Spontaneous Course of Biliary Sludge Over 12 Months in Dogs with Ultrasonographically Identified Biliary Sludge

Background

Biliary sludge is associated with gallbladder (GB) dysmotility and mucus hypersecretion suggesting a link between biliary sludge and the formation of GB mucoceles (GBM). If biliary sludge progresses to GBM, treatment to reduce the production and progression of sludge is warranted.

Hypothesis/Objectives

The objective of this study was to determine the course of biliary sludge in dogs.

Animals

Seventy‐seven healthy, client‐owned dogs ≥4 years of age screened for biliary sludge; 45 affected dogs identified.

Methods

Prospective, observational design. Serial ultrasound examinations were evaluated at 3, 6, 9, and 12 months to monitor degree of sludge based on proportion of GB filled with sludge (mild [0.01–24.4%], moderate [24.5–49.4%], moderate to severe [49.5–74.4%], severe [74.5–100%]), gravity dependency of sludge, and GB dimensions.

Results

After 1 year of follow‐up, the degree of sludge was mild (34%), moderate (47%), moderate to severe (13%), severe (3%), or absent (3%). There was no significant difference in median degree of sludge over 1 year (P = .36). There were no significant changes in the gravity dependency of sludge over 1 year. A subset of dogs, 24%, with initial gravity‐dependent sludge developed a combination of nondependent and dependent sludge. Dogs had resolved (2%), decreased (19%), static (40%), increased (29%), or recurrent (10%) sludge at the conclusion of the study.

Conclusions and Clinical Importance

Biliary sludge was prevalent, affected dogs remained asymptomatic, and it rarely resolves in healthy dogs over a period of 1 year. Some dogs developed nongravity‐dependent sludge within 1 year, which might indicate changes in consistency of sludge.

Histopathologic variation between liver lobes in dogs

BACKGROUND

Biopsy of the liver evaluates a small portion of tissue, with inferences made to the entire organ. The method and number of biopsies obtained are tempered by consideration of the risks and benefits. Recommendations often include biopsy of more than one liver lobe, although the consistency of histopathology among lobes in dogs is unknown.

HYPOTHESIS/OBJECTIVES

To describe the distribution of histopathologic abnormalities between liver lobes. We hypothesized that discordant results would be evenly distributed among all liver lobes.

ANIMALS

Seventy dogs undergoing necropsy.

METHODS

Prospective study. Liver samples were obtained from all lobes. A primary diagnosis was assigned to each liver sample based on the predominant histopathologic abnormality.

RESULTS

In this population of dogs, biopsy of at least 2 liver lobes identified the predominant histologic abnormality in 98.6% of the cases. Ten (14%) of the dogs had ≤ 3 lobes in agreement and could not be assigned a predominant diagnosis. The same diagnosis was present in 6/6 lobes in 39 (56.5%) dogs, 5/6 lobes in 10 (14.5%) dogs, 4/6 lobes in 10 (14.5%) dogs, 3/6 lobes in 7 (10.1%) dogs, and 2/6 in 3 (4.3%) dogs. The number of discordant results did not differ between the liver lobes.

CONCLUSION AND CLINICAL IMPORTANCE

The likelihood of obtaining a sample that is reflective of the predominant histologic abnormality in the liver is increased when multiple liver lobes are biopsied.

A comparison of liver sampling techniques in dogs

Background

The liver sampling technique in dogs that consistently provides samples adequate for accurate histopathologic interpretation is not known.

Hypothesis/Objectives

To compare histopathologic results of liver samples obtained by punch, cup, and 14 gauge needle to large wedge samples collected at necropsy.

Animals

Seventy dogs undergoing necropsy.

Methods

Prospective study. Liver specimens were obtained from the left lateral liver lobe with an 8 mm punch, a 5 mm cup, and a 14 gauge needle. After sample acquisition, two larger tissue samples were collected near the center of the left lateral lobe to be used as a histologic standard for comparison. Histopathologic features and numbers of portal triads in each sample were recorded.

Results

The mean number of portal triads obtained by each sampling method were 2.9 in needle samples, 3.4 in cup samples, 12 in punch samples, and 30.7 in the necropsy samples. The diagnoses in 66% of needle samples, 60% of cup samples, and 69% of punch samples were in agreement with the necropsy samples, and these proportions were not significantly different from each other. The corresponding kappa coefficients were 0.59 for needle biopsies, 0.52 for cup biopsies, and 0.62 for punch biopsies.

