metatarsal region were seen over a 7 year period. Most horses had mild to moderate lameness and distension of the digital flexor tendon sheath in the affected limb. Intrasynovial analgesia of the digital flexor tendon sheath consistently improved the degree of lameness. Ultrasonography most commonly revealed small, distinct, often circular, focal hypoechoic areas within the deep digital flexor tendon which usually extended less than 1 cm proximodistally. The degree of lameness and swelling generally improved with box rest and controlled exercise, however, exacerbation of the clinical signs and ultrasonographic lesions was common when affected horses were returned to work or allowed free exercise at pasture. Of 24 cases, only 7 horses made a full recovery and returned to their intended athletic activity.

Ultrasonography of the medial palmar intercarpal ligament in the Thoroughbred: technique and normal appearance.

REASONS FOR PERFORMING STUDY: Tearing of the medial palmar intercarpal ligament (MPICL) has been recognised as a cause of lameness in the Thoroughbred, but diagnosis is difficult due to the nonspecific clinical signs, and can be achieved only by performing arthroscopy on the mid carpal joint (MCJ). It would be beneficial to be able to image the MPICL using ultrasonography to determine whether pathology is present in the ligament in order to aid diagnosis and prognosis. OBJECTIVES: To determine whether the MPICL could be imaged using ultrasound from the dorsal aspect of the MCJ, and to describe the technique and normal ultrasonographic appearance of the ligament. METHODS: A pilot study was performed using 2 cadaver carpi. Each carpus in turn had the MPICL imaged simultaneously using arthroscopy and ultrasound, with a metallic probe positioned on the dorsal aspect of the ligament to highlight the position of the MPICL. Six further pairs of carpi had the MPICL imaged ultrasonographically followed by dissection of the carpus to evaluate the ligament and relate its anatomy to the ultrasound images. Finally, 15 Thoroughbreds with no history of lameness isolated to the carpus had their MPICLs assessed and measured ultrasonographically. RESULTS: The MPICL could be imaged via the dorsal aspect of the MCJ using standard ultrasound equipment. The body and division into medial and lateral branches could be seen as a distinct, moderately dense granular echogenic structure in the palmar aspect of the joint, with clearly defined margins. CONCLUSIONS: The normal MPICL can be imaged reliably using ultrasound in the Thoroughbred from the dorsal aspect of the MCJ. There is a wide range in the normal width of the lateral aspect of the MPICL, but there is good symmetry between contralateral limbs. POTENTIAL RELEVANCE: This report of the normal ultrasonographic appearance of the ligament will be beneficial in acting as a reference for the detection of pathology using ultrasound.

Ultrasonographic assessment of bladder neck mobility in continent bitches and bitches with urinary incontinence attributable to urethral sphincter mechanism incompetence.

OBJECTIVE: To determine bladder neck positional changes between standing and recumbent positions in bitches and whether change is related to continence status or general anesthesia, or both, and to evaluate reproducibility of measurements. ANIMALS: 45 continent animals and 46 incontinent bitches with urethral sphincter mechanism incompetence (SMI). PROCEDURE: Distance between the bladder neck and perineal skin was measured ultrasonographically via the perineum while each dog was conscious in standing and right lateral recumbency and in right lateral recumbency under general anesthesia. Measurements of the bladder neck position obtained in right lateral recumbency under anesthesia were compared with radiographic measurements of the same parameter. Reproducibility of the ultrasonographic measurements of the distance between bladder neck and perineum was assessed on 3 occasions for each position in 50 dogs. RESULTS: In all dogs, differences in bladder neck position between standing and recumbent conscious-associated positions were not significant. However, caudal bladder neck movement between standing conscious- and recumbent anesthesia-associated positions and between recumbent conscious- and anesthesia-associated positions was significant for all dogs. Incontinent bitches had greater degree of caudal bladder movement during anesthesia. Mean difference in bladder neck positions between recumbent conscious- and recumbent anesthesia-associated positions was 0.24 cm in continent, compared with 0.73 cm in incontinent, bitches. Radiographic measurements were significantly greater than ultrasonographic measurements. Differences between repeated measurements for standing position were not significant, but those for recumbent conscious- and recumbent anesthesia-associated positions were significant. CONCLUSIONS: Additional vesicourethral support mechanisms in continent dogs, are deficient in bitches with SMI, allowing the bladder neck to move further caudad.

