Computed tomographic osteoabsorptiometry of the elbow joint in clinically normal dogs

OBJECTIVE: To evaluate subchondral bone density patterns in elbow joints of clinically normal dogs by use of computed tomographic (CT) osteoabsorptiometry. SAMPLE POPULATION: 20 cadaver forelimbs from 10 clinically normal dogs. PROCEDURE: Each elbow joint was imaged in parasagittal and transverse planes of 1.5-mm thickness. Slice data were converted to dipotassium phosphate equivalent density (PPED) values. Sagittal, parasagittal, and transverse medial coronoid process topographic maps were constructed. Defined zones were created for each of the 3 CT planes, and confluence and peak PPED values were determined. RESULTS: The lowest PPED value was 340 mg/ml (articular and subchondral confluence), and the highest was 1780 mg/ml (peak subchondral density). Detectable effects of joint laterality were not found in the confluence or peak PPED measurements or in the peak-to-confluence PPED ratio for all 3 CT planes. Significant differences were found among zones in all 3 planes for confluence and peak PPED measurements and between sagittal and transverse planes for peak-to-confluence PPED ratios. Subjectively, the pattern of density distribution among dogs was fairly consistent for the sagittal and parasagittal slices. Three specific patterns of density distribution were apparent on the transverse topographic maps of the medial coronoid process that corresponded to conformational differences. CONCLUSIONS AND CLINICAL RELEVANCE: The use of CT osteoabsorptiometry provides a repeatable technique that can be used to noninvasively examine bone density and the effects of stress acting on joints in vivo. Variability in density values for any of the CT planes was not identified among clinically normal dogs.     

Computed tomography measurements of thoracic structures in 26 clinically normal goats

There is increasing evidence that activation of innate immunity, in animals and man, by live vaccines, sub-unit vaccines or synthetic or non-synthetic stimulants can induce a profound and rapidly induced resistance to pathogens, including infectious agents that are unrelated to the stimulating antigen or agent. We review the evidence for this phenomenon and present the proposition that this approach might be used to stimulate immunity during the life of the animal when susceptibility to infection is high and when normal vaccination procedures may be inappropriate.     

Computed tomography and cross-sectional anatomy of the head in the giant anteater (Myrmecophaga tridactyla)

The aim of this study was to identify the anatomical structures in the head region of the giant anteater (Myrmecophaga tridactyla) using computed tomography. For this, three giant anteater corpses, adult and female, were used. The tomographic analysis was performed in sequential order in rostrocaudal direction. Subsequently, the heads of these animals were sectioned in cross sections of approximately 1.5 cm each. Tomographic images were compared with anatomical sections. The association between computed tomography and anatomical sections allowed the visualization of anatomical structures found in the nasal, oral, cranial, pharyngeal and ear cavities. An elongated oral cavity delimited by the elongated mandible was observed. The oral cavity was mainly occupied by a thin and elongated tongue formed mainly by the union of the sternoglossal muscles. The nasopharynx and oropharynx extended up to the neck at the level of the fifth cervical vertebra. The findings of this study suggest that the giant anteater has a head with structures morphologically adapted to its feeding habits, such as an elongated skull, tongue, styloid bones and mandible. In addition, based on the results of this study, it is possible to suggest that computed tomography is a pivotal tool for the veterinary routine of wild animals, since it allowed the identification of anatomical structures found in the head of the giant anteater.     

Isoamylases in clinically normal dogs

Isoenzymes of canine serum amylase were evaluated by electrophoresis on cellulose acetate membranes in a discontinuous buffer system. Two isoamylase groups were identified in the serum of clinically normal dogs. Most of the serum amylase activity was the more cathodal isoamylase. The anodal isoamylase was rarely observed in serum from normal dogs and, when present, accounted for little of the enzymatic activity. Amylase activities of various tissues were determined and isoenzymes were identified. The anodal isoenzyme was found in the pancreas and uterus. The cathodal isoamylase had its origin mainly from the intestinal tract. Activities of other tissues were not greater than was serum amylase activity. Effects of feeding upon total serum amylase activity and isoenzyme composition also were examined over a period of 5 minutes to 7 hours. Feeding did not markedly alter the serum amylase activity.     

Diseased dogs isoamylases in clinically normal and diseased dogs

Isoamylases in normal canine sera were separated on cellulose acetate membranes using a discontinuous buffer system without EDTA. Four peaks of amylase activity were present in 17 of 24 sera. Normal values were established. The majority of activity was present in Peak 4 (cathodal isoamylase). Tissue extracts of pancreas, duodenum, kidney, lung, testis, spleen and uterus-ovaries contained Peak 4 isoamylase. Liver and salivary gland lacked all isoamylase activity. Pancreas contained Peak 3 in addition to Peak 4 isoamylase. A tissue origin for Peaks 1 and 2 was not identified. An overall lack of resolution resulted from the inclusion of EDTA in the electrophoresis buffer system. This may account for previous findings suggesting that pancreatic amylase is not present in normal canine serum. An increase in the Peak 3 isoamylase was present in dogs with pancreatitis while dogs with pancreatic atrophy had a decrease in all isoamylases. Total amylase activity was significantly (p < 0.05) decreased in dogs with pancreatic atrophy.     

