Attitudes of owners regarding tendonectomy and onychectomy in cats.

OBJECTIVE: To compare the incidence of behavior problems following tendonectomy or onychectomy in cats, as well as attitudes of owners following these procedures. DESIGN: Nonrandomized clinical trial. ANIMALS: 18 cats that underwent tendonectomy and 39 cats that underwent onychectomy. PROCEDURE: Owners of cats that underwent tendonectomy or onychectomy between February 1993 and May 1998 were contacted by telephone and asked several questions regarding reasons for surgery as well as complications and behavioral changes in cats following surgery. RESULTS: The most common reason for considering tendonectomy or onychectomy was to avoid damage caused by the cat scratching household materials. Avoidance of injury to humans or animals was chosen more often by owners whose cats underwent onychectomy than those that underwent tendonectomy. Tendonectomy was more likely to have been recommended by veterinarians than onychectomy. Significantly more cats that underwent tendonectomy (67%) than onychectomy (44%) returned to normal activity within 3 days after surgery. Significant differences were not detected regarding behavior problems after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Although tendonectomy and onychectomy involved some medical complications and behavior changes following surgery, owners had positive attitudes regarding both surgeries after the immediate postoperative period. Tendonectomy may be a humane alternative to onychectomy, although owners need to be advised that nail trimming is still necessary in cats after surgery.

Surgical options for the treatment of hyperthyroidism in the cat.

Since the first description of feline hyperthyroidism in 1978, numerous treatment options for hyperthyroidism have been reported. Surgical removal of enlarged, autonomously functioning thyroid glands is one of the most commonly used treatment options. Affected cats must have a careful pre-operative evaluation to detect concurrent medical conditions such as renal disease or cardiomyopathy. Since more than 80% of hyperthyroid cats have neoplastic changes in both thyroid glands, bilateral thyroidectomy is necessary for treatment of the majority of hyperthyroid cats. Several different thyroidectomy techniques have been developed in an attempt to minimise potential post-operative complications associated with bilateral thyroidectomy such as hypocalcemia or recurrence of hyperthyroidism. Damage to or removal of all four parathyroid glands during bilateral thyroidectomy causes hypocalcemia, the most common post-operative complication. Recurrence of hyperthyroidism can occur months after initial thyroidectomy if residual adenomatous thyroid tissue is retained in the surgical site. The most effective surgical techniques for bilateral thyroidectomy involve preservation of at least one external parathyroid gland on the surface of the thyroid capsule. Additionally, the majority of the thyroid capsule must be removed to ensure that all neoplastic thyroid tissue is removed. The most recently described feline thyroidectomy techniques involve sequential removal of bilaterally affected thyroid glands. Staging a bilateral thyroidectomy allows time for ipsilateral parathyroid tissue to revascularise before the second thyroid gland is removed and the blood supply to the contralateral parathyroid glands is potentially interrupted. Thyroidectomy is a very effective treatment option for hyperthyroid cats. Surgical treatment of hyperthyroidism in cats offers permanent cure without chronic medical management. No specialised equipment other than standard surgical instrumentation and facilities are necessary. With practice, feline thyroidectomy can become a routine procedure in most veterinary hospitals.

Evaluation of selected cardiopulmonary and cerebral responses during medetomidine, propofol, and halothane anesthesia for laparoscopy in dogs.

OBJECTIVES: To compare the dose-sparing effect of medetomidine on the propofol induction dose and concentration of halothane for maintenance of anesthesia during laparoscopy and to provide guidelines for effective and safe use of these anesthetics in dogs to ensure desirable perioperative analgesia. ANIMALS: 14 purpose-bred dogs. PROCEDURE: Cardiopulmonary and electroencephalographic responses were determined during 2 anesthesia protocols in dogs scheduled for laparoscopy. Fifteen minutes before anesthesia induction, all dogs received atropine sulfate (0.02 mg/kg of body weight, i.m.). Seven dogs were then given propofol (6.6 mg/kg, i.v.); anesthesia was maintained with halothane in oxygen. The other dogs were given medetomidine hydrochloride (10 micrograms/kg, i.m.) 5 minutes after administration of atropine sulfate; anesthesia was then induced by administration of propofol (2.8 mg/kg, i.v.) and was maintained with halothane in oxygen. RESULTS: The halothane concentration required for laparoscopy was lower in dogs given medetomidine. Anesthetic requirements were significantly increased during abdominal manipulation in both groups. Total amplitude of the electroencephalograph in medetomidine-treated dogs was not significantly lower than that in dogs not given medetomidine. Pulmonary responses were stable throughout all procedures. The primary cardiovascular response was an increase in blood pressure associated with the medetomidine-atropine preanesthetic combination. Significant differences in total amplitude or frequency shifts (spectral edge) of brain wave activity were not associated with surgical stimulation. CONCLUSION: Lack of neurologic changes during laparoscopy supports the efficacy of either medetomidine-propofol-halothane or propofol-halothane combinations at higher concentrations to provide desirable analgesia and anesthesia in this group of dogs.

