Gonadal histopathology and inflammatory response in the freshwater snail exposed to iron oxide nanoparticles and ferric chloride: Insights into reproductive nanotoxicity

Considering that most animals in an aquatic ecosystem are invertebrates, concerns about the ecotoxicological impact of emerging pollutants, such as nanomaterials, in these populations are relevant, which can lead to loss of aquatic biodiversity. However, knowledge concerning the effects of iron-based nanoparticles (IONPs) at cell and tissue-levels on freshwater gastropods remains limited. Thus, the present study aimed to analyse the histopathological changes and inflammatory response in the freshwater snail Biomphalaria glabrata after chronic exposure to gluconic-acid functionalized IONPs (GLA-IONPs) in comparison with their dissolved counterpart (FeCl₃). Snails were exposed to both iron forms (1.0, 2.5, 6.25, and 15.62 mg L^-1) for 28 days, and the qualitative and quantitative histopathological assessment on hermaphrodite gonads was conducted, following by analysis of histopathological indices and inflammatory responses. Results showed that both iron forms (GLA-IONPs and FeCl₃) induced several gonadal histopathologies in the snails, mainly atresic acini, vacuolization of pre-vitellogenic oocytes, and atresic oocytes in a concentration-dependent pattern. GLA-IONPs induced a more intense inflammatory response and high frequency of vacuolized vitellogenic oocytes in comparison with FeCl₃. Environmentally relevant concentration (2.5 mg L^-1) of GLA-IONPs and FeCl₃ induced high gonadal histopathological indices, indicating their potential reproductive toxicity. The current study showed that the chronic exposure of snails to GLA-IONPs and their dissolved counterpart (FeCl₃) induced several gonadal histopathological changes and inflammatory responses in B. glabrata, confirming their potential risk to aquatic biodiversity.

Risk assessment of iron oxide nanoparticles in an aquatic ecosystem: A case study on Biomphalaria glabrata

Iron oxide nanoparticles (IONPs) have been applied in several sectors in the environmental field, such as aquatic nanoremediation, due to their unique superparamagnetic and nanospecific properties. However, the knowledge of chronic toxicity of IONPs on aquatic invertebrate remains limited. Thus, the present study aimed to analyze the chronic toxicity of gluconic acid-functionalized IONPs (GLA-IONPs) and their dissolved counterpart (FeCl₃) to freshwater snail Biomphalaria glabrata. GLA-IONPs were synthesized and characterized by multiple techniques, and the snails were exposed to both Fe forms at environmentally relevant concentrations (1.0-15.6 mg L^-1) for 28 days. The bioaccumulation, mortality rate, behavior impairments, morphological alterations, fecundity and fertility of snails were analyzed. Results showed that GLA-IONPs induced high iron bioaccumulation in the entire soft tissue portion. Chronic exposure to GLA-IONP increased the behavioral impairments of snails compared to iron ions and control groups. Both Fe forms reduced the fecundity, while the mortality and reduced fertility were observed only after the exposure to GLA-IONPs at 15.6 mg L^-1. Overall results indicated the behavioral impairments and reproductive toxicity associated, possibly, to bioaccumulation of GLA-IONPs in the B. glabrata. These results can be useful for the development of eco-friendly nanotechnologies.

Toxicity of engineered nanomaterials to aquatic and land snails: A scientometric and systematic review

