Immunohistochemical Detection of CD4-, CD8- and MHC II-Expressing Immune Cells and Endoglin in the Canine Corpus Luteum at Different Stages of Dioestrus

Specific immunohistochemical methods were applied to detect the presence of CD4-, CD8- and major histocompatibility complex II (MHC II)-expressing immune cells and of endoglin in the canine corpus luteum between days 15 and 75, after ovulation. Corpora lutea were obtained from groups of three clinically healthy beagle bitches, ovariohysterectomized at the respective days. For all four parameters, the effect of time was highly significant. Quantitative evaluation yielded high values on day 15, followed by a decrease on day 30 (CD4, CD8 and endoglin) and day 45 (MHC II). While there were no further changes for cells staining positive for CD4 and endoglin, CD8-positive immune cells increased from day 45 to day 60 to drop again on day 75; MHC II-positive staining increased from day 45 to days 60-75. These data suggest an involvement of the immune system in control of luteal function also in the dog that may have both stimulatory and inhibiting effects.     

Pharmacokinetics of carfentanil and naltrexone in domestic goats (Capra hircus).

Using a crossover study design, the pharmacokinetics of carfentanil and naltrexone after i.v., i.m., and s.c. administration were determined in eight domestic goats (Capra hircus). Serial blood samples were taken up to 120 hr after carfentanil administration, and the plasma drug concentrations were determined using liquid chromatography and mass spectroscopy. All goats were immobilized with 40 microg/kg carfentanil i.m., although the resulting neurologic effects varied considerably. Plasma profiles showed rapid carfentanil absorption and a simple biphasic decline for 12-48 hr. Naltrexone given at 100 mg naltrexone/mg carfentanil 30 min after carfentanil administration produced rapid reversal of immobilization after all routes of administration. Variable fluctuations in the naltrexone plasma concentrations during the first 2.5-3.5 hr were observed, followed by a more consistent biphasic decline. The time to standing was significantly shorter after i.v. compared with s.c. naltrexone, although the time difference (1 min) had little clinical relevance. No statistically significant differences between the naltrexone pharmacokinetic parameters measured for the three routes of naltrexone administration were identified, although the recoveries after i.m. administration were, subjectively, the smoothest. The carfentanil half-life did not differ significantly in the goats given naltrexone by different routes. Although it is currently recommended that the naltrexone dose be divided into s.c. and i.v. portions, this practice does not appear to offer any benefit.     

Pulmonary metastatectomy in the management of four dogs with hypertrophic osteopathy

The efficacy and outcome of pulmonary metastatectomy in the management of hypertrophic osteopathy (HO) secondary to metastatic osteosarcoma was retrospectively evaluated in four dogs. Metastatectomy was performed by subpleural enucleation, partial lung lobectomy or complete lung lobectomy through either a median sternotomy or thoracoscopically. Perioperative morbidity was minimal. Clinical signs associated with HO resolved within 24 h of pulmonary metastatectomy in all dogs. Durable remission of symptomatic HO was achieved in all dogs (range, 50–294 days), although recurrence of HO was noted in one dog, 246 days postmetastatectomy due to metastasis to the lungs and chest wall. Pulmonary metastatectomy resulted in a rapid and prolonged resolution of HO, and the clinical benefits of metastatectomy potentially exceed the morbidity associated with the surgical procedure.     

Noninvasive monitoring of doxorubicin cardiotoxicity: a pilot study of two dogs

The cardiotoxicity of anthracycline anticancer agents, most notably doxorubicin, limits their use in treating a wide variety of cancers. Currently available methods for assessment of anthracycline‐induced cardiotoxicity (AIC) often lack specificity and sensitivity. The purpose of this pilot investigation was to determine noninvasive diagnostic methods that are predictive for AIC. Two mongrel dogs were anesthetized for injection of doxorubicin (22.5 mg) directly into the left coronary artery. Doxorubicin injection was repeated 2 weeks later. Dogs were followed for 12 weeks or until heart failure was documented. Dogs were monitored before and at serial time points after doxorubicin using echocardiography and signal‐averaged electrocardiography as well as ambulatory ECG monitoring. Blood was also collected for measurement of cardiac troponin I and T concentrations. Doxorubicin was readministered at 6 and 12 weeks after the second injection, as interim data analysis did not reveal adequate evidence of cardiomyopathy. Dog‐1 appeared to be more sensitive than Dog‐2 to AIC based upon gradual changes in variables of cardiac function and earlier time to failure (113 days). In contrast, Dog‐2 had inconsistent changes in cardiac function and a longer time to failure (139 days). Dog‐1 also had greater peak plasma cardiac troponin I levels (17.96 ng/ml) as compared to peak levels in Dog‐2 (4.08 ng/ml). In addition, Dog‐1 had increased ventricular extrasystolic contractions (VE)(0/day at baseline, 443/day one week prior to death), whereas dog‐2 showed very few VE's throughout. Spectral analysis of ECG data also revealed a significant decrease over time in total spectral power in Dog‐1 from 37,148 at baseline to 603 msec²/Hz one week prior to death, indicating decreased parasympathetic tone. Endomyocardial biopsies revealed minor changes despite significant clinical abnormalities. These data indicate differences in susceptibility to AIC between Dog‐1 and Dog‐2, and suggest a role for these noninvasive measures in monitoring the heart during chemotherapy.     

