Selected parameters in urine as indicators of milk production in lactating sows: a pilot study

Although insufficient milk production in lactating sows may cause tremendous economic losses, reliable methods for estimating milk production in sows under field conditions are not available. This study aimed to investigate whether urine parameters could be used to predict milk production in sows. The milk production of 18 sows was determined during early and mid-lactation. Morning (a.m.) and afternoon (p.m.) urinary levels of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), lactose and creatinine were analysed. The absolute concentrations, the ratios relative to creatinine, and the fractional excretions of all elements in urine were not significantly associated with milk production. The p.m./a.m. ratios of K, Na and Ca concentrations in urine (K(R), Na(R), and Ca(R)) were significant predictors for milk production, but only during mid-lactation. The total variation in milk production (r(2) value) explained by K(R), Na(R), Ca(R) amounted to 72%, 55%, 42%, respectively. Analysis of minerals and especially K in the a.m. and p.m. urine of sows during mid-lactation provided an acceptable indication of milk production. Further research is necessary to investigate whether the present results can be used to estimate milk production in hypogalactic sows under field conditions.     

Retrobulbar teratoma causing exophthalmos in a cat

A 3-year female-neutered domestic shorthair cat presenting with exophthalmos and an ipsilateral subzygomatic soft tissue mass lesion is described. Magnetic resonance imaging of the mass was performed followed by complete surgical excision. The mass was determined to be a retrobulbar teratoma and complete resection was curative. Teratomas are rare germ-cell tumours that uncommonly form in extragonadal sites. A retrobulbar location has not been previously reported in the cat and should be considered a rare cause of exophthalmos in this species.     

Characterization of agonist-induced endothelium-dependent vasodilatory responses in the vascular bed of the equine digit

The role of endothelium-derived relaxing factors was studied in the regulation of vascular responses in the Krebs perfused equine isolated digit. Perfusion pressure was recorded in response to bolus doses of 5-hydroxytryptamine (6 nmol) alone or co-administered with carbachol (CCh; 0.2 micromol), bradykinin (BK; 0.2 nmol), substance P (SP; 0.2 nmol) or sodium nitroprusside (SNP; 0.2 micromol). N(omega)-Nitro-L-Arginine methyl ester hydrochloride (L-NAME; 300 microm) caused partial but significant inhibition of CCh-induced vasodilatory response, whereas BK and SP-induced responses were resistant to L-NAME. High potassium (K(+), 30 mm) and the cytochrome P-450 (CYP) epoxygenase inhibitor, clotrimazole (10 microm) plus L-NAME (100 microm), completely abolished the CCh, BK and SP-induced vasodilatory responses, whereas the response to SNP was unaffected. In contrast, the L-NAME-resistant proportion of CCh, BK and SP-induced vasodilatory response was not inhibited by the highly selective CYP2C9 inhibitor, sulphaphenazole (10 microm). The cyclo-oxygenase inhibitor, ibuprofen (10 microm) did not affect the CCh, BK and SP-induced responses. These data demonstrate that CCh, BK and SP-induced relaxation in the equine digit involve a combination of the NO and endothelium-derived hyperpolarizing factor (EDHF) pathways. These results do not support the evidence for the involvement of CYP-derived epoxyeicosatrienoic acids and the exact nature of EDHF in the equine digit remains to be established.     

Bacterial infective arthritis of the coxofemoral joint in dogs with hip dysplasia

The objective of this study was to describe seven cases of unilateral bacterial infective coxarthritis from a total of 19 cases of bacterial infective arthritis (BIA), presenting over a two year period. We recorded the history, clinical signs, diagnostic process, treatment and clinical outcome in these cases. The data were obtained from medical records, review of the radiographs, and telephone follow-up with the owners. All of the dogs in this study had severe chronic osteoarthritis secondary to hip dysplasia, which caused periodic hind limb lameness. They were all admitted with severe acute hind-limb lameness. Pelvic radiographs were performed under general anaesthesia shortly after presentation, followed immediately by arthrocentesis of the affected joint. The synovial fluid was evaluated microscopically by direct smear and a sample was sent for culture and sensitivity. An attempt was not made to drain or lavage the affected joint during the course of treatment. The initial choice of antibiotics was empiric and subsequently modified, as required, based on the sensitivity results. Four of the dogs showed a rapid return to weight-bearing after the initiation of antibiotic treatment, and all of the patients returned to their pre-BIA level of function. Neither recurrent infections nor any adverse sequela requiring further intervention were reported by the owners on telephone follow-up.     

Effects of the opioid remifentanil on the arrhythmogenicity of epinephrine in halothane-anesthetized dogs

Opioids may exert a protective effect against ventricular arrhythmias via a vagally mediated mechanism. This study evaluated the effects of the opioid remifentanil on arrhythmogenicity of epinephrine during halothane anesthesia. Eight dogs were assigned to 2 treatments in a randomized crossover design, with 1-week intervals between treatments. Anesthesia was maintained with 1.3% end-tidal halothane in oxygen and mechanical ventilation to maintain eucapnia. A constant rate infusion of remifentanil (0.72 microg/kg/min) was administered throughout the study in the experimental treatment, while control animals received physiologic saline as placebo. The arrhythmogenic dose of epinephrine (ADE), defined as 4 premature ventricular complexes (PVCs) within 15 s, was determined by administering progressively increasing infusion rates of epinephrine (2.5, 5.0, and 10 microg/kg/min), allowing 20 min intervals between each infusion rate. In both treatments, epinephrine infusions induced bradyarrhythmias and atrioventricular conduction disturbances, which were followed by escape beats and PVCs. In the remifentanil treatment, mean +/- s ADE values (11.3 +/- 4.9 microg/kg) did not differ from values observed in control animals (9.9 +/- 6.1 microg/kg). On the basis of the ADE model for assessing the arrhythmogenity of drugs during halothane anesthesia, the present study did not demonstrate a protective effect of remifentanil (0.72 microg/kg/min) against ventricular arrhythmias in dogs.     