The emerging growth of nanotechnology has attracted great attention due to its application in the parasite and intermediate host control. However, the knowledge concerning the mechanism of action (MoA) and toxicity of nanomaterials (NMs) to snails remain unclear. In this context, the present study revised the historical use of snails as experimental models in nanotoxicological studies and summarized the MoA and toxicity of NMs in aquatic and land snails. The data concerning the bioaccumulation, reproductive and transgenerational toxicity, embryotoxicity, genotoxicity and potential molluscicidal activity of NMs were revised. Furthermore, the data about the experimental conditions, such as exposure time, concentrations, cell and tissue-specific responses, snail species and nanoparticle types are discussed. Revised data showed that the toxic effects of NMs were reported for 21 snail species with medical, veterinary and ecological importance. The NM toxicity to snails is dependent on the physical and chemical properties of NMs, as well as their environmental transformation and experimental design. The NM bioaccumulation on snails was related to several toxic effects, such as reactive oxygen species (ROS) production, oxidative stress, following by oxidative damage to DNA, lipids and proteins. The NM metabolism in snails remains unknown. Results showed the potential use of NMs in the snail control program. Also, significant research gaps and recommendations for future researches are indicated. The present study confirms that snails are suitable invertebrate model system to assess the nanotoxicity.

Molluscicidal activity of polyvinylpyrrolidone (PVP)-functionalized silver nanoparticles to Biomphalaria glabrata: Implications for control of intermediate host snail of Schistosoma mansoni

Silver nanoparticles (Ag NPs) have been applied in several commercial products due to their antimicrobial properties, while their molluscicide properties, mode of action and toxicity to snail species remain unclear. In this study, the comparative toxicity of polyvinylpyrrolidone (PVP)-functionalized Ag NPs and their dissolved counterpart (Ag ions) was analyzed during the early developmental stages of the freshwater snail Biomphalaria glabrata, intermediate host of Schistosoma mansoni. Ag NPs were synthesized and characterized by multiple techniques, and the snail embryotoxicity was analyzed in terms of mortality, hatching, developmental stages and morphological alterations, while the acute toxicity to newly-hatched snails was analyzed by mortality and behavioral impairments. Results showed that both Ag forms induced mortality, hatching delay and morphological alterations (especially hydropic abnormalities) in snail embryos in a concentration and exposure time dependent patterns. Ag NPs showed low embryotoxic effects and similar toxicity for newly-hatched snails when compared to their dissolved counterparts, indicating that the nanotoxicity was dependent of snail developmental stages. The knowledge about the Ag NP toxicity to different early development stages of B. glabrata contributes to its potential use as molluscicide and control of neglected tropical diseases, including schistosomiasis.

In silico-driven identification of novel molluscicides effective against Biomphalaria glabrata (Say, 1818)

Schistosomiasis control in endemic areas depends on several factors, including mass drug delivery programs and interrupting the transmission of disease by controlling the intermediate host snails in the freshwater ecosystem using molluscicides.

O Cálcio exógeno como biomarcador do uso de via metabólica alternativa por Biomphalaria spp (Mollusca, Planorbidae)

Caramujos do gênero Biomphalaria são hospedeiros do parasito Schsitosoma mansoni, bem como, bioindicadores de qualidade ambiental. Esses caramujos usam carboidratos como fonte primária de energia e aminoácidos na síntese de “novo” de glicose, pela gliconeogênese. A concentração do Ca2+ exógeno afeta o metabolismo energético dos caramujos. Este estudo avaliou o uso de uma via metabólica alternativa por Biomphalaria tenagophila e B. glabrata expostas a 20, 40, 60, 80 e 100 mg/L de CaCO3, por 30 dias, a partir das concentrações de proteína totais, ureia, ácido úrico e creatinina, obtidas utilizando espectrofotômetro. Para cada grupo, foram utilizados quinze caramujos, dos quais foram obtidos amostras compostas de hemolinfa. De maneira geral, houve aumento de proteínas totais e redução de ureia, em ambas as espécies, expostas às maiores concentrações de CaCO3, comparado ao controle. O ácido úrico também aumentou para as duas espécies nas maiores concentrações de CaCO3. Maiores valores de creatinina foram observados em B. tenagophila e B. glabrata expostas, respectivamente, a 20 e 40 mg CaCO3. O uso de proteínas como substrato energético foi observado principalmente na exposição a 20 mg de CaCO3, além de particularidades na regulação de mecanismos fisiológicos pelas espécies como hospedeiras de S. mansoni.

