Variations in dark respiration and mitochondrial numbers within needles of Pinus radiata grown in ambient or elevated CO2 partial pressure

Within-leaf variations in cell size, mitochondrial numbers and dark respiration rates were compared in the most recently expanded tip, the mid-section and base of needles of Pinus radiata D. Don trees grown for 4 years in open-top chambers at ambient (36 Pa) or elevated (65 Pa) carbon dioxide partial pressure (p(CO2)a). Mitochondrial numbers and respiratory activity varied along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Regardless of the location of the cells (tip, middle or basal sections), needles collected from trees grown in elevated p(CO2)a had nearly twice the number of mitochondria per unit cytoplasm as those grown in ambient p(CO2)a. This stimulation of mitochondrial density by growth at elevated p(CO2)a was greater at the tip of the needle (2.7 times more mitochondria than in needles grown in ambient CO2) than at the base of the needle (1.7 times). The mean size of individual mitochondria was unaffected either by growth at elevated p(CO2)a or by position along the needle. Tree growth at elevated p(CO2)a had a variable effect on respiration per unit leaf area, significantly increasing respiration in the tip of the needles (+25%) and decreasing respiration at the mid-section and base of the needles (-14% and -25%, respectively). Although a simple relationship between respiration per unit leaf area and mitochondrial number per unit cytoplasm was found within each CO2 treatment, the variable effect of growth at elevated p(CO2)a on respiration along the length of the needles indicates that a more complex relationship must determine the association between structure and function in these needles.     

Meningomyelitis in dogs: a retrospective review of 28 cases (1999 to 2007)

Objectives : To characterise dogs with meningomyelitis and to compare signalment, body temperature and vaccination status to a representative control group. Methods : Dogs with meningomyelitis were identified retrospectively. Signalment, history, vaccination status, body temperature, severity of neurological dysfunction (modified Frankel score), diagnostic procedures, aetiology, survival to discharge and long‐term survival were analysed. Results : Affected dogs were younger (P<0·05) and more frequently hound or toy breeds (P<0·05) when compared with controls. Hound and toy breed dogs less than or equal to three years of age had a 13 times higher odds of meningomyelitis compared with other breeds (P<0·001). General proprioceptive ataxia, limb paresis and paraspinal hyperaesthesia were the most common clinical signs. Meningomyelitis of unknown aetiology and granulomatous meningomyelitis were the most common diagnoses. The median time to death or continued follow‐up in dogs alive at discharge was 213 days. Meningomyelitis resulted in death or euthanasia in 14 of 28 dogs. Clinical signs improved or resolved in seven of 28 dogs. Clinical Significance : Meningomyelitis is a differential diagnosis for dogs with clinical signs of myelopathy. Young dogs and toy or hound breeds seem to be predisposed. Clinical signs of meningomyelitis improve or resolve in some dogs.     

Pemphigus foliaceus of the footpads in three dogs

Severe hyperkeratinization and villous hypertrophy of the footpads were seen in 3 middle-aged dogs. Peeling, fissuring, swelling, and ulcerations were noted on the margins of severely affected pads. Pain was evident in palpation and ambulation. Lesions were compatible with the traditional diagnosis of "hard pad disease". Histopathologic findings were diagnostic for canine pemphigus foliaceus in all 3 dogs, and direct immunofluorescence in an intercellular pattern was seen in both dogs that were tested. All 3 dogs responded to immunosuppressive dosages of corticosteroids.     

Topical 0.1% tacrolimus for the treatment of discoid lupus erythematosus and pemphigus erythematosus in dogs

Topical 0.1% tacrolimus was used for treatment of localized lesions associated with 10 cases of discoid lupus erythematosus (DLE) and two cases of pemphigus erythematosus (PE) either as a sole therapy (n=2) or as an adjunctive treatment (n=10). Eight of 10 dogs with DLE and both dogs with PE were improved following 8 weeks of topical application. In six of the eight dogs that improved, other medications were discontinued. No adverse effects in clinical or laboratory parameters were noted throughout the study.     

Investigation into intraoral approach for nerve block injection at the mental foramen in the horse

