Somatotropin and adipose tissue metabolism: substrate and temporal effects

The purpose of these studies was to determine the time course for changes in feed intake, blood metabolites, and lipogenic activity in adipose tissue in response to the initiation of porcine somatotropin (pST) treatment and following withdrawal from treatment in barrows. An initial study was conducted to determine the impact of chronic pST treatment (4 wk of daily injection; 0 vs 4 mg/d) on adipose tissue lipid metabolism in barrows (initial weight 67 kg). Feed efficiency was improved 27%, backfat thickness was decreased 43%, and glucose and lactate oxidation and incorporation into lipid in adipose tissue was reduced 70 to 86% in pST-treated pigs. Palmitate esterification was decreased 44%, whereas palmitate oxidation was unaffected. In vitro metabolism of lactate, glucose, and palmitate in liver slices was not affected by pST treatment. The time-course for changes in intake and adipose tissue metabolism in response to 7 d of pST (0 vs 4 mg/d) treatment and 7 d of withdrawal was examined in subsequent studies in barrows (initial weight 75 kg). Feed intake during pST treatment was significantly (P < .05) less than in control pigs within 24 h of the initiation of treatment and remained low through 3 d after withdrawal. Adipose tissue biopsies were obtained on d 0, 1, 2, 4, and 7 of the treatment phase and on d 2, 4, and 7 after withdrawal from 7 d of treatment. Maximal inhibition of lipogenesis by pST treatment in adipose tissue in vitro was observed on d 4 (-68%) and d 7 (-69%). Similarly, fatty acid synthase activity declined during the treatment period, with the greatest change noted on d 7 (-26%). After withdrawal from treatment, lipogenesis gradually increased, returning to control values 7 d after withdrawal. Levels of IGF-I began to increase from d 1 to d 7 of treatment, continually decreased during withdrawal, and were normalized by the end of the withdrawal period. Plasma urea nitrogen concentrations decreased during treatment, increased during the withdrawal phase, and were normalized 4 d after the last pST treatment. Overall results indicate that most of the metabolic changes in response to pST occur within 1 wk of treatment and return to pretreatment values after 7 d of withdrawal from treatment.     

Long-term outcome of horses with a slab fracture of the central or third tarsal bone treated conservatively: 25 cases (1976-1993)

OBJECTIVE: To determine clinical features of horses with a slab fracture of the central or third tarsal bone and to report outcome of horses in which treatment did not include surgery. DESIGN: Retrospective study. ANIMALS: 25 horses (14 Standardbreds, 6 Thoroughbreds, 5 Quarter Horses). PROCEDURE: Medical records of horses with a slab fracture of the central (n = 9) or third (16) tarsal bone were reviewed. Only horses for which treatment consisted of confinement to a stall were included in this study. Clinical features and radiographic findings were recorded and summarized. Outcome was determined for racing breeds by obtaining official lifetime race results. Outcome for Quarter Horses was determined by phone survey of the owners. RESULTS: 16 (64%) horses had a successful outcome. Ten of 14 (71%) Standardbreds and 2 of 6 Thoroughbreds returned to racing and started at least 5 races after injury. Four of 5 Quarter Horses for which follow-up information was available successfully returned to their previous activity. Sex, age, limb affected, or gait was not associated with final outcome. Percentage of racehorses with central tarsal bone fractures that had a successful outcome (2/7) was significantly less than percentage with third tarsal bone fractures that did (10/13). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that enforced rest without surgical fixation can be an effective therapeutic option for horses with a slab fracture of the central or third tarsal bone, even if athletic function is expected.     

Parasite control methods used by horse owners: factors predisposing to the development of anthelmintic resistance in nematodes

One hundred and fifty horse owners, primarily private owners and riding schools, replied to a questionnaire concerning the practices they used to control parasites. Twenty-seven had experienced a parasite problem. Faecal samples from 188 horses selected at random showed that worm control practices were generally successful; however, many owners were not following recommendations for slowing the development of resistant parasites. In 1996, 86 per cent of the owners were using either three or two classes of anthelmintic a year, and they used a median of six doses with a range from one to 11. Approximately half the owners, more commonly owners of up to five horses, picked up their horses' faeces at least once a week, but these owners also used more doses of anthelmintic a year than owners who did not pick up faeces. One-third of the owners manually removed Gasterophilus species eggs from the horses' hairs, but 94 per cent of them also used ivermectin. Many owners treated specifically for Anoplocephala species, cyathostome larvae and Gasterophilus species, and these owners were the most likely to use three classes of anthelmintic a year. One-hundred-and-seven owners replied to a second questionnaire asking for information about the factors that influenced their anthelmintic control practices. Many owners, particularly private owners, were not influenced by the cost of the anthelmintic. For the timing and frequency of treatment, and the choice of drug, owners were most influenced by advertisements, magazine articles and veterinary surgeons. In two magazines aimed at horse owners, the brands of drugs most frequently advertised were the brands most commonly used by the owners, and articles in the magazines recommended the use of three classes of drug per year. These results are discussed in relation to their influence on the development of anthelmintic-resistant nematodes.     

