Cardiac arrhythmias and electrolyte disturbances in colic horses

Background

Despite increased focus on cardiac arrhythmias in horses, the nature and prevalence is still poorly described. Case reports suggest that arrhythmias occurring secondary to systemic disease are seen more commonly in the clinic than arrhythmias caused by cardiac disease. The aim of this study was to investigate the prevalence of arrhythmias in colic horses referred for hospital treatment. Associations between electrolyte disturbances and arrhythmias were also investigated.The study population consisted of eight control horses and 22 referred colic horses. A Holter electrocardiography (ECG) was recorded during the first 24 hours of admission. The ECG’s were analysed by a software program followed by manual visual inspection. Arrhythmias registered included second degree atrioventricular (AV) blocks, supraventricular premature complexes (SVPCs), and ventricular premature complexes (VPCs). Blood was collected at admission and again between 12 and 24 hours after ECG was applied, and analysed for concentrations of potassium, sodium, ionised calcium, chloride, glucose, and L-lactate.

Results

Heart rate was 37.4 ± 3.7 bpm in the control group, and 51.6 ± 11.8 bpm, in the colic group, which was significantly different (P < 0.0001). AV blocks and SVPCs were found in both groups, however only colic horses showed VPCs. No significant difference between the two groups was found for AV blocks, SVPCs, and VPCs (P = 0.08 - 0.76). The mean levels of potassium, sodium, ionized calcium, and chloride were significantly lower in the colic group compared to the control group at admission. Mean levels of glucose and L-lactate were significantly elevated in the colic group (P < 0.05).

Conclusions

This study describes prevalence of cardiac arrhythmias and electrolytes concentrations in colic horses compared to healthy controls. Although we only observed VPCs in the colic horses, no significant differences between colic horses and controls were found. Despite the colic horses having electrolyte changes at admission no correlation was found between the electrolyte disturbances and cardiac arrhythmias. Although no clear conclusions can be drawn from the present study, the results indicate that relatively mild colic per se is not pro-arrhythmogenic, whereas severe colic probably are more likely to result in ventricular arrhythmia.     

Supplemental norgestomet,progesterone, or melengestrol acetate increases pregnancy rates in suckled beef cows after timed inseminations

In Exp. 1, 187 lactating beef cows were treated with injections of GnRH 7 d before and 48 h after prostaglandin F2alpha (PGF2alpha; Cosynch) or with Cosynch plus a 7-d treatment with an intravaginal progesterone (P4)-releasing insert (CIDR-B; Cosynch + CIDR). In Exp. 2, 183 lactating beef cows were treated with the Cosynch protocol or with Cosynch plus a 7-d treatment with norgestomet (Cosynch + NORG). In Exp. 1 and 2, blood samples for later P4 analyses were collected on d -17, -7 (first GnRH injection), 0 (PGF2alpha injection), and at timed artificial insemination (TAI; 48 h after PGF2alpha). In Exp. 3, 609 lactating beef cows were treated with the Cosynch + CIDR protocol or were fed 0.5 mg of melengestrol acetate (MGA) per day for 14 d before initiating the Cosynch protocol 12 d after the 14th d of MGA feeding (MGA + Cosynch). Blood samples were collected as in Exp. 1 and 2, plus additional samples on d -33 and -19 before PGF2alpha. In Exp. 4, 360 lactating beef cows were treated with a Cosynch + CIDR protocol, with TAI occurring at either 48 or 60 h after PGF2alpha, while receiving either GnRH or saline to form four treatments. Blood samples were collected as in Exp. 1 and 2. In Exp. 1, addition of P4 reduced the ability of the first GnRH injection to induce ovulation in anestrous cows with low P4 before PGF2alpha but improved (P = 0.06) pregnancy rates (61 vs 66%). In Exp. 2, the addition of NORG mimicked P4 by likewise increasing (P < 0.01) pregnancy rates (31 vs 51%) beyond those after Cosynch. In Exp. 3, the Cosynch + CIDR protocol increased (P < 0.001) pregnancy rates from 46 to 55% compared to the MGA + Cosynch protocol. In Exp. 4, administration of GnRH at TAI improved (P < 0.05) pregnancy outcomes (50 vs 42%), whereas timing of TAI had limited effects. We conclude that a progestin treatment concurrent with the Cosynch protocol improved pregnancy outcomes in all experiments, but pretreatment of cows with MGA was not as effective as the CIDR insert or NORG implants in this Cosynch-TAI model. Most of the improvement in pregnancy rates was associated with the increase in pregnancy rates of anestrous cows, regardless of whether ovulation was successfully induced in response to GnRH 7 d before PGF2alpha. Injection of GnRH at TAI following the Cosynch + CIDR protocol increased pregnancy rates in cycling cows with high P4 before the PGF2alpha injection and in anestrous cows with low P4 before PGF2alpha injection.     