Molluscicidal activity of polyhexamethylene biguanide hydrochloride on the early-life stages and adults of the Biomphalaria glabrata (Say, 1818)

Schistosomiasis is a disease that affects tropical and subtropical areas and is considered the second most prevalent parasitic disease in the world. One of the ways of combating this disease is the use of molluscicidal agents to eliminate or reduce the population of intermediate host snails. Polyhexamethylene biguanide hydrochloride (PHMB) is a chemical biocide commonly used as a disinfectant and antiseptic in the food industry and very successfully for the disinfection of swimming pools. The US Environmental Protection Agency (USEPA) indicated the PHMB as low environmental risk. The present study aimed to evaluate the molluscicidal activity of the PHMB in freshwater snail (Biomphalaria glabrata), intermediate host of Schistosoma mansoni. The PHMB showed high toxicity against all stages of the snail B. glabrata: embryos, new-borns and adults. The LC₅₀ estimated was 0.98 mg L^-1; 1.43 mg L^-1 and 1.49 mg L^-1, respectively, after exposure of 144 h for embryos and 96 h for new-borns and adults. PHMB did not prevent the development of embryos within the egg mass, since at all concentrations evaluated 80% of the embryos managed to develop until the hypo-stage, which is the last stage of development before hatching. However, PHMB inhibited the hatching of embryos by 100% at all concentrations above 1.6 mg L^-1. PHMB proved to be a promising substance in the fight against schistosomiasis by eliminating the intermediate host (B. glabrata). This was the first study that makes an experimental observation of the molluscicidal activity of PHMB.

Elucidating the influence of praziquantel nanosuspensions on the in vivo metabolism of Taenia crassiceps cysticerci

The aim of this work was to develop nanosuspensions of praziquantel (PZQ) and to evaluate their influence on the energetic metabolism of cysticerci inoculated in BALB/c mice. We analyzed metabolic alterations of glycolytic pathways and the tricarboxylic acid cycle in the parasite. The nanosuspensions were prepared by precipitation and polyvinyl alcohol (PVA), poloxamer 188 (P188) and poloxamer 407 (P407) were used as stabilizers. Nanosuspension prepared with PVA had a particle size of 100nm, while P188- and P407-based nanosuspensions had particle sizes of 74nm and 285nm, respectively. The zeta potential was -8.1, -8.6, and -13.2 for the formulations stabilized with PVA, P188 and P407, respectively. Treatments of T. crassiceps cysticerci-infected mice resulted in an increase in glycolysis organic acids, and enhanced the partial reversion of the tricarboxylic acid cycle, the urea cycle and the production of ketonic bodies in the parasites when compared to the groups treated with conventional PZQ. These data suggest that PZQ nanosuspensions greatly modified the energetic metabolism of cysticerci in vivo. Moreover, the remarkable metabolic alterations produced by the stabilizers indicate that further studies on nanoformulations are required to find potentially suitable nanomedicines.

Termination of unwanted pregnancy in dogs with the dopamine agonist, cabergoline, in combination with a synthetic analog of PGF2alpha, either cloprostenol or alphaprostol

Associations of a dopamine agonist, cabergoline, and a synthetic analog of PGF2alpha, either alphaprostol or cloprostenol, were used to induce pregnancy termination in 15 mature Beagle bitches. Alphaprostol (20 microg/kg/d) was injected subcutaneously (sc) in combination with cabergoline (1.65 microg/kg/d, sc) daily for 5 d from Day 32 after the LH peak in 5 animals. Cloprostenol 2.5 microg/kg/d in one group (n = 5) and 1 microg/kg/d in another group (n = 5) was also used in combination with the same dosage of cabergoline, following the same protocol, but starting from Day 25 after the LH peak. Treatment efficacy, defined by the number of pregnancy terminations, was 100% in all treated groups. Dose-related side effects due to PGF2alpha were observed (excessive salivation, prostration, vomiting, diarrhoea, scratching at the injection site), and were less severe with cloprostenol than with alphaprostol. In the group treated with the lowest dosage of cloprostenol, no adverse reactions were noticed. In all treated groups, interestrus intervals compared with previous cycles and in control animals were reduced after treatment.

