Influence of combined angiotensin-converting enzyme inhibitors and spironolactone on serum K, Mg, and Na concentrations in small dogs with degenerative mitral valve disease

ObjectiveTo determine if the administration of an angiotensin-converting enzyme inhibitor (ACEI) plus spironolactone caused hyperkalemia, hypermagnesemia, or hyponatremia in elderly small dogs with degenerative mitral valve disease (MVD).BackgroundACEIs and spironolactone can increase serum potassium and magnesium concentrations and lower serum sodium concentrations. It has been recommended to either not combine these drugs or to do so with caution.Animals, material and methodsFifty client-owned dogs with MVD, left atrial dilation, and without congestive heart failure or azotemia were evaluated retrospectively. Baseline data sets, followed by 1–9 (mean = 2.66) data sets, comprised of serum urea nitrogen (SUN), creatinine, sodium, potassium, and magnesium concentrations, were tabulated. Each dog received an ACEI plus spironolactone for a mean of 23.8 ± 26.6 weeks (range: 2–150) and a median of 15 weeks. No cardiac drugs other than an ACEI and spironolactone were administered during the study period.ResultsThere were no significant differences between baseline and follow-up serum sodium or potassium concentrations. Serum magnesium concentrations increased significantly (p = 0.02) with time >20 weeks compared to baseline.ConclusionsThe combination of an ACEI and spironolactone results in no significant difference between baseline and follow-up serum sodium or potassium concentrations. Although serum magnesium concentrations may increase significantly with time >20 weeks compared to baseline concentrations, hypermagnesemia appears to be rare, mild, and unlikely to be of clinical importance. The combination of an ACEI and spironolactone is safe in elderly small dogs with MVD with normal SUN and creatinine concentrations.     

The use of clinical findings in the identification of equine peritonitis cases that respond favorably to medical therapy

Objective: To compare clinical findings in horses/foals with peritonitis that: (1) had no concurrent (NCA) versus a concurrent abnormality found during hospitalization, (2) survived to discharge versus did not survive to discharge, and (3) survived to discharge without surgery versus did not survive to discharge without surgery. Design: Retrospective study. Setting: George D. Widener Hospital for Large Animals at New Bolton Center. Animals: Horses/foals admitted between 1992 and 2002 with a diagnosis of peritonitis. A diagnosis of peritonitis within 4 days of presentation and peritoneal fluid nucleated cell count >10,000/μL were required for study inclusion. Horses/foals were excluded if the peritonitis was secondary to gastrointestinal or reproductive tract perforation, a complication of exploratory celiotomy, or if peritonitis was not diagnosed until surgery or necropsy. Interventions: None. Measurements and main results: Information obtained from the medical records included clinical findings at presentation and during the initial 4 days of hospitalization. Outcome was defined as: (1) NCA (yes/no), (2) survived to discharge (yes/no), and (3) survived to discharge without surgery (yes/no). Forty‐two percent (23/55) of horses/foals had NCA; 78% (43/55) survived to discharge, and 68% (36/55) survived to discharge without surgery. Horses/foals with peritonitis that had any one of the following clinical findings were likely to survive to discharge without surgery: no signs of abdominal pain, normal/improved rectal temperature, normal/improved intestinal borborygmi, normal fecal production, no abnormal findings on abdominal palpation per rectum, no nasogastric reflux, or yellow/orange peritoneal fluid. Conclusion: Clinical findings can be used to identify equine peritonitis cases that will respond favorably to medical therapy.     

