Arterial blood pressure measurement in a population of healthy geriatric dogs

The purpose of this study was to evaluate healthy geriatric dogs for the presence of systemic hypertension. Thirty-three geriatric dogs (i.e., dogs exceeding the geriatric age range for their weight group) and 22 control dogs (i.e., dogs less than six years of age) were evaluated by measuring blood pressure with an oscillometric monitor. Five consecutive blood pressure measurements were taken in each dog, averaged, and compared. Diastolic and mean blood pressure measurements were significantly lower in the geriatric group as compared to the control group. Systolic blood pressure measurements were not significantly different between the two groups. Systemic hypertension does not appear to be a common clinical problem in the healthy geriatric dog.     

Amiodarone-induced keratopathy in healthy dogs

Amiodarone has a broad spectrum as an antiarrhythmic agent and is indicated for patients with atrial and ventricular arrhythmias. Amiodarone-induced corneal deposits are the most common reversible side effect (70-100%) in humans. Additional ocular effects in humans include deposits in the lens, retina and optic nerve. This study was conducted to determine ocular effects of chronic oral amiodarone in healthy dogs. Six chronically amiodarone-treated dogs and four controls were used for this study. Ophthalmic examination was performed using biomicroscopy and indirect ophthalmoscopy at the end of 4th, 7th and 11th weeks when dogs received amiodarone. Corneal microdeposits were observed at the end of the 7th week in one eye and at end of the 11th week in the other eye of one dog. Immediately following euthanasia, corneas and optic nerves were harvested for light and electron microscopic analysis. Light microscopic analysis showed corneal deposits in the basal epithelial cells of the cornea of the clinically affected dog. In addition, a significant increase in basal cell turnover as indicated by mitotic index was observed in the affected dog compared to both nondeposit amiodarone and control groups. All remaining animals were normal. One out of six dogs treated with amiodarone demonstrated corneal deposits (16%). This prevalence is low compared to humans. Explanations for this may include species variations particularly in volume of lacrimal secretion, or the need for longer administration. In addition, sunlight is believed to exacerbate the corneal deposits in humans and all dogs in this study were housed indoors.     

Frequency, body distribution, and population size of Malassezia species in healthy dogs and in dogs with localized cutaneous lesions.

Malassezia species are commensal organisms of human and animal skin that occasionally act as opportunistic pathogens. The lipid-dependent species are associated with human skin disorders, whereas the non-lipid-dependent species (Malassezia pachydermatis) is considered as an opportunistic secondary pathogen affecting the canine skin surface and ear canal. This study evaluated the relationship between Malassezia yeasts, their population size, and the occurrence of skin lesions from healthy and skin-diseased dogs. The efficiency of cytological examination and fungal culture for Malassezia detection was also evaluated. From March 2002 to July 2003, 33 healthy dogs and 54 dogs with pruritic localized skin diseases were examined; skin swabs (1218) were collected from 7 anatomical sites for culture and cytological examination. Malassezia prevalence according to anatomical site and the agreement between cytological results and fungal cultures were statistically analyzed. Differences in mean colony forming unit counts between positive healthy and diseased dogs were evaluated using the Bonferroni test for post hoc pair-wise comparisons. In healthy dogs, Malassezia yeasts were most frequently isolated in the perianal and perioral areas. The frequency of isolation and population size of Malassezia species were higher in dogs with localized dermatitis, especially in affected areas, indicating a role for Malassezia in the occurrence of skin lesions. Malassezia pachydermatis was the species most commonly cultured from the skin and external ear canal of healthy and diseased dogs; isolation of lipid-dependent yeasts from healthy dogs was less frequent. Using fungal culture as the gold standard, cytological examination showed good relative specificity (95%) but very low relative sensitivity (30%).     

