F. Zeugswetter

Simultaneous Canine Distemper Virus, Canine Adenovirus Type 2, and Mycoplasma Cynos Infection in a Dog with Pneumonia

The present case is the first description of a triple infection with canine distemper virus (CDV), canine adenovirus (CAV) type 2, and Mycoplasma cynos in a dog. The 5-month-old female Miniature Pinscher was euthanized because of dyspnea, croaking lung sounds, weight loss, and lymphopenia. Pathologic examination revealed a fibrinous necrotizing pneumonia with large amphophilic intranuclear and acidophilic intracytoplasmatic inclusion bodies in different lung cells. Immunohistochemically, CDV antigen was present in lung and many other organs. In situ hybridization for detection of CAV nucleic acid showed positive signals in the lung only. Polymerase chain reaction of lung tissue and consecutive sequencing of the amplification product identified CAV type 2. Bacteriologic examination of lung tissue yielded large amounts of M cynos. This infection was confirmed by immunohistochemistry detecting abundant positive signals in the lung tissue.

Lethal bronchopneumonia caused by Mycoplasma cynos in a litter of golden retriever puppies

MYCOPLASMAS are the smallest and simplest free-living organisms known; they are widespread in the animal kingdom (Waites and others 2005). It is generally accepted that the upper respiratory tract of dogs is frequently colonised by mycoplasmas, where they seem to form a part of the normal bacterial flora (Rosendal 1982, Randolph and others 1993). There are conflicting reports about infections of the lower respiratory tract (Rosendal 1972, Randolph and others 1993). Mycoplasmas have been isolated alone or in combination with other bacteria from the lungs of dogs with pulmonary disease (Kirchner and others 1990, Randolph and others 1993, Jameson and others 1995, Chandler and Lappin 2002, Chalker and others 2004). Little is known about specific infections caused by canine Mycoplasma species. Rosendal (1978) isolated various mycoplasmas, but only Mycoplasma cynos was able to induce an inflammatory response after endobronchial inoculation of one-week-old puppies. This short communication describes a case of M cynos pneumonia in a litter of golden retriever puppies. The litter originally comprised 11 puppies, of which four with a low birthweight (approximately 280 g compared with 400 to 450 g for the other puppies) had faded and died within the first two weeks of life. The breeder had noticed milk running out of the nostrils of two puppies after feeding, but cleft palates were excluded as the cause. Postmortem examinations were not performed. The litter, the seven-year-old dam (whose average litter size over the previous six years was 11 puppies) and the eight other dogs (one golden retriever, three dachshunds and four pugs) belonging to the breeder were examined by the breeder’s private veterinarian, but did not show any signs of disease. No infertility, abortions, stillbirths, illnesses or deaths had been observed within the past two years. The kennels were clean, and no obvious problems in breeding management were observed. At three weeks of age, the remaining seven puppies developed upper respiratory signs with rhinorrhoea, followed by fever (up to 41°C) and a productive cough within a few days. The dogs tested negative for canine adenovirus (CAV) types 1 (CAV-1) and 2 (CAV-2) by PCR on swabs from the nose and mouth and serum, and canine distemper virus (CDV) by PCR on conjunctival swabs and whole blood. Three puppies died despite treatment including amoxicillin (Roxilin; Norbrook Laboratories). A macroscopic postmortem examination of one of these puppies revealed pale organs and tissues, suggesting severe anaemia, a histologically confirmed low-grade serofibrinous pleurisy, and profoundly consolidated and blotchy lungs without significant adhesions. Furthermore, a heavy ascarid infection of the stomach and small intestine, without obstruction, was demonstrated. No pathological alterations were observed in the remaining organs. Histopathology of the lungs showed a severe acute generalised catarrhal-suppurative, partly haemorrhagic fibrinous necrotising bronchopneumonia. Immunohistochemical (IHC) examination of formalin-fixed, paraffin-embedded lung tissue using a polyclonal antibody to M cynos revealed Veterinary Record (2007) 161, 626-628

Efficacy of plasma ß-hydroxybutyrate concentration as a marker for diabetes mellitus in acutely sick cats☆

Urine ketone measurement is routinely performed in cats with diabetes mellitus to identify impending or established ketoacidosis. Studies using the urinary ketone dipstick test have shown that ketonuria is common in cats with newly diagnosed untreated diabetes mellitus. This test has a low sensitivity as it quantifies the less abundant ketone acetoacetate. The objective of the present study was to determine if ketonaemia is an inherent biochemical finding in untreated feline diabetes mellitus by measuring plasma ß-hydroxybutyrate (ß-OHB) in acutely sick cats. In 122 sick cats (37 diabetic and 85 non-diabetic cats) plasma ß-OHB, glucose, fructosamine, total protein and thyroxine were measured as part of the routine work up. Diabetic cats had significantly elevated ß-OHB values and ß-OHB measurement was a sensitive and specific test to identify diabetes mellitus. The area under the receiver operating characteristic (ROC) curve was 0.93. The cut off value with the highest positive likelihood ratio was 0.58 mmol/l. These results suggest that determination of plasma ß-OHB concentration is a useful method to distinguish between diabetic and non-diabetic sick cats.

