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Biomedical subjects

C R Lamb

Publications and source records attributed to C R Lamb.

At least 19 recordsLinked to original sources
PubMed1998

Evaluation of the canine tympanic membrane by positive contrast ear canalography.

Positive contrast ear canalography was described briefly in 1973 as a method for detecting rupture of the tympanic membrane in dogs with otitis media. The purpose of this study was to evaluate the sensitivity and usefulness of the technique. The ears of 10 normal canine cadavers and 31 dogs with clinical signs of ear disease were examined using otoscopy, radiography and contrast radiography after infusing 2 to 5 ml of positive contrast medium into the ear canals. These examinations were repeated in the cadavers after the tympanic membrane had been punctured with a Spreull needle. In the cadavers 14 of 19 (74 per cent) of the tympanic membranes were visible otoscopically; contrast medium did not enter the tympanic bulla of any of the ears before the tympanic membrane was ruptured, but was visible in the bulla in every ear after rupture. In the clinical study, 40 of 61 (66 per cent) of the tympanic membranes were visible otoscopically, and 12 appeared to be ruptured. Radiographic signs of otitis media (increased opacity and/or thickening of the tympanic bulla) were identified in seven ears. Canalography was positive for rupture of the tympanic membrane in 13 ears, including four in which it appeared to be intact otoscopically. In normal canine ears, canalography was a more accurate method for detecting iatrogenic tympanic membrane rupture than otoscopy. In dogs with ear disease, canalography may be more sensitive for otitis media than either otoscopy or survey radiography.

Animals↗
PubMed1998

Morphology of congenital intrahepatic portacaval shunts in dogs and cats.

The preoperative ultrasound images and biplanar operative mesenteric portograms of 28 dogs and six cats with congenital intrahepatic portacaval shunts were reviewed retrospectively. On the basis of the combined surgical, postmortem and imaging data, the shunts were classified according to their location within the liver and their shape. Thirteen dogs and four cats had a left-divisional shunt with a relatively consistent bent tubular shape that drained into the left hepatic vein. Another 13 dogs had a central-divisional shunt that took the form of a foramen between dilated portions of the intrahepatic portal vein and caudal vena cava. One cat with a central-divisional shunt had a tortuous vessel. The remaining two dogs and one cat had right-divisional shunts that were large, tortuous vessels. The morphology of a left-divisional shunt is compatible with patent ductus venosus, but the pathogenesis of central and right-divisional shunts is unknown. It is concluded that intrahepatic portacaval shunts in dogs and cats may be classified as left, central or right divisional. Ultrasound enables a preoperative morphological assessment that correlates well with the results of portography and may aid surgical planning.

Animals↗
PubMed1998

Ultrasonography of portosystemic shunts in dogs and cats.

Ultrasonography is a rapid, accurate, noninvasive diagnostic test for primary (congenital) and secondary (acquired) portosystemic shunting in dogs and cats. Two-dimensional, gray-scale ultrasonography alone enables diagnosis of most congenital portosystemic shunts and determination of intra- versus extrahepatic location. Use of duplex- and color-flow Doppler ultrasonography aids detection of congenital and acquired extrahepatic portosystemic shunts. The underlying cause of acquired portosystemic shunting is portal hypertension; this may be documented by finding either hepatofugal or reduced velocity hepatopetal portal blood flow by duplex-Doppler. Also, ultrasonography may enable detection of lesions involved in the pathogenesis of portal hypertension, for example, hepatic arterioportal fistula, hepatic parenchymal lesions, and portal vein thrombosis.

Animals↗
PubMed1998

Ultrasonography of the ureters.

It is difficult to visualize the normal canine or feline ureters ultrasonographically; however, diagnosis of various abnormalities associated with ureteral dilation is possible in many instances. Ultrasonography is a practical method for diagnosis of ectopic ureter, ureterocele, and certain causes of ureteral obstruction that compares favorably with contrast radiography because it is quicker, does not involve use of contrast media or ionizing radiation, and usually requires no sedation or anesthesia. Ultrasonography is a convenient method for examining adjacent organs, principally the kidneys and bladder, that may be affected in animals with ureteral abnormalities. Also, ultrasound guidance facilitates certain interventional diagnostic procedures for the ureters.

Anesthesia, General↗
PubMed1998

Assessment of the accuracy of thoracic radiography in the diagnosis of canine chronic bronchitis.

Thoracic radiographs from 23 dogs with chronic bronchitis were mixed with those taken from 11 dogs (matched by age and bodyweight) without respiratory disease and interpreted twice by two blinded, independent examiners in an attempt to determine the accuracy of radiography for the diagnosis of chronic bronchitis. The only radiographic signs found more often in dogs with chronic bronchitis were thickening of the bronchial walls and increased numbers of visible bronchial walls (P < 0.01). Other signs, including bronchial calcification and interstitial pattern, occurred with similar frequency in both groups of dogs. The examiners were consistent in their interpretations (kappa > 0.64). The accuracy of radiographic diagnosis of chronic bronchitis is limited principally by insensitivity for bronchial lesions.