Fertility following CIDR based synchronization regimens in anoestrous Nili-Ravi buffaloes

The objective of this study was to compare oestrus expression and fertility rate in used and new controlled internal drug releasing (CIDR) device treated anoestrous buffaloes. Furthermore, to determine the timing of ovulation, and fertility rate in estradiol benzoate (EB) and GnRH-administered CIDR-treated anoestrous Nili-Ravi buffaloes. In experiment 1, buffaloes received either a used CIDR (UCIDR, n = 35) or a new CIDR (NCIDR, n = 36) for 7 day and PGF2α on day 6. Oestrous expression was similar (p > 0.05) between UCIDR (88.5%) and NCIDR (96.6%) buffaloes. The pregnancy rate did not differ (p > 0.05) because of treatment (37.1% in UCIDR vs 36.6% in NCIDR). In experiment 2, buffaloes (n = 55) received CIDR device for 7 days and PGF2α, on day 6 and randomly assigned into three treatment groups: (i) CIDR-EB (n = 17) received EB on day 8, (ii) CIDR-GnRH (n = 18) received GnRH on day 9 and (iii) control (n = 20) received no further treatment. Mean interval from CIDR removal to ovulation in CIDR-EB, CIDR-GnRH and CIDR group were 61.3 ± 0.8, 64.9 ± 1.8 and 65.1 ± 16.7 h, respectively. However, the buffaloes in the CIDR-EB and CIDR-GnRH group had lesser variability in the timing of ovulation compared to control. The pregnancy rate of both CIDR-EB group (58%) and CIDR-GnRH group (61%) were tended to be higher (p < 0.1) than control (30%). In conclusion, compared to NCIDR devices, previously UCIDR devices are equally effective to induce oestrus in anoestrous buffaloes resulting optimal pregnancy rate. Administration of EB and GnRH after CIDR removal results in tighter synchrony (less variability) and improved fertility in anoestrous buffaloes. CIDR based synchronization regimens have great potential in fertility improvement in anoestrous buffaloes.     

Study of programmed cell death in bovine herpesvirus 1 infected MDBK cells and the possible role of nitric oxide in this process

Bovine herpesvirus 1 (BHV-1) is the aetiological agent of many disease types and may predispose infected animals, possibly through immunosuppression, to secondary bacterial infections. Immunosuppression may directly be associated with the induction of programmed cell death (PCD) in some virus-infected cells. Nitric oxide (NO) has an important mediating role against fungal, bacterial, protozoal, viral pathogens and tumours. BHV-1 induced apoptosis between 0.5-3 h postinfection (PI) in MDBK cells; however, between 3 and 6 h PI the PCD response was found to be decreased. It was interesting to see that BHV-I inhibited staurosporin-induced PCD after 1 h. These results showed similarities with those obtained from herpes simplex type I infections in human epithelial cells. PCD response decreased 1 h following caspase-3 inhibitor applications, whereas NO response increased 3 h following infection in the presence of caspase-8 and -9 inhibitory peptides. In conclusion, BHV-1 inhibited the staurosporin-induced apoptotic response and also the NO response. We propose that this inhibition is caspase-3 dependent.     

Influence of S. babylonica extract on feed intake, growth performance and diet in vitro gas production profile in young lambs

An experiment was completed to determine the effect of Salix babylonica (SB) extract supplementation to the diet of growing lambs. Eighteen Katahdin × Pelibuey male lambs (14?±?2 kg live body weight) were divided randomly in individual cages into three groups and fed three diets varying in SB: a control group was fed on total mixed ration (TMR) without SB (SB0), an SB25 group was fed on TMR plus SB extract at 25 mL/lamb/day, and an SB50 group was fed on TMR plus SB extract at 50 mL/lamb/day on dry matter intake (DMI), average daily gain (ADG), feed efficiency, and in vitro gas production (GP) in lambs fed on TMR. In vitro GP of the TMR fed to lambs was recorded at 2, 4, 6, 8, 10, 12, 24, 48, and 72 h of incubation with 0, 0.6, 1.2, and 1.8 mL extract per gram of DM. Addition of SB extract at low and high doses improved the DMI of lambs by 59.9 and 33.2 %, respectively. Relative to the control, low and high extract doses achieved greater lamb ADG during the experimental period. The asymptotic GP increased (P?<?0.05) with increasing dose of SB extract without affecting the rate of GP or the initial delay before GP begins. Linear increases for in vitro GP with advancing time with different SB extract doses were observed. It is suggested that the use of S. babylonica extract with the rate of 25 mL/lamb/day is beneficial to young lamb’s performance growth and thus can be safely used as a feed additive in diets without any negative effects on animal health.     

Monitoring and treatment of Fascioloides magna in semi-farm red deer husbandry in Croatia

The presence of American liver fluke (Fascioloides magna) in Croatian wild ruminant species was detected for the first time in January 2000. At the same time, the problem of adequate parasitological monitoring and treatment appeared in the captive deer population. Quarantine and health screening protocols, as well as migration and transportation influence had to be evaluated in red deer husbandry. Non-invasive methods were introduced to estimate the prevalence of F. magna in the semi-farm rearing system. Coprological analysis has been performed on 264 faecal samples. The most effective antiparasitic treatment was implemented on herd and individual treatment. Treatment was extended to the free-ranging population of deer in the same region.     