Mineral metabolism in healthy geriatric dogs

To study mineral metabolism in geriatric dogs, parathyroid hormone, calcitriol, ionised calcium, phosphorus, blood urea nitrogen and creatinine were evaluated in 35 geriatric dogs (> 10 years) and in 20 young adult dogs (2–5 years). Parathyroid hormone levels were within the normal range in both groups, but values (mean ± SEM) were greater in the old dogs (34·8 ± 3·6 vs 21·2 ± 2·3 pg ml⁻¹, P=0·005). Calcitriol and ionised calcium were similar in the two groups, and the values for both parameters were within the normal reference range. Plasma phosphorus levels were in the normal range in both groups but tended to be greater in the older dogs (P=0·09). While blood urea nitrogen was similar in the two groups, creatinine levels (mean ± SEM) were higher in the young dogs (82·2 ± 3·5 vs 101 ·7 ± 4·4 μmol litre⁻¹). Even when the dogs were matched for weight, plasma creatinine concentration was still greater in the younger dogs. In conclusion, an increase in parathyroid hormone without changes in calcium, phosphorus and calcitriol has been identified in geriatric dogs.     

Salmonellosis in apparently healthy dogs.

When rectal swabs were examined from 672 dogs in Tehran, Iran, 52 (7-7 per cent) yielded Salmonellae of 20 different serotypes. The 672 dogs examined comprised 472 household pets, 181 kennel dogs and 19 strays. Tehy showed an incidence of 4-4 per cent, 15-5 per cent and 15-8 per cent respectively.     

Endostatin concentrations in healthy dogs and dogs with selected neoplasms

Endostatin prevents angiogenesis and tumor growth by inhibiting endothelial cell proliferation and migration. The purpose of this study was to determine serum endostatin concentrations in 53 healthy dogs and in 38 dogs with confirmed malignant neoplasms. Endostatin concentration was determined with a competitive enzymatic immunoassay (EIA) with rabbit polyclonal antibody generated against a recombinant canine endostatin protein. Both the presence of cancer and increasing age were associated with increased serum concentration of endostatin. Endostatin concentration in healthy dogs was 87.7 +/- 3.5 ng/mL. Upper and lower limits of the reference range for serum endostatin concentration in healthy dogs were 60 and 113 ng/mL. Dogs with lymphoma (LSA) and hemangiosarcoma (HSA) had endostatin concentrations of 107 +/- 9.3 ng/mL. In conclusion, this study demonstrates that endostatin can be quantified in dogs and that endostatin concentrations are high in dogs with HSA and LSA.     

Plasma L-carnitine concentration in healthy dogs and dogs with hepatopathy

BACKGROUND: L-Carnitine has an essential role in lipid metabolism. Disturbances of L-carnitine metabolism can influence the energy supply of the organism. L-Carnitine is synthesized exclusively in the liver. Hence, we hypothesized that liver disease can influence L-carnitine metabolism. OBJECTIVES: The goal of this study was to compare plasma L-carnitine concentrations in dogs with different liver diseases of differing severity with the plasma L-carnitine concentrations of healthy dogs. METHODS: Sixteen dogs with inflammatory liver disease and 12 dogs with liver neoplasia were included in the study. Liver disease was diagnosed by clinical chemistry, ultrasonography, and histology of liver biopsy specimens. L-Carnitine concentration was measured in plasma samples using mass spectrometry, and compared among groups using unpaired Student's t-tests. RESULTS: Compared with healthy controls (24.4 +/- 8.4 micromol/L), the plasma L-carnitine concentration in dogs with liver disease (44.2 +/- 23.7 micromol/L) was significantly higher (P<.0001). The difference in L-carnitine concentration between dogs with moderate (n=8; 33.6 +/- 13.7 micromol/L) and severe (n=8; 57.4 +/- 22.9 micromol/L) hepatitis was also significant (P=.02). No difference in plasma L-carnitine concentration was found between dogs with hepatitis and those with liver tumors. CONCLUSIONS: Liver disease in dogs was accompanied by elevated plasma L-carnitine concentration. The severity of hepatitis appears to influence L-carnitine concentration.     