Animals↗
PubMed1998

Ultrasonographic features of intestinal intussusception in 10 dogs.

Records of dogs that had abdominal ultrasonography and surgical or pathological diagnosis of intestinal intussusception between February 1992 and June 1997 were reviewed retrospectively. Ultrasound images were reviewed with respect to appearance of the intussusception, suspected location, evidence of predisposing cause and concurrent lesions. Ten intussusceptions were found, affecting a variety of breeds. The mean (range) age of affected dogs was 2.5 (0.3 to seven) years (four females and six males) and the reported duration of clinical signs, 48 (one to 150) days. Intussusceptions were jejunojejunal (five dogs), ileocolic (three), caecocolic (one) and colocolic (one). A concentric ring sign was identified ultrasonographically in each dog and anatomical location predicted correctly in five instances. Additional ultrasonographic findings associated with intussusceptions included intestinal neoplasm in two dogs, enlarged abdominal lymph nodes in two, multiple mesenteric cysts in one and intestinal foreign body in a further dog. Thus, ultrasonography enables accurate diagnosis of intestinal intussusception and is a useful method for searching for concurrent or predisposing lesions.

Animals↗
PubMed1997

Arteriovenous fistula involving the prepuce of a dog.

A nine-year-old male Ibizan hound had a network of large tortuous pulsating blood vessels on the prepuce that enlarged gradually over a five month period. A diagnosis of arteriovenous fistula was based on clinical signs, angiography and Doppler ultrasonography. Ligation of the major vascular supply to the fistula resulted in only temporary improvement. Definitive treatment was by wide excision, with penile amputation and scrotal urethrostomy.

Angiography↗
PubMed1997

Polyostotic lymphoma in a young dog: a case report and literature review.

An eight-month-old female German shepherd dog had pathological fractures affecting the distal radius and ulna and ribs. Radiographically, there were bilaterally symmetrical osteolytic lesions affecting the metaphyses of multiple long bones, ribs and skull and the dog had splenomegaly. Histologically, the spleen, thymus and bones were infiltrated with large lymphoblastic cells with a high mitotic rate; the diagnosis was lymphoma. Lymphoma primarily affecting bone is an uncommon diagnosis in the dog but it should be considered in young animals with osteolytic lesions affecting multiple bones.

Animals↗
PubMed1996

Surgical treatment of intrahepatic portosystemic shunts in six cats.

The surgical treatment of intrahepatic portosystemic shunts in six cats is described. The preoperative diagnoses were based on the results of abdominal ultrasonography, and mesenteric portography was used during surgery to confirm the diagnosis and establish the morphology of the shunting vessel. In four of the cats the shunt vessel passed through the left division of the liver, compatible with a patent ductus venosus (PDV), in one cat the shunt passed through the central hepatic division and in the other cat it passed through the right hepatic division. During surgery the shunt vessel was manipulated directly either intrahepatically, or post hepatically in the four cats with PDV. In five cats the shunt vessel was partially ligated, and in the other the vessel was completely ligated. The attenuation procedure produced a mean increase in mesenteric venous pressure of 17 cm H2O, with a range from 14 to 20 cm. All the cats recovered from the surgical procedure, but one developed neurological signs shortly after the operation and died from respiratory failure. Four of the cats were clinically normal and required no medication by one month after the operation. One cat required long-term medication to control its continued clinical signs.

Animals↗
PubMed1996

Ultrasonographic diagnosis of congenital portosystemic shunt in 14 cats.

Twenty-four cats with clinical and, or, clinicopathological signs compatible with portosystemic shunting were examined prospectively using two-dimensional grey-scale, duplex and colour-flow Doppler ultrasonography. Diagnosis of congenital portosystemic shunt was subsequently confirmed in 14 cats using operative mesenteric portography and surgery. Of the 14 affected cats, nine were purebred; eight were male and six female. The mean age at the time of diagnosis was nine months (range four to 27 months). Ultrasonographic evidence of a small liver was present in seven cats (50 per cent); visibility of intrahepatic portal vessels was reduced in three (21 per cent). An anomalous blood vessel was identified ultrasonographically in each cat; in 10 cats (71 per cent) the vessel was observed to originate from the portal vein and drain into the caudal vena cava. Abnormally variable portal blood flow was present in eight of the 10 cats in which it was measured. At surgery, six shunts were intrahepatic and eight extrahepatic; the ultrasonographic diagnosis of intra- versus extrahepatic shunt was correct in 13 cats (93 per cent). No anomalous blood vessels or abnormalities affecting the portal vein were detected ultrasonographically in any of the 10 cats that did not have congenital portosystemic shunting. Hence, the accuracy of ultrasonography for diagnosis of congenital portosystemic shunting in this series was 100 per cent.

Animals↗
PubMed1996

Per rectal portal scintigraphy in the diagnosis and management of feline congenital portosystemic shunts.