Conclusion and Clinical Importance

The histopathologic interpretation of a liver sample in the dog is unlikely to vary if the liver biopsy specimen contains at least 3–12 portal triads. However, in comparison large necropsy samples, the accuracy of all tested methods was relatively low.

Diagnostic utility of abdominal ultrasonography in dogs with chronic diarrhea

BACKGROUND

Chronic diarrhea is common in dogs and has many causes. Ultrasonographic descriptions of many gastrointestinal diseases have been published, but the diagnostic utility of ultrasonography in dogs with chronic diarrhea has not been investigated.

HYPOTHESIS

Diagnostic utility of abdominal ultrasound will be highest in dogs with GI neoplasia and lowest in those with inflammatory disorders.

ANIMALS

87 pet dogs with chronic diarrhea.

METHODS

Prospective study in which medical records were reviewed and contribution of abdominal ultrasound toward making diagnosis was scored.

RESULTS

In 57/87 (66%) of dogs, the same diagnosis would have been reached without ultrasonography. In 13/87 (15%) of dogs, the ultrasound examination was vital or beneficial to making the diagnosis. Univariable analysis identified that increased diagnostic utility was associated with weight loss (P = .0086), palpation of an abdominal or rectal mass (P = .0031), diseases that commonly have mass lesions visible on ultrasound examination (P < .0001), and a final diagnosis of GI neoplasia. Multivariable regression indicated that utility of abdominal ultrasonography would be 30 times more likely to be high in dogs in which an abdominal or rectal mass was palpated (odds ratio 30.5, 95% CI 5.5-169.6) (P < .0001) versus dogs without a palpable mass. In 15/87 (17%) of dogs, additional benefits of ultrasonography to case management, independent of the contribution to the diagnosis of diarrhea, were identified.

CONCLUSIONS AND CLINICAL IMPORTANCE

Overall, the diagnostic utility of abdominal ultrasonography was low in dogs with chronic diarrhea. Identification of factors associated with high diagnostic utility is an indication to perform abdominal ultrasonography in dogs with chronic diarrhea.

Safety and efficacy of oral low-volume sodium phosphate bowel preparation for colonoscopy in dogs

BACKGROUND

Sodium phosphate (NaP) is a low-volume, hyperosmolar laxative that is an effective bowel-cleansing agent in humans.

HYPOTHESIS

NaP will be as safe and efficacious as polyethylene glycol (PEG) bowel preparation for colonoscopy in dogs.

ANIMALS

Eight purpose-bred healthy dogs.

METHODS

In phase I, standard (NaP and enemas; NaP(1)) and control preparations (PEG and enemas) were compared in a crossover design to determine the safety and efficacy of NaP. Serial clinical and serum analytical evaluations were used to determine the safety of NaP. In phase II, the efficacy of the standard NaP preparation was compared with 3 other NaP variations, which excluded enema or included bisacodyl, with or without enemas in a crossover design. An observer blinded to the bowel preparation assigned a score of 1-4 (1=clean colon; 4=unacceptable colon cleansing preventing adequate endoscopic evaluation) to each of 5 regions of the colon.

RESULTS

The mean total colon cleansing score (TCS), defined as the sum of scores from each region, of the control (9.4) was less than NaP(1) (13.6) (P < 0.05). There were no significant differences in regional or TCS for the remaining 4 NaP protocols. NaP(1) resulted in moderate, but clinically occult, hyperphosphatemia and hypocalcemia, which resolved within 24 hours.

CONCLUSIONS AND CLINICAL IMPORTANCE

Despite the safety and ease of administration of the NaP preparations, the NaP bowel-cleansing preparations used in this study cannot be recommended for use because of the inadequate quality of bowel preparation compared with the protocol using PEG-containing fluids.