The effect of unilateral arytenoid lateralization on rima glottidis area in canine cadaver larynges.

Five modifications of a cricoarytenoid lateralization and two modifications of a thyroarytenoid lateralization laryngoplasty technique were evaluated for their effect on rima glottidis area. All procedures and evaluations were performed on canine cadaver larynges. Cricoarytenoid lateralization (CAL) techniques provided a greater increase of the size of the glottic opening than did any of the thyroarytenoid lateralization techniques. Cricoarytenoid and interarytenoid disarticulation associated with CAL did not significantly increase glottic size compared with normal. After disarticulation of the cricoarytenoid joint, there was no difference in glottic enlargement whether the suture was placed through the muscular process or through the articular facet of the arytenoid cartilage. Transection of the sesamoid band combined with cricoarytenoid diarticulation distorted the dorsal margin of the rima glottidis.

The diagnosis and surgical correction of congenital portosystemic vascular anomalies in two calves and two foals.

Two calves and two foals presented with episodic clinical signs of diffuse central nervous system disease. Portosystemic anomalies were tentatively diagnosed based on the history, clinical signs and increased serum concentrations of blood ammonia and total serum bile acids with normal concentrations of liver derived enzymes. one calf died before intraoperative contrast portography, whereas the other calf and both foals had marked clinical improvement after intensive medical therapy. Surgical correction was attempted in these three animals and was successful in one foal. A right paracostal celiotomy was superior to a ventral median approach for exposure to the portal vascular system and shunt access.

Biomechanical and histological evaluation of a laparoscopic stapled gastropexy technique in dogs.

The biochemical holding strength and histological characteristics of a laparoscopic stapled gastropexy (LG) adhesion were compared with that of an incisional gastropexy (IG) adhesion. An LG was performed in 14 dogs and an IG was performed in six dogs. During the LG procedure, the abdomen was insufflated with carbon dioxide and three cannulae were placed in the caudal aspect of the right side of the abdomen. A 35 mm laparoscopic stapler was used to staple the gastric antrum to the adjacent right lateral abdominal wall. The IG procedure was performed through ventral midline celiotomy. A 35 mm IG was made by apposing the gastric antrum to the adjacent right lateral abdominal wall with two continuous rows of suture. Half of each group of dogs was euthanatized at 7 and 30 days after surgery. The mean tensile load to failure at 7 days was 44.86 +/- 18.54 N for the LG group and 85.33 +/- 23.59 N for the IG group (P < .05). At 30 days the values were 72.39 +/- 18.01 N for the LG group and 71.17 +/-12.11 N for the IG group (P = .41). The gastropexy adhesions in the 7-day postoperative group contained variable amounts of fibrin, hemorrhage, mononuclear cell inflammation, loose fibrovascular tissue, and mature collagenous connective tissue. Adhesions in the 7-day postoperative group were divided subjectively into three histological subgroups based on the relative amounts of mature connective tissue within the adhesion. The LG and IG adhesions were randomly distributed among these subgroups (P = 1.0). Adhesions in the 30-day postoperative group contained well-organized fibrous connective tissue. No difference in the amount of connective tissue could be detected histologically in the LG or IG adhesions. Complications with the LG procedure included stomach perforation (2 cases), splenic puncture (2 cases), and subcutaneous emphysema (4 cases).

Use of a vascular access system for administration of chemotherapeutic agents to a ferret with lymphoma.

