Effects of hyperbaric oxygen on full-thickness meshed sheet skin grafts applied to fresh and granulating wounds in horses

OBJECTIVE: To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. ANIMALS: 6 horses. PROCEDURES: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the granulating wounds, and wounds grafted on day 0 were biopsied. On day 14, 1 wound was created on each of the 2 unwounded limbs, and the wounds that were grafted on day 7 were biopsied. All 4 ungrafted wounds (ie, 2 fresh wounds and 2 wounds with 1-week-old granulation beds) were grafted. The horses then received HBOT for 1 hour daily at 23 PSI for 7 days. On day 21, the grafts applied on day 14 were biopsied. RESULTS: Histologic examination of biopsy specimens revealed that grafts treated with HBOT developed less granulation tissue, edema, and neovascularization, but more inflammation. The superficial portion of the graft was also less viable than the superficial portion of those not treated with HBOT. CONCLUSIONS AND CLINICAL RELEVANCE: The use of HBOT after full-thickness skin grafting of uncompromised fresh and granulating wounds of horses is not indicated.     

Comparative evaluation of the liver in dogs with a splenic mass by using ultrasonography and contrast-enhanced computed tomography

Evaluation of dogs with splenic masses to better educate owners as to the extent of the disease is a goal of many research studies. We compared the use of ultrasonography (US) and contrast-enhanced computed tomography (CT) to evaluate the accuracy of detecting hepatic neoplasia in dogs with splenic masses, independently, in series, or in parallel. No significant difference was found between US and CT. If the presence or absence of ascites, as detected with US, was used as a pretest probability of disease in our population, the positive predictive value increased to 94% if the tests were run in series, and the negative predictive value increased to 95% if the tests were run in parallel. The study showed that CT combined with US could be a valuable tool in evaluation of dogs with splenic masses.     

Sciatic nerve block in dogs: description and evaluation of a modified ultrasound-guided parasacral approach

Objective

To develop a modified ultrasound-guided parasacral approach to the sciatic nerve and compare the effects of a volume of 0.2 mL kg^–1 of 0.5% levobupivacaine with an equivalent volume of 0.9% saline injected near the sciatic nerve.

Ameliorative Effects of Melatonin against Hydrogen Peroxide‐Induced Oxidative Stress on Boar Sperm Characteristics and Subsequent In Vitro Embryo Development

Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H₂O₂) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ). The sperm were treated with melatonin in the presence or absence of H₂O₂ for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H₂O₂ groups were lower than H₂O₂ only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.     

A survey of ovine parasite control practices in Tennessee.

A sample of 126 sheep producers in Tennessee was randomly selected from the members of a statewide organization of sheep producers. Data about the participants' farms, sheep, parasite control practices and sources of information regarding ovine parasite control were obtained by a telephone survey. The response rate was 99%. The typical respondent kept 20 lambs, 20 ewes and 2 rams on three pastures totalling 20 acres. In order of decreasing frequency, anthelmintics were given according to a regular schedule, to coincide with breeding management procedures, or to treat clinical signs of parasitism. Proportions of producers deworming the various classes of sheep zero, one, two, three, four or more than four times annually were as follows: lambs--3, 28, 40, 16, 9 and 8%, respectively; ewes--3, 8, 20, 16, 34 and 22%, respectively; rams--1, 9, 19, 15, 38 and 19%, respectively. The majority of respondents planned to deworm lambs (89%) and ewes (82%) the same number of times in the following year. Of the producers who dewormed sheep two or more times during 1989, 39-49% (ranges include different proportions for lambs, ewes and rams) used the same anthelmintic exclusively, and 51-61% used two or more drug classes. Of the owners using a single anthelmintic exclusively, most (39-66%) used ivermectin, followed by levamisole (19-33%) and benzimidazoles (13-24%). One hundred and three of 124 (83%) producers intended to use the same anthelmintics in the future. Sixty-four of 124 (52%) producers had discontinued using at least one ovine anthelmintic. The most common reasons for discontinuance were dissatisfaction with the clinical response after treatment and inconvenience of administration. Sheep-oriented publications, other sheep producers and veterinarians were considered the most important sources of information about deworming programs and choice of anthelmintics.     

Effects of intravenous lidocaine, ketamine, and the combination on the minimum alveolar concentration of sevoflurane in dogs