Endoscopic balloon dilation of benign esophageal strictures in dogs and cats

Endoscopic balloon dilation of benign esophageal strictures was performed in 18 dogs and 10 cats with a median age of 4 years. Stricture formation was associated with a recent anesthetic episode in 18 patients. Regurgitation was the most common clinical sign and was present a median of 4 weeks before dilation. Most animals had a single stricture; median diameter was 5 mm, and median length was 1 cm. Esophagitis and mucosal fibrosis were detected in 9 patients each. Dilation was performed with progressively increasing diameter balloons, from 6 to 20 mm. After dilation, mucosal hemorrhage was mild to moderate in most patients. Esophageal perforation was the only serious complication and occurred in 1 patient. Postdilation therapy consisted of administration of cimetidine, metoclopramide, sucralfate, and prednisone in most animals. The median number of dilation procedures performed in each animal was 2, with a range of 1-5. The median interval between dilations was 13 days. Stricture diameter markedly increased with subsequent dilations. Median duration of follow-up was 131 weeks. A successful outcome occurred in 88% of patients, with most animals able to eat canned, mashed, or dry food without regurgitation. Mucosal fibrosis was associated with a better clinical response score, while increasing age was weakly associated with fewer dilations. The dilation protocol used in this group of animals was safe and efficacious.

Using the World Wide Web to enhance the problem-solving skills of third-year veterinary students

A Web site was created for the small animal problem-solving elective at Virginia Tech. In addition to signalment, history, physical examination findings, and results of routine laboratory tests, students were able to view images of cytologic and histologic specimens, radiographs, and endoscopic findings and hear examples of breath and cardiac sounds. Students commented that the availability of Web-based case materials allowed them increased opportunities to practice problem-solving skills.

Evaluation of the bromosulfophthalein 30-minute retention test for the diagnosis of hepatic disease in dogs

The purpose of this study was to evaluate efficacy of bromosulfophthalein (BSP) retention testing in dogs with and without histopathologically confirmed hepatobiliary disease. Medical records of 150 dogs with hepatobiliary disease having both a BSP test and hepatic biopsy were retrieved. Histopathologic slides of liver tissue were reviewed, and dogs were classified according to 1 of 11 histopathologic categories. Twenty-five clinically normal random-source dogs were used as controls for hepatic biopsy and BSP testing. No dogs suffered adverse effects due to BSP administration. BSP retention was significantly (P < .05) higher in hospitalized (13.9%) than control (3.2%) dogs, but the test could not distinguish between hospitalized dogs with different types of hepatobiliary disease. Sensitivity, specificity, and predictive values of BSP retention as a test for hepatic disease were calculated. Using 5.0% as a cutoff for normal BSP retention resulted in a specificity of 88% and a sensitivity of 76%. Using 6.0% as a cutoff for normal BSP retention resulted in a specificity of 100% and a sensitivity of 70%. Dogs of this study having BSP retention of >6% had at least an 86% chance of having an abnormal liver. We concluded that continued use of BSP retention testing is warranted as a noninvasive diagnostic test for liver disease in dogs.

Treatment of chronic idiopathic large-bowel diarrhea in dogs with a highly digestible diet and soluble fiber: a retrospective review of 37 cases

The medical records of 37 dogs diagnosed with chronic idiopathic large-bowel diarrhea were reviewed. The median age of affected dogs was 6 years. The median body weight was 13.9 kg. The median duration of clinical signs before diagnosis was 32 weeks. Diarrhea usually was intermittent and characterized by increasing frequency, fecal mucus, hematochezia, and tenesmus. Vomiting was common but usually much less frequent and severe than the diarrhea. A variety of stressful factors and abnormal personality traits were identified. CBC and serum biochemistry usually were normal. Fecal examination rarely identified parasites. Rectal cytology specimens were most often normal, but some dogs had increased numbers of neutrophils. The colonic mucosa often was normal during colonoscopy, but decreased numbers of lymphoid follicles were found in some dogs. Histopathologic evaluation found that colonic mucosa was within normal limits. Treatment with soluble fiber (Metamucil) added to a highly digestible diet (Hills i/d) resulted in a very good to excellent response in most dogs. The median initial dosage of Metamucil was 2 tablespoons (2 T) per day. In some dogs, the fiber dosage was reduced or eliminated, or a grocery store brand of dog food was substituted, without causing diarrhea to return.