Determination of the role of cervical closure in fertility regulation after mating or artificial insemination in beagle bitches

In the present study, the pregnancy rate after one insemination with fresh semen performed at the optimum period of fertilization (control) was compared with the pregnancy rate after insemination by either vaginal deposition of semen or transcervical uterine insemination at 24, 48 or 72 h after closure of the cervix (n = 5 bitches per time period and group). In the group of bitches inseminated into the uterus, 2 ml of a fresh pool of semen from four male dogs was deposited transcervically or by laparoscopy into the uterus, whereas in the vaginally inseminated animals, 2 ml fresh semen was extended with 4 ml prostatic fluid. The study was performed over 5 years; some bitches were used twice during two consecutive oestrous cycles. Closure of the cervix was determined once a day by retrograde vaginogram using a radiopaque contrast dye. Closure of the cervix occurred 6.9 +/- 1.1 days (mean +/- SD) after the LH peak and 1.5 +/- 0.9 days before the first day of cytological metoestrus. The hormone values at the time of closure were 81.2 +/- 12.3 nmol progesterone l-1 and 28.4 +/- 23.2 pmol oestradiol l-1; there were no differences between groups. Of the bitches inseminated before closure of the cervix, five and four bitches became pregnant after uterine and vaginal insemination, respectively. Of the bitches inseminated into the vagina 24, 48 or 72 h after cervical closure, none became pregnant, whereas three, three and one bitches became pregnant after insemination directly into the uterus at 24, 48 or 72 h after cervical closure, respectively. The mean litter size was 3.9 +/- 1.4 pups among all pregnant animals and there were no significant differences between groups. The results of the present study indicate that mature canine oocytes may remain fertile for > 200 h after ovulation, rather than for 48-60 h as was previously believed, and that cervical closure may be a limiting factor for reproductive success after natural mating.

Magnetic resonance cholangiopancreatography in cystic lesions of the pancreas

There are few reports about magnetic resonance cholangiopancreatography (MRCP) in cystic lesions of the pancreas (KLP). For this reason, we have undertaken a prospective study evaluating the diagnostic efficiency of MRCP as compared with ultrasonography. Twenty-four patients with KLP were examined with magnetic resonance imaging (MRI), and standard and cholangiopancreatography. There were seven cases of cysts associated with acute pancreatitis, 11 patients with KLP and chronic calcifying pancreatitis, five cases of cystic neoplasms of the pancreas, and one polycystic disease of the gland. All cases were first submitted to ultrasonography, which failed to diagnose only a case of cyst associated with chronic pancreatitis depicted by MRCP. We used a GE Signa Horizon 1.5-T system (20 examinations) and a Siemens Magneton Plus 1.5-T machine (four examinations). Eleven patients were operated on. In all cases, it was possible to identify the cysts, the main pancreatic duct and the biliary tree, and verify the relationship of the cyst with neighboring organs. Communication of the cyst with the main pancreatic duct was described in five instances, but we cannot be sure that MRCP would have depicted all cyst-duct communications. The MRI and MRCP images were confirmed by surgery in the 11 operated-on cases. The diagnosis of duct alterations and small pancreatic stones in initial cases of chronic calcifying pancreatitis may be problematic. Clinical findings are very important data to be considered in the differential diagnosis of KLP. Together with the clinical data, MRCP is a very important technique in the diagnostic and therapeutic decision making of KLP. Standard magnetic resonance is advisable as part of the examination in all cases. MRCP is not invasive, is reliable if one knows its limitations, and the patient can return at once to his activities. It allows the analysis of many variables in one examination, contributing to better therapy.