ObjectiveTo evaluate the effects of intravenous lidocaine (L) and ketamine (K) alone and their combination (LK) on the minimum alveolar concentration (MAC) of sevoflurane (SEVO) in dogs.Study designProspective randomized, Latin-square experimental study.AnimalsSix, healthy, adult Beagles, 2 males, 4 females, weighing 7.8 – 12.8 kg.MethodsAnesthesia was induced with SEVO in oxygen delivered by face mask. The tracheas were intubated and the lungs ventilated to maintain normocapnia. Baseline minimum alveolar concentration of SEVO (MAC_B) was determined in duplicate for each dog using an electrical stimulus and then the treatment was initiated. Each dog received each of the following treatments, intravenously as a loading dose (LD) followed by a constant rate infusion (CRI): lidocaine (LD 2 mg kg⁻¹, CRI 50 μg kg⁻¹minute⁻¹), lidocaine (LD 2 mg kg⁻¹, CRI 100 μgkg⁻¹ minute⁻¹), lidocaine (LD 2 mg kg⁻¹, CRI 200 μg kg⁻¹ minute⁻¹), ketamine (LD 3 mg kg⁻¹, CRI 50 μg kg⁻¹ minute⁻¹), ketamine (LD 3 mgkg⁻¹, CRI 100 μg kg⁻¹ minute⁻¹), or lidocaine (LD 2 mg kg⁻¹, CRI 100 μg kg⁻¹ minute⁻¹) + ketamine (LD 3 mg kg⁻¹, CRI 100 μg kg⁻¹ minute⁻¹) in combination. Post-treatment MAC (MAC_T) determination started 30 minutes after initiation of treatment.ResultsLeast squares mean ± SEM MAC_B of all groups was 1.9 ± 0.2%. Lidocaine infusions of 50, 100, and 200 μg kg⁻¹ minute⁻¹ significantly reduced MAC_B by 22.6%, 29.0%, and 39.6%, respectively. Ketamine infusions of 50 and 100 μg kg⁻¹ minute⁻¹ significantly reduced MAC_B by 40.0% and 44.7%, respectively. The combination of K and L significantly reduced MAC_B by 62.8%.Conclusions and clinical relevanceLidocaine and K, alone and in combination, decrease SEVO MAC in dogs. Their use, at the doses studied, provides a clinically important reduction in the concentration of SEVO during anesthesia in dogs.     

Prevalence and risk factors for medical events following exercise at Australian Greyhound race meetings

Aim

A prospective, observational study to determine the prevalence of post‐exercise conditions at Australian Greyhound race meetings and to assess association with race performance and other environmental, race‐ and dog‐related factors was undertaken.

Methods

A total of 4020 starters were observed (2813 Greyhounds, 1009 trainers, 536 races, 52 race meets, 48 race dates and 11 race tracks) following a race. The presence of diaphragmatic flutter (DF), ataxia, seizure, collapse or sudden death was recorded. Risk factors were screened by univariable logistic regression prior to multivariable backward stepwise model building.

Results

In this study, 962 starters (n = 768 dogs) had DF (23.9%), 16 starters were ataxic (0.4%) and there were no observed cases of collapse, seizure or sudden death. Race track location, increasing race distance, race grade based on increasing 1st place prize value, lower (earlier) race number at the meeting, age, a previous observation of DF at the last start, females, colour (white) and better finishing position were all associated with an increased risk of a Greyhound being observed with DF. However, when logistic regression assessing the random effect of dog was performed, the presence of previous DF was not significant. In this cohort, DF was common following strenuous exercise in Greyhounds and on its own does not appear to result in reduced performance or distress to the animal.

Conclusion

The incidence of ataxia was low and collapse, seizure and sudden death were not observed. However, even though uncommon, ataxia has welfare concerns for racing Greyhounds that warrants further investigation.     

Effects of early experience on food acceptance in a colony of adult research cats: A preliminary study

Acceptance of feline commercial canned and raw-type moist foods was evaluated in 18 adult cats with and without dietary pre-exposure to the same moist foods in the postweaning period. We hypothesized that cats pre-exposed to moist foods would readily accept canned or raw foods on re-exposure as adults, despite consuming a commercial expanded dry food for a period of 7-23 months. A total of 13 cats were fed 1 of 3 moist foods (commercial canned, commercial raw, or homemade raw foods) exclusively between 9 and 20 weeks of age (exposed), and 5 adult cats were offered only dry food during the postweaning period (unexposed). All 18 cats were offered 1 of 3 moist foods as adults. The relative risk, confidence intervals, and P values were determined for weight maintenance and food intake between the exposed and nonexposed cats when they were fed moist foods as adults. Moist food acceptance was generally poor when offered to adult cats accustomed to eating an expanded dry diet for >7 months. There was no difference (P = 0.61) in weight maintenance between those cats fed a moist food or expanded dry food as kittens and the later acceptance of a commercial canned or raw-type moist food as an adult. Similarly, adequacy of food intake measured as a proportion of estimated resting energy expenditure was not different between groups. The shorter the duration of dry food feeding, the greater was the likelihood of weight maintenance on reintroduction of moist foods. Kittens fed canned foods showed greater adaptability and acceptance of both raw and canned foods than those pre-exposed to either of the raw foods.In conclusion, prefeeding kittens a raw or canned food during the postweaning period between 9 and 20 weeks of age, followed by a period of dry foods for >7 months, did not increase later acceptance of the foods as an adult as compared with feeding expanded dry foods alone. Further studies with larger numbers of cats are needed to verify these observations and determine statistical significance.