Five cats with a congenital portosystemic shunt (CPSS) were examined using transcolonic portal scintigraphy before and after surgical ligation of the shunting vessel. The mean shunt index before surgery was 52 per cent (range 45 to 61 per cent). Repeat portal scintigraphy, six to eight weeks after surgery, indicated a significant reduction in shunt index (mean 13 per cent, range 5 to 25 per cent) in four cats. In one of these cats a marked reduction in the shunt index, as determined by scintigraphy, preceded normal fasting blood ammonia. In the fifth cat there was no significant change in the shunt index, fasting serum bile acids and blood ammonia six months after surgery, although its clinical signs of hepatic encephalopathy had improved. Portal scintigraphy is useful in the diagnosis of CPSS and enables a quantitative assessment of the effects of surgery and may be a more accurate indicator of the degree of shunting after surgery than blood ammonia and serum bile acids.

Ammonia↗
PubMed1996

Ultrasound-guided catheter biopsy of the lower urinary tract: technique and results in 12 dogs.

Ultrasound-guided catheter biopsy of lesions affecting the lower urinary tract was attempted in 12 dogs with mucosal lesions affecting the bladder (nine) or urethra (three). Histological biopsies were obtained by catheter biopsy in 10 dogs, enabling diagnosis of transitional cell carcinoma in five, papilloma in two, prostatic carcinoma in two and chronic cystitis in one. Cytological samples alone were obtained in two dogs, one of which enabled a diagnosis of transitional cell carcinoma; the other contained evidence of haemorrhage and inflammation, but squamous cell carcinoma was found in a subsequent excisional biopsy. Intravesicular haemorrhage after biopsy was observed ultrasonographically in two dogs. Ultrasound guidance enables accurate determination of biopsy catheter position. The size of biopsies obtained by this method may limit the accuracy of histological diagnosis.

Animals↗
PubMed1995

Ultrasonography of pancreatic neoplasia in the dog: a retrospective review of 16 cases.

The history, clinical signs and radiographic and ultrasonographic findings in 16 dogs with pancreatic neoplasia were reviewed retrospectively. Thirteen of the dogs had islet cell carcinoma compatible with insulinoma, one had a pancreatic adenocarcinoma and two had secondary invasion of the pancreas, one by a gastric carcinoma and one by an intestinal lymphoma. The clinical signs in the 13 dogs with insulinoma included collapse in 10 dogs, ataxia in seven, weakness in five, and seizures in two. Two of the 16 dogs had jaundice due to biliary obstruction by the primary tumour or metastases. The sensitivities for pancreatic neoplasia were three of 16 (19 per cent) for radiography and 12 of 16 (75 per cent) for ultrasonography; the sensitivities for metastasis were two of 11 (18 per cent) for radiography and six of 11 (55 per cent) for ultrasonography. Biliary obstruction was detected by ultrasonography in both affected dogs.

Adenocarcinoma↗
PubMed1995

Cholecystokinin-8 induces edematous pancreatitis in dogs associated with short burst of trypsinogen activation.

To study the early pathogenesis of acute edematous pancreatitis in dogs, we examined the relationship of pancreatic hyperstimulation with cholecystokinin-8 (10 micrograms/kg/hr intravenously for 6 hr) to alterations in circulating pancreatic enzymes and pancreatic morphology with special reference to trypsinogen activation. Cholecystokinin-8 infusion was associated with increases in plasma amylase, lipase, trypsin-like immunoreactivity, and plasma and urine trypsinogen activation peptide. Pancreatic parenchymal swelling and interlobular and subcapsular fluid accumulations were detected ultrasonographically within 2 hr of cholecystokinin-8. Circulating trypsin-like immunoreactivity and trypsinogen activation peptide in urine reached a peak at 2 and 4 hr, respectively, then declined despite progressive increases in circulating amylase and lipase and intrapancreatic fluid. No significant changes were observed in dogs receiving a saline infusion. This study illustrates that cholecystokinin-8 induces edematous pancreatitis in dogs that is associated with a short-lived burst of trypsinogen activation.

Acute Disease↗
PubMed1994

Osteomyelitis and disseminated infection caused by Corynebacterium renale in a goat.

A 1.5-year-old female goat was examined for recurrence of lameness involving the right forelimb. Radiography of the thorax and right scapulohumeral joint revealed a pathologic fracture of the supraglenoid tubercle, and circumscribed radiolucent lesions in the right third and fourth ribs, and the base of the spinous process of T3. Bone scintigraphy demonstrated additional lesions in the lumbar spine and the wings of the ilium. At necropsy, disseminated infection and hematogenous osteomyelitis were diagnosed. Corynebacterium renale was cultured from the rib lesions. In food animals, osteomyelitis usually develops secondary to traumatic wounds, and members of the genus Actinomyces are frequently incriminated as the causative organism. This case is unusual because the osteomyelitis was unrelated to a traumatic wound, and the gross and microscopic lesions were reminiscent of caseous lymphadenitis, an infection caused by C pseudotuberculosis.

Animals↗