Hypokalemia in cats: 186 cases (1984-1987).

Retrospective review of serum biochemical data obtained from 501 cats over a 3-year period (1984-1987) indicated that 186 (37%) had hypokalemia (serum potassium concentration less than 4.1 mEq/L). After adjusting for disease diagnosis, cats fed either of 2 commercial diets were 4 times more likely to be hypokalemic than cats fed other diets. Odds ratios (OR; measure of association), adjusted for diet type, were calculated to determine the odds of hypokalemia for a given disease, compared with odds of normokalemia for the same disease. Chronic renal failure (OR = 14.4), hepatic disease (OR = 5.7), systemic infectious diseases (viral or bacterial; OR = 2.7), and neuromuscular or CNS disease (OR = 2.4) were all significantly associated (P less than 0.05) with the occurrence of hypokalemia. Significant differences in age or sex between hypokalemic and normokalemic cats were not found. Within the group of 186 hypokalemic cats, hypercholesterolemia (89 cats; 48%), hyperglycemia (88 cats; 47%), high serum urea nitrogen concentration (86 cats; 46%), hyperchloridemia (80 cats; 43%), and high serum creatinine concentration (73 cats; 39%) were the most common biochemical abnormalities. When disease diagnosis was compared among cats with severe hypokalemia (serum potassium concentration less than 3.0 mEq/L) and those with moderate hypokalemia, cats with severe hypokalemia were 3.5 times more likely to have chronic renal failure than cats with less severe hypokalemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjustment of total serum calcium concentration for binding to albumin and protein in cats: 291 cases (1986-1987).

The relationships between total serum calcium and serum albumin and total serum calcium and serum protein concentrations were examined in 291 cats. There was a significant (P less than 0.001) linear relationship between serum calcium and serum albumin concentrations. Because of extreme variability among the calcium and albumin concentrations (R2 = 0.18), however, a dependable formula to adjust total serum calcium values for albumin or protein binding in the cat could not be constructed. An adjustment formula could not be based on the relationship between calcium and total protein concentrations because of the lack of a significant relationship (P = 0.21). The association between serum calcium and serum albumin or serum calcium and total protein concentrations is weaker in cats than in dogs or man.

Effect of dietary protein level on nitrogen metabolism in the growing bovine: I. Nitrogen recycling and intestinal protein supply in calves.

Eight Angus heifer calves (234 kg) were assigned to either a high (HP; 126 g N/d) or low (LP; 66.5 g N/d) protein intake. Calves received 4.8 kg DM/d consisting of 30% cottonseed hulls and 70% corn-soybean meal in equal portions at 4-h intervals. Single doses of 14C- and 15N-urea and 15N-ammonium sulfate were injected into the blood urea-N (BUN) and ruminal NH3-N (RAN) pools, respectively, to measure rate of flux through, and transfer of N between, these and bacterial N. Nitrogen balance was greater (P less than .05) for HP than for LP (56.9 vs 25.1 g N/d), but abomasal N flow as a percentage of N intake was greater (P less than .05) for LP than for HP (124 vs 71.1%). Pool size and net synthesis rate for both RAN and BUN pools were greater (P less than .05) for HP than for LP. Calves fed HP degraded more (P less than .05) BUN in the gastrointestinal tract than calves fed LP (37.4 vs 14.0 g N/d). Quantities of RAN absorbed from the rumen also were greater (P less than .05) for HP than for LP (14.2 vs 2.8 g N/d). The proportion of total gastrointestinal BUN degradation occurring in the rumen averaged 53 and 26% for LP and HP. Data are interpreted to suggest that net incorporation of BUN into bacterial protein (urea recycling) is inversely related to level of protein intake.

Characterization of inheritance patterns of blood pressure in Macaca fascicularis.

A breeding colony of Macaca fascicularis was established at the New England Regional Primate Center in 1977 and continued through 1984. Characterization of the offspring of this colony at 18 and 30 months of age suggested that higher blood pressure levels are hereditary in M. fascicularis, but evidence to date cannot determine if this condition is harmful to the animals.

Ureterocolonic anastomosis in ten dogs with transitional cell carcinoma.

Ureterocolonic anastomosis (UCA) was performed in 10 dogs with transitional cell carcinoma of the urinary bladder trigone or the urethra, or both. All grossly visible tumor was excised. All of the dogs recovered from anesthesia and surgery and had anal continence with no urine leakage. One dog died of undetermined causes 7 days after surgery. Nine dogs survived 1 to 5 months. The owners of eight of the dogs considered their dog's quality of life to be acceptable. Four dogs were euthanatized because of neurologic disease, three of which also had nausea and vomiting. The neurologic and gastrointestinal signs may have been caused by hyperammonemia, metabolic acidosis, and uremia. Blood ammonia levels were elevated in two dogs with neurologic signs. Hyperchloremic metabolic acidosis that was reversible with bicarbonate therapy was diagnosed in five dogs. All of the dogs were azotemic because of intestinal recycling of urea. Serum creatinine concentrations increased in four dogs after surgery. Drug-induced renal disease may have developed in two dogs. Pyelonephritis developed in five kidneys, two of which had outflow obstruction and two had bilateral hydroureteronephrosis before the UCA. In this small number of dogs, surgical excision of transitional cell carcinoma was not curative with six dogs having confirmed metastatic lesions at the time of death.

