Cephalothin and Cefazolin In Vitro Antibacterial Activity and Pharmacokinetics in Dogs

The periods of time that cephalothin and cefazolin serum concentration remained above minimum inhibitory concentration (MIC) for beta hemolytic, coagulase positive staphylococcal, and Escherichia coli clinical isolates were compared. Cephalothin and cefazolin were similarly very effective in vitro against staphylococcal isolates, with an MIC₉₀ of 0.12 μg/mL and 0.25 μg/mL, respectively. In contrast, cefazolin was more effective than cephalothin against E coli isolates; the cefazolin MIC₉₀ for E coli was 16 μg/mL and for cephalothin 64 μg/mL. Cefazolin (20 mg/kg intravenously [IV]) serum concentration remained more than MIC₉₀ for E coli isolates significantly longer than serum concentration of cephalothin (40 mg/kg IV) ( P <.001).     

Gastric Drainage Procedures: Effects in Normal Dogs I. Introduction and Description of Surgical Procedures

Gastric drainage procedures are commonly used in veterinary medicine, particularly in dogs in attempts to prevent recurrence of gastric dilatation-volvulus (GDV). The following five different procedures have been most commonly described: the Fredet-Ramstedt pyloromyotomy (FRP); Heineke-Mikulicz pyloroplasty (HMP); Finney pyloroplasty (FP); Jaboulay's gastroduodenostomy (JG); and antral gastrojejunostomy (AG). These surgical procedures have not been compared in a controlled study. This first article of a series of three describes the gastric drainage procedures performed in 30 normal dogs for a comparative study. The FRP and HMP were the fastest and easiest procedures to perform. The degree of difficulty was found to be increased but similar for FP, JG, and AG. No complication occurred during or immediately after surgery.     

Intracapsular Subtotal Prostatectomy in Normal Dogs: Use of an Ultrasonic Surgical Aspirator

In an attempt to reduce postoperative incontinence associated with excisional prostatectomy and the recurrence of prostatic disease after less radical surgeries, a new technique for subtotal prostatectomy was developed using an ultrasonic surgical aspirator. During laparotomy, a longitudinal incision was made in the ventral surface of each lobe of the prostate gland. Biopsies for histology and culture were taken. Through the ventral incisions, the ultrasonic surgical aspirator     

Gastric Drainage Procedures: Effects in Normal Dogs III. Postmortem Evaluation

Postmortem macroscopic examination of the gastrointestinal tract and plastic moldings of the gastrointestinal communication were done in 29 dogs which had been subjected 3 to 4 weeks previously to one of the following gastric drainage procedure: (1) Fredet-Ramstedt pyloromyotomy (FRP) (6 dogs); (2) Heineke-Mikulicz pyloroplasty (HMP) (6 dogs); (3) Finney pyloroplasty (FP) (6 dogs); (4) Jaboulay's gastroduodenostomy (JG) (6 dogs); and (5) antral gastrojejunostomy (AG) (5 dogs). Plastic moldings were also done in nine normal dogs of similar size for comparative measurements. Postmortem examinations and plastic casts of the antropyloroduodenal segment and antrojejunal communication showed significantly widened pyloric canal or large gastrointestinal communication compared to control dogs in all groups except for the FRP group. Almost complete healing had occurred at the myotomy site in FRP dogs, and the pyloric lumen was not significantly larger (less than 0.05) than the pyloric lumen of the control dogs. The lumen of the gastrointestinal junction was increased approximately 4.5 times in the HMP group, 12.0 times in the FP group, 7.2 times in the JG group, and 10.0 times in the AG group.     

Clinical Effects of Longitudinal Division of the Corpus Callosum in Normal Dogs

Longitudinal division of the corpus callosum was performed in six normal beagles to determine surgical morbidity. The corpus callosum was divided sagittally on the midline and the effect on neurological function was determined. Five of six dogs were clinically normal within 14 days or less after surgery. One dog had persistent but improving clinical signs consistent with a forebrain disturbance at 30 days after surgery. Overall, minimal morbidity and no mortality was associated with this surgical procedure. Further study is indicated to determine the efficacy of this surgical treatment for seizure control in dogs with idiopathic epilepsy.     