Artifacts in digital radiography

Digital radiography is becoming more prevalent in veterinary medicine, and with its increased use has come the recognition of a number of artifacts. Artifacts in digital radiography can decrease image quality and mask or mimic pathologic changes. They can be categorized according to the step during which they are created and include preexposure, exposure, postexposure, reading, and workstation artifacts. The recognition and understanding of artifacts in digital radiography facilitates their reduction and decreases misinterpretation. The purpose of this review is to name, describe the appearance, identify the cause, and provide methods of resolution of artifacts in digital radiography.     

A survey of beef cattle farmers in New Zealand, examining management practices of primiparous breeding heifers

AIM: To obtain an estimate of the incidence of assistance at calving in primiparous (first-calving) beef heifers and the prevalence of breeding heifers at 15 months of age in New Zealand in 2006, and to identify factors contributing to farmers' decisions regarding breeding strategies for heifers, using a survey of beef cattle farmers. METHODS: A questionnaire was sent to farmers listed in a Massey University database and to members of selected breed societies, as well as published in an industry newspaper; 331 valid responses were received. Information was gathered on the age and number of primiparous heifers, number of heifers assisted, and the importance of various reasons for and against breeding heifers at 15 months of age. Respondents were also required to outline the criteria used for selecting bulls to join with heifers, and the strategies used to manage dystocia in primiparous heifers. RESULTS: Sixty-five (95% CI=58-71)% of respondents had only 2-year-old primiparous heifers in 2006, whilst a further 11 (95% CI=8-16)% had both 2- and 3-year-old primiparous heifers. The mean reported incidence of assisted calving was 7.0 (95% CI=6.4-7.5)% for 2-year-old primiparous heifers and 1.7 (95% CI=1.2-2.2)% for 3-year-old primiparous heifers. The reported incidence of assistance at calving within individual herds ranged from 0 to 100% for 2-year-old heifers. Respondents with bull-breeding herds most commonly observed their primiparous 2-year-old heifers twice daily, whilst respondents with commercial herds most commonly observed them once daily during calving. The most important reason for breeding heifers at 15 months of age was increased profit, whereas the most important reason for not breeding them at that age was concern about rebreeding performance of 2-year-old heifers. Estimated breeding value (EBV) for birthweight was the factor considered most frequently when selecting bulls to join with maiden heifers; age of bull and body shape of bull were the next most frequently considered factors. Selection of an appropriate bull was the most common strategy used to manage dystocia in 2-year-old beef heifers. CONCLUSIONS: The majority of respondents calved their heifers at 2 years of age, and increased profit was the primary motivator. Concern about the rebreeding performance of 2-year-old heifers was the most important reason among the remainder of respondents for not breeding heifers at 15 months of age. Dystocia in 2-year-old heifers was not a problem or a minor problem in most herds, but there was much variation amongst herds.     

Canine lymphoproliferative disease characterized by lymphocytosis: immunophenotypic markers of prognosis

BACKGROUND: Canine lymphoproliferative disease often presents with lymphocytosis and is immunophenotypically diverse. HYPOTHESIS: Immunophenotype predicts prognosis in canine lymphoproliferative disorders involving circulating lymphocytosis. ANIMALS: Dogs that had peripheral blood evaluation performed by flow cytometry by the Clinical Immunology Service at Colorado State University between 2003 and 2005. METHODS: Outcome data regarding treatment and survival were sought on patients with lymphocytosis comprising a single lymphocyte subset. Ninety-six patients that met the inclusion criteria had sufficient follow-up information to be included in the study. RESULTS: Four main phenotypic classifications were found: CD8+ T-cell, CD21+ B-cell, CD4-8-5+ (aberrant T-cell phenotype), and CD34+ (undifferentiated progenitor). Expression of CD34 predicted poor outcome with median survival of 16 days (P < .0001) compared with other phenotypes. Within the CD8+ phenotype, dogs presenting with a lymphocytosis >30,000 lymphocytes/muL had significantly shorter median survival (131 days) than those presenting with <30,000 lymphocytes/muL (1098 days, P < .0008). Within the T-cell leukemias, there was no difference in outcome between dogs with CD4-8-5+ leukemia and dogs with the CD8+ T-cell phenotype nor was the loss of expression of the pan-leukocyte marker CD45 associated with decreased survival time. A CD21+ lymphocytosis composed of large cells was associated with shorter survival time (129 days) than those with smaller circulating cells (median survival not reached, P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Immunophenotyping provides an objective method for determining prognosis in lymphoproliferative disorders characterized by lymphocytosis.