Reference values of blood parameters in beef cattle of different ages and stages of lactation.

Reference (normal) values for 12 blood serum components were determined for 48 Shorthorn cows (2-10 years old) and their 48 calves, 357 crossbred cows (12-14 years old), 36 feedlot bulls and 36 feedlot steers. In addition, hemoglobin, hematocrit, triiodothyronine, thyroxine and cortisol levels were determined for the crossbred cows, and feedlot bulls and steers. Reference values were tabulated according to sex, age and stage of lactation. Serum concentrations of urea, total protein and bilirubin, and serum activity of aspartate aminotransferase and lactate dehydrogenase increased with age (P less than 0.05), while calcium, phosphorus and alkaline phosphatase decreased with age (P less than 0.05) from birth to the age of ten years. The Shorthorn cows had the highest levels of glucose at parturition (P less than 0.05) with decreasing levels during lactation. Creatinine concentration decreased during lactation and increased during postweaning. Both lactate dehydrogenase and aspartate aminotransferase levels increased (P less than 0.05) during lactation. Urea and uric acid were present at higher concentrations in lactating than nonlactating cows (P less than 0.05). The values reported, based on a wide age range and large number of cattle, could serve as clinical guides and a basis for further research.

Percutaneous nephrolithotomy in the dog. An experimental study.

Percutaneous nephrostomies (PN) were created with teflon fascial dilators under fluoroscopic guidance, to implant stones bilaterally into the renal pelves of five dogs weighing 7 to 35 kg. Between one and seven stones of 0.25 to 1.00 cm diameter were implanted into each renal pelvis. Two to 4 weeks later, PN tracts were recreated, and the implanted renal stones were successfully removed under fluoroscopic and endoscopic visualization. Results of gross and histopathologic evaluation of the kidneys 2, 7, 14, 30, and 90 days after stone removal showed minimal, localized renal parenchymal trauma. Complications, although infrequent, included proximal ureteral tears and hemorrhage. Difficulty was encountered in maneuvering equipment around large or numerous stones. Canine percutaneous nephrolithotomy was successful despite great variation in kidney size, as well as variations in the number, size, and shape of stones in the upper urinary tract.

Primary hyperparathyroidism in dogs: 21 cases (1976-1986).

Case records from 21 dogs with hypercalcemia and hyperparathyroidism were evaluated. The dogs were greater than or equal to 7 years old, and 6 were Keeshonds. The most common clinical signs were polydipsia/polyuria, listlessness, and muscle weakness. The serum calcium concentrations were 12.1 to 19.6 mg/dl. Serum phosphorus concentrations were low in 5 dogs, within the reference range in 13 dogs, and high in 3 dogs that also had high concentrations of BUN. Twenty dogs had a parathyroid adenoma, and 1 had a parathyroid carcinoma. Nineteen dogs had their parathyroid tumor surgically removed. Within 5 days of tumor removal, 11 of the 19 dogs became hypocalcemic and the remaining 8, normocalcemic. Nine of the 11 hypocalcemic dogs developed clinical signs. Iatrogenic hypercalcemia was induced in 7 of 16 dogs treated orally with calcium carbonate plus vitamin D. Only 1 of 19 dogs that had their parathyroid tumor excised died in hypocalcemic tetany. Two additional dogs died within 2 weeks of surgery, one because of pancreatitis, the other due to renal failure. Eight dogs died 9 to 37 months after surgery of unrelated problems. Eight dogs were alive for at least 7 to 28 months after surgery.

Intrapelvic urethral anastomosis. A comparison of three techniques.

