Elisabetta Giudice

Daytime profile of the intraocular pressure and tear production in normal dog

OBJECTIVE To evaluate the circadian rhythms of intraocular pressure (IOP) and tear production in dog exposed to a natural photoperiod. ANIMALS STUDIED We used 12 clinically healthy Beagles dog housed under natural photoperiod at indoor temperature and humidity. PROCEDURE Intraocular pressure and Schirmer tear test (STT) I were measured every 4 h over a 48-h period in both eyes in each animal. Statistical analysis of the data was performed by one-way repeated-measures anova, Students t-test, and single cosinor method. RESULTS On each day, there was a highly significant effect of time on both parameters. A statistically significant difference of STT I values was observed comparing left and right eyes (P < 0.0001). Robust daily rhythms were observed for both parameters, IOP values showed diurnal acrophase (left eye: 09:33 +/- 00:50 h; right eye: 09:25 +/- 00:22 h), while STT I values showed nocturnal acrophase (left eye: 20:27 +/- 00:46 h; right eye: 20:00 +/- 00:05 h). CONCLUSION This study has demonstrated circadian rhythms in both IOP and STT I.

Daily rhythm of tear production in normal horse

OBJECTIVE This study was designed to assess the daily rhythm of tear production in clinically healthy horses, to compare left eye and right eye, and to evaluate the influence of time and gender. ANIMAL STUDIED For our study 18 horses (nine female and nine male) were subjected to three different light/dark (L/D) schedules: 12/12 L/D cycles, constant light (24/0 L/D) and constant darkness (0/24 L/D). PROCEDURES In all subjects Schirmer tear tests were performed at 4-h intervals over a 24-h period. RESULTS A circadian rhythm of tear production was found during the 12/12 L/D period and during constant darkness. Also our results showed a statistical significant difference comparing left eye and right eye, and between gender. CONCLUSIONS Our findings would suggest that the time of tear evaluation is significant in the diagnosis of tear film disorders, and that the difference between the two eyes and the two genders should be taken into consideration during the ophthalmic exam.

Circadian Intraocular Pressure Rhythms in Athletic Horses under Different Lighting Regime

The present study was undertaken to investigate the existence of intraocular pressure (IOP) rhythms in athletic thoroughbred horses maintained under a 24 h cycle of light and darkness (LD) or under constant light (LL) or constant dark (DD) conditions. We identified an IOP circadian rhythm that is entrained to the 24 h LD cycle. IOP was low during the dark phase and high during the light phase, with a peak at the end of the light phase (ZT10). The circadian rhythm of IOP persisted in DD (with a peak at CT9.5), demonstrating an endogenous component in IOP rhythm. As previously shown in other mammalian species, horse IOP circadian rhythmicity was abolished in LL. Because tonometry is performed in horses for the diagnosis of ophthalmologic diseases, such as glaucoma or anterior uveitis, the daily variation in IOP must be taken into account in clinical practice to properly time tests and to interpret clinical findings.

Influence of transportation on serum concentrations of acute phase proteins in horse

The modifications of Haptoglobin (Hp), Serum Amyloid A (SAA), Fibrinogen (Fbg) and White Blood Cells (WBCs) were evaluated in 15 Saddle Italian horses. Ten horses were transported covering a distance of about 320 km within 4 h with an average speed of 80 km/h (experimental group) and five horses were not subject to transportation (control group). Blood was collected via jugular venipuncture before the transportation (T0), immediately after the transportation (T1), 12 (T12), 24 (T24) and 48 (T48)hours after the transportation in experimental group and at the same time point in control group. For each parameter statistical analysis of different groups and sampling time was performed using a two-way analysis of covariance, with the data before the transportation (T0) as the covariate, by the GLM procedure of SAS. For all parameters the interaction (Group × Time) was tested and it was resulted no significant. The application of statistical analysis showed significant differences between the control group and horses subjected to transportation (P<0.01), and the influence of sampling time (P<0.05) on Hp, SAA and WBCs. These modifications appeared to be innovative showing that equine Hp, generally considered as moderate acute phase protein, increases more rapidly than the SAA after transportation-induced stress.

