Creatinine is the analyte most frequently measured in human and veterinary clinical chemistry laboratories as an indirect measure of glomerular filtration rate (GFR). Although creatinine metabolism and the difficulties of creatinine measurement have been reviewed in human medicine, similar reviews are lacking in veterinary medicine. The aim of this review is to summarize information and data about creatinine metabolism, measurement, and diagnostic significance in the dog. Plasma creatinine originates from the degradation of creatine and creatine phosphate, which are present mainly in muscle and in food. Creatinine is cleared by glomerular filtration with negligible renal secretion and extrarenal metabolism, and its clearance is a good estimate of GFR. Plasma and urine creatinine measurements are based on the nonspecific Jaffé reaction or specific enzymatic reactions; lack of assay accuracy precludes proper interlaboratory comparison of results. Preanalytical factors such as age and breed can have an impact on plasma creatinine (P-creatinine) concentration, while many intraindividual factors of variation have little effect. Dehydration and drugs mainly affect P-creatinine concentration in dogs by decreasing GFR. P-creatinine is increased in renal failure, whatever its cause, and correlates with a decrease in GFR according to a curvilinear relationship, such that P-creatinine is insensitive for detecting moderate decreases of GFR or for monitoring progression of GFR in dogs with severely reduced kidney function. Low sensitivity can be obviated by determining endogenous or exogenous clearance rates of creatinine. A technique for determining plasma clearance following IV bolus injection of exogenous creatinine and subsequent serial measurement of P-creatinine does not require urine collection and with additional studies may become an established technique for creatinine clearance in dogs.

Background -Patients with chronic disease comply with about 50% of their treatment. The complex and time consuming daily drug regimens needed in the care of adult patients with cystic fibrosis encourage non-compliance with prescribed treatments. Understanding the reasons for, and the extent of, non-compliance is essential for a realistic appraisal of the patient's condition and sensible planning of future treatment programmes.

Plasma clearance of creatinine was evaluated for assessment of glomerular filtration rate (GFR) in dogs. In 6 healthy dogs (Experiment 1), we determined 24-hour urine clearance of endogenous creatinine, plasma, and urine clearances of exogenous creatinine administered at 40, 80, and 160 mg/kg in a crossover design (linearity study), plasma iothalamate clearance, and plasma and urine clearances of 14 C-inulin. In Experiment 2, plasma creatinine and iothalamate clearances were compared, and a linearity study was performed as for Experiment 1 in 6 dogs with surgically induced renal impairment. Experiment 3 compared plasma creatinine clearance with plasma iothalamate clearance before and 3 weeks after induction of moderate renal impairment in 6 dogs. Plasma creatinine clearances were calculated by both noncompartmental and compartmental analyses. In Experiment 1, plasma inulin clearance was higher (P Ͻ .001) than other clearance values. Plasma creatinine clearances at the 3 dose rates did not differ from urine inulin clearance and each other. In Experiment 2, plasma creatinine clearances were about 14% lower than plasma iothalamate clearance (P Ͻ .05). In Experiment 3, decreases in GFR assessed by plasma clearances of iothalamate and creatinine were similar. Renal failure decreased the daily endogenous input rate of creatinine by 25%. Limiting sampling strategies for optimizing GFR calculation were proposed, allowing an error lower than 6.5% with 4 blood samples. These results suggest that determination of plasma creatinine clearance by a noncompartmental approach offers a reliable, inexpensive, rapid, and convenient means of estimating GFR in routine practice.

