ANATOMY OF THE PORTAL AND HEPATIC VEINS OF THE DOG: A BASIS FOR SYSTEMATIC EVALUATION OF THE LIVER BY ULTRASONOGRAPHY

The objective of this study was to define, in detail, the anatomy of the portal and hepatic veins in the dog in order to establish a procedure for the systematic evaluation of the liver by ultrasonography. Anatomical details were obtained from the formalin fixed livers of ten dogs. The hepatic and portal veins were removed intact from these livers so that a detailed pattern of distribution could be established and the numbers of branches could be counted. Silastic casts were also made of the hepatic and portal veins of two livers, one in situ and one in which it had been removed. The former was to enable the relationship of the portal to the hepatic veins to be established as closely as possible within the animal and the other to provide a model of the distribution of each venous system within the liver. Contrast medium was infused into two other livers and radiographs taken to establish the relationship of each branch to each lobe. It was found that there was a consistent pattern of venous branching to each lobe of the liver in the dog with little variation between individual specimens. All liver lobes contained definite venous branches so that the left lateral and medial, quadrate, right medial and lateral, caudate and papillary veins could be distinguished in each venous system. We believe that an appreciation of this venous distribution will aid in the systematic evaluation of the liver during ultrasonography by enabling identification of each liver lobe. It should be of value for differentiating portal from hepatic veins and veins from dilated bile ducts.     

MULTICENTRIC LYMPHOMA WITH INTESTINAL INVOLVEMENT IN A DOG

A 5-year-old, male German shepherd dog was evaluated for a 5-week history of vomiting, diarrhea, lethargy, and weight loss. In abdominal radiographs, there was an unusual corrugated appearance within a loop of intestine. Sonographically, this loop also had a similar corrugated appearance with alternating hyperechoic and hypoechoic bands. Lymph nodes within the abdomen and thorax were enlarged, and a thoracic mass was also detected. Ultrasound-guided fine-needle aspirates of the mesenteric lymph nodes were highly suggestive of lymphoma. After postmortem examination, a diagnosis of multicentric lymphoma with involvement of the gastrointestinal tract was made.     

A COMPUTERIZED WORD-BASED DATA SYSTEM FOR A VETERINARY RADIOLOGY DEPARTMENT

Computer programs were developed to record and retrieve the diagnostic findings of a veterinary radiology department. The concluding statements of reports are abstracted into a data file. Records may be retrieved by the computer after selecting any of the following: owner's name, patient number, date, species, breed, sex, age, state of residence, imaging type and diagnosis (word or statement). Also, information retrieved from the hospital financial records (procedures performed) and medical record databases may be combined with imaging report information to provide a powerful tool for clinical research and teaching.     

Prognostic Factors in Dogs with Lymphoma and Associated Hypercalcemia

Lymphoma and hypercalcemia were diagnosed in 37 dogs. Twenty-six of the dogs received chemotherapy. The association between some prognostic factors including clinical stage of disease, illness status, presence of bone marrow involvement, and presence of an anterior mediastinal mass and remission duration and survival time was evaluated. Statistical analysis of the prognostic factors showed that the presence of an anterior mediastinal mass had an adverse effect on remission duration (P less than 0.03). Calcium concentration was not significantly related to any of the prognostic factors evaluated. Dogs that received chemotherapy were more likely to be self-supporting than the dogs that were not treated (P less than 0.005). However, initial illness status was not significantly related to remission duration or survival time in the 26 dogs that were treated. Six dogs (25% of dogs treated) survived longer than 14 months. Five of these dogs were female. Overall mean and median remission times were 10.4 and 6 months, respectively.     

ECTRODACTYLY (SPLIT-HAND DEFORMITY) IN THE DOG

Radiographs of 14 dogs with ectrodactyly of the forelimb were evaluated and the defect classified according to the site of division of the longitudinal axis of the paw. The majority of separations occurred between metacarpal bones one and two, although separations were also noted between metacarpal bones two and three, two and four, and three and four. Other lesions noted in affected limbs included digit contracture, digit aplasia, metacarpal hypoplasia and metacarpal fusions. Bilateral involvement was noted in only one of 14 cases. No breed or sex predisposition was found and there was equal involvement of the left and right limbs.     

Equine Degenerative Myeloencephalopathy: A Vitamin E Deficiency That May Be Familial

Two horse farms, on which there was a high incidence of proven and suspected equine degenerative myeloencephalopathy (EDM), were studied. Symmetric ataxia and paresis, along with laryngeal adductor, cervicofacial, local cervical, and cutaneous trunci hyporeflexia, characterized the syndrome. Serum vitamin E concentration reflected a deficient state in affected and unaffected horses on both farms when compared with selected reference groups and with published values. A high incidence of the disease was evident in offspring of two particular sires on one farm. Vitamin E supplementation resulted in correction of the deficient state in most horses and was associated with a drastic reduction in the incidence of EDM on one farm from 40% to less than 10% the year following vitamin E supplementation. In addition, during the last year, the severity of signs in the few cases was dramatically reduced. This information substantiates the hypothesis that EDM is a vitamin E-responsive disorder of Equidae with a possible familial predisposition.     