Assessment of urinary bladder volume in dogs by use of linear ultrasonographic measurements.

OBJECTIVE: To evaluate accuracy of formulas derived from linear ultrasonographic measurements and used in human beings to assess urinary bladder volume as a method of estimating bladder volume in dogs and to test reproducibility of ultrasonographic measurements of linear bladder dimensions. ANIMALS: 64 live dogs (for bladder volume determination) and 31 fresh canine cadavers (for ultrasonographic assessment of reproducibility of measurements). PROCEDURE: Maximal length, longitudinal and transverse depth (DL and DT), and width were measured from the maximal longitudinal and transverse images. Bladder volume was estimated, using 6 formulas, and calculated volumes were compared statistically with the actual volume obtained by catheterization, using paired nonparametric tests. Reproducibility of bladder dimensions was investigated by measuring length, DL, DT, and width 3 times from each image of section. Measurements of depth (DL and DT) also were compared. RESULTS: Calculations of bladder volume from linear dimensions, using a formula described for use in human beings, gave a satisfactory indication of actual bladder volume; the median difference between actual and calculated volumes was only 5 ml. Bladder volume estimations were less accurate when large-volume bladders were measured. Matching between repeated measurements was significant (P < 0.005 for longitudinal bladder length and P < 0.0001 for bladder depth and width). Measurements of DL and DT were significantly (P < 0.01) different, with DL greater than DT. CONCLUSIONS: Ultrasonographic assessment of bladder volume in dogs by application of the formula is sufficiently accurate for most clinical purposes. CLINICAL RELEVANCE: Ultrasonography would be a useful method of estimating bladder volume in dogs with severe obstruction or dysfunctional voiding of urine.

Determination of solid- and liquid-phase gastric emptying half times in cats by use of nuclear scintigraphy.

OBJECTIVE: To use nuclear scintigraphy to establish a range of gastric emptying half times (t1/2) following a liquid or solid meal in nonsedated cats. ANIMALS: 12 clinically normal 3-year-old domestic shorthair cats. PROCEDURE: A test meal of 75 g of scrambled eggs labeled with technetium Tc 99m tin colloid was fed to 10 of the cats, and solid-phase gastric emptying t1/2 were determined by use of nuclear scintigraphy. In a separate experiment, 8 of these cats plus an additional 2 cats were fed 18 ml (n = 5) or 36 ml (n = 5) of a nutrient liquid meal labeled with technetium Tc 99m pentetate. Liquid-phase gastric emptying t1/2 then were determined by use of scintigraphy. RESULTS: Solid-phase gastric emptying t1/2 were between 210 and 769 minutes (median, 330 minutes). Median liquid-phase gastric emptying t1/2 after ingestion of 18 or 36 ml of the test meal were 67 minutes (range, 60 to 96 minutes) and 117 minutes (range, 101 to 170 minutes), respectively. The median t1/2 determined for cats receiving 18 ml of the radiolabeled liquid was significantly less than that determined for cats receiving 36 ml of the test meal. CONCLUSIONS AND CLINICAL RELEVANCE: The protocol was tolerated by nonsedated cats. Solid-phase gastric emptying t1/2 were prolonged, compared with liquid-phase t1/2, and a major factor governing the emptying rate of liquids was the volume consumed. Nuclear scintigraphy may prove useful in assessing gastric motility disorders in cats.

Ultrasonographic appearance of the superficial supramammary lymph nodes in lactating dairy cattle.