Abstractresolved during or shortly after treatment. Significant changes were seen in mean Background -Patients with cystic fibrosis serum urea levels in both groups, but in have received more intravenous antibiotic only four patients to a level above the norcourses as median survival has steadily mal range, and in creatinine clearance in increased. A number of centres have adthe dual therapy group. At 24 month follow opted a policy of regular (three monthly) up no long term adverse consequences rather than on demand intravenous antifrom intravenous colistin were found in pseudomonal antibiotics. More widepatients who completed the study. spread bacterial antibiotic resistance has Conclusions -Intravenous colistin is an resulted from this increased antibiotic use.effective treatment for Pseudomonas Most Pseudomonas aeruginosa strains reaeruginosa associated pulmonary exmain fully sensitive to colistin but its use acerbations in patients with cystic fibrosis. has been resisted owing to concerns about Assessment of the individual effect of each neurotoxicity and nephrotoxicity. A study treatment regimen suggests a greater was carried out to assess the safety and efficacy when colistin is combined with a efficacy of intravenous colistin in the treatsecond antibiotic to which the pseudoment of acute respiratory exacerbations in monas shows in vitro sensitivity. Changes adult patients with cystic fibrosis.in renal function should be monitored. Methods -Patients with chronic Pseudo- (Thorax 1997;52:987-993) monas aeruginosa colonisation who presented with protocol defined respiratory Keywords: colistin, cystic fibrosis, Pseudomonas aerutract exacerbations were randomised to ginosa, nephrotoxicity, neurotoxicity. receive treatment for 12 days with either colistin (2 MU tds intravenously) alone or with a second anti-pseudomonal anti-Cohort survival curves from 1968 for children biotic. Comparisons of the absolute values born with cystic fibrosis show an increasing life of respiratory function tests on days 1, 5, expectancy with a median survival presently and 12 and of overnight oxygen saturation of about 29 years 1 2 and an expected median on days 1 and 12 were the primary outcome survival for today's children of 40 years.3 This measures. Patient's weight, clinical and success directly reflects better patient nutrition, chest radiographic scores, and peripheral better and individualised physiotherapy, and blood markers of inflammation were also the advent of effective anti-pseudomonal antidocumented. The effect of each treatment biotics. 4 More frequent antibiotic usage inregimen individually was assessed by the evitably has resulted in a greater prevalence change in clinical measurements from of bacterial antibiotic resistance and patient baseline values. Adverse renal effects were hypersensitivity reactions. 5-9Resistance of monitored by measurement of serum Pseudomonas aeruginosa to colistin is still unlevels of urea and electrolytes, creatinine usual 7 but cystic fibrosis specialist physicians clearance, and war...

Trilostane administration controlled pituitary-dependent hyperadrenocorticism in these dogs. It was safe, effective and free of side-effects at the doses used. Most dogs were initially quite sensitive to the drug for 10 to 30 days, then required higher doses until a prolonged phase of stable dose requirements occurred. Urinary corticoid:creatinine ratio was useful in assessing duration of drug effect. Some dogs treated for more than 2 years required reduction or temporary cessation of drug because of iatrogenic hypoadrenocorticism.

Responses (486) were collared from a survey of 5054 Australian veterinarians on their use of anti-inflammatory and analgesic drugs in dogs and cats. Almost all respondents used glucocorticoids (usually prednisolone) to treat allergic, pruritic dermatoses in dogs, while two-thirds also gave fatty acid supplements and one-half used antihistamines. Almost 60% of respondents initially injected a glucocorticoid (frequently a long-acting preparation) when treating inflammatory skin diseases in dogs. More than 90% of respondents used glucocorticoids to treat immune-mediated haemolytic anaemia or thrombocytopenia, and about one-third also gave cytotoxic drugs. Administration of prednisolone on alternate days was generally favoured for long-term enteral steroid therapy. Phenylbutazone was the most preferred treatment for painful or inflammatory musculoskeletal disorders of dogs, but aspirin and pentosan polysulphate were also used widely. Regarding the use of analgesics drugs generally, both narcotic analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) were used more widely in dogs than in cats, but alpha-2 agonists were used similarly in both species. The most commonly used narcotic analgesics were pethidine and buprenorphine in both species, while the NSAIDs used most often were flunixin and dipyrone in dogs and ketoprofen in cats. More than 80% of respondents generally used analgesic drugs with potentially painful surgical procedures, with doses given usually before anaesthetic recovery. Analgesic use rates varied with the condition, ranging from 94% for patients with acute severe trauma, through 60% for cruciate ligament repair and 29% for perineal herniorrahphy, to about 5% for ovariohysterectomy and dog castration. The three clinical signs most frequently nominated as indicators of pain in dogs and cats were (in descending order) vocalisation, response to handling or palpating the affected area, and mental depression. Other items mentioned frequently were behavioural changes and immobility (in both species), inappetence/anorexia in cats, and altered respiration in dogs.

Extranodal lymphosarcoma seemed more prevalent in this study than reported elsewhere. Siamese cats in the study population may have had a genetic predisposition to lymphosarcoma. Limited evidence suggested feline leukaemia virus may be less important, and feline immunodeficiency virus more important, in the local population than indicated in overseas reports. Additional studies are needed to investigate breed predisposition and feline leukaemia virus and feline immunodeficiency virus status in Australian cats with lymphosarcoma.

Over an 8‐month period, samples were obtained from normal conjunctival sacs of 100 dogs, for aerobic and anaerobic culture. No organisms were isolated from 22% of the samples, while a single isolate was obtained from 46% and in 32% two to four species were identified. Gram‐positive organisms predominated, with Staphylococcus spp., Bacillus spp. and Corynebacterium spp. accounting for 76% of the total isolates. Gram‐negative bacteria comprised 8‐4% of the total. Only one obligate anaerobe, a Clostridium sp., was isolated.