The gastroduodenal effects of buffered aspirin, carprofen, and etodolac in healthy dogs

Twenty-four healthy mixed-breed dogs were divided into 4 groups. Group 1 received a placebo p.o. q12h, group 2 received an average of 16.5 (15.1-17.8) mg/kg buffered aspirin p.o. q12h, group 3 received an average of 2.2 (2.0-2.4) mg/kg carprofen p.o. q12h, and group 4 received an average of 12.8 (11.7-13.8) mg/kg etodolac p.o. q24h (with a placebo in the PM). All treatments continued for 28 consecutive days. Gastroduodenal endoscopy was performed on days -9, 0, 5, 14, and 28. Multiple gastric biopsies were obtained endoscopically on day -9 to determine each dog's Helicobacter infection status. Four regions in the stomach and 1 region in the proximal duodenum were evaluated endoscopically, and each was assigned a score from 1 to 11. Scores for each region then were summed to give a total score for each endoscopic evaluation. Erosions and submucosal hemorrhages were seen in all dogs receiving aspirin. Only minor gastric lesions were observed in the carprofen, etodolac, and control groups. No adverse clinical signs were noted in any dog given any treatment. Median total score on days 0, 5, 14, and 28, respectively, were as follows: group 1: 5.0, 5.0, 5.0, 5.0; group 2: 5.0, 27.0, 26.0, 27.5; group 3: 5.0, 5.0, 6.0, 5.0, group 4: 5.0, 7.0, 5.0, 5.0. There was no significant difference among dogs receiving carprofen, etodolac, or placebo. The administration of carprofen, etodolac, or placebo to healthy dogs resulted in significantly less gastroduodenal lesion development than in dogs receiving buffered aspirin.

Endoscopic aspiration of intestinal contents in dogs and cats: 394 cases

Medical records from 394 dogs and cats that had endoscopic aspiration of intestinal contents for identification of Giardia sp. trophozoites were retrospectively reviewed. The most common indications for endoscopy were chronic vomiting (152), chronic diarrhea (108), chronic vomiting and diarrhea (58), and acute vomiting (33). Metronidazole had been previously administered to 111 animals (28.2%), and to 58.6% of those with chronic diarrhea. Six aspirate samples (1.5%) were positive for Giardia sp. In 3 of these cases a single fecal flotation identified Giardia cysts before endoscopy. The authors conclude that intestinal aspiration in animals from a primarily referral population undergoing upper gastrointestinal endoscopy rarely identifies Giardia and should not be routinely performed. However, animals in which zinc sulfate flotation was not performed or those that did not previously receive metronidazole might benefit from intestinal aspiration.

Rectal ganglioneuroma in a dog

An 18-month-old, spayed female Australian terrier cross was presented with a 10-month history of chronic large bowel diarrhea. Ulceration and two proliferative masses in the rectum were seen on colonoscopy. Surgical resection was performed to remove the masses, and the dog recovered without complications related to surgery. Histopathology was consistent with the diagnosis of ganglioneuroma. The dog had no clinical signs of disease within three months of surgery and was completely normal 2.5 years after diagnosis. This is the first report providing follow-up and successful outcome of a ganglioneuroma in the gastrointestinal tract of a dog.

Evaluation of horizontal and vertical tracheotomy healing after short-duration tracheostomy in dogs

PURPOSE

The purpose of the study was to assess healing of horizontal and vertical tracheotomy after short-duration tracheostomy in dogs using clinical, radiographic, endoscopic, and histologic methods.

MATERIALS AND METHODS

Horizontal tracheotomy (n = 6) between the third and fourth tracheal rings or vertical tracheotomy (n = 6) across tracheal rings three through five was performed for airway management during laryngoplasty. Tracheostomy tubes were maintained for 6 hours with low-pressure cuff inflation time limited to the first 1.5 hours. Cervical radiographs and tracheoscopy were performed preoperatively and at postoperative weeks 2, 4, 8, and 12. Ten of the 12 dogs were killed 12 weeks after tracheostomy.

RESULTS

There was no significant difference in preoperative and postoperative tracheal diameter or change in endoscopic tracheal circumference at the tracheostomy site when dogs were compared based on type of tracheotomy. Three dogs with horizontal tracheotomies had evidence of scar (web) within the tracheal lumen 12 weeks after surgery. All vertical tracheotomies had a mild, ventral, triangular deformity. Histologic examination of vertical tracheotomy sites showed complete restoration of the pseudostratified columnar epithelium. Horizontal tracheotomies healed with a single layer of columnar epithelium. Intraluminal scar was composed primarily of loose connective tissue.

CONCLUSION

Based on the results of this study, vertical tracheotomy shows more consistent healing compared with horizontal tracheotomy after short-duration tracheostomy. No evidence was found to support the preferential recommendation of horizontal tracheotomy for short-duration tracheostomy airway management.