Quantitative genetic aspects of coat color in horses

The aim of this study was to estimate genetic parameters for coat color in horses. Besides defining coat color classes (gray, chestnut, bay, and black), the phenotypes were also measured quantitatively according to standardized international procedures (Commission Internationale de l'Eclairage L*, a*, b*), where L* describes lightness, a* describes color saturation from red to green, and b* describes color saturation from yellow to blue. The total color saturation was derived from a* and b* and referred to as Chroma. A total of 294 horses from the breeds Lipizzan, Nonius, Arabian Pure Bred, Shagya Arabian, and Gidran were measured at neck, shoulder, and belly. Heritabilities (within and between breeds or color classes) and repeatabilities were estimated using REML from univariate animal models defined separately for gray and nongray horses. For gray horses, the estimated within-breed heritabilities for L* ranged from 0.45 to 0.49 and for a*, b*, and Chroma from 0.09 to 0.52, indicating moderate polygenic effect. For nongray horses, between-color class heritabilities were high (0.70 to 0.85) and within-color class heritabilities were negligible (except for L* measured on neck and belly, 0.21 and 0.34, respectively). Additionally, the importance of L* was described by the relation with the total melanin content of horse coat hair; for gray and nongray horses, a strong negative linear relationship was detected (P < 0.01). The spectrometric measures and the results of this study demonstrate a possible approach to the estimation of the polygenic component involved in coat color inheritance.     

Gastrointestinal and body growth in colostrum-deprived piglets in response to whey, casein or soy protein diets

Cow's milk stimulates growth in neonates and supplementation with specific milk proteins may benefit immuno-compromized neonates exhibiting poor growth. We investigated the effects of specific milk proteins (casein and whey) and plant protein (hydrolysed soy) on body and organ growth and bone mineralization in colostrum-deprived newborn pigs. Six days after birth, both casein and whey increased body and small intestinal weight relative to soy protein. Villus morphology and epithelial permeability were similar among groups. Casein significantly increased bone mineralization, while whey stimulated soft tissue growth (internal organs, muscle and fat). The differential effects of casein and whey proteins in the early postnatal period show that specific milk proteins rapidly affect whole body and gut development, even in a state of impaired growth induced by artificial feeding of colostrum-deprived pigs.     

Pregnancy‐Associated Glycoprotein and Progesterone Concentrations during Pregnancy Failure in Bedouin Goat from the Southwest of Algeria

Thirteen female Bedouin goats living in arid land of Algeria Sahara desert were used in this study. These goats were pregnant but they sustained an abortion because of unidentified causes. None of the goats showed any signs of general disease. Plasma concentrations of caprine pregnancy‐associated glycoproteins (cPAGs) and progesterone (P4) were determined during pregnancy using radioimmunoassay. The cPAGs concentration was undetectable (<0.8 ng/ml) throughout the first 2 weeks of gestation. From week 3 after mating, cPAGs concentration was detectable with significant individual variations (p < 0.05) reaching a maximum secretion (436.1 ng/ml). Throughout gestation, cPAGs concentration remained relatively constant but decreased few days before abortion, on an average of 9.2 ± 1.2 days (n = 11), except for two females where the concentrations decreased later (1–2 days before abortion). One or two peaks of cPAGs concentrations (in 4/13 and in 9/13 females, respectively) have been measured few weeks before abortion (77–124 days after mating), when a decline of cPAGs was detected. The P4 concentration increased after mating, and was high from the first week till the end of pregnancy. The P4 concentration (9.1 ± 0.9 ng/ml) decreased rapidly (<0.5 ng/ml) after 4 ± 0.7 days (n = 6) or 9.4 ± 1.6 days (n = 7) before abortion. A positive relationship (p < 0.01) was found between P4 and cPAGs concentrations during gestation. Results indicate that cPAGs and P4 measurements can be used for monitoring gestation and for abortion prediction.     

Pine branch of Araucaria angustifolia in horse bronchi: A series of four cases

Horses at pasture are susceptible to the aspiration of foreign bodies. In Curitiba, southern Brazil, four horses of different breeds and ages were examined with regards to a persistent cough that lasted for several months, fetid breath, and no fever. The animals were referred for bronchoscopic examination performed under sedation and tracheobronchial topical anaesthesia. Bronchoscopies in all four horses revealed a pine branch of the species Araucaria angustifolia, native to southern Brazil, in the lumen of a third to fifth generation bronchus. Complete removal of the branch was possible in one case using a polypectomy loop inserted through the biopsy channel of the bronchoscope. In two cases, partial removal was possible. In one case the branch was adhered to the swollen mucosa and could not be extracted; this animal is being kept at pasture with intermittent antibiotic treatment as necessary. In conclusion, foreign bodies consisting of pine branches in the tracheobronchial tree of horses may be more common than currently recognised, as Araucaria genus is present in other countries and should be suspected in horses with chronic coughing associated with fetid breath and a history of reoccurrence following symptomatic treatments.