Preliminary Results of Clinical Renal Allograft Transplantation in the Dog and Cat

Renal allograft transplantation was performed as treatment for terminal renal failure in six veterinary patients. Three patients failed to survive the postsurgical period, one patient died due to acute allograft rejection, one patient died subsequent to complications of previous parenteral hyperalimentation and infection, and one patient was euthanatized due to the inability of the clients to maintain the effort necessary to manage a transplant recipient. Further clinical studies are necessary to determine if renal transplantation with cyclosporine (cyclosporin A)/prednisolone immunosuppression has the potential to provide practical treatment of terminal renal disease in clinical veterinary medicine. Pharmacologic and immunologic monitoring of transplant recipients with individualized immunosuppression is imperative. Careful surveillance is necessary to identify and eliminate nosocomial sources of infection. Candidates for transplantation cannot be critically ill or malnourished prior to surgery, and pet owners must be prepared for the financial and time commitments associated with caring for a renal allograft recipient.     

FRACTURED SCLERAL OSSICLES IN A RED TAIL HAWK

Following head trauma, the left globe of a Red Tail Hawk showed demonstrable indentation on palpation. Recurrent anterior chamber collapse and reformation dependent on head position was the most significant clinical finding. A fracture of the scleral ossicles in the caudal portion of the scleral ring was identified in the rostrocaudal radiograph of the skull. Conservative management of the fracture resulted in phthisis bulbi. Fractured scleral ossicles have been shown radiographically in the enucleated globe but have not been previously demonstrated in the eye of the living bird.     

XERORADIOGRAPHIC ANATOMY OF THE EQUINE DIGIT AND METACARPOPHALANGEAL REGION

The purpose of the project was to use xeroradiography to provide a reference for radiographic anatomy of the equine digit and metacarpophalangeal region. The left foredigits and metacarpophalangeal joints of a mature horse and a 30-day-old foal were radiographed, using xeroradiographic techniques. Fifteen xeroradiographs, illustrating standard projections of each area, were selected and appropriately labeled to demonstrate normal radiographic anatomy of these regions. These xeroradiographs have been used successfully for several years to teach radiographic anatomy of these areas to first-year veterinary students at North Carolina State University.     

Effect of Restricted Grazing on Hindgut pH and Fluid Balance

Six mature idle geldings were used in a crossover design to determine the effects of restricted grazing on hindgut pH and fluid balance. Initially, horses were randomly assigned to a control group (CTRL: n = 3) having access to warm-season grass pasture continuously, or a restricted grazing (RG: n = 3) group having access to pasture for 12 consecutive hours (1900-700 hours) per 24-hour period for 7 days; they were then reassigned to the opposite treatment for an additional 7 days (i.e., CTRL: n = 6; RG: n = 6). Fecal samples were collected from each horse at 700 hours on day 7 of each period and analyzed for pH and dry matter (DM) as indicators of hindgut pH and fluid balance, respectively. Jugular blood samples were also collected at 700, 1300, and 1900 hours on day 7 and were analyzed for plasma protein as an indicator of systematic fluid balance. Fecal pH and DM data were analyzed using a paired t test. Plasma protein data were analyzed as a repeated-measures design. The mean (± SE) difference between CTRL and RG for fecal pH (.01 ± .16) and fecal DM (.68 ± .6%) was not significant (P = .93 and .52, respectively). Mean plasma protein concentrations were not affected by treatment or by treatment × sample time interaction, but tended to increase (P = .07) during the sampling period regardless of treatment. In conclusion, 12 hours of grazing restriction followed by 12 hours of grazing did not negatively impact hindgut pH or fluid balance.     