Hepatotoxicity of stanozolol in cats

OBJECTIVE: To determine hepatotoxicity of stanozolol in cats and to identify clinicopathologic and histopathologic abnormalities in cats with stanozolol-induced hepatotoxicosis. DESIGN: Clinical trial and case series. ANIMALS: 12 healthy cats, 6 cats with chronic renal failure, and 3 cats with gingivitis and stomatitis. PROCEDURES: Healthy cats and cats with renal failure were treated with stanozolol (25 mg, i.m., on the first day, then 2 mg, p.o., q 12 h) for 4 weeks. Cats with gingivitis were treated with stanozolol at a dosage of 1 mg, p.o., every 24 hours. RESULTS: Most healthy cats and cats with renal failure developed marked inappetence, groomed less, and were less active within 7 to 10 days after initiation of stanozolol administration. Serum alanine transaminase (ALT) activity was significantly increased in 14 of 18 cats after stanozolol administration, but serum alkaline phosphatase activity was mildly increased in only 3. Four cats with serum ALT activity > 1,000 U/L after only 2 weeks of stanozolol administration had coagulopathies; administration of vitamin K resolved the coagulopathy in 3 of the 4 within 48 hours. All 18 cats survived, and hepatic enzyme activities were normal in all cats tested more than 4 weeks after stanozolol administration was discontinued. Two of the 3 cats with gingivitis developed evidence of severe hepatic failure 2 to 3 months after initiation of stanozolol treatment; both cats developed coagulopathies. Histologic evaluation of hepatic biopsy specimens from 5 cats revealed diffuse hepatic lipidosis and cholestasis without evidence of hepatocellular necrosis. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that stanozolol is hepatotoxic in cats.     

Ultrasound therapy for the prevention and correction of contractures and bone mineral loss associated with wing bandaging in the domestic pigeon (Columba livia).

Figure-of-eight wing bandaging is widely used to treat wing injuries, to immobilize wings before and after fracture repair, and during transient wing paralysis. However, prolonged bandaging can lead to bone loss and to contractures and reduced range of joint motion. Studies evaluating the efficacy of therapeutic ultrasound to reverse and prevent bandaging-associated contractures in pigeons (Columba livia) showed a significant increase in elbow and carpal extension after 10 twice weekly ultrasound treatments when started either 4 or 11 days after bandage placement. In addition, after 42 days of wing bandaging, three ultrasound treatments stimulated a faster reversal of carpal wing rotation loss than removal of the bandage over the 10-day treatment period. Finally, bone loss in response to 28 days of bandaging was significant, progressed at 2.8% per week, and was not affected by ultrasound treatment twice weekly during this period. Therefore, therapeutic ultrasound prevented and reversed loss of wing extension associated with figure-of-eight bandaging but did not lessen the disuse osteoporosis created by bandaging in these birds.     

Squamous cell carcinoma of the nasal planum in 17 dogs

Squamous cell carcinoma of the nasal planum was diagnosed in 17 dogs over a period of 11 years. Ulceration, bleeding and sneezing were the most common clinical signs. One dog had cytological evidence of metastasis to the local lymph node. The dogs were treated by surgical resection, fractionated megavoltage irradiation, or a combination of the two. Surgical resection gave the most favourable results; four of six dogs were cured but a recurrence of the tumour was predicted in the other two on the basis of incomplete or marginal resection. Radiotherapy alone was not as effective; one of four dogs was cured, and the tumour recurred in the others within 24 weeks (median eight weeks). Combined surgical resection and radiotherapy did not produce a cure in any of the seven remaining dogs, and the tumour recurred within 12 weeks (median nine weeks). Three dogs had cytological evidence of lymph node metastasis when the tumour recurred. The dogs' prognosis was adversely affected by the interval between their initial examination and treatment, but there was no apparent association between the histological grade of the tumour and the clinical outcome.     

