Comparative evaluation of net digestive and absorptive efficiency in dogs and cats fed a variety of contrasting diet types

Comparative net digestive and absorptive efficiency was assessed with adult Beagles and domestic cats by apparent digestibility assays. Eight foods were used comprising two canned dog foods; canned cat foods; two samples of semipurified diet; and single samples of experimental dry cat food and fresh mince. Apparent digestibility percentages of crude protein, fat, nitrogen-free extract (NFE) and gross energy were all significantly higher in dogs than cats. Mean values obtained for dogs were (per cent): crude protein 87; fat 92; NFE 70 and energy 89. Respective values for cats were 82, 76, 67 and 79. On average, dogs obtained 11 and 9 per cent more digestible energy and protein per unit food eaten than cats. Most digestibility characteristics of foods measured in cats were significantly correlated with those for dogs and regression equations are presented predicting digestibility in cats from dog data.     

Popliteal Tendon Transposition for Stabilization of the Cranial Cruciate Ligament Deficient Stifle Joint in Dogs: An Experimental Study

Popliteal tendon transposition was performed in five dogs with surgically induced cranial cruciate ligament rupture. After a lateral approach to the stifle joint, the popliteal tendon was severed distal to the sesamoid bone and transposed cranially onto the tibial crest to mimic the sagittal orientation of the cranial cruciate ligament. The origin of the popliteal tendon on the lateral femoral condyle was preserved. Lameness was not clinically detectable 2 months after surgery. At 6 months postoperatively, there was minimal radiographic and histopathologic evidence of degenerative joint disease in the stifle joints that had underwent surgery. There was no gross or microscopic evidence of meniscal damage found at necropsy 6 months after surgery. Biome-chanical studies are warranted before recommending the procedure.     

Feline pancreatic Islet cell hyalinosis associated with diabetes mellitus and lowered serum-insulin concentrations

A case of feline spontaneous diabetes mellitus with an absolute deficiency of insulin is presented. The characteristic hypertrophy of the Islets and hyalinosis is described and compared to the disease in dogs.
Résumé. On présente un cas de diabète sucré spontané chez un chat, avec une insuffisance totale d'insuline. L'hypertrophie caractéristique des îlots et l'hyalinose sont décrites et comparées avec les lésions observées chez le chien.
Zusammenfassung. Ein Fall von spontanem Diabetes mellitus mit absolutem Insulinmangel wird beschrieben. Die charakteristische Hypertrophie der Inseln und Hyalinose werden beschrieben und mit der Krankheit bei Hunden verglichen.     

COMPARATIVE POPLITEAL AND MESENTERIC COMPUTED TOMOGRAPHY LYMPHANGIOGRAPHY OF THE CANINE THORACIC DUCT

Thoracic duct computed tomography (CT) lymphangiograms were performed on seven clinically normal dogs. The appearance of the thoracic duct system was compared following administration of contrast medium through a mesenteric lymphatic vessel vs. ultrasound guided percutaneous injection into a popliteal lymph node using helical and sequential CT acquisition modes. The number of visible thoracic duct branches and the largest thoracic duct branch cross‐sectional area and mean Hounsfield units (HU) were determined from thoracic vertebra 9 to lumbar vertebra 1. Procedural time and patient discomfort were also assessed. Popliteal administration produced a successful thoracic duct lymphangiogram in eight of 11 dogs (73%) after two attempts, while mesenteric administration was successful in eight of 10 dogs (80%) after a single attempt. Popliteal lymphography required 46% of the time and was associated with less patient discomfort than mesenteric lymphangiography. The number of thoracic duct branches seen was not significantly different for either administration technique (P=0.256) or CT acquisition mode (P=0.417). However, the cross‐sectional area and mean HU of the largest thoracic duct branch were greater with mesenteric administration (P<0.001), and helical image acquisition (P<0.001). The thoracic duct branch number, size, and location were highly variable between dogs. Percutaneous popliteal lymphography appears to be an acceptable alternative to mesenteric lymphangiography for the detection of thoracic duct branches in the dog when using either helical or sequential CT acquisition modes.     

Evaluation of an Esophageal Stethoscope as an Early Predictor of Serious Cardiovascular Insufficiency in the Dog

Accuracy of an esophageal stethoscope combined with a vital signs monitor (VSM) was evaluated as an early predictor of cardiovascular failure during anesthesia. In 10 anesthetized dogs, hypotension and reduction in cardiac output were induced by gradually increasing the inspired halothane concentration. Cardiovascular performance and intensity of heart sounds recorded by the esophageal stethoscope and amplified by the VSM were assessed as depth of anesthesia was increased. Halothane concentration was increased until cardiovascular performance was reduced to a point where heart sounds were no longer audible from the VSM. The esophageal stethoscope in combination with the VSM was easy to use and the unit had an excellent signal to noise ratio. However, usefulness of the esophageal stethoscope as an early predictor of serious cardiovascular depression could not be substantiated. In three dogs, cardiac arrest occurred simultaneously with the loss of heart sounds and in the remaining seven dogs, sound loss occurred when the degree of cardiovascular depression was life threatening.     

Use of Computed Tomography in Standing Position to Identify Guidelines for Screw Insertion in the Distal Phalanx of Horses: An Ex Vivo Study

Objectives— To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning.
Study Design— Experimental ex vivo study.
Animals— Cadaveric equine thoracic limb pairs (n=10).
Methods— Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n=10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the implant were determined by radiography, and in the other group, by CT. Accuracy of screw placement was verified by specimen dissection. Outcomes were (1) absence of penetration of the articular surface, the solar surface, or the semilunar canal (2) appropriate length and direction of the screw. Surgical time was also measured.
Results— No screw penetrated the articular surface, the solar surface, or the semilunar canal in either group. CT was more accurate to identify guidelines for screw insertion (U=23.50, P =.049). With CT, surgical time (mean, 7.7 minutes) was significantly shorter (U=0.000, P =.000) than with radiography (mean, 12.7 minutes).
Conclusion— Standing CT can be used to accurately determine anatomic landmarks for screw insertion in lag fashion in sagittal fractures of the distal phalanx.
Clinical Relevance— This study has a clear clinical relevance for improved internal fixation of sagittal fractures of the distal phalanx.     