The effect of misoprostol on aspirin-induced gastroduodenal lesions in dogs

Misoprostol, a synthetic prostaglandin E1 analog, is effective in treating and preventing nonsteroidal antiinflammatory drug (NSAID)--induced gastrointestinal lesions in humans. The effectiveness of misoprostol in preventing aspirin-induced gastroduodenal injury was studied in 3 groups of 6 adult mixed breed dogs. Group I received 3 micrograms/kg misoprostol PO tid. Group II received 3 micrograms/kg misoprostol PO tid and 35 mg/kg aspirin PO tid. Group III received 35 mg/kg aspirin PO tid. Endoscopy was performed on days 0, 5, 14, and 30. Five regions of the upper gastrointestinal tract were qualitatively scored from 1 to 12 based on the presence of submucosal hemorrhage, erosion, or ulceration, with ulceration receiving a higher numerical score than submucosal hemorrhage. A total score was assigned based on the sum of the scores from all regions. Comparisons among groups on each day were performed using the Kruskal-Wallis test. Differences within a group among different time periods were determined using appropriate multiple comparisons. Significant difference in mean gastroduodenal lesion score was found among all groups at 5, 14, and 30 days. Mean total score on days 5, 14, and 30 were as follows: group I, 5.0, 5.2, 9.0; group II, 12.0, 12.7, 16.2; and group III, 26.0, 23.8, 21.5, respectively. Significant differences within a group among different time periods were found from days 0 to 5 in groups I and II, and from days 14 to 30 in group I. It was concluded that misoprostol effectively decreased endoscopically detectable mucosal lesions in dogs given aspirin.

Endoscopic diagnosis of chronic hypertrophic pyloric gastropathy in dogs

The endoscopic appearance of chronic hypertrophic pyloric gastropathy (CHPG) in five dogs is described. Several patterns of enlarged mucosal folds that surrounded and obstructed the pyloric canal were observed. Initially, endoscopically obtained biopsy samples of mucosa were judged to be histologically normal. Diagnosis of CHPG was confirmed and relief of pyloric obstruction accomplished at exploratory laparotomy (in four dogs). Retrospective evaluation of pyloric tissue samples, obtained during endoscopy, identified subtle histological characteristics of CHPG. Gastric and duodenal neoplasia or antral polyps can mimic the endoscopic appearance of CHPG but can be differentiated based on their endoscopic and histological appearance. These cases show that endoscopic examination is a valuable procedure for the diagnosis of CHPG in dogs that chronically vomit.

Effect of preanesthetic medication on ease of endoscopic intubation of the duodenum in anesthetized dogs

The effects of preanesthetic medication on ease of duodenal endoscopic intubation in dogs was evaluated. One of 12 combinations of preanesthetic medications (using atropine, glycopyrrolate, morphine, meperidine, acepromazine, and 0.9% NaCl solution) was administered IM to each of 12 dogs in a trial. Twelve endoscopic trials were performed so that each dog received each treatment combination once. Anesthesia was induced with thiamylal administered IV and maintained with halothane vaporized in oxygen. Electrocardiographic recordings, indirect blood pressure measurements, end-tidal carbon dioxide partial pressures, and halothane concentrations were monitored during the anesthetic period. The ease with which the fiberoptic endoscope was passed into the proximal portion of the duodenum was qualitatively score on the basis of time and maneuvering effort. None of the preanesthetic combinations made intubation of the duodenum significantly easier than that with 0.9% NaCl solution (control). Only the combination of morphine and atropine induced gastro-pyloric conditions that resulted in significantly higher (more difficult) endoscopic scores than those after preanesthetic medication with 0.9% NaCl solution.

Metastatic extramedullary plasmacytoma of the colon and rectum in a dog

Stage-3 extramedullary plasmacytoma of the large intestine was diagnosed in an 8-year-old Labrador Retriever. Three primary tumors were located in the colon and rectum, with metastasis to local lymph nodes and the spleen. The disease was associated with a monoclonal serum protein spike identified as IgG. Treatment consisted of surgical excision followed by chemotherapy, using melphalan and prednisone. The dog remained free from clinical signs of disease and adverse effects of the chemotherapy at 9 months. Findings in this dog indicated that extramedullary plasmacytoma may be an aggressive disease, associated with spread to distant sites and monoclonal gammopathy.

