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Biomedical subjects

R L Cowell

Publications and source records attributed to R L Cowell.

30 records · Page 2Linked to original sources

Detection of anticytauxzoon antibodies in cats infected with a Cytauxzoon organism from bobcats.

A microfluorometric immunoassay was developed for the detection of antibodies to a Cytauxzoon organism of bobcat origin. A homogenated antigen of RBC-parasite lysate was used to measure antibody levels in sera from cats experimentally infected with the non-pathogenic erythrocyte form of the bobcat Cytauxzoon organism. Antibody levels in sera collected at weekly intervals, expressed as FIAX values, were correlated with parasitemia levels and erythrocyte packed cell volume (PCV). The antibody levels tended to be highest and the PCV lowest at or near the peak parasitemias. Splenectomized cats developed higher antibody and parasitemia levels than non-splenectomized cats. Single serum samples collected from 31 cats were used to establish a baseline response level for normal domestic cat populations.

Animals↗

Renal concentrating ability in dehydrated hyponatremic dogs.

Eleven hyponatremic dogs were unable to concentrate their urine during periods of severe dehydration and azotemia. When normonatremia was reestablished in eight of the dogs, their renal concentrating ability returned. Six dogs, including the 3 dogs in which normonatremia was not reestablished, died or were euthanatized; renal lesions were not found during postmortem examination. Two dogs had hypoadrenocorticism, which has been documented as a cause of hyponatremia and impaired renal concentrating ability. Two dogs had gastrointestinal disease, which has been documented as a cause of hyponatremia, but not of impairment of renal concentrating ability. All dogs without hypoadrenocorticism had clinical and clinicopathologic indications of blood loss, which has not been documented as a cause of hyponatremia or impairment of renal concentrating ability. Hyponatremia (less than 120 mEq/L) was induced by chronic blood removal in a dog maintained on a low-sodium diet. During the period of hyponatremia, the dog became azotemic, hypotensive, and severely dehydrated; renal concentrating ability was impaired. We conclude that hyponatremia may be caused by hemorrhage, but irrespective of the cause, hyponatremia impairs renal concentrating ability.

Adrenal Cortex Diseases↗

Disseminated histoplasmosis in cats: 12 cases (1981-1986).

Anemia, weight loss, lethargy, fever, anorexia, and interstitial lung disease were the predominant clinical findings in 12 cats with disseminated histoplasmosis. Some cats were examined because of dysfunction or lesions of bone, eyes, or skin. In most cases, the clinical signs were observed by the owner for 4 weeks or less before seeking veterinary care. Young cats were most commonly affected, with 7 of the 12 cats less than or equal to 1 year old. Identification of Histoplasma organisms in bone marrow aspirates was used to confirm the diagnosis of histoplasmosis in 11 of the 12 cats. Histoplasma infection of multiple organs was found at necropsy. In this study, disseminated histoplasmosis had a higher prevalence in cats than in dogs at the same veterinary medical teaching hospital. Feline disseminated histoplasmosis was not associated with FeLV infection. Treatment was attempted in 7 of the 12 cats.

Animals↗

Hematologic values in horses and interpretation of hematologic data.

Normal reference ranges and pertinent background information on equine hematology are presented and briefly discussed. Diagnostic interpretation of hematologic data is discussed and three diagnostic algorithms and two diagnostic tables are provided to facilitate the use of the presented information for diagnosis. Two cases are presented and the information presented in the article is used to interpret the case data.

Animals↗

Collection and evaluation of equine peritoneal and pleural effusions.

This article discusses collection, slide preparation, culture technique, fluid analysis and evaluation, and cytologic evaluation of peritoneal and pleural effusions. The morphologic characteristics of various effusions are described, and the physical characteristics (volume, color, turbidity) of effusions are discussed. An algorithm for classifying effusions as transudates, modified transudates, or exudates is included, and each category is discussed.

Animals↗

An overview of serological tests currently available for laboratory diagnosis of parasitic infections.

Current methods and commercial test systems for the diagnosis of parasitic infections in both animals and humans are reviewed. Lists of test kits and their manufacturers are provided along with ordering information: the only commercially available test kits are for the diagnosis of toxoplasmosis in humans or animals and dirofilariasis (heartworm) in dogs. A partial list of diagnostic laboratories and the parasite tests they perform is also provided. Complete lists of diagnostic tests that could be obtained in the private sector are not available but would be useful. Two microfluorometric solid-phase assay systems are reviewed, and adaptations to custom assays for several kinds of parasites are briefly described. User problems in performing tests and interpreting results are stressed with emphasis placed on diagnosis of dirofilariasis in dogs. False-positive serology in dogs without heartworms and negative antibody responses in micro-filariae-positive animals are discussed with respect to proper interpretation of results.