Oestrous Behaviour and Timing of Ovulation in Relation to Onset of Oestrus and LH Peak in Mithun (Bos frontalis) Cows

The objectives of the study were to evaluate the oestrus behaviour and to determine the timing of ovulation in relation to onset of oestrus and the pre-ovulatory LH surge in mithun (Bos frontalis). For this purpose, the blood samples collected at 15-min intervals for 9 h period following onset of oestrus and thereafter, at an interval of 2 h till 4 h post-ovulation for three consecutive cycles from 12 mithun cows were assayed for plasma LH and progesterone. Ovulation was confirmed by palpation of ovaries per rectum at hourly intervals. Various signs of behavioural oestrus were also recorded. The common signs of oestrus and their frequency of occurrence in mithuns were following and mounting by male mithuns (100%), standing to be mounted (100%), frequent urination (62.33%), raising of tail (65.23%), swelling of vulva (54.26%) and congestion of vulvar mucous membrane (69.87%). The pre-ovulatory LH surges consisted of several pulses (2.92 +/- 0.26 pulses/animal; range, 1-4). The mean (+/-SEM) peak level of LH for individual mithun varied from 6.99 +/- 0.44 to 12.69 +/- 2.10 ng/ml and the mean pooled LH peak concentration was 9.10 +/- 0.60 ng/ml. The highest peak (highest amplitude of LH during LH surge) was 10.83 +/- 0.76 ng/ml (range, 8.07-16.49 ng/ml). The duration of LH surge was 6.98 +/- 0.22 h (6-8 h). Onset of LH surge was at 1.23 +/- 0.17 h post-oestrus onset (range, 0.25-2.25 h). Mean plasma progesterone stayed low (<0.24 ng/ml) during the entire duration of sampling. Ovulation occurred at 26.92 +/- 0.31 (range, 26-29 h) after the onset of oestrus and 18.63 +/- 0.35 h (range, 17-20.75 h) after the end of LH surge. The occurrence of the highest LH peaks within a narrow time frame of 2- to 5-h post-oestrus onset in mithuns could have contributed to the animals ovulating within a narrow time interval. These results are very promising from a practical standpoint of potential success when AI program in this species is implemented in a big way. Furthermore, the results of the occurrence of LH pulses during pre-ovulatory LH surges, which are required for ovulation in this species of animals, is unique and species specific.     

An overview of potentially life-threatening poisonous plants in dogs and cats

Objectives: This article discusses the toxicity of the most common poisonous plants known to cause life‐threatening systemic effects or death in dogs and cats as reported to the ASPCA Animal Poison Control Center (APCC). Data sources: The article presents an overview of geographic distribution, toxic principle, clinical signs, clinical chemistry alterations, and treatment of intoxication as reported in the literature and based upon data retrieved from the APCC between January 2001 and December 2003. Summary: Most plant exposures in dogs or cats result in mild to moderate signs of vomiting and diarrhea while liver, kidney, central nervous system, or cardiovascular effects are rare. Some garden or household plants can cause serious systemic effects or death when a small amount of plant material has been ingested. Based on APCC records, the most frequently reported poisonous plants causing serious systemic effects include Lily (Lilium and Hemerocallis spp.), Azalea (Rhododendron spp.), Oleander (Nerium oleander), Sago palm (Cycas spp.), Castor bean (Ricinus communis), Kalanchoe (Kalanchoe spp.), and Autumn Crocus (Colchicum autumnale). Conclusion: Despite the variety of toxins present in the plants listed above, early clinical signs of toxicosis in dogs and cats can be nonspecific and can include vomiting, lethargy, anorexia, salivation, or diarrhea. Cardiac arrhythmias may be present with oleander, azalea, or kalanchoe ingestion. Evidence of liver or kidney damage (Cycas, Lilium, Hemerocallis spp., Ricinus communis) may occur 1–2 days after the exposure. Treatment consists of early decontamination and supportive care and may vary according to the type of plant involved and clinical signs present.     