D-dimer concentrations in healthy dogs and dogs with disseminated intravascular coagulation

OBJECTIVE: To determine sensitivity and specificity of assays of D-dimer concentrations in dogs with disseminated intravascular coagulation (DIC) and healthy dogs and to compare these results with those of serum and plasma fibrin-fibrinogen degradation product (FDP) assays. ANIMALS: 20 dogs with DIC and 30 healthy dogs. PROCEDURE: Semi-quantitative and quantitative D-dimer concentrations were determined by use of latex-agglutination and immunoturbidometry, respectively. Fibrin-fibrinogen degradation products were measured by use of latex-agglutination. A reference range for the immunoturbidometric D-dimer concentration assay was established; sensitivity and specificity of the assay were determined at 2 cutoff concentrations (0.30 microg/ml and 0.39 microg/ml). RESULTS: Reference range for the immunoturbidometric D-dimer concentration assay was 0.08 to 0.39 microg/ml; median concentrations were significantly higher in dogs with DIC than in healthy dogs. Latex-agglutination D-dimer and serum and plasma FDP assays had similar sensitivity (85 to 100%) and specificity (90 to 100%); the immunoturbidometric assay had lower specificity (77%) at the 0.30 microg/ml cutoff and lower sensitivity (65%) at the 0.39 microg/ml cutoff. Sensitivity or specificity of the latex-agglutination D-dimer assay was not significantly improved when interpreted in series or parallel with FDP assays. CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of D-dimer concentrations by latex-agglutination appears to be a sensitive and specific ancillary test for DIC in dogs. Specificity of D-dimer concentrations in dogs with systemic disease other than DIC has not been determined, therefore FDP and D-dimer assays should be performed concurrently as supportive tests for the diagnosis of DIC in dogs.     

Anticardiolipin antibodies in healthy and diseased dogs

The concentrations of anticardiolipin immunoglobulin G (IgG) were measured in 134 healthy dogs and 63 diseased dogs by an elisa. The mean (sd) concentration in the healthy dogs was 5.40 (2.60) IgG phospholipid (gpl) units, and concentrations greater than 11 gpl were considered as above the normal range. On this basis, 30 (47.6 per cent) of the diseased dogs were within the normal range, with a mean of 5.45 (3.07) gpl and the other 33 had levels above the normal range (P<0.001); 19 of them had a mean level of 22.2 (5.66) gpl, 10 had a mean level of 49.1 (11.2) gpl, and four had a mean level of 85.8 (9.64) gpl. Levels above the normal range were more frequent in females (59.4 per cent) than in males (45.1 per cent), but were higher in males (45.5 [34.71] v 42.91 [22.0] gpl). In addition, they were more frequent and higher in older dogs (66.7 per cent, 40.4 [24.0] gpl) than in younger dogs (33.3 per cent, 33.5 [21.4] gpl).     

Clinical pharmacology of clemastine in healthy dogs

The pharmacokinetic properties of clemastine were investigated in six healthy dogs and compared with the effect of the drug recorded as inhibition of wheal formation induced by intradermal injections of histamine. Clemastine clearance was high (median: 2.1 L h(-1) kg(-1)) and the volume of distribution large (13.4 L kg(-1)). The half-life after intravenous administration was 3.8 h and the plasma protein binding level in vitro was 98%. After oral administration, the bioavailability was only 3%. Given intravenously, clemastine (0.1 mg kg(-1)) inhibited wheal formation completely for 7 h, whereas the effect after oral administration (0.5 mg kg(-1)) was minor. The data show that most dosage regimens suggested in the literature for the oral administration of clemastine to dogs are likely to give too low a systemic exposure of the drug to allow effective therapy.     

Plasma ascorbic acid concentrations in healthy dogs

Using a highly sensitive and selective analytical method and careful stability control, plasma concentrations of ascorbic acid were determined in German Shepherd Dogs, Labrador Retrievers and Siberian Huskies, a total 99 animals. Mean concentration was 35.9 micromol l(-1)(range 18.2-50.7), and no significant variation was observed neither between breeds nor between females and males. These and previous reported data on plasma ascorbic acid levels in dogs are discussed in the light of methodological aspects.     

Dermatophytes in clinically healthy dogs and cats

The hair and skin of 300 clinically healthy animals, 268 dogs and 32 cats, were examined mycologically. The method described by Mariat and Tapia (1966) was used for the examination, along with square pieces of the fitted carpet Kovral. The dermatophytes were isolated in 12 samples, all from the material taken from dogs. Trichophyton mentagrophytes was isolated six times, Microsporum canis four times, Trichophyton gallinae once, Trichophyton rubrum once. The origin of the dermatophyte Trichophyton gallinae, found in a village dog, was not determined. In one case of occurrence of the dermatophyte Trichophyton mentagrophytes in a dog the dermatophyte was probably transmitted from man to the dog. Microsporum canis was not proved to be the most frequent dermatophyte in dogs or cats in this country.     

