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Abstract

Objective—To determine features of lymphoma of the tarsus in cats.

Design—Multi-institutional retrospective study.

Animals—23 cats with cutaneous lymphoma of the tarsus.

Procedures—Veterinary oncologists were requested to submit cases fitting the following criteria: histologically or cytologically confirmed lymphoma with a location at or near the tarsus and described as subcutaneous or mass-like. Data regarding breed, sex, age, FeLV and FIV status, and reason for evaluation were collected. Results of staging tests, location of the tumor, immunophenotype, and histopathologic description were recorded. Type of treatments, outcome, survival time, presence or absence of progressive disease, and cause of death or reason for euthanasia were also recorded.

Results—Most cats were older, with a median age of 12 years (range, 7 to 18 years). No association with positive retroviral status was found. Popliteal lymph node involvement at diagnosis was reported in 5 cats, and a suspicion of lymphoma at a different site on the basis of results of abdominal ultrasonography was reported in 4 cats. Treatments were variable and included corticosteroids alone (n = 2), chemotherapy (9), radiation and chemotherapy (7), or surgery with or without chemotherapy (5). Thirteen cats were reported to have lymphoma at a different site at the time of last follow-up, death, or euthanasia. Median survival time for all cats in the study was 190 days (range, 17 to 1,011 days).

Conclusions and Clinical Relevance—Results suggested that tarsal lymphoma is an uncommon manifestation of lymphoma in cats, and in this study was most commonly nonepitheliotropic and of high grade as determined on histologic evaluation. Systemic involvement was identified; therefore, thorough staging is recommended prior to initiating treatment. Future studies are warranted to evaluate effective treatment protocols.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To describe the kinetics of demethylation of 13C-aminopyrine in healthy dogs for use in determining the most appropriate time for collection of blood samples for a 13C-aminopyrine demethylation blood test for evaluation of hepatic function.

Animals—9 healthy dogs.

Procedures—A 2-mL baseline blood sample was collected into an evacuated heparinized tube, and 13Caminopyrine was administered to each dog (2 mg/kg, IV). Additional 2-mL blood samples were collected 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 180, 240, 300, and 360 minutes after 13C-aminopyrine administration. The CO2 was extracted from blood samples by addition of a strong acid, and the percentage dose of 13CO2 (PCD) in the extracted gas was determined by fractional mass spectrometry.

Results—No dogs had gross evidence of adverse effects, and all had an increase in PCD after IV administration of 13C-aminopyrine. The PCD had the least variability among 5 variables used to evaluate hepatic demethylating capacity. Peak PCD was detected at 30 minutes in 1 dog, 45 minutes in 5 dogs, 60 minutes in 2 dogs, and 75 minutes in 1 dog. The mean PCD for the 9 dogs peaked at 45 minutes after 13C-aminopyrine administration.

Conclusions and Clinical Relevance—PCD appears to be the preferable variable for evaluation of hepatic demethylating capacity. Intravenous administration of 13C-aminopyrine leads to a consistent increase in PCD. Mean PCD peaked 45 minutes after administration, suggesting that blood sample collection 45 minutes after 13C-aminopyrine administration may be appropriate for use in estimating hepatic demethylating capacity. (Am J Vet Res 2004;65:159–162)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine an optimal dose of carbon 13 (13C)-labeled aminopyrine for use in a 13C-aminopyrine demethylation blood test in healthy dogs.

Animals—9 adult dogs.

Procedures—Food was withheld from each dog for 12 hours. A 2-mL baseline blood sample was obtained from each dog and placed into an evacuated tube containing sodium heparin. Carbon 13-labeled aminopyrine was administered IV at doses of 1, 2, 5, or 10 mg/kg. Additional blood samples (2 mL) were obtained and placed into evacuated tubes containing sodium heparin 30, 45, 60, and 75 minutes after 13C-aminopyrine administration. Hydrochloric acid was used to extract CO2 from blood samples. The extracted gas was analyzed by fractional mass spectrometry to determine the percentage dose of 13C administered as 13C-aminopyrine and recovered in extracted gas (PCD).

Results—Gross evidence of clinical adverse effects was not detected in any dog after administration of 13C-aminopyrine. The mean coefficient of variation (CV) for PCD was significantly lower than the mean CV for the summation of PCD values up to a given sampling time (CUMPCD). Mean PCD values among the 4 doses for each sample time were not significantly different. Administration of 13C-aminopyrine at a dose of 2 mg/kg resulted in the lowest interindividual variability.

Conclusions and Clinical Relevance—The PCD is superior to CUMPCD for the quantification of aminopyrine demethylation. Administration of 13C-13C-aminopyrine at a dose of 2 mg/kg is appropriate for use in the 13C-aminopyrine demethylation blood test in healthy dogs.

Full access
in American Journal of Veterinary Research

Objective—

To measure and compare blood values in sled dogs before and after long-distance racing.

Design—

Prospective study.

Animals—

17 adult sled dogs in the 1991 Iditarod Trail Sled Dog Race and 21 in a simulated sled dog race.