Three intrapelvic urethral anastomosis techniques were performed on 12 mature male dogs to compare the degree of stricture. The intrapelvic urethra was transected 1 cm caudal to the prostate, and anastomosis was performed using either suturing of the urethra over an indwelling catheter, suturing of the urethra without an indwelling catheter, or apposition of the urethra without sutures over an indwelling catheter. Postoperatively, the dogs were evaluated using clinical urination patterns, biochemical tests, radiography, and pathology. Three of four suture-catheter dogs and one of four catheter-only dogs had normal urinary patterns. Stricture (25-84%) with urethral dilation or fistulas tracts was visible on retrograde, positive contrast urethrograms of 3 of 12 intact dogs 20 weeks after surgery, and on all 12 excised lower urinary tracts. Suture-catheter dogs subjectively had the least amount of stricture. All eight dogs (1 suture-catheter dog, 4 suture-only dogs, and 3 catheter-only dogs) with severe stricture (greater than 60% lumen diameter reduction) had histopathologic signs of chronic, inflammatory urinary tract disease, including four with chronic, ascending lymphocytic pyelonephritis. Hydroureter and hydronephrosis developed in two catheter-only dogs. Complete urethral transection resulted in some degree of stricture, regardless of technique used for anastomosis. Urethral anastomosis over an indwelling catheter appeared to result in a lesser degree of stricture and clinical and histopathologic derangement.

Changes in urea nitrogen and creatinine concentrations in the vitreous humor of cattle after death.

The mean urea nitrogen concentration in vitreous humor (VUN) in 97 healthy steers after death was 15.7 mg/dl. The mean serum urea nitrogen concentration in the same cattle was 20.0 mg/dl. The mean vitreous creatinine (VC) concentration was 0.7 mg/dl, and the serum creatinine value was 1.5 mg/dl. The VUN and VC were both significantly lower than serum urea nitrogen and serum creatinine, respectively, but varied in a consistent, predictable manner. In tests with 10 cows, postmortem intervals as long as 36 hours and ambient temperatures up to 30 C had no significant effects on VUN and VC. Evaluation of 8 animals with uremia confirmed that the vitreous humor is a stable fluid compartment after death, usable as an indicator of serum urea nitrogen and creatinine.

Effects of three diets on dogs with induced chronic renal failure.

Healthy mixed-bred dogs of both sexes had renal mass surgically reduced and were allowed 2 to 3 months for hypertrophy of the remnant kidney. They were then allotted into 3 groups with equal renal function and were fed 1 of 3 diets that differed in composition. Group 1 dogs (n = 6) were fed moist food that contained 50% protein, 2.34% Ca, and 1.64% P with a P-binding agent (basic aluminum carbonate gel) added. Group 2 dogs (n = 6) were fed a dry diet that contained 24.5% protein, 1.26% Ca, 1.21% P, and the same P-binding agent as used for group 1. Group 3 dogs (n = 7) were fed a moist diet that contained 16.1% protein, 0.38% Ca, and 0.3% P without a P-binding agent. Each group was fed its diet for 92 days and monitored for responses. Mortality associated with uremia occurred in 2 of 6 group 1 dogs, 0 of 6 group 2 dogs, and in 2 of 7 group 3 dogs. Among survivors, clinical signs were seen in the more azotemic dogs of group 1, but not in dogs of groups 2 and 3. The blood urea nitrogen, plasma P concentrations, and PCV values were most favorable in group 3 and least favorable in group 1. Marked differences between groups were not seen in plasma concentrations of protein, albumin, or Ca or in plasma alkaline phosphatase activity. Values for glomerular filtration rate did not change in any group during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Arginine infusion stimulates prolactin, growth hormone, insulin, and subsequent lactation in pregnant dairy cows.

L-Arginine or saline was administered intravenously by rapid infusion into 16 late-pregnant Holstein cows to study changes of prolactin, growth hormone, insulin, total protein, urea nitrogen, and subsequent lactation. Arginine was infused daily at .1 g/kg body weight starting about 7 days prior to predicted calving until calving. Blood was sampled via a jugular cannula at 0700, 0715, 0730 (infusion immediately followed 0730 h sample), 0745, 0815, 0845, 1100, 1300, 1500, 1700, and 1900 h. Arginine infusion evoked dramatic but transient increase of concentrations of blood serum prolactin, growth hormone, and insulin. Urea nitrogen also was elevated in blood serum but not total protein. The secretory response of prolactin, growth hormone, and insulin to daily arginine infusion during the entire prepartum period was not diminished. Milk production for the first 22 wk of lactation tended to be higher (by about 10%) for cows infused with arginine as compared to cows infused with saline. Therefore, repeated arginine infusion in late-pregnant cows dramatically increased prolactin, growth hormone, and insulin and tended to increase subsequent milk yield.

Acute experimentally induced aflatoxicosis in the weanling pony.