Subacute ruminal acidosis and evaluation of blood gas analysis in dairy cow.

Subacute Ruminal Acidosis (SARA) corresponds to an imbalance between lactate-producing bacteria and lactate-using bacteria, which results in a change in ruminal pH associated with a prevalent consumption of rapidly fermentable carbohydrates. In our study, 216 primiparus and multiparus dairy cows were selected from 20 Italian intensive dairy herds and were divided into three groups based on the risk of SARA. All the dairy cows had high average milk production. After blood sampling, a complete blood gas analysis was performed. One-way ANOVA was performed to compare the three groups. O(2) Cont, PCO(2), blood pH, O(2)Hb, urinary pH, and rumen pH were significantly lower in cows with rumen pH < 5.5. These results indicate that blood gas analysis is a valuable tool to diagnose acidosis in dairy cows because it provides good assessment of acidosis while being less invasive than rumen pH analysis.

Assessment of oxidative stress in dry and lactating cows

The increasing production level requested of livestock, with particular relevance to milk producers, requires scientific studies in order to address management towards breeding that supports, in a qualitative-quantitative manner, production performance and animal welfare. Modern breeding is a rationalized management essentially based on genetic selection, type of breeding, feeding and health of the animals. The high productivity of lactating cows and the physiological phenomenon that characterizes the lactation phase determine endocrine and metabolic modifications, with enhancement of anabolic and catabolic processes. Oxidation leads to an increase of electron flow in the respiratory chain that involves the formation of ‘refuse products’ defined as free radicals. A free radical is defined as any species capable of independent existence that contains one or more unpaired electrons (Auroma, 1994). It should be noted that the terms reactive oxygen species (ROS) and free radicals are often used interchangeably in the literature. ROS are capable of attacking all of the major classes of biomolecules, although lipids are particularly susceptible (McBride & Kraemer, 1999). Oxidative stress, a particular kind of chemical stress, is caused by an imbalance between the production of free radicals and the capability of an organism to absorb their excess. Oxidative stress is extremely dangerous because it does not exhibit any symptoms and is recognizable with great difficulty by means of common methods of analysis. Physiologically, free radicals supply the immune system in defence against bacteria; in case of excess in production that cannot be counteracted by cytoprotective mechanisms, there is an ‘oxidative stress’ that promotes the insurgence of serious pathologies as a result of the degenerative damage of cellular structures (Freidovich, 1999; Matsuo & Kaneko, 2000; McCord, 2000). It seems obvious that free radicals constitute an important factor of risk for health and it is therefore imperative to maintain their levels at basal values. Measure of oxidative stress allows estimation of the real ‘status’ of physiological defence and prevention of the appearance of correlated pathologies. Recently, some preliminary investigations have addressed oxidative status in dairy cows during the ovarian cycle (Trout et al., 1998) and in the periparturition period (Kimura et al., 1999; Stefanon et al., 2005). Given the remarkable zooeconomic impact of metabolic stress, it is interesting to establish in an objective manner the effects of the different lactating phases on the efficiency of the antioxidant mechanisms. The aim of our study was to bring new knowledge to the physiology of lactation, in order to optimize productive performance with respect to animal welfare; it is thus important to consider oxidative stress as a potential index of animal welfare to be able to detect, preventively, excessive animal exploitation, thus protecting health status.

Influence of age on profile of serum proteins in the calf.