Effects of feed form on growth and blood glucose in weanling horses

Eight weanling Standardbred horses were used to evaluate the effects on growth and plasma glucose of two differently processed diets with identical ingredients fed at a rate of 3% of body weight, as fed, daily. The daily ration was divided into two equal feedings at 7:00 am and 7:00 pm. The hay and grain diet (diet HG) consisted of 50% alfalfa hay cubes and 50% of a commercial growing horse texturized grain mix fed as is, without any further processing, with each part fed in separate containers. The completely pelleted diet (diet P) consisted of the same proportions of the hay cubes and grain mix that was ground, pelleted, and fed in a single container. Two groups of four horses were fed either diet P or diet HG for two 21-day periods such that each horse consumed each diet for 21 days. On the last day of each feeding period, 7-mL blood samples were drawn into heparinized evacuated blood tubes for determination of plasma glucose concentration. Blood samples were drawn 30 minutes before the afternoon feeding, immediately before, and every 30 minutes thereafter for 5 hours. Analysis of variance found greater (P = .027) average daily gain for horses fed diet P versus diet HG. A nonsignificant difference was seen in feed efficiency (P = .057) for horses fed diet P versus diet HG. Plasma glucose changes were compared across treatments using area under the curve analysis. No difference (P > .05) was found in the postprandial plasma glucose changes between diet treatments.     

Double-Outlet Right Ventricle for Relief of Pulmonic Stenosis in Dogs An Experimental Study

Relief of right ventricular outflow obstruction with a valveless Dacron conduit from the right ventricle to pulmonary artery was accomplished in 12 normal dogs. The procedure involved the development of a surgical technique without cardiopulmonary bypass, hypothermia, and/or venous occlusion; the development of a ventricular coring instrument; the fabrication of a wire supported Dacron conduit; the development of a basketed insert cannula; and the creation of an experimental model of pulmonic stenosis. Of the 12 dogs operated, two died intraoperatively, three died postoperatively, and seven were electively euthanized postoperatively. Relief of the right ventricular outflow obstruction was documented in all cases by a reduction in mean peak right ventricular pressure, improvement of mean arterial pressure, decrease in mean right atrial pressure, and an increase in mean pulmonary artery pressure. The pulmonary insufficiency created was considered a tolerable although not benign condition. The technique would be of particular value in dogs with severe right ventricular hypertrophy.     

Analgesic Effect of the Transdermal Fentanyl Patch During and After Feline Ovariohysterectomy

OBJECTIVE: To evaluate the efficacy of the transdermal fentanyl patch in relieving perioperative pain and stress associated with ovariohysterectomy in cats. STUDY DESIGN: Prospective laboratory trial. ANIMALS: Twenty-four female, purpose-bred cats. METHODS: Each cat was randomly assigned to groups 1-3. Group 1 received a 25-microg/h transdermal fentanyl patch only. Group 2 received the patch and anesthesia. Group 3 received anesthesia only. Patches were left in place for 72 hours. Rectal temperature, heart rate, respiratory rate, indirect blood pressure, blood glucose, serum cortisol concentration, plasma fentanyl concentration, pain score, and excitement/sedation score were monitored at prescribed intervals over an 81-hour period. Cats from groups 1-3 were reassigned to groups 4 and 5. Group 4 received the patch, anesthesia, and an ovariohysterectomy. Group 5 received anesthesia and an ovariohysterectomy only. The study period and monitored parameters were the same as for groups 1-3. RESULTS: Serum cortisol concentrations were significantly lower in group 4 than group 5 during the surgical and early postsurgical time periods. A similar effect was noted in blood glucose concentrations during the surgical period. Rectal temperature was significantly higher in group 2 when comparing all anesthetized groups during the early postsurgical period. Pain scores were significantly higher in groups 4 and 5 than in groups 2 and 3 during the early postsurgical period. There was no significant difference in pain scores between groups 4 and 5 during this period, however. CONCLUSIONS: The transdermal fentanyl patch affects biochemical markers of perioperative pain and stress associated with ovariohysterectomy in cats, attenuating rises in serum cortisol and blood glucose concentrations during the surgical and early postsurgical periods. CLINICAL RELEVANCE: The transdermal fentanyl patch is effective in alleviating perioperative pain and stress associated with ovariohysterectomy in cats as evidenced by attenuated rises in cortisol and blood glucose concentrations in cats that were operated on and treated with the patch.