Anaplasmosis↗

Low-dose ethanol in the treatment of ethylene glycol poisoning.

A pharmacokinetic study was conducted to determine the effectiveness of lower doses of ethanol in the treatment of ethylene glycol (EG) poisoning. Four dogs were maintained at serum ethanol concentrations of 0, 35 and 140 mg/dl prior to EG (i.v., 2 ml/kg) administration. The serum EG concentration-time data showed that the 35 mg/dl ethanol level provided as effective an inhibition of EG metabolism as did the 140 mg/dl level. The average urinary excretion rate of oxalic acid post EG administration was reduced to control levels by ethanol. The 35 mg/dl serum ethanol level reduced the total body clearance of EG from 93.9 to 50.0 ml/h/kg and increased the effective half-life from 5.78 to 11.4 h. Clinical testing was accomplished by giving the dogs 12 ml EG/kg body weight orally. One hour later, the dogs were either not treated or treated with a sodium bicarbonate-ethanol solution to obtain a serum ethanol concentration of 50 mg/dl. The clinical test performed in the ethanol-treated dogs showed little change from normal limits. Urine calcium oxalate crystals were seldom found. The dogs given EG (12 ml/kg) but not treated with ethanol were in a coma at 13 h and showed severe metabolic acidosis, dehydration, mild hepatocellular disease and acute renal damage. Urine calcium oxalate crystals were found in high numbers. The rapid death associated with EG poisoning appeared to be due to metabolic acidosis in combination with dehydration.

Animals↗

Familial canine dermatomyositis: clinicopathologic, immunologic, and serologic studies.

Laboratory studies were performed on 3 Collies with familial canine dermatomyositis, 6 progeny from a breeding of 2 of the Collies (incross litter), and 4 progeny from the breeding of an affected Collie male and a normal Labrador Retriever (outcross litter). Hematologic abnormalities were leukogram changes consistent with inflammation, and, in 2 severely affected incross dogs, anemia of inflammatory disease. Serum muscle enzyme activities were not markedly increased. High concentrations of immune complexes and proportionally increased total immunoglobulin G were present in the sera of moderately and severely affected incross dogs. The same dogs had weakly positive direct Coombs' tests, and 1 affected outcross dog had a strongly positive direct Coombs' test. Rheumatoid factor was present in a severely affected incross dog. A few dogs had polyclonal globulin increases that were attributed to inflammation. Low antibody titers to canine calicivirus were present in 3 dogs and a low titer to canine coronavirus was present in 1 dog.

Animals↗

X-ray powder diffraction and microscopic analysis of crystalluria in dogs with ethylene glycol poisoning.

Most of the urinary crystals in 2 dogs intoxicated with ethylene glycol had prismatic (rod-like, hippurate-like), and to a less extent, hemp seed or spindle shapes. Using X-ray powder diffraction and optical analysis, these crystals were identified as calcium oxalate monohydrate. A few crystals of calcium oxalate dihydrate (envelope shape) were also observed in the urine sediment. Their presence was confirmed by the appearance of weak X-ray peaks having interplanar spacings ranging from 0.617 to 0.620 nm, which are thought to correspond to the 200 X-ray reflection of calcium oxalate dihydrate. Thus, the 6-sided hippurate-like crystals in the urine of ethylene glycol-poisoned dogs are actually calcium oxalate monohydrate.

Animals↗

Metastatic carcinoma presenting as hind-limb lameness: diagnosis by synovial fluid cytology.

A dog presented for evaluation of left hind-limb lameness and pain associated with manipulation of the tail. Synovial metastasis of a carcinoma was diagnosed by joint fluid examination. A primary bronchiolar-alveolar carcinoma with widespread (including synovial and skeletal) metastases was diagnosed on postmortem examination. Metastasis to synovial surfaces is uncommon, but when it occurs, the metastasis-induced arthritis may be the initial presenting complaint for which medical attention is sought. Although rarely reported, cytological examination of synovial fluid may be diagnostic. This paper presents an interesting clinical case and reviews the literature concerning metastatic disease of the synovium.

Animals↗