Mechanical Evaluation of Three Methods of Plating Distal Radial Osteotomies

Eighteen intact canine cadaver radii underwent nondestructive axial testing, and were osteotomized, plated, and retested. Each bone was tested with and without mediolateral or craniocaudal restriction of motion. Fixation of the osteotomies was performed under static compression with a cranially applied 5-hole 3.5 mm dynamic compression plate, a cranially applied 7-hole 3.5 mm T-plate, or a medially applied 7-hole 2.7 mm dynamic compression plate. There was no loss of axial stiffness after osteotomy and fixation, and there were no differences in axial stiffness between the methods of fixation. Mediolateral stiffness (bending around the craniocaudal axis) was consistently greater than craniocaudal stiffness (bending around the mediolateral axis) before and after osteotomy and plate fixation. There was no difference in the axial stiffness of otherwise intact radii when craniocaudal or mediolateral screw holes were drilled; however, all radii with craniocaudal screw holes and one radius with mediolateral screw holes fractured at a screw hole at high axial loads.     

Phenylbutazone in the horse: a review

Phenylbutazone is an acidic, lipophilic, non-steroidal anti-inflammatory drug (NSAID). It is extensively metabolized in the horse. The metabolites so far identified, oxyphenbutazone, gamma-hydroxyoxyphenbutazone, account for some 25-30% of administered dose over 24 h. The plasma half-life of phenylbutazone and termination of its pharmacological action are determined primarily by its rate of hepatic metabolism. Phenylbutazone acts by inhibiting the cyclooxygenase enzyme system, which is responsible for synthesis of prostanoids such as PGE2. It appears to act on prostaglandin-H synthase and prostacyclin synthase, after conversion by prostaglandin-H synthase to reactive intermediates. It markedly reduces prostanoid-dependent swelling, edema, erythema, and hypersensitivity to pain in inflamed tissues. Its principal use in the horse is for treatment of soft tissue inflammation. Phenylbutazone is highly bound (greater than 98%) to plasma protein. After i.v. injection, blood levels decline with an elimination half-life of 3-10 h. The plasma kinetics of phenylbutazone may be dose dependent, with the plasma half-life increasing as the drug dosage level increases. Plasma residues of the drug at 24 h after a single i.v. dose of 2 g/450 kg average about 0.9 microgram/ml, but considerable variation occurs. If dosing is repeated, the plasma residue accumulates to give mean residual blood levels of approximately 4.5 microgram/ml on Day 5 after 4 days of dosing. Approximately similar blood levels are found after a combination of oral and i.v. dosing. Experiments on large numbers of horses in training have been undertaken to ascertain the population distributions of residual blood levels after such dosing schedules. Absorption of phenylbutazone from the gastrointestinal tract is influenced by the dose administered and the relationship of dosing to feeding. Access to hay can delay the time of peak plasma concentration to 18 h or longer. Under optimal conditions, the bioavailability of oral phenylbutazone is probably in the region of 70%. Paste preparations may be more slowly absorbed than other preparations and yield higher residual plasma levels at 24 h after dosing, but further controlled studies are required. Phenylbutazone is easily detected in the plasma and urine of horses but concentrations in saliva are low. It is quantitated for forensic purposes by HPLC. The variability of this method between laboratories is about +/- 25%. Increasing urinary pH increases the urinary concentration of phenylbutazone and its metabolites up to 200-fold.(ABSTRACT TRUNCATED AT 400 WORDS)     

Mechanical Evaluation of Half-Pin (Type 1) External Skeletal Fixation in Combination with a Single Intramedullary Pin

Half-pin (type 1) external skeletal fixators with four, three, and two fixation pins and an intramedullary pin, and four-pin external skeletal fixators without an intramedullary pin were applied to prepared canine femurs. Load to failure, load to yield, safe load, and stiffness under compressive and torsional loads were calculated. When tested in compression, all measurements for the four-pin fixators with an intramedullary pin were significantly higher than for the two-pin fixators with an intramedullary pin. The values for all parameters except load to yield were significantly higher for the four-pin fixators with an intramedullary pin than for the four-pin fixators without an intramedullary pin. When tested in torsion, all measurements for the four-pin fixators with an intramedullary pin were significantly higher than for the two or three-pin fixators with an intramedullary pin.     

Induction of Anesthesia with Diazepam-Ketamine and Midazolam-Ketamine in Greyhounds

Anesthesia was induced in 14 greyhounds with a mixture of diazepam or midazolam (0.28 mg/kg) and ketamine (5.5 mg/kg), and maintained with halothane. There were no significant differences in weight, age, or duration of anesthesia between the treatment groups. Time to intubation with diazepam-ketamine (4.07 +/- 1.43 min) was significantly longer than with midazolam-ketamine (2.73 +/- 0.84 min). Heart rate, respiratory rate, PaCO2, and arterial pH did not vary significantly during anesthesia in either treatment group. Arterial blood pressures, PaO2, halothane vaporizer setting, and body temperature changed significantly from baseline values in both treatment groups during anesthesia. Times to sternal recumbency and times to standing were not significantly different. These data suggest that both diazepam-ketamine and midazolam-ketamine are useful anesthetic combinations in greyhounds. In combination with ketamine, midazolam offers little advantage over diazepam.