Two months after initiation of chemotherapy, a totally implantable vascular access system was used for the continuing administration of chemotherapeutic agents to a ferret with multicentric lymphoma. The subcutaneously located injection port minimized the need for restraint and facilitated repeated IV administration of drugs. Treatment with a combination of L-asparaginase, vincristine sulfate, doxorubicin, cyclophosphamide, methotrexate, chlorambucil, and prednisone failed to induce complete remission. Survival time (interval from histologic diagnosis to euthanasia) was 10 months. The vascular access system remained patent and did not cause infection in the surrounding subcutaneous tissues during the 5-month period that it was in position.

Surgical therapy of the thyroid.

The surgical treatment of thyroid cancer in the cat involves excision of one or both thyroid glands while sparing at least one parathyroid gland. The most common postoperative complication of bilateral thyroidectomy is transient hypocalcemia. Most feline thyroid tumors are benign, hyperfunctional thyroid adenomas. Surgical excision is usually curative. Canine thyroid cancer is most commonly malignant and nonfunctional. Successful surgical treatment of canine thyroid cancer depends on histologic and early diagnosis prior to metastasis or invasion of the cancer into adjacent structures within the neck.

Exposure and postoperative stability of three medial surgical approaches to the canine elbow.

Articular cartilage exposure and immediate postoperative stability provided by three medial surgical approaches in canine cadaver elbows were compared. The approaches evaluated were a desmotomy of the medial collateral ligament (DMCL) that included a tenotomy of the pronator teres muscle, a longitudinal myotomy of the flexor carpi radialis (MFCR), and an osteotomy of the medial epicondyle (OME). Nondestructive biomechanical testing was performed before the surgical approach and repeated after surgery. The stiffness at 13 degrees valgus deviation of the elbow and energy absorption up to 13 degrees valgus deviation of the elbow were determined from the preoperative and postoperative torque-rotation curves. The perimeters of the ulnar and humeral articular cartilage that were visualized through the approach were scored with a dental pick. Latex casts were made of articular surfaces of the elbow. The humeral and ulnar articular exposures were determined by computerized planimetric analysis of latex cast photocopies. The humeral cartilage exposure of the OME approach was significantly greater than either the MFCR or DMCL approaches. The DMCL approach provided a significantly greater humeral cartilage exposure than the MFCR approach. All three approaches provided statistically similar percentages of ulnar cartilage exposure. The stiffness and energy absorption of the OME and MFCR approaches were similar and significantly greater than the DMCL approach. The OME approach provided the best combination of exposure and immediate postoperative stability.

The effect of long-term bone plate application for fixation of radial fractures in dogs.

This study was divided into two phases. In the in vitro phase, a stainless steel bone plate was applied to the cranial surface of the radius in 14 canine limbs. The effect of the presence of a bone plate on bone density analysis using radiographic photodensitometry (RP) was evaluated by comparing the density measurement of the unplated limb to the density measurement of the plated limb. The optical density of the plated bones was 12% greater than that of the unplated bones. This information was used as a correction factor for the in vivo study. In the in vivo phase, 23 dogs with radial and ulnar fractures were examined for complications associated with the long-term application of a stainless steel plate applied to the cranial surface of the radius. In 14 dogs, RP analysis was used to compare the plated limb with the normal, contralateral limb. No significant differences in radial cortical bone density existed between the plated limb and the contralateral limb after taking into account the effect a bone plate had on photodensitometry readings. There was no significant correlation between the change in radial cortical density and the duration of bone plate application, suggesting that a steady state between bone loss and bone production occurs after long-term plate fixation of the fractured canine radius. The majority (87%) of the dogs with a plate applied to the radius greater than 1 year had normal limb usage when standing, walking, or running.

Treatment of experimentally induced trichinosis in dogs and cats.

Studies were undertaken to determine the efficacy of milbemycin oxime against the enteric adult stages of Trichinella spiralis and of albendazole against the muscle stage larvae in experimentally infected dogs and cats. Specific-pathogen-free Beagle pups (n = 6) and domestic shorthair kittens (n = 6) were inoculated with 7,500 first-stage larvae of Trichinella spiralis. Physical examination (including collection of blood and fecal samples) was performed weekly. During the first week after inoculation, all animals had mild gastrointestinal tract disturbances, but stages of T spiralis were not observed in the feces. Beginning on postinoculation day (PID) 10, 3 pups and 3 kittens were treated with milbemycin oxime (1.25 mg/kg of body weight, PO, q 12 h) for 10 days. Muscle biopsy specimens were taken from dogs and cats on PID 26 and 29, respectively. Mean numbers of larvae per gram of muscle were 30.3 in the control and 37.7 in the treated dogs. Mean numbers of larvae per gram of muscle in the control and treated cats were 318.7 and 89.3, respectively. Two dogs and 2 cats were removed from the study at that time. The remaining animals, 2 each of the control and milbemycin oxime-treated animals, were given albendazole (50 mg/kg, PO, q 12 h) for 7 days starting at PID 31 and 34 in dogs and cats, respectively. Muscle biopsy specimens were again taken at PID 46 and 49, for dogs and cats, respectively; mean numbers of larvae recovered from muscle were 0.6 for dogs and 13.5 for cats.