The superficial supramammary lymph nodes of 54 lactating dairy cows were examined ultrasonographically with a 7.5 MHz linear transducer; each node was measured in two planes within 24 hours of recording the milk somatic cell count. In most cows, the nodes were well demarcated from the surrounding tissue. The parenchyma of the nodes ranged from hypoechoic to anechoic, with a central bright hyperechoic area, and a thin hyperechoic line surrounded the nodes. The size of the nodes varied, but their internal architecture remained relatively consistent. Their mean length was 7.4 cm (range 3.5 to 15 cm) and their mean depth was 2.5 cm (range 1.2 to 5.7 cm). They were significantly larger in cows with more lactations (P<0.05), but there were no correlations between their size and either the time calved or the milk somatic cell count. The lymph nodes on sides which were positive in a California milk test were significantly larger than those on sides which were negative (P<0.05).

Multiple discospondylitis associated with Aspergillus species infection in a dog.

Multiple discospondylitis was diagnosed in a four-year-old, neutered female German shepherd dog which had suffered intermittent pain of the axial skeleton for 10 months, which was followed by the sudden onset of paraplegia associated with the rupture of an affected disc. After surgical and medical management the dog began to improve but then deteriorated as a result of a pathological fracture of the fifth lumbar vertebra. A histological examination revealed fungal hyphae at the sites affected radiographically and they were identified by immunohistochemistry as Aspergillus species. No fungal hyphae were identified in other tissues. This is the first report of canine mycotic discospondylitis in the United Kingdom.

Atrial septal defect and atrial fibrillation in a foal.

Clinical examination of a four-and-a-half-month old foal revealed evidence of progressive heart failure associated with an atrial septal defect and atrial fibrillation. Atrial septal defects are rarely reported in foals and the foal's growth, development and demeanour were normal until a sudden onset of lethargic behaviour. The value of B-mode echocardiography in identifying the congenital lesion is indicated.

Anatomical, cytogenetic and behavioural studies of freemartin ewes.

The external phenotype and reproductive behaviour of 21 freemartin sheep and two male pseudohermaphrodite sheep were recorded with the aim of identifying any characteristics which might be used to predict a failure to breed. The size and shape of the vulva and clitoris, the length of the vagina, the size of the teats, the presence or absence of inguinal gonads, and the ultrasonographic characteristics of the inguinal gonads were recorded. A subjective assessment of the masculinity of each animal's body form was also made, and its behavioural responses to a virile ram and to an oestrus ewe were recorded. A number of physical and behavioural abnormalities were detected but the only consistent finding in all 23 animals was a short vagina which varied in length from 3.1 to 7.0 cm, compared with 10 to 14 cm in normal animals.

Clinical signs and radiographic diagnosis of a portosystemic shunt in a foal.

A three-month-old native pony foal had a history of recurrent episodes of bizarre neurological behaviour. The results of clinical examinations were non-specific but clinicopathological investigations indicated hepatic encephalopathy. A percutaneous, needle liver biopsy revealed histopathological changes consistent with a portosystemic shunt, which was later identified by operative mesenteric portovenography, and confirmed at post mortem.

Prevalence of polycystic kidney disease in Persian cats in the United Kingdom.

The prevalence of polycystic kidney disease was assessed in 132 Persian cats, 46 of them referred for the investigation and treatment of medical or surgical conditions, and 86 apparently healthy cats referred specifically to be screened for the disease. Cats referred for the investigation of renomegaly or renal failure were excluded, and cats under 10 months old were only included if they had been examined postmortem. One hundred and twenty-six of the cats were examined ultrasonographically with a 7.5 MHz sector scanner, and the other six cats were examined postmortem. Forty-nine of the 86 cats referred specifically for screening (57.0 per cent) and 16 of the 46 cats referred for other clinical reasons (34.8 per cent) were affected by the disease, giving an overall prevalence of 49.2 per cent.