Transconjunctival oxygen index in healthy awake dogs

Transconjunctival oxygen tension (PcjO2) has been used clinically in human beings and experimentally in dogs to evaluate tissue perfusion and to estimate arterial O2 tension (PaO2); however, normal values in awake healthy dogs have not been reported. In this study, transconjunctival oxygen tension and arterial oxygen tension were measured once a week in 6 healthy conditioned dogs (15 to 28 kg) for 8 weeks. The conjunctival oxygen index (PcjO2 index = PcjO2/PaO2) was calculated. Mean PcjO2 index for all dogs was 0.47 +/- 0.08 (X +/- SD). The variability of repeated measurements on the same dog and between dogs was evaluated. A difference (P less than 0.05) in PcjO2 index among dogs was evident, and although there was not a difference in the same dog over time, there was a high coefficient of variability.     

Clostridium difficile in faeces from healthy dogs and dogs with diarrhea

Background

This study was conducted to evaluate the faecal occurrence and characterization of Clostridium difficile in clinically healthy dogs (N = 50) and in dogs with diarrhea (N = 20) in the Stockholm-Uppsala region of Sweden.

Findings

Clostridium difficile was isolated from 2/50 healthy dogs and from 2/20 diarrheic dogs. Isolates from healthy dogs were negative for toxin A and B and for the tcdA and tcdB genes. Both isolates from diarrheic dogs were positive for toxin B and for the tcdA and tcdB genes. The C. difficile isolates from healthy dogs had PCR ribotype 009 (SE-type 6) and 010 (SE-type 3) whereas both isolates from dogs with diarrhoea had the toxigenic ribotype 014 (SE-type 21). One of the isolates from healthy dogs was initially resistant to metronidazole.

Conclusions

This study revealed presence of toxigenic C. difficile in faecal samples of diarrheic dogs and low number of non- toxigenic isolates in healthy dogs from Uppsala-Stockholm region in Sweden. However, more comprehensive studies are warranted to investigate the role of C. difficile in gastrointestinal disease in dogs.     

Pharmacokinetics of hydromorphone hydrochloride in healthy dogs

ObjectiveTo assess the pharmacokinetics of hydromorphone administered intravenously (IV) or subcutaneously (SC) to dogs.Study designRandomized experimental trial.AnimalsSeven healthy male neutered Beagles aged 12.13 ± 1.2 months and weighing 11.72 ± 1.10 kg.MethodsThe study was a randomized Latin square block design. Dogs were randomly assigned to receive hydromorphone hydrochloride 0.1 mg kg⁻¹ or 0.5 mg kg⁻¹ IV (n = 4 dogs) or 0.1 mg kg⁻¹ (n = 6) or 0.5 mg kg⁻¹ (n = 5) SC on separate occasions with a minimum 14-day washout between experiments. Blood was sampled via a vascular access port at serial intervals after drug administration. Serum was analyzed by mass spectrometry. Pharmacokinetic parameters were determined with computer software.ResultsSerum concentrations of hydromorphone decreased quickly after both routes of administration of either dose. The serum half-life, clearance, and volume of distribution after IV hydromorphone at 0.1 mg kg⁻¹ were 0.57 hours (geometric mean), 106.28 mL minute⁻¹ kg⁻¹, and 5.35 L kg⁻¹, and at 0.5 mg kg⁻¹ were 1.00 hour, 60.30 mL minute⁻¹ kg⁻¹, and 5.23 L kg⁻¹, respectively. The serum half-life after SC hydromorphone at 0.1 mg kg⁻¹ and 0.5 mg kg⁻¹ was 0.66 hours and 1.11 hours, respectively.Conclusions and clinical relevanceHydromorphone has a short half-life, suggesting that frequent dosing intervals are needed. Based on pharmacokinetic parameters calculated in this study, 0.1 mg kg⁻¹ IV or SC q 2 hours or a constant rate infusion of hydromorphone at 0.03 mg kg⁻¹ hour⁻¹ are suggested for future studies to assess the analgesic effect of hydromorphone.