Salmonella choleraesuis pneumonia in a cat without signs of gastrointestinal tract disease

Primary Salmonella choleraesuis pneumonia without enteric manifestations was diagnosed in an 8-year-old cat. The diagnosis was based on culture of the organism from bronchial brushings. Pathogens were not isolated from multiple fecal samples. The cat initially responded to treatment with sulfamethoxazole trimethoprim, but relapsed after the owner discontinued treatment because of difficulty in administration. Treatment with ampicillin, followed by amoxicillin, resulted in complete resolution of all pulmonary infiltrates. Possible mechanisms of Salmonella infection in this cat included nosocomial infection from a nonclinical carrier, as well as Salmonella bacteremia initiated during a dental procedure performed prior to the onset of clinical signs of pneumonia.

Evaluation of metoclopramide hydrochloride as an aid for passage of a flexible endoscope into the duodenum of dogs

The purposes of this study were to evaluate the efficacy of metoclopramide to aid passage of a flexible endoscope into the duodenum of dogs, and to determine whether the effect of metoclopramide is dependent on dose. In a randomized, blinded, complete-block design, 6 healthy dogs were anesthetized, then each was given saline solution or 1 of 4 doses of metoclopramide on different days. The ease of passage of a flexible, fiberoptic gastroscope through the pylorus was assessed independently by 3 endoscopists. Administration of metoclopramide hydrochloride at a dosage of 0.4 mg/kg of body weight, iv, made passage of a flexible endoscope into the duodenum significantly (P = 0.009) more difficult than when saline solution was administered; however, dosages of 0.1, 0.2 and 0.8 mg of metoclopramide/kg did not (P = 0.489, 0.842, and 0.092 respectively). It was concluded that metoclopramide did not facilitate, and at one dosage hindered, successful passage of a flexible endoscope into the duodenum of healthy dogs under the conditions of the study. Metoclopramide, therefore, cannot be recommended as an aid for passage of a flexible endoscope into the duodenum of dogs.

Evaluation of atropine, glucagon, and metoclopramide for facilitation of endoscopic intubation of the duodenum in dogs

Modification of gastroduodenal motility has been proposed to aid endoscopic examination of the duodenum in dogs. The objective of this study was to evaluate the use of the following pharmacologic agents for facilitation of endoscopic intubation of the duodenum in 6 clinically normal dogs: metoclopramide HCl (0.2 mg/kg of body weight), atropine sulfate (0.045 mg/kg), glucagon (0.06 mg/kg), and isotonic saline solution. In a randomized, blinded, crossover design, the ease of endoscopic duodenal intubation was qualitatively scored by 3 endoscopists (in random order), using the following scale: 1 - immediate entry; 2 - rapid entry--moderate manipulation; 3 - difficult entry--multiple attempts; and 4 - no entry after 2 minutes [corrected]. Anesthesia was induced with thiopental and maintained with halothane. The 4 agents were diluted to a fixed volume and randomly administered. Duodenal intubation was attempted 2 minutes after IV injection of 1 of the agents. Four endoscopic procedures (1 for each agent) were performed on each dog with a minimum of 5 days between each procedure. In this study, no agent facilitated endoscopic duodenal intubation at the dose used. Instead, atropine and metoclopramide made duodenal intubation significantly more difficult, compared with use of saline solution. Difference between intubation after administration of glucagon and saline solution was not seen. On the basis of our findings, the use of these agents for facilitating endoscopic duodenal intubation is not recommended. In addition, in this study, we found that experience in endoscopic intubation is an important factor in determining the ease of duodenal intubation.

A grading system for lymphocytic plasmacytic colitis in dogs

Colonic mucosal samples were obtained every 4 weeks for 13 months from 6 clinically normal dogs and from 47 dogs with a clinical diagnosis of chronic inflammatory bowel disease. All samples were graded on a scale of 0-5, based upon the quantity of lymphocytes and plasma cells in the lamina propria, epithelial changes, and the presence of ulcers and erosions. A grade of less than or equal to 2.0 was considered normal and was assigned to 77 of 78 samples from clinically normal dogs and 28 of 48 samples from dogs with diarrhea. A transient increase in cellularity was noted in 1 sample from 1 control dog. Nineteen dogs with clinical disease had obvious histologic abnormalities. The grading scheme described provides the pathologist with an objective criterion for the microscopic evaluation of colonic mucosal samples obtained by endoscopic techniques and offers clinicians a method of assessing the dog's progress and response to therapy.