Surgical Treatment of Pheochromocytoma: Technique, Complications, and Results in Six Dogs

Six dogs were diagnosed with phcochromocyloma and staged according to the World Health Organization's system for tumor classification. Two dogs had benign tumors (Tl, NO, M0) and four dogs had malignant tumors (T2, NO. M 1 or T3, N0, M0). All dogs had adrenalectomy, two dogs had concurrent nephrectomy, and three dogs had concurrent resection of a tumor thrombus from the vena cava. Anesthetic complications occurred in five dogs, including wide variations in heart rate (four dogs), blood pressure (five dogs), and cardiac arrythmias (one dog). One dog died 12 hours after surgery from partial dehiscence of the suture line and hemorrhage from the vena cava, and one dog died 6 days after surgery during general anesthesia for treatment of laryngeal paralysis. Four dogs survived from 3 to 23 months (median, 15 months). One dog remained hypertensive after surgery. Benign and malignant pheochromocytomas seem to be amenable to surgical resection. © Copyright 1994 by The American College of Veterinary Surgeons     

Gastric Drainage Procedures: Effects in Normal Dogs II. Clinical Observations and Gastric Emptying

Complete gastric emptying time using barium sulfate mixed with commercial canned dog food was measured radiographically in 29 mature mixed breed dogs before and 3 to 4 weeks after Fredet-Ramstedt pyloromyotomy (FRP) (6 dogs), Heineke-Mikulicz pyloroplasty (HMP) (6 dogs), Finney pyloroplasty (FP) (6 dogs), Jaboulay's gastroduodenostomy (JG) (6 dogs), and antral gastrojejunostomy (AG) (5 dogs). The dogs were observed for clinical evidence of side effects. Postoperative endoscopic examination and double contrast gastrography were performed to subjectively evaluate the diameter of the gastrointestinal communication and the amount of enterogastric reflux. Although none of the procedures significantly (p < 0.05) altered gastric emptying time, the overall tendency was toward slowing down gastric emptying time. The severity of gastrointestinal side effects and enterogastric reflux appeared to be related to the size and/or location of the gastrointestinal opening.     

Ultrasonographic Characteristics of the Adrenal Glands in Dogs With Pituitary-Dependent Hyperadrenocorticism: Comparison With Normal Dogs

Ultrasonographic evaluation of the adrenal glands was performed in 10 dogs with pituitary-dependent hyperadrenocorticism (PDH) and in 10 age- and weight-matched healthy control dogs. Thickness, shape, and echogenicity were determined for each adrenal gland. Adrenal thickness in dogs with PDH (median, 10 mm-left; 8.5 mm-right) was significantly greater than thickness in control dogs (median, 6 mm-left; 6 mm-right). Other ultrasonographic characteristics associated with PDH included bilaterally symmetrical adrenomegaly and maintenance of normal adrenal shape. Adrenal echogenicity was homogeneous and less than that of the adjacent renal cortex in 8 of 10 dogs with PDH and in 10 of 10 control dogs. Heterogenous echogenicity was present in 2 of 10 dogs with PDH, and was associated with nodular cortical hyperplasia in one of those dogs. Results of this study confirm the difference in sonographic appearance between PDH-induced bilateral cortical hyperplasia and functional adrenocortical neoplasia, and show a difference in so-nographically determined adrenal size between healthy dogs and dogs with PDH. J Vet Intern Med 1996; 10:110–115. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

Renal Effects of Long Term Administration of Triamcinolone Acetonide in Normal Dogs

Triamcinolone acetonide was administered in excessive dosage to dogs to study the renal mechanism responsible for polyuria which is a clinically undesirable side effect of long term glucocorticoid therapy.

Polyuria occurred coincident with a significant increase in urinary solute output. Although continuous administration of triamcinolone acetonide at 0.1 or 0.2 mg/lb/day caused a small but significant increase in creatinine output, the primary mechanism for the polyuria was increased solute excretion. Associated with the polyuria was pronounced hyperphagia and polydipsia. The cause of the hyperphagia was not established. The increase in electrolyte excretion caused by this synthetic steroid was probably compensated for by the hyperphagia. Because all the dogs showed muscle weakness and loss of body condition, it is likely that alteration in protein and amino acid metabolism was responsible for the hyperphagia.

