Hypercalcemia

Elevated serum calcium occurs relatively uncommonly in dogs and rarely in cats. Hypercalcemia can serve as a marker of disease that enables diagnosis but may also contribute to development of lesions and the clinical signs of disease. Specific clinical signs do not necessarily accompany hypercalcemia, and its presence will frequently be unsuspected. Fortuitous hypercalcemia is often discovered after a review of serum biochemical profile results. This article emphasizes malignancy-associated hypercalcemia and the emergence of cholecalciferol rodenticide toxicity as an important cause of hypercalcemia, as well as its treatment.     

Early effects of ethylene glycol on the ultrastructure of the renal cortex in dogs

A sublethal dose of ethylene glycol was administered orally to 3 groups of dogs; dogs of a control group were given distilled water instead. Renal cortical biopsy samples were obtained from dogs of experimental and control groups at various times after treatment. Tissue was examined by use of light microscopy and transmission electron microscopy. In dogs of the control group, the light and electron microscopic appearances of tissue were within normal limits at all sample collection hours. In dogs of the experimental groups, renal corpuscular structure remained within normal limits by use of light and electron microscopy throughout the study, though morphologic change was seen in other structures of the cortex. Light microscopic lesions first appeared at 12 hours, and were similar to those reported in the literature. Ultrastructural lesions were first observed in the 5-hour samples, and similar to the light microscopic lesions, were most common in the proximal convoluted tubules (PCT). Initial PCT cellular changes included vacuolization of cells and distention of the parabasal extracellular spaces; PCT cellular lesions seen in later-hour samples included formation of apical buds and cellular rupture. Internalization or sloughing of the PCT brush border was not observed. Distal convoluted tubules (DCT) were frequently dilated and/or packed with cellular debris. A few DCT cells had degenerative or necrotic changes. In PCT and DCT, abnormal cells were frequently flanked by normal or nearly normal cells. During later hours, a few cells with types of changes first observed in early hours continued to be observed, implying ongoing response of cells to the toxin.     

Hemodialysis of a dog with acute renal failure

A dog with oliguric acute renal failure presumed to have been caused by ethylene glycol ingestion was treated by hemodialysis for 1 month. Hemodialysis was effective in controlling azotemia, hyperphosphatemia, and hyperkalemia when performed on a daily or alternate-day basis. The major complications during treatment were infection and severe weight loss. Serial renal biopsies disclosed a progression from initial acute tubular necrosis to severe diffuse interstitial fibrosis and mononuclear cell inflammation. Infection, cachexia, development of end-stage renal lesions, and terminal hyperkalemia contributed to the eventual death of the dog.     

Effect of vitamin A deficiency on mammary gland development and susceptibility to mastitis through intramammary infusion with Staphylococcus aureus in mice

Weanling mice were fed 0 or 150 micrograms retinol equivalent/kg of diet for 5 weeks, were bred, and allowed to complete gestation. On day 3 of lactation, all mice were separated from their litters for 1 hour and were then anesthetized. The 4th right or left mammary gland was inoculated with 0.1 ml of S Aureus (10(10) colony-forming units/0.1 ml). Exactly 24 hours after inoculation, the mice were euthanatized and the mammary glands were removed and fixed for histologic evaluations. Vitamin A-deficient dams had smaller litter size and lower liver stores of vitamin A; however, deficiency was not severe enough to produce external signs of vitamin A deficiency in the dams. Morphologic studies showed large areas of adipose tissue, greatly reduced ductal and lobule-alveolar development, and decreased total secretory activity in mammary glands from vitamin A-deficient females. On the other hand, mammary glands from vitamin A-supplemented mice had extensive lobule-alveolar development and highly distended alveoli. Extensive necrosis of alveolar tissue was observed in staphylococcus-infused mammary glands of all mice. Large numbers of leukocytes and cell debris were present in the lumen of alveoli and ducts. However, mammary glands from vitamin A-deficient females had more extensive pathologic damage compared with corresponding glands from vitamin A-supplemented mice. Results indicted that vitamin A-deficient mice had reduced mammary development and increased pathologic damage to the mammary gland after intramammary challenge with staphylococcus.     