Effect of stage of anestrus on the induction of estrus by the dopamine agonist cabergoline in dogs

Beagle bitches were administered the dopamine D2 receptor agonist cabergoline in 3 groups of 5 animals each, starting on known days of the estrous cycle. Cabergoline treatment was started in either early anestrus (Days 93 to 108), mid-anestrus (Days 123 to 156), or late anestrus (Days 161 to 192) at doses of 5 ug/kg/d, per os, and was continued until the confirmation of induced proestrus or for 40 d. Reproductive parameters were compared with those in 5 control anestrous bitches (Days 90 to 150). In control bitches, the mean (+/- SEM) interval to the next proestrus (73+/-11 d) resulted in an interestrus interval (192+/-9 d) similar to that of the previous cycles (196+/-11 d). In 14 of the 15 cabergoline-treated bitches, the next proestrus occurred within 4 to 30 d, was premature in early and mid-anestrous bitches and developed with low variability within groups. The resulting intervals to proestrus in bitches treated with cabergoline in early anestrus (20+/-2 d), mid-anestrus (14+/-3 d) and late anestrus (6+/-1 d) resulted in interestrus intervals in those groups of 131+/-5, 166+/-7 and 196+/-2 d, respectively. In response to treatment, interestrus intervals were reduced (P<0.05) and more synchronous (P<0.05) in early and mid-anestrus bitches, and were more synchronous (P<0.05) in late-anestrous bitches compared with those of control bitches or those of the previous cycle. Periovulatory estradiol and progesterone profiles of induced cycles in treated bitches were similar to those of spontaneous cycles in control bitches. Four of 5 control bitches and 12 of the 14 responding cabergoline-treated bitches became pregnant and produced normal litters. Plasma prolactin concentrations at Days 2 and 5 of treatment (0.3+/-0.1 ng/mL) and at the onset of proestrus shortly before the end of treatment (0.4+/-0.1 ng/mL) were lower (P<0.05) than those present in anestrus prior to treatment (1.7+/-0.6 ng/mL) or in control bitches. Prolactin was also low at the onset of proestrus in control bitches (0.5+/-0.2 ng/mL). The results demonstrate that prolactin-lowering doses of the dopamine agonist cabergoline can terminate the normal obligate anestrus in dogs, and that the effect occurs more slowly in early anestrus than in mid or late anestrus.

[Study of intestinal malabsorption diseases as cause of monosymptomatic short stature]

OBJECTIVE: This study was carried out in order to evaluate the etiology of monosymptomatic childhood short stature (below the third percentile or with growth rate of less than 5 cm/year) with emphasis on causes due to intestinal malabsorption. METHODS: Each patient was submitted to endocrinological, biochemical and hematological investigation. Determination of serum anti-gliadin antibodies, fecal fat, chloride levels in sweat, jejunal biopsy and bone age was also obtained.RESULTS: A total of 51 children was studied, most of them belonging to the group of normal variants. Four children had abnormally high sweat chloride, compatible with the diagnosis of cystic fibrosis. These children were asymptomatic regarding respiratory and gastrointestinal tract. CONCLUSIONS: We conclude that cystic fibrosis, besides celiac disease, must be included in the differential diagnosis of short stature in childhood.

Comparisons of intravaginal and intrauterine insemination of bitches with fresh or frozen semen

To compare the importance of the route of insemination when using fresh or frozen semen, six groups of five bitches were inseminated either into the uterus (groups 4, 5 and 6) or the vagina (groups 1, 2 and 3) with fresh (groups 1 and 4) or frozen semen (groups 2, 3, 5 and 6). The fresh semen was collected when needed from the same dog. The frozen semen used in groups 2 and 5 was obtained from seven dogs on the same day, and pooled and processed simultaneously so that the groups were inseminated with exactly the same semen. The frozen semen used in groups 3 and 6 was obtained from different dogs and processed independently to evaluate not only the effect of the route of insemination but also the potential effect of the dog. The mean concentration of the fresh semen was 310 x 10(6) spermatozoa/ml, its motility was greater than 80 per cent and the percentage of normal live spermatozoa was 80 to 92 per cent. The mean spermatozoal concentration of the frozen semen was 200 x 10(6) spermatozoa/ml, its motility was greater than 60 per cent and the percentage of normal live spermatozoa was 80 per cent. In all the groups there were fewer than 15 per cent abnormal spermatozoa. The animals inseminated with fresh semen received significantly more spermatozoa than the others. The bitches were inseminated twice, three and five days after the estimated peak of luteinising hormone, with a total volume of 5 ml for the vaginal inseminations and 2 ml for the intrauterine inseminations. Sixty per cent of the bitches inseminated with frozen semen and 100 per cent of the bitches inseminated with fresh semen became pregnant, irrespective of the insemination technique used.

