Congenital cardiac disease in dogs

Pulmonic stenosis is caused by a malformed pulmonic valve, stricture of the right ventricular outflow tract or stricture of the pulmonary artery. English Bulldogs, Beagles, Samoyeds, Fox Terriers and Chihuahuas are predisposed. Clinical signs in severely affected dogs include exercise intolerance, stunting, dyspnea, syncope and ascites. Auscultation reveals a high-frequency, crescendo-decrescendo murmur during systole, loudest over the left side of the thorax, near the sternal cardiac border. An ECG may reveal a right-axis deviation of greater than 120 degrees, S waves in leads I, II and III, deep S waves in CV6LL, CV6LU and V10, Q waves deeper than 0.5 mv in leads II, III and AVF, and positive T waves in lead V10. Plain film LAT thoracic radiographs reveal an elevated carina, increased sternal contact of the heart, loss of the cranial cardiac waist and a widened cardiac silhouette, with normal pulmonary vasculature. A DV projection reveals an inverted "D" shape of the right ventricle and a pulmonary artery bulge. A nonselective angiocardiogram reveals poststenotic dilation of the main pulmonary artery. Treatment involves surgical correction of the stenosis.     

In situ hybridization for the detection and localization of swine Chlamydia trachomatis

Gnotobiotic piglets were inoculated intralaryngeally with swine Chlamydia trachomatis strain R33 or orally with swine C. trachmatis strain R27. Archived formalin-fixed, paraffin-embedded tissues from piglets euthanatized 4-7 days postinoculation were examined by in situ hybridization for C. trachomatis nucleic acid using a nonradioactive digoxigenin-labeled DNA probes that targeted specific ribosomal RNA or omp1 mRNA molecules of the swine C. trachomatis strains. Positive hybridization signals were detected in bronchial epithelial cells, bronchiolar epithelial cells, pneumocytes, alveolar and interstitial macrophages, and jejunal and ileal enterocytes. Chlamydia-infected cells had a strong signal that was confined to the intracytoplasmic inclusions. Positive hybridization signals were not detected in tissue sections from an uninfected control piglet or in C. psittaci-infected sheep placenta. The morphology of host cells was preserved despite the relatively high temperature required in parts of the incubation procedure. The data indicate that in situ hybridization can be used to detect swine C. trachomatis in formalin-fixed, paraffin-embedded tissue specimens.     

The ecology of the free living stages of Nematodirus filicollis.

The development and survival of the eggs of Nematodirus filicollis placed on grass plots over a period of a year were studied. Development took place at every season although it was more rapid in the warmer months. Yields of larvae were highest from eggs placed outside during February, March and April. Larvae persisted for two to two and a half years after eggs were placed on the pastures. The extraordinary persistence of the eggs and larvae of N filicollis makes control of the parasite difficult.     

Retroperitoneal fibrosis in four cats following renal transplantation

Four cats developed fibrosis within the retroperitoneal space following renal transplantation. In human transplant patients, retroperitoneal fibrosis is an uncommon complication following surgery and may be secondary to operative trauma, infection, deposition of foreign material in the operative field, urinary extravasation, and perirenal hemorrhage caused by trauma to the allograft. Possible causes of fibrosis in the cats of this report include abdominal inflammation associated with allograft rejection, pyelonephritis, and septic peritoneal effusion. All of the cats of this report were readmitted to the veterinary teaching hospital following renal transplantation because of recurrence of azotemia 1 to 5 months after transplantation. Abdominal ultrasonography revealed a 2- to 4-mm-thick capsule surrounding the allograft in 2 of 4 cats, hydronephrosis in 4 cats, and hydroureter proximally in 2 cats. An exploratory laparotomy was performed in all cats to remove the fibrotic tissue causing the ureteral obstruction. Normal renal function was restored in all cats following surgery. Histologic evaluation of biopsy specimens revealed smooth muscle (3 cats) and fibrous connective tissue (4). All 4 cats, regardless of the cause, responded well to surgical resection of the scar tissue that was causing a ureteral obstruction. None of the cats had recurrence of obstruction following surgery.     

Hypercalcemia following renal transplantation in a cat

An 11-year-old 3.0-kg (6.6-lb) neutered male Persian was referred for renal transplantation. Serum total calcium concentration was slightly high prior to surgery, but the week after surgery, total and ionized calcium concentrations were extremely high, and a small mass was palpable on the right side of the trachea at the level of the thyroid and parathyroid glands. Exploratory surgery of the ventral aspect of the neck was performed, and a right external parathyroid mass was removed. One hour after surgery, the serum ionized calcium concentration was within reference limits, and the serum calcium concentration remained normal for the next 14 months without any specific treatment. The gross and histologic appearance of the mass, combined with the rapid decrease in serum calcium concentration following its removal, confirmed that the mass was a functional parathyroid adenoma. Although a common postoperative complication in people, hypercalcemia following renal transplantation appears to be a rare complication in cats. Surgery should be considered if the condition is a result of a parathyroid adenoma.     

Hepatic microvascular dysplasia in dogs: a retrospective study of 24 cases (1987-1995)

Hepatic microvascular dysplasia (HMD) is a disease involving a microscopic shunting of blood through the liver without the presence of a macroscopic portosystemic shunt (PSS). Data was collected from medical records and telephone conversations with referring veterinarians and owners of 24 dogs diagnosed with HMD. Criteria for diagnosis included histopathological evidence of microvascular dysplasia on hepatic biopsy as well as surgical exploration and a normal mesenteric portogram to rule out a macroscopic PSS. Dogs with HMD frequently have less severe clinical signs and a better long-term prognosis than do those with a PSS that are managed medically.     

Reclassification of an isolate of Guignardia citricarpa from New Zealand as Guignardia mangiferae by sequence analysis

Citrus black spot was recorded as present in New Zealand in international databases on the basis of one isolate (ICMP 8336) identified by morphological features as Guignardia citricarpa . This isolate was from a soft rot, not a typical symptom of citrus black spot, on a Seminole tangerine fruit grown in the northern region of New Zealand. Sequence analysis of the internal transcribed spacer (ITS) region (ITS1, 5·8S and ITS2) showed that this isolate was 99% identical to the ITS region of G. mangiferae , a closely related saprotroph. Despite climatic conditions being suitable for this disease, citrus black spot symptoms have never been seen on citrus fruits grown in New Zealand. Thus the absence of symptoms on citrus in New Zealand is probably because G. citricarpa is not present. On the basis of these results, the record of citrus black spot occurring in New Zealand should be re-examined.     

Comparison of two real-time RT-PCR assays for differentiation of C-strain vaccinated from classical swine fever infected pigs and wild boars

Classical swine fever is one of the most important infectious diseases for the pig industry worldwide due to its economic impact. Vaccination is an effective means to control disease, however within the EU its regular use is banned owing to the inability to differentiate infected and vaccinated animals, the so called DIVA principle. This inability complicates monitoring of disease and stops international trade thereby limiting use of the vaccine in many regions. The C-strain vaccine is safe to use and gives good protection. It is licensed for emergency vaccination in the EU in event of an outbreak. Two genetic assays that can distinguish between wild type virus and C-strain vaccines have recently been developed. Here the results from a comparison of these two real-time RT-PCR assays in an interlaboratory exercise are presented. Both assays showed similar performance.