Background

Urinary tract infections (UTIs) are common in dogs. The responsible bacterial populations have evolved with increasing resistance to many antimicrobials.

Objective

To characterize the antimicrobial susceptibility patterns of canine urinary tract isolates over a 51-month period.

Animals

One thousand six hundred and thirty-six bacterial isolates from 1,028 dogs.

Methods

Aerobic bacterial isolate growth and susceptibility data from urine cultures of dogs were identified, retrospectively. Medical records were reviewed to obtain signalment, comorbidities, and antimicrobial use in the previous 30 days. The UTIs were further categorized as uncomplicated, complicated, or pyelonephritis.

Results

Common bacterial isolates identified were Escherichia coli (52.5%), Staphylococcus spp. (13.6%), and Enterococcus spp. (13.3%). In vitro susceptibility among all isolates varied for commonly prescribed antimicrobials (amoxicillin [59%], amoxicillin/clavulanic acid [76%], cephalexin [66%], enrofloxacin [74%] and trimethoprim-sulfamethoxazole [86%]). For all antimicrobials tested (except aminoglycosides), in vitro susceptibility was higher in uncomplicated versus complicated infections (P < .05). Uncomplicated infection isolate susceptibility rates remained ≤90% for PO administered antimicrobials. Administration of amoxicillin, doxycycline, and enrofloxacin, but not amoxicillin/clavulanic acid in the previous 30 days was associated with resistance to that antimicrobial. Multidrug resistant isolates of E. coli and Staphylococcus spp. were more common in dogs with complicated than uncomplicated UTIs (36% versus 21%, P < .0001).

Conclusions and clinical importance

In vitro susceptibility was highly variable and no PO administered antimicrobial had >90% efficacy among isolates tested. Multidrug resistance was frequent among isolates tested suggesting that routine culture and susceptibility testing is indicated. Previously prescribed antimicrobials may affect empirical choices made pending susceptibility testing.

Background

Potassium (K+) supplementation of isotonic crystalloid fluids in daily fluid therapy is commonly performed, yet its accuracy in veterinary medicine is undetermined.

Objective

To investigate the accuracy of K+ supplementation in isotonic crystalloid fluids.

Animals

None.

Methods

Observational study. 210 bags of fluid supplemented with KCl being administered to hospitalized dogs and cats intravenously (IV) were sampled over a 3-month period. Measured K+ concentration ([K+]) was compared to the intended [K+] of the bag. In a second experiment, 60 stock fluid bags were supplemented to achieve a concentration of 20 mmol/L K+, mixed well and [K+] was measured. In another 12 bags of 0.9% NaCl, K+ was added without mixing the bag, and [K+ ] of the delivered fluid was measured at regular time points during constant rate infusion.

Results

The measured [K+] was significantly higher than intended [K+] (mean difference 9.0 mmol/L, range 6.5 to >280 mmol/L, P < .0001). In 28% of clinical samples measured [K+] was ≥5 mmol/L different than intended [K+]. With adequate mixing, K+ supplementation of fluids can be accurate with the mean difference between measured and intended [K+] of 0.7 (95% CI -0.32 to 1.7) mmol/L. When not mixed, K(+) supplementation of 20 mmol/L can lead to very high [K+] of delivered fluid (up to 1410 mmol/L).

Conclusions and clinical importance

Inadequate mixing following K+ supplementation of fluid bags can lead to potentially life threatening IV infused [K+]. Standard protocols for K+ supplementation should be established to ensure adequate mixing.

Background

Hypernatremia has been associated with substantial morbidity and death in human patients. The incidence and importance of hypernatremia in dogs and cats has not been determined.

Hypothesis/objectives

To describe the incidence of and prognosis associated with hypernatremia in dogs and cats at a university teaching hospital.

Animals

A total of 16,691 dogs and 4,211 cats with measured blood or serum sodium concentration.

Methods

Retrospective study. Medical records of animals with a blood or serum sodium concentration measured during a 60-month period were reviewed to determine the severity of hypernatremia and its associated case fatality rate. Cases with moderate (11-15 mmol/L above the reference range) or severe hypernatremia (≥16 mmol/L above the reference range) were further reviewed.