Field comparison of the interferon-gamma assay and the intradermal tuberculin test for the diagnosis of bovine tuberculosis

An extensive field comparison of the gamma interferon (IFN-gamma) assay and the single intradermal tuberculin test for the diagnosis of bovine tuberculosis was conducted in Australia. The specificity of the IFN-gamma assay was determined by testing more than 6000 cattle from tuberculosis-free herds and varied from 96.2% to 98.1%, depending on the cut-off point chosen to define a positive reactor. For the sensitivity trial, cattle from herds being de-populated because of bovine tuberculosis were examined with both assays. The sensitivity of the IFN-gamma assay was shown to be significantly higher than the single intradermal tuberculin test and varied from 76.8% to 93.6% depending on the method of interpretation. A maximum overall sensitivity of 95.2% was obtained by testing with the IFN-gamma and the tuberculin test in parallel. The superior sensitivity of the IFN-gamma assay and the ability to adjust the sensitivity of the system depending on the task involved, will provide the Australian Tuberculosis Eradication Campaign with a valuable additional test to enable it to accomplish its goals.     

When, how and why to perform a double ballooning technique for dogs with valvular pulmonic stenosis

Pulmonic valvuloplasty is a well-established method for the treatment of valvular pulmonic stenosis in people and dogs. In dogs, pulmonic valvuloplasty has been restricted to a single balloon; however, the simultaneous use of two balloons is common in pediatric cardiology. The use of two balloons provides an alternative to the use of a single large balloon in small dogs with a pulmonic anulus size that requires a large dilation catheter and large diameter introducer. Moreover, double balloon valvuloplasty permits dilation in large dogs with large pulmonic anulus sizes for which standard dilation catheters are not available. This report outlines the materials required, describes the technique, gives the advantages and disadvantages encountered when performing percutaneous double balloon valvuloplasty and provides some ‘tips’ for a successful outcome.     

Genetic-diet interactions in the Hyperkalemic Periodic Paralysis syndrome in quarter horses fed varying amounts of potassium: IV. Pre-cecal and post-ileal absorption of potassium and sodium

During an experiment to determine the genetic-diet interactions in genetically predisposed Quarter Horses, biphasic symptoms of Hyperkalemic Periodic Paralysis (HYPP) were observed when the HYPP H/N broodmares were fed the higher potassium rations. ¹ The cause of those symptoms was assumed to be: 1) the difference in absorption times of the highly absorbable potassium citrate in the concentrates and the potassium contained in the cells of the grains and hays in the rest of the rations, 2) partial absorption of potassium in the small intestine followed by no absorption from the cecum and further absorption in the large colon or 3) a combination of both of the above explanations. Since previously cannulated ponies were available in this laboratory, an experiment was designed to determine which of those possibilities was the most likely.

Three ponies, weighing an average of 132 kg, with posterior-ileal cannulas were used in a 3×3 Latin square experiment to determine the amounts of potassium and sodium that would be absorbed pre-cecally and post-ilealy. The ponies were fed the same rations as the mares in the previously described experiment (see part I), which provided approximately 1.1, 1.9 and 2.9% potassium by weight as fed. Samples of water, feces, ileal contents and blood were collected. Water, feed, ileal and fecal samples were analyzed for sodium and potassium concentration.

Apparent absorption of potassium prior to the cecum was 97% when the ponies were fed the low potassium diet and 98% when they were fed the higher potassium diets. Three percent and 2% of the potassium was absorbed from the hindgut when the ponies were fed the low potassium diet and the higher potassium diets, respectively. Nine percent and 16% of sodium was absorbed pre-cecally when the ponies were fed the low potassium diet and the higher potassium diets, respectively. Ninety-one and 84% of the sodium was absorbed from the hindgut, when the ponies were fed the low potassium diet and the higher potassium diets, respectively for 99–100% total absorption of both sodium and potassium from all diets.

These results indicate that the potassium from the three diets was absorbed pre-cecally, and that the process took up to nine hours, resulting in bi-phasic HYPP symptoms in the HYPP H/N mares in the companion experiment. This information can be used to better understand the relationship between dietary potassium, plasma K⁺ concentration and HYPP symptoms.