Evaluation of the repeatability of ultrasound scanning for detection of feline polycystic kidney disease.

Polycystic kidney disease (PKD) is the most prevalent inherited genetic disease in cats with Persian and Persian-related breeds predominantly affected. Diagnosis of PKD relied on ultrasound scanning until the recent development of the PKD gene test. However, gene testing has limitations as it will only identify the autosomal dominant form of PKD and not other forms of cystic kidney disease. Ultrasound scanning also has the advantage of being able to assess the severity and progression of disease in PKD affected cats. The aim of this study was to demonstrate the repeatability of ultrasound scanning in the detection of PKD and to assess progression of the disease over time. This study demonstrated 100% repeatability of ultrasound scanning in the detection of PKD and has also demonstrated progression of disease in 75% of PKD positive cats assessed over a 1-year period.

Laryngeal disease in cats: a retrospective study of 35 cases.

The aim of this retrospective study was to review the medical records of cats referred to the University of Bristol for investigation of laryngeal disease (n=35). Cases were categorised into one of four groups: cats with laryngeal paralysis (LP, n=14), laryngeal neoplasia (n=10), laryngeal inflammation (n=6), or miscellaneous laryngeal diseases (n=5). Laryngoscopy and echolaryngography were useful diagnostic techniques but histology was required for diagnosis of diseases other than LP. Two cats with lymphoma received chemotherapy achieving survival times of 60 and 1440 days. Four cats with LP were treated surgically, with a median survival time of 300 days (range 10-360 days) and six were treated conservatively with a median survival time of 780 days (range 300-2520 days). Three cats with inflammatory disease were treated medically and one by excision of the lesion. Two cats achieved survival times of 120 and 2800 days. Cats with LP, laryngeal lymphoma or laryngitis had excellent long-term survival following appropriate treatment.

Lumbosacral transitional vertebrae in cats and their effects on morphology of adjacent joints.

The present study aimed to describe the radiographic appearance of lumbosacral transitional vertebrae in the cat and compare prevalence of hip dysplasia and lumbosacral spondylosis with a population of cats without transitional vertebrae. Pelvic radiographs of cats were reviewed retrospectively, providing a population of 100 cats without transitional vertebrae and 14 examples of lumbosacral transitional vertebrae. All cats were assessed for hip dysplasia and lumbosacral spondylosis; the lumbosacral transitional vertebrae identified were also assessed for asymmetry or rotation of sacro-iliac (SI) attachment. The transitional vertebrae demonstrated a wide variety of morphology; six cats had asymmetry or rotation of SI attachment in a dorsal plane; four of those six cats had lumbosacral spondylosis and two of these had hip dysplasia. No further examples of degenerative changes were identified in the remaining eight cats with lumbosacral transitional vertebrae. The frequency of lumbosacral spondylosis was higher in the population with lumbosacral transitional vertebrae, but this was not statistically significant. There was a marked trend towards lumbosacral spondylosis in cats with pelvic rotation or asymmetry. The frequency of hip dysplasia in cats with lumbosacral transitional vertebrae was very similar to those without.

Radiographic and ultrasonographic features of canine paraprostatic cysts.

Mineralization of paraprostatic cysts is reported to be uncommon. This retrospective study was performed to review the imaging findings of eight histologically confirmed canine paraprostatic cysts. Radiographic patterns of mineralization seen are described. Four of the eight dogs had mineralized cysts. Mineralization seen on radiography was not consistently seen on ultrasonography, probably due to the lack of acoustic shadowing artefact from the small depth of mineralized tissue. It is thus concluded that mineralization of paraprostatic cysts is more common than implied in the literature, and that radiography is superior to ultrasonography in identifying its presence.

Congenital abnormalities of the feline vertebral column.

Radiographs of vertebral segments from 200 cats were retrospectively assessed to determine the incidence of congenital axial skeletal abnormalities. The axial skeleton was divided into cervical, thoracic, lumbar, sacral, and caudal segments and the presence and types of congenital abnormalities present were recorded for each segment. A total of 598 axial skeletal segments were examined. Congenital abnormalities were found in 46 cats and involved 54 spinal segments. Block vertebrae were identified in three cats. No hemivertebrae or spina bifida were noted. Transitional abnormalities were most common, and were identified in 51 spinal segments. Abnormalities at the sacrocaudal junction were the most common of these; 19 examples were found. The second most common transitional abnormality was thoracicization of L1, with 18 such cats identified. Extra ribs on L1 were often smaller and fragmented and it may be possible for an inexperienced clinician to confuse these with rib fractures. The last rib(s) are also often used for anatomic localization of surgical procedures; the presence of a transitional lumbar vertebra with one or two extra ribs introduces the possibility of error or confusion about choice of surgical site.