Invasive dental procedures performed in the standing, sedated horse are facilitated by local and regional anaesthesia. The traditional transcutaneous approach to the mental foramen is used to desensitise the incisive region including the mandibular incisors, but is not well tolerated by many sedated patients. In this study, a new, intraoral needle insertion technique for nerve block at the mental foramen was investigated. In 15 equine cadaver heads and two live horses, computed tomography (CT) was used to verify Tuohy needle placement into each mental foramen using an intraoral technique. Varying volumes of contrast medium (3, 6, 10 mL) were injected into the mandibular canal with and without digital occlusion of the mental foramen. The distance of retrograde flow was measured. Additionally, measurements were taken to determine the position of the mental foramen within the interdental space. Correct placement of Tuohy needles and injection of contrast medium into the mandibular canal using an intraoral approach at the mental foramen was achieved in all injections. Retrograde flow of contrast medium was accomplished with all volumes, regardless of occlusion. Although not statistically significant, the 10 mL group appeared to have a greater distance of flow. The needle insertion technique described here appears to be a potential alternative to traditional transcutaneous approaches to mental nerve block for procedures involving the incisive region. In addition, it was found that 79% of the mandibular canals injected with 10 mL of contrast medium had retrograde flow to the position of PM4, suggesting this method may be a useful alternative technique for nerve block for the more rostrally located cheek teeth. The location of the mental foramen was consistently found in the distal third of the interdental space (approximately 60–80% of the distance between the distal aspect of the lateral corner incisor and the mesial aspect of the second premolar).     

Canine plasma and erythrocyte response to a docosahexaenoic acid-enriched supplement: characterization and potential benefits

Results of this study confirm that dietary supplementation in dogs with a natural source of omega-3 fatty acids (salmon oil), with a docosahexaenoic acid:eicosapentaenoic acid (DHA:EPA) ratio of 1.5:1, increases plasma and red blood cell levels of these fatty acids. Supplementation with this DHA-enriched oil improves the long-chain polyunsaturated fatty acid omega-6:omega-3 (n-6:n-3) ratio, which may benefit dogs of all ages. Studies describing some of the neurologic, renal, cardiovascular, immune, and musculoskeletal effects of elevated blood levels of n-3 fatty acids, especially DHA, are reviewed. The importance of providing an enriched source of DHA, instead of its shorter precursors, is emphasized.     

Evaluation of 2 sources of Angus cattle under South Florida subtropical conditions

The objective of this study was to compare performance and aspects of adaptability attributes of cattle from a Florida Angus bloodline (local source from a mostly closed herd for over 50 yr) to cattle that are representative of modern Angus bloodlines (outside source) in US subtropical conditions. Embryos from both sources were transferred to Brahman-crossbred cows in South Florida, and calves (n=82) were born in 3 yr. Before weaning, summer tympanic temperatures were recorded hourly for 3 d in each year. Heifers were placed with fertile bulls until diagnosed pregnant. Traits relative to sexual maturation of bulls were recorded at 1- or 2-mo intervals until approximately 17 mo of age. Calves from outside sources had greater hip height at weaning than calves from the local source (P<0.001; 108.8 ± 0.62 and 104.7 ± 0.68 cm, respectively). Local-source calves (n=37) had greater (P=0.03) exit velocity (2.7 ± 0.3 m/s) than outside-source (n=45) calves (2.0 ± 0.29 m/s), which may be indicative of more nervous or temperamental disposition. However, no source differences were detected for other assessments of disposition (chute or pen score, P>0.8). Few source differences for minimum, maximum, or range of daily tympanic (inner ear) temperatures were detected. At 17 mo of age, outside-source heifers were heavier (P = 0.05) and had greater (P<0.001) hip height than Angus heifers from the local source. Heifers from the outside source were younger (P<0.001) at the time of their first conception (454 ± 17.5 d) than heifers from the local source (550 ± 16.9 d). Outside-source heifers also had greater (P<0.02) pregnancy and calving rates (0.7 ± 0.119 and 0.62 ± 0.125, respectively) from exposure to bulls within a year from weaning than the heifers from the local source (0.29 ± 0.089 and 0.19 ± 0.077, respectively). Bulls from the outside source were heavier (P=0.05) at 320 d of age than local-source bulls. From 14 through 17 mo of age, outside-source bulls had greater (P≤0.05) scrotal circumference and tended (P≤0.15) to be heavier than local-source bulls. There appeared to be no performance or adaptation advantages for the local-source Angus through 17 mo of age. The large source difference for age at first conception in heifers merits additional attention and comparison with cow lifetime production performance for the 2 sources.     

Effects of maternally-derived antibodies on serologic responses to vaccination in kittens

The optimal vaccination protocol to induce immunity in kittens with maternal antibodies is unknown. The objective of this study was to determine the effects of maternally-derived antibody (MDA) on serologic responses to vaccination in kittens. Vaccination with a modified live virus (MLV) product was more effective than an inactivated (IA) product at inducing protective antibody titers (PAT) against feline panleukopenia virus (FPV). IA vaccination against feline herpesvirus-1 (FHV) and feline calicivirus (FCV) was more effective in the presence of low MDA than high MDA. Among kittens with low MDA, MLV vaccination against FCV was more effective than IA vaccination. A total of 15%, 44% and 4% of kittens had insufficient titers against FPV, FHV and FCV, respectively, at 17 weeks of age. Serologic response to vaccination of kittens varies based on vaccination type and MDA level. In most situations, MLV vaccination should be utilized and protocols continued beyond 14 weeks of age to optimize response by all kittens.