Comparisons between endoscopic and histologic evaluation of the gastrointestinal tract in dogs and cats: 75 cases (1984-1987)

Observations made during endoscopic evaluation of the stomach, duodenum, and colon of 58 dogs and 17 cats with a history of regurgitation, vomiting, and/or diarrhea were compared with results of histologic examination of tissues obtained during the procedures. Endoscopic observations included normal mucosa, alternations in mucosal color and texture, and luminal masses. Although endoscopy alone is a useful technique for detecting alterations of the gastrointestinal mucosa, histologic assessment of tissues obtained is necessary to confirm either an inflammatory or a neoplastic process.

Bilateral hydronephrosis attributable to bilateral ureteral fibrosis in a cat

A 4-year-old castrated male Burmese cat was evaluated because of nonregenerative anemia (PCV, 20%) and was found to have renal failure. Renal ultrasonography revealed bilateral hydronephrosis. Antegrade pyelography of the right kidney failed to indicate obstructive disease. Necropsy and histologic examination of the ureters revealed a markedly stenotic lumen and massive fibrosis of the mucosa. An etiologic agent could not be found.

Suspected chronic gastric volvulus in a dog with normal gastric emptying of liquids

A 10-year-old German Shepherd Dog with intermittent eructation, borborygmi, flatulence, abdominal bloating, and vomiting was found to have gastric volvulus. Gastric emptying of liquids (determined with a modified emptying-time technique) was normal. Circumcostal gastropexy vastly reduced clinical signs and resulted in weight gain.

Familial motor neuron disease in Rottweiler dogs: neuropathologic studies

Two 6-week-old female Rottweiler littermates were evaluated for regurgitation, diminished growth, progressive ataxia, and pelvic limb weakness. Clinical examination indicated a progressive, diffuse, lower motor neuron disorder and megaesophagus. The pups were killed at 6 and 8 weeks of age. Lesions included central chromatolysis and swelling of the perikarya in many large motor neurons in the ventral gray matter of the spinal cord. Some involvement of red, oculomotor, trigeminal motor, and ambiguus nuclei of the brainstem was noted. Ultrastructurally, chromatolytic neurons had excess neurofilaments, and an increase in and enlargement of Golgi complexes. Wallerian-like degeneration was prominent in neuropil of spinal cord and in peripheral nerve. Clinical, histological, and ultrastructural findings were consistent with a progressive motor neuron disease.

Gastric emptying of liquids in the dog: effect of volume

Effect of liquid test meal volume on gastric emptying was investigated in healthy nonoperated dogs fed meal sizes of 6.6 to 110 ml/kg of body weight. For meals less than or equal to 66 ml/kg, the amount of test meal emptied from the stomach in 30 minutes vs meal size could be described as following a linear, exponential, or square root pattern. Deviation from these patterns was seen with test meals of 77, 88, and 110 ml/kg. A mean +/- SEM maximum of 0.99 +/- 0.06 ml/kg/min of liquid test meal was emptied from the stomach of dogs fed test meals of 77, 88, and 110 ml/kg. Massive gastric distension induced in dogs during this study did not alter gastric emptying of the liquid test meal.

Suppurative colitis in a cat

A young cat with chronic large bowel diarrhea was found to have suppurative colitis. Treatment with sulfasalazine resulted in prompt clinical improvement, although histologic abnormalities persisted. Three months later, the cat was euthanatized because of effusive feline infectious peritonitis. Histologic examination revealed a normal colon.

Gastric emptying of glucose in the dog

The 30-minute gastric emptying of test meals consisting of 2.5%, 4%, 7%, 15%, or 25% glucose was evaluated in healthy, nonoperated dogs, using an orogastric intubation technique. An inversely proportional exponential relationship was found between test meal glucose concentration and amount of test meal emptied from the stomach in 30 minutes. For the 7%, 15%, and 25% glucose test meals, a mean (+/- SEM) of 1.11 +/- 0.03 kcal/min emptied into the duodenum, which represented 0.054 +/- 0.004 kcal/min/kg of body weight. Test meals of 2.5% and 4% glucose supplied significantly fewer kcal per minute to the duodenum than did the other 3 meals, indicating that control of gastric emptying of hypotonic glucose meals may be different than that of isotonic or hypertonic test meals in the dog.