Adherence of Actinobacillus pleuropneumoniae serotype 1 to swine buccal epithelial cells involves fibronectin

The swine pathogen Actinobacillus pleuropneumoniae serotype 1 was investigated for its ability to adhere to swine, rat, and human buccal epithelial cells (BEC). The highest number of bacteria adhered was to swine BEC. This binding ability was affected by heating, extreme pH, treatment with sodium dodecyl sulfate, ethylenediamine tetraacetate, or periodate, and proteolysis, suggesting that cell-surface glycoproteins participate in adherence and that adherence is based mostly on ionic interactions. Mannose and swine fibronectin may play a direct role in this interaction. Convalescent-phase serum from naturally infected pigs inhibited the adhesion. There was a correlation between bacterial pathogenicity as well as host specificity and the capacity for adherence to swine BEC. Adhesion to swine BEC provides a convenient method to study in vitro the adherence of A. pleuropneumoniae and other pathogens of the pig respiratory tract.     

Manipulation of Ovarian Function for the Reproductive Management of Dairy Cows

Veterinary Research Communications -     

Patch test reactions to house dust mites in dogs with atopic dermatitis

The purpose of this study was to determine the percentage of dogs with spontaneous atopic dermatitis that show a positive patch test reaction to a commercially available 20% house dust mites mixture containing equal parts of Dermatophagoides farinae and Dermatophagoides pteronyssinus in white petrolatum. In addition, we evaluated whether skin reactions induced after the epicutaneous application of house dust mites were clinically and histologically similar to naturally developed skin lesions of dogs with atopic dermatitis. Furthermore, we investigated if the reactions induced by house dust mites were true allergic reactions by comparing them to atopic lesional skin and to patch test reactions induced by an irritant substance (sodium lauryl sulphate). White petrolatum alone and nonlesional skin sites were used as negative controls. Macroscopic and microscopic evaluations of the patch test and control sites were performed in a blinded fashion at 48 and 72 h after patch test application. Microscopic results were evaluated in a qualitative and quantitative manner. A chi‐square test for homogenicity was used for the quantitative analysis to compare the proportion of each dermal inflammatory cell type among positive histopathological tested sites. P values ≤ 0.05 were considered significant. The study included 12 healthy nonatopic dogs and 13 dogs with nonseasonal atopic dermatitis. None of the nonatopic dogs reacted to house dust mites and white petrolatum. Ten (77%) of the 13 atopic dogs reacted macroscopically and histopathologically to house dust mites. Macroscopic reactions induced by house dust mites were characterized by erythema, oedema and papules. The macroscopic reactions induced by house dust mites were identical to lesional skin in 20% of the dogs and identical to reactions induced by sodium lauryl sulphate in 40% of the dogs. Qualitative histopathological findings showed that the reactions induced by house dust mites were similar to atopic lesional skin in 80% of the dogs and were similar to sodium lauryl sulphate in 20% of the dogs. Quantitative analyses showed that the proportion of neutrophils in reactions induced by sodium lauryl sulphate was significantly higher (P < 0.05) compared to house dust mites reactions, which could be a differentiator factor between an allergic and an irritant reaction. These results showed that the epicutaneous application of house dust mites in dogs with atopic dermatitis induced histopathological lesions similar to spontaneous atopic lesions in dogs. Therefore, this study demonstrated that house dust mites penetrated the skin of dogs with atopic dermatitis and induced an inflammatory response that resembled a true allergic reaction. Funding: Small Companion Animal Grant, University of Minnesota.     

P‐81 A retrospective study of equine sarcoidosis

The purpose of this retrospective study was to evaluate six cases of equine sarcoidosis for initial presenting symptoms, response to therapy and actual outcome. Dermatologists and dermatopathologists from Europe, the United States, Australia and Canada were contacted to obtain these six cases, as this is a rare disease. Signalment, clinical signs, histological findings, clinical management and outcome were determined via a questionnaire and compared to former reports. There was no age or breed predilection, and four of six horses were geldings. Age of onset ranged from 3 months to 17 years. Onset of the disease was insidious or rapid. Interestingly, in five of six cases, scaling began on the trunk (girth and shoulder). Scaling, crusting and alopecia were seen in all six horses. In one horse, clinical signs of systemic disease were reported and included intermittent fever, prescapular lymphadenopathy, depression, poor body condition and nasal discharge. Treatment included phenylbutazone, deworming agents, antibiotics, short‐term low‐dose corticosteroids, and 1–1.5 mg/kg of prednisolone. One horse showed a partial response to trimethoprim and sulfonamide, and five of six went into clinical remission with corticosteroid treatment. Five of six horses were still alive 1 year after diagnosis; one horse was diagnosed <12 months ago. Two horses are in complete remission 4 and 8 years after diagnosis. In both horses, clinical signs recurred after cessation of therapy and went into remission again with reintroduction of treatment. Both of these horses have been in remission for several years without therapy. Funding: Self‐funded.