Procedure—

Blood samples were obtained from 17 dogs 7 days before they began and after they finished (finisher group) or were eliminated from (nonfinisher group) the Iditarod Trail Sled Dog Race. Blood samples were also obtained from 21 dogs before and after a simulated sled dog race.

Results—

In finisher-group dogs, BUN and uric acid (UA) concentrations were increased after racing; nonfinisher-group dogs had significantly lower postrace BUN and UA concentrations. Significant increases in creatine kinase (CK) and aspartate transferase (AST) activities were detected in all dogs after racing, and postrace values were higher in nonfinisher-group dogs, compared with finisher-group dogs. Mean alkaline phosphate activities were significantly increased after racing in nonfinisher-group dogs only. In dogs that ran the simulated race, postrace values for serum albumin, total protein, calcium, and potassium concentrations, as well as Hct, hemoglobin concentration, and RBC count, were significantly lower than prerace values. Postrace values for alkaline phosphate, alanine transaminase, AST, lactate dehydrogenase, CK, BUN, and UA were significantly higher than prerace values.

Clinical Implications—

High CK activities are indicative of severe muscle degeneration and, in sled dogs, may represent a degree of muscle breakdown beyond which a dog cannot continue to work. Markedly high CK, and possibly AST, serum activities may be indicators of performance failure in sled dogs competing in long-distance races. (J Am Vet Med Assoc 1997; 211:175–179)

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Objective

To measure energy expenditures of Alaskan sled dogs at rest and during racing under frigid conditions, using the doubly labeled water (DLW) technique.

Animals

18 fit Alaskan sled dogs.

Procedure

Energy expenditure was measured in 9 dogs during a 490-km sled dog race by use of the DLW technique, whereby dogs were administered water enriched with nonradioactive isotopes of hydrogen and oxygen. Energy intake was determined by dietary analysis. Changes in background abundance of the isotopes 2H and 18O were monitored in 5 dogs that did not receive isotope-enriched water.

Results

Dogs completed the 490-km race at an average speed of 7 km/h at ambient temperature of −35 to −10 C. Total energy expenditure, measured by the DLW technique, was 47,100 ± 5,900 kJ/d (4,400 ± 400 kJ·kg-0.75/d), and metabolizable energy intake was 44,600 kJ/d (4,100 kJ·kg-0.75/d) during the 70-hour race.

Conclusions

The sustained metabolic rate for these sled dogs during racing was extraordinarily high for a large mammal. This study validated use of the DLW technique in dogs with exceptionally high energy expenditure associated with prolonged exercise in the cold. (Am J Vet Res 1997;58:1457–1462)

Free access
in American Journal of Veterinary Research

Objective—

To determine the knowledge and expectations of veterinarians and clients regarding heart-worm preventives and annual vaccinations for dogs.

Design—

Practitioner and client survey.

Sample Population—

435 veterinarians and 1,805 clients.

Procedure—

A survey was mailed to veterinarians requesting information from them and their dog-owning clients on expectations and knowledge regarding heartworm preventives and annual vaccinations. Responses of veterinarians were compared with those of clients, and both were compared with label indications.

Results—

Expectations of veterinarians and clients regarding heartworm preventives were similar and usually were consistent with regulatory interpretation of label terms. Of clients purchasing heartworm preventives, 38% did not know that the medication was effective against intestinal nematodes. Veterinarians and clients would be unsatisfied with a product that reduced, but did not eliminate, all intestinal nematodes. Most clients knew that annual vaccinations included distemper virus, parvovirus, and rabies virus, but about half of them did not know that other antigens were in the vaccines.

Clinical Implications—

Effects of heartworm preventives and diseases for which dogs are annually vaccinated should be explained fully to clients. (J Am Vet Med Assoc 1997;211:434–437)

Free access
in Journal of the American Veterinary Medical Association

Objective—

To examine the effect of participation in a long-distance race on serum electrolyte concentrations, estimated exchangeable cation content, and acid-base status of Alaskan sled dogs.

Design—

Prospective study.

Animals—

9 male and 5 female, sexually intact, physically fit Alaskan sled dogs between 18 and 48 months old.

Procedure—

Body weight was recorded, and blood samples were collected from dogs before, during, and after a 300-mile race.

Results—

Serum sodium and potassium concentrations decreased during the race, as did serum total protein, albumin, and globulin concentrations and PCV. Effects on acid-base status were minimal. Body weight and estimated total exchangeable cation content in dogs also decreased significantly during the race.

Clinical Implications—

Prolonged running is associated with decreases in serum cation concentration and estimated total exchangeable cation content in dogs, as in human beings and horses. However, the mechanism of the decrease in serum cation concentration likely differs among species. Clinical abnormalities associated with cation depletion were not observed in the dogs in this study. (J Am Vet Med Assoc 1997;210: 1615–1618)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether dietary antioxidants would attenuate exercise-induced increases in plasma creatine kinase (CK) activity in sled dogs.