Sudden death in a dog with lymphoplasmacytic hypophysitis.

A 10-year-old dog with a history of progressive anorexia and weight loss died suddenly despite treatment. Histopathological examination revealed severe follicular lymphoplasmacytic adenohypophysitis and atrophy of the zona fasciculata and zona reticularis of the adrenal cortex. It is likely that lack of production of adrenocorticotropic hormone and cortisol was the cause of death of this dog.

Configuration of antibodies for assay of urinary cortisol in dogs influences analytic specificity

Whether the variation in the reported urinary corticoid-to-creatinine ratio in dogs is affected by the application of 2 commonly applied anticortisol antibodies was investigated. Free-catch morning urine samples of 50 healthy dogs were analyzed in duplicate with the use of 2 different polyclonal antibodies (antibody A and B) raised in different rabbits. Antibody A was raised against cortisol-3-carboxymethyl-oxime and antibody B against cortisol-21-hemisuccinate linked to BSA. Enzyme immunoassays were applied by using corresponding biotinylated labels. To examine possible cross-reactions with conjugated and nonconjugated cortisol metabolites, EIA measurements were performed with urine samples both before (directly assayed) and after diethyl-ether extraction, as well as after reversed-phase HPLC. Although the results correlated (P < 0.001), urinary corticoid concentrations and accordingly the urinary corticoid-to-creatinine ratios were 8 times higher when using antibody A than when using antibody B (mean ± SD corticoid concentrations, 223 ± 131 vs 29 ± 12 nmol/L; P < 0.001). Irrespective of the antibody used, extraction significantly decreased measured corticoid concentrations (antibody A, 158 ± 120 nmol/L; antibody B, 15 ± 8 nmol/L; P < 0.001), but the decrease was conspicuous when antibody A was used. Antibody A cross-reacted significantly with polar (eg, conjugated) metabolites, clearly depicted in the chromatogram by 3 additional peaks in earlier fractions well separated from cortisol. In contrast the assay that used antibody B was specific, showing only 1 major peak in the fractions eluting authentic cortisol. In summary, the study indicates that the configuration of the antibody considerably influences the analytic specificity of cortisol assays and underlines the pivotal importance of assay validation for each species and sample material.

Tailored reference limits for urine corticoid:creatinine ratio in dogs to answer distinct clinical questions

To establish reference intervals for the urinary corticoid:creatinine ratio (UCCR) determined by chemiluminometric immunoassay, UCCR was measured by this method in 50 healthy dogs. To assess the diagnostic performance of different cut-off levels, the UCCR of 66 dogs with hyperadrenocorticism and 87 dogs with diseases mimicking hyperadrenocorticism were used to construct a receiver operating characteristic (ROC) curve. The upper reference limit derived from morning samples in healthy dogs was 30.81 × 10−6. The area under the ROC curve was 0.94. The diagnostic cut-off with the highest negative likelihood ratio was 26.5 × 10−6 (sensitivity 1, specificity 0.54), whereas the cut-off with the highest positive likelihood ratio was 161.2 × 10−6 (specificity 0.988, sensitivity 0.515). The application of these two different diagnostic cut-offs eliminated the necessity to perform additional tests in 53 per cent of the patient population.

Alternative sampling site for blood glucose testing in cats: giving the ears a rest.

Background and study rationale Home monitoring is an important part of the long-term management of diabetic cats. Despite the extensive use of glucometers in this species, up until now only the pinna of the ear has been validated as a testing site. This cross-sectional study investigated the feasibility and validity of sampling from the metacarpal/metatarsal pads in hospitalised cats with various diseases. Investigations The large pads were compared with the ear as a sampling site in 75 cats. Lancing the pads was tolerated very well. If the initial drop of blood was too small, an adequate volume of blood was almost always achieved by squeezing the pads. No significant differences were observed in first-attempt success rate or glucose values between the two sites. Due to the inability to obtain an adequate volume of blood or struggling, no measurement was possible in four cats. Practical relevance While further work is necessary to assess the utility of this technique, especially in the home environment, the results indicate that the metacarpal pads, in particular, may offer a viable alternative testing site for the measurement of blood glucose concentrations, especially if ear sampling fails.

