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Summary

Seventy-four cats (52 treated and 22 untreated) were evaluated in efficacy studies of interferon (ifn), Propionibacterium acnes, or a combination of these drugs against experimentally induced feline infectious peritonitis (fip). Cats were given doses of recombinant human leukocyte (α) ifn (rHuIFN-α), feline fibroblastic (β) ifn (FIFN-β) or P acnes at regular intervals before and after inoculation of virulent fip virus (fipv). Prophylactic and therapeutic administration of high doses (106 U/kg of body weight) or moderate doses (104 U/kg) of rHuIFN-α, FIFN-β (103 U/kg), or P acnes (0.4 or 4 mg) did not significantly reduce mortality in treated vs untreated cats. However, the mean survival time in cats treated with 106 U of rHuIFN-α-/kg alone or combined with doses of P acnes was significantly (P = 0.03) increased after inoculation of highly lethal amounts (200 LD 100) of FIPV vs survival time in untreated cats. Although P acnes alone was ineffective, there was some indication that a combination of P acnes and high doses of rHuIFN-α was more effective than rHuIFN-α alone. Seemingly, the efficacy of rHuIFN-α treatment was improved in cats challenge-exposed with less fipv; in 1 trial, 4 of 5 cats (80%) treated with high doses of rHuIFN-α survived after inoculation of minimal lethal amounts (0.6 LD100) of fipv, whereas only 2 of 5 untreated cats (40%) survived.

Pretreatment of cats with 106 U of rHuIFN-α/kg resulted in detectable serum ifn activity 24 hours later; serum ifn activity was not detected in cats pretreated with P acnes, fifn-β, or 104 U of rHulFn-α/kg. After inoculation of fipv, increase in serum ifn activity and virus-neutralizing antibody (vna) titer was observed in treated or untreated cats, but increase in serum ifn activity or vna titer was not associated with protective immunity. In contrast to untreated cats, those treated with high doses of rHuIFN-α had temporary suppression of clinical signs of fip and decreased serum ifn or vna responses to fipv, suggesting some antiviral or immunomodulatory (or both) activities. Immunomodulation by rHuIFN-α in cats inoculated with fipv also was suggested by necropsy findings of increased paracortical hyperplasia and decreased necrosis in lymphoid tissues of ifn-treated vs untreated cats.

Results indicated that intensive treatment alone with ifn or P acnes failed to protect most cats against fatal disease after challenge exposure with lethal doses of fipv. High doses of rHuIFN-α alone or combined with P acnes, however, temporarily suppressed disease signs and extended survival time, suggesting a potential role of rHulFN-α as adjunctive, rather than primary, treatment for fip.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine quantitative values for components of body composition in clinically normal dogs of various breeds by use of dual energy x-ray absorptiometry (DEXA) and validate the precision and accuracy of DEXA technology in dogs.

Animals—103 clinically normal sexually intact adult dogs.

Procedure—In a cross-sectional study, Beagles, Pembroke Welsh Corgis, Golden Retrievers, Great Danes, Pointers, Rottweilers, and nonpurebred dogs received total body DEXA scans. For the validation portion of the study, the results of DEXA scans of 6 dogs were compared with values obtained by chemical analyses of tissues from euthanatized dogs to determine the accuracy of this modality in dogs.

Results—Results (coefficient of variation) of the precision tests ranged from 0.10% for lean tissue to 5.19% for fat tissue, whereas accuracy tests revealed a difference between percentage bone mineral content and ash values. Body composition differed by sex, such as higher lean tissue and bone mineral content in males within some breeds, and among breeds. Regardless of body size or weight, the percentage of body weight that was bone mineral ranged from 3 to 4.0%.

Conclusions and Clinical Relevance—Results of this cross-sectional study provide valuable body composition data for clinically normal adult dogs, which may have research and clinical applications. (Am J Vet Res 2001;62:1295–1301)

Full access
in American Journal of Veterinary Research

Summary

Ultrasound-guided brain biopsy of the cingulate gyrus and the head of the caudate nucleus was performed in clinically normal dogs. Dogs survived the surgery, and neurologic deficits were not detected in the 14-day postoperative period. Magnetic resonance imaging detected changes in the brain associated with biopsy in 9 dogs (90%) immediately after surgery and in 6 dogs (60%) 14 days after surgery. Fourteen days after surgery, sonography of the brain, performed through the skin overlying the burr hole, detected changes associated with biopsy in 9 dogs (90%). Histopathologic changes evident in the brain 14 days after surgery consisted of focal malacia and hemorrhage with associated subacute encephalomeningitis. Postmortem examination indicated that the biopsy specimen was accurately obtained from the desired site in 9 dogs (90%). Tissue specimens suitable for histologic examination were obtained from 10 dogs (100%). Accuracy and low morbidity of ultrasound-guided biopsy indicate that this may be a useful technique for diagnosis of focal brain disease in dogs.

Free access
in American Journal of Veterinary Research

SUMMARY

During 1986 and 1987, electroencephalographic examinations were done on 8 dogs with intracranial mass lesions confirmed by computerized tomography, biopsy, necropsy, or a combination of these techniques. Tumor types included 1 astrocytoma, 1 undifferentiated glioma, 2 mixed gliomas, 2 meningiomas, 1 choroid plexus papilloma, and 1 cholesterol granuloma. It was found that no eeg pattern was pathognomonic for tumor type or location. Slow-wave activity was observed in the eeg of most of the dogs; asymmetry in amplitude or frequency was observed in approximately half the cases.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To study the musculoskeletal development of Great Dane puppies fed various dietary concentrations of calcium (Ca) and phosphorus (P) in fixed ratio by use of dual energy x-ray absorptiometry (DEXA), determination of serum insulin-like growth factor I and parathyroid hormone concentrations, radiography, and blood chemistry analysis results.

Animals—32 purebred Great Dane puppies from 4 litters.

Procedure—At weaning, puppies were assigned randomly to 1 of 3 diets. Blood was collected for biochemical analyses and hormone assays, and radiography and DEXA were performed through 18 months of age. Changes in body weight, bone mineral content, fat tissue weight, lean mass, result of serum biochemical analyses, hormonal concentrations, and radius lengths were analyzed through 18 months of age.

Results—Bone mineral content of puppies correlated positively with Ca and P content of the diets fed. Significant differences between groups in bone mineral content, lean mass, and body fat were apparent early. The disparity among groups increased until 6 months of age and then declined until body composition was no longer different at 12 months of age. Accretion rates for skeletal mineral content, fat, and lean tissue differed from each other and by diet group.

Conclusions and Clinical Relevance—Ca and P concentrations in the diet of young Great Dane puppies are rapidly reflected in the bone mineral content of the puppies until 5 to 6 months of age, after which hormonal regulation adjusts absorption and excretion of these minerals. Appropriate Ca and P concentrations in diets are important in young puppies < 6 months of age. (Am J Vet Res 2002;63:1036–1047)

Full access
in American Journal of Veterinary Research