The authors studied the course of serum proteins during the first week and the first month of life in the calf in order to obtain useful information for neonatal care. Eight Limousine calves, four males and four females, clinically healthy, were used. From all animals blood samples were collected from the external jugular vein from the day after the birth every day for one week and every five days for thirty days. Blood samples were taken at the same hour (09:00), and the serum concentrations of albumin, globulins (α1-globulins, α2-globulins, β- globulins, γ-globulins) and total proteins were determined by means of automated multiparametric agarose gel electrophoresis system. One-way repeated measures analysis of variance (ANOVA), followed by the Bonferronis test, was used to determine significant differences. Data analysis of variance showed a significant effect of days of life, with p < 0.05, only on albumin, α1-globulins and α2-globulins during the first month of life. These results confirm that despite the fact that newborns must adapt to various environmental factors after birth, including nutrition that can influence the serum protein profile during neonatal period, the evaluation of electrophoretics parameters during the first months of life results useful for the diagnosis and treatment of neonatal diseases.

A Molecular Survey of Rickettsia felis in Fleas from Cats and Dogs in Sicily (Southern Italy)

Rickettsia felis, the agent of flea-borne spotted fever, has a cosmopolitan distribution. Its pathogenic role in humans has been demonstrated through molecular and serologic tests in several cases. The cat flea (Ctenocephalides felis) is considered the main reservoir and the biological vector. The aim of this study was to assess the presence and occurrence of R. felis in fleas collected from dogs and cats in various sites of Palermo (Sicily). Between August and October 2012, 134 fleas were collected from 42 animals: 37 fleas from 13 dogs and 97 fleas from 29 cats. Two species of fleas were identified: 132 Ctenocephalides felis (98.51%) collected on all animals and only two C. canis (1.49%) on one dog. Out of 132 C. felis, 34 (25.76%), 12 from dogs (32.43%) and 22 (22.68%) from cats, were positive for R. felis DNA by a polymerase chain reaction (PCR), confirmed by sequencing. The only two C. canis fleas were negative. About half of examined animals (47.62%, 20/42) were infested with at least one infected flea; in particular 46.15% of dogs (6/13) and 48.28% of cats (14/29). It seems that in the Palermo district there is a peri-domestic cycle, with a relatively high prevalence of R. felis infection in the cat flea, an insect widely diffused in home environments and which can frequently bite humans. The results also suggest that R. felis should be considered in the human differential diagnosis of any spotted-like fever or febrile illness without a clear source of infection in Sicily, especially if the patient is known to have been exposed to flea bites.

Blood gas analyses, ruminal and blood pH, urine and faecal pH in dairy cows during subacute ruminal acidosis

The aim of this study was to investigate the variations of some physiological parameters in dairy cows during subacute ruminal acidosis (SARA), a common important disorder of dairy cows that occurs in early lactation. pH changes in ruminal fluid collected by rumenocentesis were measured at ten farms stationed in different zones in the north of Italy. Additionally, the following parameters were measured: blood pH, faecal pH, urine pH, partial pressure of carbon dioxide oxygen, partial pressure of oxygen, bicarbonate level, base excess of extracellular fluid and oxygen content. Herds were divided into two groups according to their average ruminal pH: group A included farms with average ruminal pH > 5.8 (normal) and group B farms with average ruminal pH < 5.8 (acidosis). Unpaired Student’s t test was used to reveal statistical significances between the two groups. Ruminal pH changes due to pathogenesis can be diagnostic for SARA.

Clotting Profiles in Newborn Maltese Kids during the First Week of Life

The neonatal period is probably the only time when a higher incidence of spontaneous thromboembolic complications may occur in the otherwise normal, healthy individual. This study was designed to determine the postnatal development of the kid coagulation system. Ten clinically healthy and full-term-born Maltese kid goats (5 males and 5 females) were used. In each kid, during the first week after birth, the prothrombin time (FT), the activated partial thromboplastin time (aPTT), the thrombin time (TT), and fibrinogen were assessed. Analysis of variance showed a highly significant effect of age on PT, TT, and fibrinogen. Our results of this study indicate that the clotting mechanism in kids is influenced by growth. This investigation contributes to the knowledge of clotting adaptations in kids during the first 7 days of life and provides useful information for the diagnosis and treatment of some neonatal diseases.