Metabolic and hormonal responses to subcutaneous glucagon in healthy beagles

Objective To compare the effects of subcutaneous (SC) and intravenous (IV) glucagon on glucose concentrations, and insulin and cortisol secretion. Design Prospective randomized 3-way crossover study. Setting University teaching hospital. Animals Five healthy beagles. Interventions Diabetes mellitus and adrenal insufficiency were excluded by repeated glucose and fructosamine measurements, urinalysis, abdominal ultrasonography, and ACTH stimulation tests. Blood samples were collected before and after the SC and IV injection of 1 milligram (1 mg = 1 mL) commercially available synthetic glucagon and analyzed for insulin-like immunoreactivity (insulin-imr), glucose, ACTH and cortisol concentrations. The results were compared with those obtained after the SC injection of 1 mL saline (placebo). Measurements were performed over a period of up to 3 hours. Measurements and Main Results SC glucagon significantly increased glucose and insulin-imr (P 0.05). Aside from somnolence, no adverse events were recorded. Conclusions SC glucagon has the potential to be used as a simple and safe test in diabetic animals, but is of little use in animals with suspected corticotrophic insufficiency. The hyperglycemic effects are significant, implying that the commercially available human emergency kit could be useful in the home treatment of canine hypoglycemic emergencies.OBJECTIVE To compare the effects of subcutaneous (SC) and intravenous (IV) glucagon on glucose concentrations, and insulin and cortisol secretion. DESIGN Prospective randomized 3-way crossover study. SETTING University teaching hospital. ANIMALS Five healthy beagles. INTERVENTIONS Diabetes mellitus and adrenal insufficiency were excluded by repeated glucose and fructosamine measurements, urinalysis, abdominal ultrasonography, and ACTH stimulation tests. Blood samples were collected before and after the SC and IV injection of 1 milligram (1 mg = 1 mL) commercially available synthetic glucagon and analyzed for insulin-like immunoreactivity (insulin-imr), glucose, ACTH and cortisol concentrations. The results were compared with those obtained after the SC injection of 1 mL saline (placebo). Measurements were performed over a period of up to 3 hours. MEASUREMENTS AND MAIN RESULTS SC glucagon significantly increased glucose and insulin-imr (P < 0.001 and 0.043, respectively). Peak glucose concentrations were observed after 20 minutes and were lower than after IV injection (mean ± SD: 6.5 ± 1.1 mmol/L versus 9.3 ± 0.8 mmol/L [117.1 ± 19.8 mg/dL versus 167.6 ± 14.4 mg/dL]; P = 0.001). The route of application had no significant effect on insulin-imr (peak concentration: median [range]: 83.3 [13.9-312.5] pmol/L versus 194.5 [118.1-284.7] pmol/L [12 [2-45] μU/mL versus 28 [17-41] μU/mL; P = 0.151). SC glucagon did not increase cortisol or ACTH concentrations at any time point of observation (P > 0.05). Aside from somnolence, no adverse events were recorded. CONCLUSIONS SC glucagon has the potential to be used as a simple and safe test in diabetic animals, but is of little use in animals with suspected corticotrophic insufficiency. The hyperglycemic effects are significant, implying that the commercially available human emergency kit could be useful in the home treatment of canine hypoglycemic emergencies.

Elevated fructosamine concentrations caused by IgA paraproteinemia in two dogs.

An 8-year-old male Austrian Pinscher and a 14-year-old male Golden Retriever were presented for evaluation due to unexplainable high fructosamine values despite euglycemia and epistaxis in combination with polydipsia/polyuria, respectively. Blood analysis revealed severe hyperglobulinemia, hypoalbuminemia and markedly elevated fructosamine concentrations in both dogs. Multiple myeloma with IgA-monoclonal gammopathy was diagnosed by serum and urine electrophoresis including immunodetection with an anti-dog IgA antibody and bone marrow aspirations. Diabetes mellitus was excluded by repeated plasma and urine glucose measurements. Fructosamine values were positively correlated with globulin, but negatively correlated with albumin concentrations. These cases suggest that, as in human patients, monoclonal IgA gammopathy should be considered as a possible differential diagnosis for dogs with high fructosamine concentrations.

Spuriously high thyroid hormone concentrations measured by chemiluminescent immunoassay attributable to anti-iodothyronine antibodies in a dog

A 2.5-year-old female English setter was presented with clinicopathological findings suggestive of hypothyroidism. Thyroid-stimulating hormone (TSH: 4.3 ng/ml, normal <0.5), but also free thyroxine (FT4: 77 pmol/l, normal 7.7–48), total thyroxine (67 nmol/l, normal 17–58) and total triiodothyronine (8.7 nmol/l, normal 0.3–3.2) measured with a chemiluminescent immunoassay (CLIA) were elevated. Further investigations revealed oval-shaped hypoechoic thyroid glands characteristic of thyroiditis and very high titres for thyroglobulin autoantibodies, T4 autoantibodies and T3 autoantibodies. As expected the FT4 concentration determined by equilibrium dialysis (ED) to exclude analyte-dependent interferences was low. With levothyroxine therapy clinical signs disappeared and the concentrations of TSH and FT4 (ED) were within the respective reference intervals again. This case demonstrates that anti-thyroid hormone antibodies can cause erroneous CLIA readings, and that their presence should be clarified if thyroid hormone results do not match the clinical presentation or are discordant with TSH results.