Gastric emptying of liquids in the dog: serial test meal and modified emptying-time techniques

A serial test meal technique was used in the dog to evaluate the gastric emptying of a liquid test meal. On separate days, a phenol red test meal was placed in the stomach and completely aspirated at different times. A composite representation of the gastric emptying pattern was obtained for each dog, and a set of normative data was generated. Three emptying determinants (emptying time, half-life, and starting index) were calculated. The basic pattern of canine gastric emptying was linear and declined exponentially or as a function of the square root of the gastric volume. A modified emptying-time technique (METT) correlated well with the serial test meal and a set of normative values was determined. The METT was performed by aspirating test meal from the stomach 30 minutes after instillation. The METT was a simple and inexpensive technique that could be performed in 1 short testing period. With the METT, the half-life of gastric emptying was calculated, using the log of the percentage of retention of test meal; gastric emptying time was calculated, using the square root of the percentage of retention of test meal. Acetylpromazine was shown not to alter gastric emptying of a liquid test meal.

Gastric distention and gastrin in the dog

Gastric distention was induced in intact dogs by giving a wide range of volumes (11 to 111 ml/kg) of a liquid test meal resulting in a significant (P less than 0.05) increase in plasma gastrin immunoreactivity at 10 and 25 minutes after distention. There was no significant decrease in gastrin immunoreactivity from 10 to 25 minutes of gastric distention. Pretreatment with atropine abolished the distention-induced gastrin release, indicating that distention-induced gastrin release in the intact dog was partially under cholinergic control. There was no relationship between the distending volume and magnitude of gastrin increase.

Circumcostal gastropexy for preventing recurrence of gastric dilatation-volvulus in the dog: an evaluation of 30 cases

Follow-up evaluation (mean, 13.7 months) was obtained in 30 dogs with gastric dilatation-volvulus that were surgically treated with circumcostal gastropexy. Evaluation was performed by questionnaire (29 dogs), radiographic contrast studies (23 dogs), and necropsy (6 dogs). The gastropexy was thought to be intact in all 23 dogs examined radiographically. Necropsy of 6 dogs dying from causes unrelated to gastric dilatation-volvulus (mean of 12.7 months after surgery) revealed an intact gastropexy site in each dog. Only 1 (3.3%) dog had clinical recurrence of gastric dilatation after surgery. Five additional dogs dying postoperatively were necropsied and had intact gastropexy sites.

Plasma gastrin immunoreactivity in dogs with acute gastric dilatation-volvulus

Plasma gastrin immunoreactivity was measured by radioimmunoassay in 45 dogs with acute gastric dilatation-volvulus (GDV). Significant increases (P less than 0.05) were found in dogs with acute GDV and in the fasted state after surgical treatment and recovery. The data suggested that dogs that have had GDV may have preexisting high plasma gastrin immunoreactivity. In dogs with acute GDV, plasma gastrin immunoreactivity was not found to be helpful in formulating prognosis. Circumcostal gastropexy did not affect plasma gastrin immunoreactivity.

Propylthiouracil-associated hemolytic anemia, thrombocytopenia, and antinuclear antibodies in cats with hyperthyroidism

Nine of 105 cats with hyperthyroidism treated with propylthiouracil developed a serious immune-mediated drug reaction during treatment. Adverse clinical signs, which developed after 19 to 37 days (mean, 24.8 days) of propylthiouracil administration, included lethargy, weakness, anorexia, and bleeding diathesis. Physical examination revealed pale mucous membranes, and petechial hemorrhages of the skin and oral cavity. Results of hematologic testing revealed severe anemia and thrombocytopenia. The direct antiglobulin (Coombs') test was positive in all 7 cats evaluated, whereas the serum antinuclear antibody titer was greater than or equal to 1:10 in 5 of the 8 cats tested. In 4 of the cats, treatment included appropriate supportive therapy and cessation of propylthiouracil; in these cats, anemia and thrombocytopenia resolved and Coombs' and antinuclear antibody tests became negative within 2 weeks.

Acid-base and electrolyte values in dogs with acute gastric dilatation-volvulus

Twenty dogs with acute gastric dilatation-volvulus (GDV) and 37 clinically normal dogs had arterial blood drawn for analysis of pH and blood gases. There was no statistically significant difference between values from the 2 groups. By calculation of the anion gap and by assessing arterial bicarbonate concentration, it appeared there were concomitant and offsetting factors, resulting in normal values for pH, blood gases, and anion gap in dogs with GDV. The results obtained indicated that sodium bicarbonate therapy should not be used in dogs with GDV.