Decreased incidence of postoperative urinary incontinence with a modified Penrose drain technique for treatment of prostatic abscesses in dogs.

Drainage with multiple Penrose drains is currently recommended as the primary treatment for canine prostatic abscesses. A recent report indicated that short term and long term urinary incontinence is a frequent complication associated with this technique. In this study, a modified multiple Penrose drain technique that avoids dissection dorsal to the prostate gland was performed in 17 dogs. Long term follow up information was obtained by telephone interview with the owners. Three dogs had urinary incontinence that resolved spontaneously within 3 days of surgery. Within the first year after that period, no other dogs developed incontinence. An excellent result was recorded in 12 dogs (71%) and a good result in 5 dogs (29%) having prostatic abscess drainage.

Unilateral adrenalectomy as a treatment for adrenocortical tumors in ferrets: five cases (1990-1992).

Adrenocortical tumors were diagnosed in 5 adult spayed ferrets. Four ferrets had bilaterally symmetrical alopecia of the caudal femoral region, abdomen, and tail, and 1 had alopecia of the distal limbs and feet. All 5 ferrets had vulvar swelling. During abdominal ultrasonography, irregular masses, believed to involve the adrenal glands, were seen in all 5 ferrets. Unilateral adrenalectomy was performed successfully in each ferret by use of ventral midline celiotomy. On histologic examination of biopsy samples, 4 ferrets were found to have adrenocortical adenomas, and 1 ferret was found to have an adrenocortical adenocarcinoma. All clinical signs resolved after adrenalectomy, suggesting that the adrenocortical tumors had been secreting adrenocortical hormones.

Cecal-colic volvulus in two dogs.

Cecal-colic volvulus was confirmed by surgery in two dogs. Both dogs were intact, male Great Danes. The clinical and diagnostic findings were not specific for large bowel volvulus. Clinical signs included peracute to acute onset of vomiting, mild abdominal distention and pain, lack of feces, and tenesmus. Abdominal radiographs demonstrated severe dilatation of bowel loops in both dogs. One dog survived.

Differentiation-dependent expression of lectin binding sites on normal and neoplastic keratinocytes in vivo and in vitro.

We used lectins as probes to demonstrate the composition of membrane carbohydrates of canine keratinocytes in various functional stages and various degrees of differentiation. Keratinocytes during normal epidermal turnover were compared by lectin immunohistochemistry to cells of hyperplastic epidermis and neoplastic keratinocytes. Three types of epidermal tumors and oral squamous cell carcinomas were examined. In addition, two in vitro tissue culture systems for keratinocytes were studied and compared with in vivo epithelium. In normal skin, PNA reacted only weakly with basal cells, whereas in hyperplastic skin basal cells bound this lectin strongly, demonstrating increasing expression of PNA binding sites with increasing thickness of the stratified squamous epithelium. ConA bound to basal cell tumors only. In oral squamous cell carcinomas, the expression of distinct lectin binding sites correlated with certain histological growth patterns, e.g., UEA-I reacted with highly invasive tumors but not with tumors showing a solid growth pattern. Using cell surface iodination and polyacrylamide gel electrophoresis, distinct differences in cell membrane protein expression were demonstrated between normal and neoplastic keratinocytes. SDS-polyacrylamide gel electrophoresis of cultured normal and neoplastic keratinocytes revealed several cell surface proteins that are specific for either cell type. Neoplastic cells specifically express a 140 KD lectin binding cell surface glycoprotein. The results of this study show that lectin binding patterns of keratinocytes are dependent on the functional state and the degree of differentiation of the cells and demonstrate correlation of some histological growth patterns with distinct lectin binding phenotypes, suggesting association of expression of cell membrane carbohydrate moieties with growth patterns. In addition, close similarities between "lifted cultures" grown at the air-liquid interface and native tissue demonstrate the value of this culture system as a model for differentiated stratified squamous epithelium.