Ureterocolonic anastomosis in clinically normal dogs

Ureterocolonic anastomosis was evaluated in 13 clinically normal dogs. Urinary continence was maintained after surgery, and the procedure was completed without technique errors in all but 2 dogs. Three dogs died within 5 weeks (2 of undetermined causes and 1 of aspiration pneumonia and neurologic disease), and 1 dog was euthanatized 4 months after surgery because of neurologic signs. Two healthy dogs were euthanatized 3 months after surgery for light microscopic evaluation of their kidneys. Five dogs were euthanatized 6 months after surgery for light microscopic evaluation of their kidneys. Gastrointestinal and neurologic disturbances developed in 4 dogs at various postoperative intervals. Plasma ammonia concentration measured in 2 dogs with neurologic signs was increased. Plasma ammonia concentration measured in 5 dogs without neurologic signs was within normal limits. All 5 dogs, in which metabolic acidosis was diagnosed, had high normal or above normal serum chloride concentration. Serum urea nitrogen values were increased after surgery because of colonic absorption of urea. Serum creatinine concentration was increased in 1 dog 6 months after surgery. Individual kidney glomerular filtration rate was reduced in 38% (3/8) of the kidneys from 4 other dogs at 6 months after surgery. Of 5 dogs euthanatized at 3 to 4 months after surgery, 4 had bilateral pyelitis, and 1 had unilateral pyelonephritis. Six months after surgery, pyelonephritis was diagnosed in 40% (4/10) of the kidneys from 5 dogs. The ureterocolonic anastomosis procedure is a salvage procedure that should allow complete cystectomy. However, variable degrees of metabolic acidosis, hyperammonemia, and neurologic disease may result.     

Impedance audiometric measurements in clinically normal dogs

OBJECTIVE: To measure impedance audiometric values in clinically normal dogs that were sedated or anesthetized, evaluate effects of ear flushing on tympanometric measurements, and determine effects of performing acoustic reflex testing in a sound-attenuated room. ANIMALS: 35 mixed-breed and purebred client-owned dogs and 21 laboratory-bred Beagles. PROCEDURES: Tympanometry and acoustic reflex testing were performed on 27 mixed-breed and purebred dogs under isoflurane anesthesia in a non-sound-attenuated room and 21 Beagles under sedation in a sound-attenuated room. Tympanometry was performed on 8 mixed-breed dogs under halothane anesthesia before and after ear canal flushing. RESULTS: Among impedance audiometric values, ear canal volume and compliance peak were smaller in Beagles than in mixed-breed dogs; differences among other values were not detected. Ear canal volume was dependent on body weight. Differences were not found for tympanometric values measured before and after ear canal flushing. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study established reference range values for impedance audiometric measurements in clinically normal dogs under isoflurane anesthesia or sedation. Acoustic reflex testing does not need to be performed in a sound-attenuated room. The ear canals of clinically normal dogs can be flushed prior to performing tympanometry without altering the results. Impedance audiometry may be a useful noninvasive procedure for the diagnosis of otitis media in dogs.     

Telomerase activity in clinically normal dogs and dogs with malignant lymphoma

OBJECTIVES: To determine whether telomerase activity was present in lymph nodes, buffy coat, and serum samples from dogs with malignant lymphoma (ML) and in liver, lymph node, buffy coat, and serum samples from clinically normal dogs SAMPLE POPULATION: Tissue specimens and blood samples were obtained from 11 clinically normal adult dogs (age range, 1 to 4 years) and 14 client-owned dogs with ML. PROCEDURE: The telomere repeat amplification protocol assay was used to quantify telomerase activity in the tissues from clinically normal dogs and dogs with ML. RESULTS: Of 11 clinically normal dogs, 8 had lymph node samples, 5 had liver samples, and 1 had buffy coat samples with detectable telomerase activity. None of the serum samples from the clinically normal dogs had detectable telomerase activity. Of 14 dogs with ML, 9 had lymph node samples, 3 had buffy coat samples, and 1 had serum samples with measurable telomerase activity. CONCLUSIONS AND CLINICAL RELEVANCE: Telomerase activity was not specific to tumor cells and overlapped with that found in cells from clinically normal dogs. Telomerase activity in neoplastic lymph nodes was not substantially different from that found in lymph nodes from clinically normal dogs. The determination of telomerase activity cannot be used as a sole diagnostic test for cancer. Therapeutic modalities directed toward the telomerase enzyme may not be feasible in dogs, because somatic tissues from clinically normal dogs possess variable amounts of telomerase activity.