Results

A total of 957 dogs (5.7%) and 338 cats (8.0%) were diagnosed with hypernatremia. Case fatality rates of dogs and cats with hypernatremia was 20.6 and 28.1%, respectively compared to 4.4 and 4.5% with a normal blood or serum sodium concentration (P < .0001). The magnitude of hypernatremia was linearly associated with a higher case fatality rate (P < .0001). Hypernatremia was associated with a higher case fatality rate than hyponatremia. Among the animals with moderate or severe hypernatremia, 50% of dogs and 38.5% of cats presented with community-acquired hypernatremia, and 50% of dogs and 61.5% of cats developed hospital-acquired hypernatremia.

Conclusions and clinical importance

Hypernatremia was found infrequently in this population but was associated with increased case fatality rates in dogs and cats. Presence and severity of hypernatremia might be useful as a prognostic indicator.

Background

Renal replacement therapies can be life-saving for dogs with severe acute kidney injury (AKI), however, comorbidities including pancreatitis might affect outcome.

Hypothesis/objectives

To investigate the prevalence of pancreas-specific lipase (Spec cPL) measurements consistent with pancreatitis (≥400 μg/L) in dogs undergoing intermittent hemodialysis (IHD) for treatment of AKI and to determine whether there were associations between 30-days outcomes and Spec cPL measurements.

Animals

Fifty-three client-owned dogs presented to teaching hospitals between November 2008 and September 2016 that underwent IHD.

Methods

Retrospective medical record review from dogs that received IHD for management of AKI and also had a Spec cPL measurement. Association between survival, dialysis-dependency, and Spec cPL measurements was assessed.

Results

Forty of 53 (76%) dogs were alive at 30-days and 33/53(62%) had a Spec cPL result ≥400 μg/L. Spec cPL was not significantly different either between surviving (635.5 μg/L, range 29-1,001) and nonsurviving dogs (860 μg/L, range 56-1,001; P = 0.75) or between dialysis-dependent (1,001 μg/L, range 177-1,001) and nondialysis-dependent dogs (520 μg/L, range 29-1,001; P = 0.08). Spec cPL ≥400 μg/L was not significantly associated either with survival (P = 0.74) or dialysis-dependency (P = 0.33).

Conclusions and clinical importance

Results revealed a high prevalence of Spec cPL ≥400 μg/L in dogs with AKI treated with IHD. No significant associations between Spec cPL and survival or dialysis-dependency in dogs with AKI at 30 days were identified in the current study, however, the latter could be due to lack of power in this study.

Background

Pericardial effusion cytology is believed by many to be of limited value, yet few studies have evaluated its diagnostic utility.

Objectives

To determine the diagnostic utility of cytologic analysis of pericardial effusion in dogs and to determine if consideration of additional data could improve the diagnostic yield.

Animals

Two hundred and fifty-nine dogs with cytologic analysis of pericardial effusion performed between April 1990 and June 2012.

Methods

Electronic medical records from a university teaching hospital were retrospectively reviewed; signalment, complete blood count, serum biochemistry, cytologic analysis of pericardial effusion, and echocardiographic data were recorded. Cytology was classified as diagnostic (infectious or neoplastic) or nondiagnostic (hemorrhagic or other) and groups were compared with multiple Student's t-tests.

Results

Cytology was grouped as nondiagnostic (92.3%) or diagnostic (7.7%) and characterized as hemorrhagic (90%), neoplastic (4.6%), infectious (3.1%), or other (2.3%). Overall cytologic analysis of pericardial effusion diagnostic utility was 7.7% and increased to 20.3% if the effusion hematocrit (HCT) <10%; echocardiographic evidence of a mass did not result in a significant increase in the diagnostic utility.

Conclusions and clinical importance

The diagnostic utility of cytologic analysis of canine pericardial effusion is variable depending on the underlying etiology. In this group of dogs, the diagnostic yield of cytologic analysis was greater for pericardial effusion samples in which the HCT was less than 10%.