Cytosine Arabinoside as a Single Agent for the Induction of Remission in Canine Lymphoma

Cytosine arabinoside (AraC) was administered as a continuous IV infusion to 15 dogs with malignant lymphoma at a dose of 300 mg/m²/d for 2 consecutive days. Dogs were re-examined 7 d after treatment for response to therapy and for hematologic toxicity. Regardless of response, all dogs were started on combination chemotherapy at this time. Other toxicities were reported by owners. No dog responded objectively to Ara-C treatment, although 1 dog with circulating lymphoblasts had partial regression of lymphadenopathy but persistent blastemia. Thrombocytopenia (platelet count < 200,000/μL) 7 days posttreatment was the most commonly encountered hematologic toxicity, occurring in 10 of 14 dogs. Three of these 10 dogs were also mildly neutropenic (neutrophil counts of 2000 to 3000 cell/μL). Nonhematologic toxicity occurred in 8 of 15 dogs and was principally gastrointestinal in nature and mild in severity. Cytosine arabinoside at a dose of 300 mg/m²/day was not considered an active drug for the induction of remission in dogs with lymphoma.     

Diagnostic and Surgical Arthroscopy of the Equine Shoulder Joint

An arthroscopic technique for examination and surgical treatment of conditions of the shoulder joint was evaluated in eight normal horses and two horses with osteochondrosis lesions. A single arthroscope entry point caudal to the infraspinatus tendon allowed inspection of the cranial, lateral, and caudal surfaces of the shoulder joint. With the humeral head and glenoid cavity distracted by a curved forceps, the entire cartilage surface of the shoulder could be examined. The caudomedial portion of the humeral head was seen better with a 70 degree angled arthroscope. Instruments for intra-articular manipulation were introduced through a separate skin incision 2 to 4 cm caudal to the arthroscope entry point. Two horses with osteochondrosis lesions of the shoulder were examined arthroscopically and debrided with instrument triangulation. Five normal horses and both horses with osteochondrosis lesions were euthanized immediately after the procedure and a necropsy was performed. Minor iatrogenic damage to the cartilage surfaces and joint capsule resulted from the technique. Three horses recovered from anesthesia and were killed 3, 30, or 60 days after surgery. Subcutaneous fluid that accumulated during surgery had resorbed by 3 days and lameness was evident for 12 to 24 hours. Gross examination and histopathologic findings of specimens collected at 30 and 60 days showed several small nonhealing partial-thickness cartilage defects attributed to instrument insertion. Arthroscopy is a satisfactory method to examine the joint surfaces and to evaluate and treat osteochondrosis lesions of the shoulder joint in horses.     

Controlled Cross Circulation in Dogs: Effects on Donor Hemodynamics

Controlled cross circulation (CCC) was performed in six pairs of dogs for 45 minutes with aortic cross clamping and cardioplegia. Data were collected in donor dogs at 10 minute intervals three times before, three times during, and three times after CCC and included arterial blood pressure, pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), cardiac index (CI), heart rate (HR), blood gas analysis, temperature, maximum rate of rise of left ventricular pressure dP/dt max/End diastolic volume (EDV), blood volume (BV), complete blood count (CBC) and activated clotting times (ACT). Pulse pressure (PP), systemic vascular resistance (SVR), oxygen delivery (Do₂), and left ventricular cardiac work (LVCW) were calculated. Arterial blood pressure, CVP, blood gas analysis, temperature, BV, CBC, and ACT were measured in recipient dogs. During CCC, donor hemodynamic changes resembled those observed in models of acute onset arteriovenous fistulas. Insidious BV shifts can occur despite the use of occlusive roller pumps. After CCC, donor hemodynamics resembled acute blood loss, characterized by decreases in mean arterial pressure (MAP), CVP, PCWP, and CI, and increases in SVR and dP/dt max/EDV. These changes were probably caused by pump imbalance and BV shift to the recipient dog.     

Carotid Body Tumors in the Dog Eleven Cases (1978–1988)

Case records of 11 dogs with histologically confirmed carotid body tumors were reviewed. Surgical excision had been attempted in ten dogs with carotid body tumors, and one dog had been euthanatized at diagnosis. There were no intraoperative deaths but perioperative mortality was 40%. Horner's syndrome and laryngeal paralysis were the most common postoperative morbidities. The median survival time after surgery alone in the four dogs that survived the perioperative period was 25.5 months (range, 12-45 months). Two dogs treated with postoperative radiation therapy had survival times of 6 and 27 months. Of the six dogs surviving the perioperative period, two dogs are still alive at 19 and 32 months postoperatively. Of the four dogs that died, one was euthanatized 12 months postoperatively for nontumor-related causes. The remaining three dogs died of distant metastases. The carotid body tumors studied were characterized by local tissue invasion, neurovascular complications after therapy, and a propensity to metastasize to multiple sites in the body.