     

Effect of Desmopresssin in Normal Dogs and Dogs with von Willebrand's Disease

Desmopressin acetate (DDAVP(R)), a synthetic analogue of vasopressin was slowly administered intravenously to 12 healthy dogs of various breeds and 10 Doberman Pinschers with mild-to-moderate type I von Willebrand's disease at a dose of 0.3, 1.0 and 3.0 micro g/kg body weight. Plasma von Willebrand factor:antigen was measured by an electroimmunoassay prior to and 30, 60, 90, 120 and 180 minutes after desmopressin infusion. Desmopressin induced only very modest and statistically insignificant increases in von Willebrand factor in both groups. We conclude that the response to desmopressin as measured by circulating von Willebrand factor is much less pronounced in healthy dogs and in Doberman Pinschers with von Willebrand's disease than in humans.     

Achilles Tendon Repair in Dogs Using the Semitendinosus Muscle: Surgical Technique and Short-Term Outcome in Five Dogs

Objective— To describe augmentation of primary Achilles tendon repair using suture with a semitendinosus muscle flap and report outcome in 5 dogs.
Study Design— Prospective clinical study.
Animals— Dogs (n=5) with Achilles tendon rupture (n=6).
Methods— After tendon repair with #2 polypropylene in a 3-loop pulley suture pattern, the lateral one-half of the semitendinosus muscle was transected from the ischium, rotated distally then sutured with #2 polypropylene to the calcaneus in a 3-loop pulley pattern. The epitenon was sutured to the muscle flap fascia with interrupted sutures. All dogs had a bivalved cast for 2 weeks then a cranial splint for 2–6 weeks. Lameness scores (0=stands and walks normally to 4=non-weight-bearing lameness, plantigrade stance on affected pelvic limb) were determined every 2–3 weeks postoperatively for 12 weeks. Outcome was determined from telephone questionnaire of owners.
Results— Four had lameness scores of 0, the 5th had a score of 1 at 12 weeks. Three owners were very satisfied with outcome. Minor complications included cast sores (2 dogs), infection (2), and acute swelling (1); 1 major complication occurred (infection resulting in reoperation).
Conclusions— Semitendinosus flap augmentation resulted in early return to function without prolonged postoperative immobilization. Three dogs returned to full work/activity after repair.
Clinical Relevance— Augmentation of primary Achilles tendon repair with a semitendinosus flap can be considered in dogs with chronic rupture but further investigation of the long-term outcome using this technique is needed.     

Cemented Total Knee Replacement in 24 Dogs: Surgical Technique, Clinical Results, and Complications

Objective— To characterize the performance of cemented total knee replacement (TKR) in dogs.
Study Design— Preclinical research study.
Animals— Skeletally mature, male Hounds (25–30 kg; n=24) with no preexisting joint pathology.
Methods— Dogs had unilateral cemented TKR and were evaluated at 6, 12, 26, or 52 weeks (6 dogs/time point) by radiography, bone density analysis, visual gait assessment, and direct measurement of thigh circumference and stifle joint range of motion as indicators of functional recovery. At study end, the stability of the cemented tibial component was determined by destructive mechanical testing.
Results— Joint stability was excellent in 16 dogs (67%) and good in 8 dogs. None of the tibial components had evidence of migration or periprosthetic osteolysis whereas 1 femoral component was loose at 52 weeks. There was an early and significant decrease in tibial bone density, likely because of disuse of the operated limb. Dogs returned to full activity by 12 weeks. The tibial cement–bone interface maintained its strength over 52 weeks.
Conclusions— Cement provides stable fixation of the tibial component in canine TKR.
Clinical Relevance— Cemented TKR yields adequate clinical function and stifle joint excursion in the dog. Clinical studies are needed to determine the long-term fate of cemented TKR implants, to assess the influence of implant design on implant fixation and wear, and to obtain objective functional data.     