Animals—41 trained adult sled dogs.

Procedure—Dogs, randomly assigned to 2 groups, received the same base diet throughout the study. After 8 weeks on that diet, 1 group (21 dogs) received a daily supplement containing vitamins E (457 U) and C (706 mg) and β-carotene (5.1 mg), and a control group (20 dogs) received a supplement containing minimal amounts of antioxidants. After 3 weeks, both groups performed identical endurance exercise on each of 3 days. Blood samples were collected before and 3 weeks after addition of supplements and after each day of exercise. Plasma was analyzed for vitamins E and C, retinol, uric acid, triglyceride, and cholesterol concentrations, total antioxidant status (TAS), and CK activity.

Results—Feeding supplements containing antioxidants caused a significant increase in vitamin E concentration but did not change retinol or vitamin C concentrations or TAS. Exercise caused significantly higher CK activity, but did not cause a significant difference in CK activity between groups. Exercise was associated with significantly lower vitamin E, retinol, and cholesterol concentrations and TAS but significantly higher vitamin C, triglyceride, and uric acid concentrations in both groups.

Conclusions and Clinical Relevance—Use of supplements containing the doses of antioxidants used here failed to attenuate exercise-induced increases in CK activity. Muscle damage in sled dogs, as measured by plasma CK activity, may be caused by a mechanism other than oxidant stress. (Am J Vet Res 2000;61:1438–1445)

Full access
in American Journal of Veterinary Research

Abstract

Objectives—To determine effects of dietary antioxidant supplementation on plasma concentrations of antioxidants, exercise-induced oxidative damage, and resistance to oxidative damage during exercise in Alaskan sled dogs.

Animals—62 Alaskan sled dogs.

Procedure—Dogs were matched for age, sex, and ability and assigned to 1 of 3 groups: sedentary and nonsupplemented (control [C]; n = 21), exercised and supplemented (S; 22), and exercised and nonsupplemented (N; 19). Dogs in group S were given 400 units of α- tocopherol acetate, 3 mg of β-carotene, and 20 mg of lutein orally per day for 1 month, then dogs in groups S and N completed 3 days of exercise. Blood samples were collected before and after 1 and 3 days of exercise and after 3 days of rest. Plasma antioxidant concentrations were determined, and oxidative damage to DNA (plasma 7,8 dihydro-8-oxo-2'deoxyguanosine [8-oxodG] concentration) and membrane lipids (plasma hydroperoxide concentration) and resistance of plasma lipoproteins to oxidation were assessed.

Results—Supplementation increased plasma concentrations of α-tocopherol, β-carotene, and lutein. Plasma concentration of α-tocopherol increased and concentration of lutein decreased in group S with exercise. Concentration of 8-oxodG decreased in group S but increased in group N during and after exercise. Lag time of in vitro oxidation of lipoprotein particles increased with exercise in group S only.

Conclusions and Clinical Relevance—Dietary supplementation with antioxidants resulted in increased plasma concentrations of antioxidants. Moreover, supplementation decreased DNA oxidation and increased resistance of lipoprotein particles to in vitro oxidation. Antioxidant supplementation of sled dogs may attenuate exercise-induced oxidative damage. (Am J Vet Res 2000;61:886–891)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine comparative efficacy of vaccines administered IM and intranasally, used alone or sequentially, to protect puppies from infection with Bordetella bronchiseptica and determine whether systemic or mucosal antibody response correlated with protection.

Design—Randomized controlled trial.

Animals—50 specific-pathogen-free Beagle puppies.

Procedure—In 2 replicates of 25 dogs each, 14-weekold puppies that were vaccinated against canine distemper virus and parvovirus were vaccinated against B bronchiseptica via intranasal, IM, intranasal-IM, or IMintranasal administration or were unvaccinated controls. Puppies were challenge exposed via aerosol administration of B bronchiseptica 2 weeks after final vaccination. Clinical variables and systemic and mucosal antibody responses were monitored for 10 days after challenge exposure. Puppies in replicate 1 were necropsied for histologic and immunohistochemical studies.

Results—Control puppies that were seronegative before challenge exposure developed paroxysmal coughing, signs of depression, anorexia, and fever. Vaccinated puppies (either vaccine) that were seronegative before challenge exposure had fewer clinical signs. Puppies that received both vaccines had the least severe clinical signs and fewest lesions in the respiratory tract. Vaccinated dogs had significantly higher concentrations of B bronchiseptica-reactive antibodies in serum saliva before and after challenge. Antibody concentrations were negatively correlated with bacterial growth in nasal cavity and pharyngeal samples after challenge exposure.

Conclusions and Clinical Relevance—Parenterally and intranasally administered vaccines containing B bronchiseptica may provide substantial protection from clinical signs of respiratory tract disease associated with infection by this bacterium. Administration of both types of vaccines in sequence afforded the greatest degree of protection against disease. (J Am Vet Med Assoc 2001;218:367–375)

Full access
in Journal of the American Veterinary Medical Association