Effect of citrate concentration on coagulation test results in dogs

OBJECTIVE: To determine the effect of citrate concentration (3.2 vs 3.8%) on coagulation tests in dogs. DESIGN: Original study. ANIMALS: 30 clinically healthy dogs and 12 dogs with hereditary hemostatic disorders. PROCEDURE: Blood was collected from all dogs directly into collection tubes containing 3.2 or 3.8% buffered citrate. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen concentration were measured by use of 3 clot-detection assay systems (2 mechanical and 1 photo-optic). Factor VIII and factor IX coagulant activities (FVIII:C and FIX:C, respectively) were determined by use of a manual tilt-tube method and a mechanical clot-detection device. RESULTS: Significant differences were not detected in median PT, fibrinogen concentration, FVIII:C, or FIX:C between 3.2 and 3.8% citrate for any assay system. A significant prolongation in aPTT for 3.2% citrate, compared with 3.8% citrate, was found in 1 mechanical system. CONCLUSIONS AND CLINICAL RELEVANCE: Citrate concentration does not significantly affect results of most coagulation assays, regardless of assay system. The aPTT was mildly influenced by the citrate concentration, although this was animal-, instrument-, and reagent-dependent. The choice of 3.2 or 3.8% citrate as an anticoagulant for coagulation tests has minimal influence on assay results in healthy dogs or dogs with hereditary hemostatic disorders.     

Aerobic intestinal flora of wild-caught African dwarf crocodiles Osteolaemus tetraspis

Intestinal contents were collected from wild-caught African dwarf crocodiles (Osteolaemus tetraspis) in 1993 and 1995 which were slaughtered at urban markets in the Congo Republic. The samples were kept frozen and brought back to Onderstepoort for aerobic culture. Out of 29 specimens, 33 species of bacteria and 20 species of fungi were isolated. The bacteria included three isolates of Salmonella and eight isolates of Escherichia coli, most of the latter being rough strains. The flora of individual specimens contained 1-5 bacterial and 0-5 fungal species. Neither Aeromonas hydrophila nor Edwardsiella tarda were isolated from any of the samples.     

Presence of fluoroquinolone-resistant coliforms in poultry litter

Litter was collected from four turkey farms (eight houses) with a history of fluoroquinolone (FQ) treatment failure, 10 adult broiler breeder chicken farms (43 houses) with one having a history of FQ treatment, and 30 broiler chicken farms (110 houses) with 24 having a history of FQ treatment. In the turkey litter, the percentage of nalidixic acid-resistant (at 100 microg/ml) coliforms/total number of coliforms ranged from 0.6% to 61.9%. Two of the four farms had houses containing coliforms resistant to the two FQs, enrofloxacin (1 microg/ml) and sarafloxacin (1 microg/ml). There was also multiple resistance to other antimicrobials on all four turkey farms (ampicillin, tetracycline, chloramphenicol, kanamycin). The level of total coliforms from the adult broiler breeder litter was low, and there were no nalidixic acid-resistant isolates from any of the 10 farms. In the broiler chickens, 7 of 91 houses with a history of FQ usage contained coliforms resistant to nalidixic acid; however, 2 of the 19 houses on farms with no history of FQ usage had nalidixic acid-resistant coliforms. All of the broiler farms with nalidixic acid-resistant isolates were also resistant to the FQ sarafloxacin, whereas only 3 of the 24 treatment history farms and 1 of the no-treatment history farms exhibited enrofloxacin-resistant coliforms in the litter.     

Gender, age, breed and distribution of morbidity and mortality in insured dogs in Sweden during 1995 and 1996

More than 200,000 dogs insured by one Swedish company at the beginning of either 1995 or 1996 were included in a retrospective, cross-sectional study. They could be covered for veterinary care at any age, but were eligible for life insurance only up to 10 years of age. Accessions for veterinary care that exceeded the deductible cost were used to calculate the risk of morbidity. The morbidity and mortality data have been stratified by gender, age, breed, location and human population density. In each year, 13 per cent of the dogs experienced at least one veterinary care event and the mortality risk was 3.0 per cent. The risk of morbidity varied with age, gender, breed, and location. The risk of mortality increased principally with age. It was possible to derive population-based risks of morbidity and mortality from these insurance data.