Liver size, bodyweight, and tolerance to acute complete occlusion of congenital extrahepatic portosystemic shunts in dogs.

OBJECTIVE: To investigate the relationship between preoperative liver size, bodyweight, and tolerance to shunt occlusion in dogs with congenital extrahepatic portosystemic shunt(s) (CPSS). STUDY DESIGN: Longitudinal cohort study. ANIMALS: Dogs with CPSS (n=35). METHODS: Ultrasonography was used to measure preoperative maximum transverse dimension of the liver (TS) of each dog. Intraoperative portal pressures were measured, before and after CPSS occlusion, via a jejunal vein catheter. Tolerance to shunt occlusion was judged on gross visceral observations, and on changes in portal pressure, central venous and mean arterial pressures. RESULTS: TS was significantly related to bodyweight (P<.05). Mean ratios for TS/bodyweight were calculated for dogs tolerant and intolerant of acute complete shunt occlusion. Dogs tolerant to occlusion had significantly higher TS/bodyweight ratios than dogs intolerant to occlusion (P=.025). Dogs with a TS/bodyweight ratio of >7 were more likely to tolerate CPSS occlusion than dogs with a TS/bodyweight ratio of <5 (P=.036). A model was generated to predict portal pressure rise after shunt occlusion, based on liver dimensions and bodyweight (R=0.668). Intestinal oxygenation did not correlate significantly with tolerance to CPSS occlusion (P=.29). CONCLUSION: In dogs with CPSS, liver size (relative to bodyweight) is significantly greater (P=.025) in dogs that are tolerant of full ligation than intolerant of occlusion. CLINICAL RELEVANCE: Preoperative measurement of bodyweight and liver size help indicate the likelihood of tolerance to acute complete occlusion of CPSS in dogs.

Treatment and long-term follow-up of extrahepatic biliary obstruction with bilirubin cholelithiasis in a Somali cat with pyruvate kinase deficiency.

A 2-year-old female neutered Somali cat was presented with vomiting and acute onset jaundice 1 year after diagnosis of pyruvate kinase (PK) deficiency. Diagnostic investigations revealed a moderate regenerative haemolytic anaemia, severe hyperbilirubinaemia and elevated liver enzymes. Ultrasonography revealed marked distension of the gall bladder and common bile duct (CBD), consistent with extrahepatic biliary obstruction (EHBO). At cholecystotomy, the gall bladder contained purulent material, and two obstructive choleliths were removed from the CBD by choledochotomy. The cat recovered from surgery uneventfully, and serum liver enzymes and bilirubin normalised within 10 days. Postoperative treatment consisted of cephalexin, metronidazole and ursodeoxycholic acid (UDCA). Bacterial culture of the gall bladder contents yielded a pure growth of an Actinomyces species. Cholelith analysis revealed that they consisted of 100% bilirubin. Antibiotic treatment was stopped 4 weeks after surgery but UDCA was continued indefinitely. The cat remains clinically well with no recurrence of cholelithiasis 20 months after initial presentation. This is the first report of successful treatment and long-term follow-up of a cat with EHBO due to bilirubin cholelithiasis in association with PK deficiency-induced chronic haemolysis.

Detection of the single nucleotide polymorphism causing feline autosomal-dominant polycystic kidney disease in Persians from the UK using a novel real-time PCR assay.

Autosomal-dominant polycystic kidney disease (AD-PKD) is the most prevalent inherited genetic disease of cats, particularly affecting Persians. Until recently the condition has been diagnosed by renal ultrasound screening. With the identification of the genetic mutation responsible for AD-PKD it is now possible to use advanced molecular techniques to screen for the disease. We have developed a rapid, sensitive and specific real-time PCR genotyping assay that can detect the single nucleotide polymorphism responsible for AD-PKD. Of 72 UK Persian and Exotic Shorthair cats submitted for AD-PKD ultrasound screening, 29 were found to have the disease, 41 were negative and 2 were equivocal. The recently published PCR-RFLP method showed the AD-PKD mutation to be present in all 29 diseased cats and absent in the 41 negative and 2 equivocal cats. Our real-time PCR genotyping assay was in complete agreement with the PCR-RFLP results. Of 600 blood or buccal swabs analysed from April 2005 to January 2006, 165 were found to be AD-PKD positive and 435 were negative, giving a prevalence of 27.5%. All 194 cats with AD-PKD were found to be heterozygous for the mutation.