Functional analysis of ectopic parathyroid activity in cats.

The ability of ectopic parathyroid tissue to support calcium homeostasis was evaluated by measuring serum concentrations of calcium, phosphorus, albumin, magnesium, and parathyroid hormone before and for 12 weeks after bilateral thyroparathyroidectomy in 14 cats. During the immediate postoperative period, significant decrease was observed in serum calcium, magnesium, and parathyroid hormone (PTH) concentrations. Serum PTH concentration remained subnormal and did not significantly increase during the 12-week observation period. Despite persistent hypoparathyroidism, serum calcium and magnesium concentrations gradually increased. Ectopic parathyroid tissue is not capable of maintaining normal serum calcium concentration immediately after thyroparathyroidectomy. Serum calcium concentration gradually normalizes after thyroparathyroidectomy, apparently by means of a PTH-independent mechanism.

Comparison of growth and differentiation of normal and neoplastic canine keratinocyte cultures.

Neoplastic canine keratinocytes derived from a spontaneous oral squamous cell carcinoma were maintained in culture for more than 45 passages. The presence of desmosomes and keratin filaments was demonstrated by electron microscopy and immunohistochemistry. The keratinocytes were grown in two different culture conditions to induce variations in the stage of differentiation, i.e., in submerged cultures and at the air-liquid interface. For comparison, normal canine keratinocytes were grown under the same conditions. Anisocytosis was present in neoplastic cultures grown submerged in medium. Grown at the air-liquid interface, neoplastic keratinocytes differentiated into a well-organized, multilayered stratified squamous epithelium analogous to normal keratinocytes. Rare areas of irregular growth and formation of whorls were detected. Expression of lectin binding sites and specific cell surface antigens of neoplastic and normal keratinocytes demonstrated marked similarities between the two cell lines. Neoplastic cells lacked certain surface antigens that are present on normal cells. Squamous cell carcinoma cells grew faster than normal canine keratinocytes as demonstrated by growth curve evaluation. Neoplastic keratinocytes responded to growth stimulation by epidermal growth factor and cholera toxin as do normal keratinocytes. Neoplastic cells grown in medium lacking these factors proliferated faster than growth factor stimulated normal keratinocytes.

Extrahepatic biliary tract rupture: evaluation of the relationship between the site of rupture and the cause of rupture in 15 dogs.

We performed a retrospective study of 15 cases of extrahepatic biliary tract rupture in dogs. Nine of the 15 dogs had ductal rupture associated with blunt abdominal trauma. The remaining 6 dogs had gallbladder rupture associated with cholelithiasis and/or cholecystitis. The relationship between site of rupture and cause of rupture was significant (p = 0.0002). A review of 60 dogs with extrahepatic biliary tract rupture reported in the veterinary literature revealed a similar relationship (p = 0.0001). Thirty-two of 33 cases of ductal rupture were associated with blunt abdominal trauma and 25 of 27 cases of gallbladder rupture were associated with cholelithiasis and/or cholecystitis. Totals after combining our cases with those from the literature suggests the most frequent area of ductal rupture is the common bile duct distal to the last hepatic duct, followed by the junction of the common bile duct with the duodenum.

Nuclear medical bone imaging and targeted radiography for evaluation of skeletal neoplasms in 23 dogs.

Nuclear medical bone imaging was used in combination with targeted radiography to detect metastatic or multicentric lesions in 23 dogs with skeletal neoplasms. Each dog with a radiographically diagnosed skeletal neoplasm was injected with Technetium-99m labeled methylene diphosphonate (99mTc-MDP) (15.0 mCi intravenously) for whole body imaging. All areas with increased uptake of 99mTc-MDP were radiographed. In 19 dogs, the amount of bone shaft involvement in primary sites indicated by bone imaging was larger than the amount indicated by radiography. Eighteen dogs had secondary areas of increased 99mTc-MDP uptake, six of which had secondary areas that were suspected radiographically to be neoplastic. Four dogs had lesions characterized histologically as neoplasia, one as bone infarction and one as normal cortical bone. Positive predictive value for this strategy was 66.7%. Results of this study suggest that nuclear medical bone imaging with targeted radiography is a quick, noninvasive technique with a good positive predictive value for evaluation of the skeleton for metastatic or multicentric sites of neoplasia.