Nineteen weanling ponies and 1 adult pony were given a single oral dose of aflatoxin B1 (AFB1). Dosages were: 0, 0.5, 1, 2, 4, 5, 6, and 7.4 mg of AFB1/kg of body weight. Vital signs were monitored, and whole blood and serum collected for analysis of serum enzymes, prothrombin time, blood cell counts, and serum urea nitrogen. Ponies that died were examined for gross lesions, and tissues were collected for histopathologic examination and analysis of AFB1 and AFM1 residues. Two of the 4 ponies given the 2 mg/kg dose and all ponies given the larger dosages died within 76 hours. Clinical signs included increased rectal temperature, faster heart and respiratory rates, abdominal straining, bloody feces, and tetanic convulsions. At necropsy, ponies that died of acute aflatoxicosis showed visceral petechiae and hepatic focal lesions. Histopathologic changes included severe hepatic necrosis, vacuolation, and bile duct hyperplasia. Aflatoxins B1 and M1 were recovered from liver, kidney, skeletal muscle, and gastrointestinal contents. One other pony given the 2 mg/kg dose died 32 days after dosing, and 1 control pony died after 70 days. Continuous elevations in prothrombin time and serum aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase levels were observed in ponies dosed at 4 mg/kg or more. Significant (P less than 0.05) elevations in these values, which peaked 2 to 3 days after dosing, were seen in ponies given the 2 mg/kg dose. This group also had significant increases over controls in PCV and hemoglobin concentration 5 days after dosing.

Hematologic and biochemical abnormalities associated with induced extrahepatic bile duct obstruction in the cat.

Bile duct obstruction was induced in 6 cats by surgical ligation and transection of the common bile duct. Clinical and laboratory changes were monitored weekly for 25 to 54 days. Clinical signs of obstruction were similar in all cats and included anorexia, pyrexia, lethargy, intermittent vomiting, weight loss, palpable gallbladder, hepatomegaly, and bleeding tendencies. Tissue jaundice and acholic feces were evident grossly as early as postsurgical day (PSD) 4 with a mean onset of jaundice at PSD 5.3 +/- 0.4. Hematologic changes were initially characterized by a mild neutrophilic leukocytosis that increased with the chronicity of bile duct obstruction. Regenerative anemia developed in 4 cats associated with gastrointestinal blood loss. Acute serum biochemical changes were characterized by a marked increase in the mean values of aspartate aminotransferase, alanine aminotransferase, total cholesterol, and copper. Comparatively, only moderate increases in mean serum alkaline phosphatase activity were observed. Mean total bilirubin values increased remarkably at postsurgical week (PSW) 1, reaching a maximal value of 23.1 +/- 4.4 mg/dl at PSW 3 with 71.6 +/- 2.7% direct bilirubin. With chronicity of bile duct obstruction ranging from PSW 3 to PSW 7, the mean serum values of aspartate aminotransferase, alanine aminotransferase, total cholesterol, serum alkaline phosphatase, and total and direct bilirubin stabilized and then declined, whereas the increased mean serum copper values persisted. At PSD 25 to 54, hepatic copper values and serum bile acids were markedly increased. Seemingly, clinicopathologic changes of induced cholestatic hepatic injury depended largely on the duration of biliary obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Kochia scoparia poisoning in cattle.

Cattle consuming only high-sulfate water (2.3 g/L) and Kochia scoparia in a marginal pasture in southeastern Colorado were periodically monitored by serum chemical profiles. Serum glutamic oxaloacetic transaminase, serum sorbitol dehydrogenase, and serum bilirubin values were abnormally high over extended periods, suggesting chronic toxicosis, but the toxicosis seemed accentuated after substantial rains, when plant growth was accelerated, and flowering, pollination, and early seed development were occurring. Clinical disease was manifested primarily as photosensitization. Polioencephalomalacia was also produced. Evidence of a thiamin-destructive principle in K scoparia was obtained.

Net absorption and ruminal concentrations of metabolites in nonpregnant dry Holstein cows before and after intraruminal acetic acid infusion.

Objectives were to define daily patterns of net absorption of various nutrients and to assess effects of intraruminal infusion of acetic acid on concentrations of ruminal fluid and net absorption of various metabolites. These characteristics were measured in three nonpregnant, dry Holstein cows (491 kg) at hourly intervals for 24 h before and after 5 days of intraruminal infusion of acetic acid to provide energy equal to 10% of daily intake of metabolizable energy. Cows were fed a completely mixed, 60% corn silage, 40% grain supplement diet at maintenance intake; daily rations were split into two feedings. Net rates of absorption were greatest after feeding and least during early morning. Net absorption of all metabolites measured was similar for the two daily feeding intervals, indicating daily net absorption could be calculated from either feeding interval. Intraruminal infusion of acetic acid caused increased ruminal and plasma concentrations of acetate, increased net absorption of acetate, and almost a twofold increased loss of urea-nitrogen from plasma to the gut. Sixty-nine percent of acetic acid infused was accounted for by increased net absorption of acetate. Ruminal fluid concentrations and net absorption of other volatile fatty acids were not affected by infusion of acetic acid. Net absorptions of ammonia-nitrogen, L-lactate, and glucose likewise were not affected. Net absorption of volatile fatty acid and L-lactate was 43% of daily intake of metabolizable energy.