Micro Total Hip Replacement for Dogs and Cats: Surgical Technique and Outcomes

Objective: To describe the surgical technique for the micro total hip replacement (Micro THR) system and report clinical outcomes. Study Design: Prospective study. Animals: Dogs (n=49) and cats (n=8) with coxofemoral arthropathy. Methods: Small breed dogs and cats with coxofemoral arthritis were enrolled for Micro THR. Patient data were recorded. Implant positioning and cement mantle quality were evaluated radiographically. Orthopedic examinations and client interviews were used to assess outcome. Results: Micro THR was performed unilaterally (40 dogs, 8 cats) and staged bilaterally (9 dogs) to resolve pain associated with osteoarthritis or trauma. Mean body weight was 7.2 kg. Postoperative complications included prosthesis luxation (9), cup aseptic loosening (1), and sciatic neurapraxia (1). Mean radiographic follow up was 96.1 weeks; 10 joints were followed for ≥3.0 years. Sixty of the 66 (91%) Micro THRs had excellent outcomes. Two dogs (<2.75 kg) were too small for the prosthesis and 4 dogs with unmanageable luxation had explantation. Conclusions: Micro THR is considered a satisfactory procedure for management of small breed dogs and cats with coxofemoral disease unresponsive to medical management. Clinical Relevance: Micro THR is a viable option to treat disabling disorders of the hip. More than 170 cat and small dog breeds, and many mixed breeds, could benefit from Micro THR surgery.     

Abnormalities of Serum Magnesium in Critically III Dogs: Incidence and Implications

Serum magnesium (Mg) is an infrequnetly measured electrolyte in small animal patients. Currently, little is known about the prevalence and significance of abnormalities in serum Mg in animals. Therefore, a prospective study was performed to examine the incidence and clinical implications of abnormalities in serum Mg levels in critically ill dogs.
Serum Mg and other electrolytes were measured in 93 normal dogs housed at the Purina Pet Care Center and in 48 ill dogs admitted to a small animal critical care unit. The normal reference range for canine serum Mg was determined to be 1.89 – 2.51 mg/dl. Based on this range, 54% of the critically ill dogs were hypomagnesemic (< 1.89 mg/dl) and 13% were hypermagnesemic (> 2.51 mg/dl). Of the electrolytes measured in these patients, serum Mg had the highest prevalence of abnormal values. Hypomagnesemic patients had a significantly higher incidence of concurrent hypokalemia and hyponatremia (p < 0.05), as well as a longer length of hospitalization (p < 0.05) than their normomagnesemic counterparts. Hypermagnesemic patients were 2.6 times more likely not to survive their illness when compared to patients with normal serum Mg levels.
Abnormalities in serum Mg appear to be common in critically ill dogs. These patients commonly have other concurrent electrolyte abnormalities. Since serum Mg is not routinely measured, the presence of hypokalemia or hyponatremia should alert the clinician to the possibility of coexisting hypomagnesemia. The clinical implications of hypomagnesemia and hypermagnesemia in ill dogs appear to involve prolonged hospitalization and increased mortality, respectively: however, the exact etiology remains undetermined.     

A Temporal Study Comparing the Carriage of Staphylococcus intermedius on Normal Dogs with Atopic Dogs in Clinical Remission

Résumé— Le portage de Staphylococcus intermedius dans les narines, le pourtour anal et la ligne blanche a été compare chez 10 chiens sains et 19 chiens atopiques cliniquement controlés, recevant de faibles doses, à jours alternés, de prednisone pendant une période six mois. Un test du x² n'a pas permis de mettre en évidence une différence significative du taux d'isolement de S. intermedius entre les deux groupes en aucune localisation ni en regroupant l'ensemble des localisations [Harvey, R. G., Noble, W. C. A temporal study comparing the carriage of Saphylococcus intermedius on normal dogs with atopic dogs in clinical remission (Etue comparative du portage de Staphylococcus intermedius chez les chiens sains et atopiques cliniquement guéris).
Abstract— A temporal study of the carriage of Staphylococcus intermedius from the nares, anal ring and ventral midline of 10 normal dogs was compared to that of 19 atopic dogs receiving low dose, alternate-day prednisolone over a period of six months and maintained in clinical remission.
Chi-squared comparison of the two groups revealed no difference between the groups in the recovery rate of S. intermedius at any single site and no significant difference when all sites were pooled.