Raw diets for dogs and cats: Potential health benefits and threats.

Raw meat-based diets for pet nutrition are becoming increasingly popular. The percentage of meat content, composition of nutrients, and amount of additives started to play an important role in the recipe of a given food. However, the use of healthier and unprocessed food must also be balanced with the animal's specific needs based on its anatomy, physiology, and behavior. There are many potential advantages and disadvantages of a biologically appropriate raw food (BARF) diet, and all of them should be considered before switching to this approach. Raw meat is considered a diet closest to nature and least processed. However, raw diets threaten pet health because of the potential for nutrient imbalances. The choice of raw meat in pets' everyday diet should be supported by the veterinarian's medical decision and preferably also with nutritionist help. Growing animals require a specific Ca:P ratio in their diet, which may be improper in raw meat. For cats, taurine levels must be carefully checked. In addition, an imbalanced raw-meat diet can be the cause of poor semen quality in males. Females are prone to inhibition of the estrus cycle, especially due to hyperthyroidism. Exogenous thyroid hormone intake is a real concern when feeding a neck/head meat with thyroid glands. There is also a possibility of bacterial or parasitic presence in raw meat. The present paper aims to summarize the current state of knowledge about the benefits and threats of eating a raw meat diet for the health concerns of companion animals.

Mitochondrial characteristics in oocytes of the domestic cat (Felis catus) after in vitro maturation and vitrification.

CONTENTS: The objective of this study was to evaluate mitochondria in immature and in vitro-matured domestic cat oocytes and to assess for the first time the effect of vitrification on mitochondrial traits. Mitochondrial distribution and aggregation were assessed using confocal microscopy after staining with the fluorescent dye-MitoTracker® Red CMXRos. Only cells at the germinal vesicle and the metaphase II stages of nuclear development, representing immature and mature oocytes, respectively, were included in our study. Our study shows that 80% of immature and 100% of mature oocytes exhibit a peripheral pattern of mitochondria distribution, indicating that, in contrast to the situation in other species, the mitochondria of cat oocytes are not dispersed throughout the cell after in vitro maturation but instead maintain a strong affinity for the oocyte periphery near the membrane. However, a loss of aggregation was observed during in vitro maturation-78% of immature oocytes showed homogeneous granulation versus only 18% of mature oocytes (p < .001). The increased intensity of MitoTracker® Red CMXRos staining after in vitro maturation (p < .05) may be tentatively attributed to an increase in mitochondrial activity but could likewise reflect a concomitant appearance of sulphhydryl groups in cytoplasm (known to be targeted by the dye). Mitochondrial distribution did not change upon vitrification; however, dye intensity decreased (p < .05) and mitochondrial aggregation was intensified in both immature and mature vitrified cat oocytes.

The effect of cumulus cells on domestic cat (Felis catus) oocytes during in vitro maturation and fertilization.

The aim of this study was to evaluate the effect of co-culture of denuded oocytes with cumulus cells (CC) or cumulus-oocyte complexes (COCs) on in vitro maturation (IVM) and in vitro fertilization (IVF). Immature oocytes were collected from ovaries of domestic cats following a routine ovariectomy. Oocytes were matured in vitro for 24 hr within four groups: (i) denuded oocytes (DO), (ii) DO co-cultured with CC, (iii) DO co-cultured with COC and (iv) COC as a control group. In further experiments, COCs were matured in vitro for 24 hr, and then, oocytes were randomly divided into four groups as previously described and fertilized in vitro. Embryos were cultured for up to 7 days. At the end of each experiment, oocytes/embryos were stained with Hoechst 33342 solution and observed under an inverted fluorescence microscope. The results of oocyte maturation showed that their meiotic competence decreased significantly in all experimental groups, compared to the control group. The maturation rates were approximately 45%, 24%, 43% and 76% in experiment 1, and 21%, 14%, 33% and 50% in experiment 2 in groups (i), (ii), (iii) and (iv), respectively. Examination of in vitro fertilization revealed that embryos developed up to the morula stage in all experimental groups. DO and oocytes cultured with COC during fertilization showed a lower cleavage rate-36% and 25% as opposed to those co-cultured with loose CC and the control group-43% and 42%, respectively. Results of this study indicate that cumulus cells connected with an oocyte into a cumulus-oocyte complex are irreplaceable for the maturation of domestic cat oocyte, but that the addition of loose CC may be beneficial for IVF.