Peritoneal dialysis in dogs and cats: 27 cases (1976-1987)

The records of 25 dogs and 2 cats treated with peritoneal dialysis during an 11-year period were evaluated. The indications for peritoneal dialysis were acute renal failure in 21 animals, chronic renal failure in 5 animals, and azotemia of undetermined cause in 1 animal. Peritoneal dialysis resulted in a significant (P less than 0.05) decrease in serum urea nitrogen concentration in 19 of the dogs and a significant (P less than 0.05) decrease in serum creatinine in 20 dogs. The most common complication of peritoneal dialysis was hypoalbuminemia (11 animals affected). Other common complications were dialysate retention/catheter obstruction (8 animals), peritonitis (6 animals), hypochloremia (6 animals), and subcutaneous leakage of dialysate (6 animals). Twelve dogs and 2 cats died during treatment, 6 dogs were euthanatized, and 1 dog was lost to follow-up evaluation. The remaining 6 dogs survived and were discharged from the hospital after successful peritoneal dialysis. On the basis of the results of this study, the authors concluded that peritoneal dialysis, although associated with a high complication rate, was a successful technique for reducing azotemia in dogs with acute and chronic renal failure. Survival rates were poor because of the severity of the underlying renal diseases.     

Kinetic characteristics of beta-carotene uptake after an injection of beta-carotene in pigs.

Two experiments were conducted to study the uptake of beta-carotene in plasma, lipoproteins, and blood cells in pigs (50 to 55 kg; n = 40) after an i.m. injection of 0, 10, 20, or 40 mg of beta-carotene. Blood was sampled at 0, 3, 6, 12, 24, and 48 h postinjection. beta-Carotene was not detectable in plasma, lipoproteins, or blood cells of control pigs. However, concentrations of beta-carotene in plasma and lipoproteins increased in a dose-related manner in injected animals. Distribution of beta-carotene in the lipoproteins changed with time postinjection. The beta-carotene associated with very low density lipoproteins increased and that in low density lipoproteins decreased with time in treated pigs. Concentrations of beta-carotene in lymphocytes of treated pigs also increased within 3 h postinjection. The profile of beta-carotene in lymphocytes was different from that observed in plasma and lipoproteins. Carotene was not detectable in neutrophils and erythrocytes. Treatment did not alter concentrations of retinol or alpha-tocopherol in plasma, lipoproteins, or blood cells. Therefore, lymphocytes specifically take up beta-carotene, thereby suggesting a possible role of beta-carotene in this immune cell.     

Dietary astaxanthin enhances immune response in dogs

No information is available on the possible role of astaxanthin on immune response in domestic canine. Female Beagle dogs (9-10 mo old; 8.2 ± 0.2 kg body weight) were fed 0, 10, 20 or 40 mg astaxanthin daily and blood sampled on wk 0, 6, 12, and 16 for assessing the following: lymphoproliferation, leukocyte subpopulations, natural killer (NK) cell cytotoxicity, and concentrations of blood astaxanthin, IgG, IgM and acute phase proteins. Delayed-type hypersensitivity (DTH) response was assessed on wk 0, 12 and 16. Plasma astaxanthin increased dose-dependently and reached maximum concentrations on wk 6. Dietary astaxanthin enhanced DTH response to vaccine, concanavalin A-induced lymphocyte proliferation (with the 20mg dose at wk 12) and NK cell cytotoxic activity. In addition, dietary astaxanthin increased concentrations of IgG and IgM, and B cell population. Plasma concentrations of C reactive protein were lower in astaxanthin-fed dogs. Therefore, dietary astaxanthin heightened cell-mediated and humoral immune response and reduced DNA damage and inflammation in dogs.     

Hematuria and transitional cell papilloma of the renal pelvis treated via unilateral nephrectomy in an alpaca

CASE DESCRIPTION: An 11-year-old 72-kg (158-lb) sexually intact female alpaca was examined for diagnosis and treatment of hematuria of 4 months' duration. CLINICAL FINDINGS: Pigmenturia was detected by the owner when the alpaca was 8 months pregnant. Radiographic, ultrasonographic, vaginal speculum, and cystoscopic evaluation of the urinary tract revealed normal vaginal and urethral epithelia and increased bladder vessel tortuosity, with pulses of hemorrhage from the left ureter. Regenerative anemia and mild leukopenia were detected and serum urea nitrogen and creatinine concentrations were within reference ranges. TREATMENT AND OUTCOME: Chronic hematuria resolved after unilateral nephrectomy of the left kidney, and no dysfunction was detected in the remaining kidney. Histologic evaluation of the kidney revealed a transitional cell tumor in the renal pelvis. CLINICAL RELEVANCE: Although anemia is common in South American camelids, hematuria is an uncommon sign of this condition. Chronic urinary tract infection, toxin ingestion, and neoplasia causing hematuria or hemoglobinuria should be considered in South American camelids with pigmenturia. Thorough and systematic evaluation of the urinary tract should be performed to locate the site of hemorrhage to treat hematuria appropriately.