Comparisons between three different extenders for canine intrauterine insemination with frozen-thawed spermatozoa

Ejaculates from 7 dogs were obtained on the same day and were pooled. This pooled semen was separated into 3 equal fractions and processed simultaneously, the only difference being in the extender used for freezing. The extenders were laiciphos (containing laiciphos, egg yolk, distilled water and glycerol- Group 1); Tes/Tris (containing Tes/Tris, egg yolk, distilled water and glycerol- Group 2); and biociphos (containing biociphos with glycerol in it, egg yolk and distilled water- Group 3). Spermatozoa were conditioned in 0.5ml French straws and presented normal characteristics before freezing and after thawing. The sperm concentration of the pooled was 683 x 10(6) sperm/ml; sperm motility was above 95%, the percentage of live spermatozoa was above 95% and was of good quality and mobility. Characteristics of the spermatozoa after thawing were the same for spermatozoa frozen with laiciphos and Tes/Tris. Mean sperm concentration was 201.5 +/- 4.95 x 10(6) sperm/ml, sperm motility was 65%, the percentage of live spermatozoa was 80% and the quality of motility.was good. Spermtozoa frozen with biociphos had the following post-thaw characteristics: sperm concentration was 201 x 10(6) sperm/ml, sperm motility was 50%, the percentage of live spermatozoa was 78% and the quality of mobility was medium. Abnormalities were less than 15% for all spermatozoa after thawing. Intrauterine artificial inseminations were performed by laparoscopic intrauterine insemination twice at Days 3 and 5 after the estimated LH peak in 15 normally cyclic Beagle bitches (5 per group) presenting normal hormonal profiles. There were no differences between groups. The females were inseminated with 1.0 ml of spermoatozoa (concentration of 200 x 10(6) sperm/ml) diluted with 1.0 ml of extender. A 60% pregnancy rate was obtained in bitches inseminated with frozen-thawed spermatozoa extended with laiciphos or Tes/Tris and 100% in bitches inseminated with spermatozoa extended with biociphos. Females inseminated with laiciphos, Tes/Tris and biociphos had a mean litter size of 5 +/- 2.6, 3 +/- 1 and 3.4 +/- 1.3 pups, respectively. This study demonstrated that post-thaw assessment of sperm characteristics is not the best technique for evaluating sperm fertility after freezing or for assessing different semen extenders.

Cervical opening in relation to progesterone and oestradiol during heat in beagle bitches

The relationship between hormonal profile and cervical opening and closure was analysed during heat in seven bitches. The bitches were studied each day from the beginning of pro-oestrus until 5 days after cytological metoestrus. Vaginography was performed using a radiopaque contrast dye injected through an insemination probe and blood samples were collected daily. The opening of the cervix was observed, in pro-oestrus, 2.6 +/- 2.8 days before the LH peak. The progesterone and oestradiol values at that time were 2.0 +/- 2.4 nmol l-1 and 171.1 +/- 133.1 pmol l-1, respectively. The opening of the cervix was observed concurrent with the day of the maximal value of the oestradiol:progesterone ratio, just before the decline of oestrogen preceding the LH peak. Differences between the oestradiol:progesterone ratio the day before, the day of and the day after opening were significant. The closure of the cervix occurred 6.7 +/- 1.4 days after the LH peak and 2.6 +/- 1 days before the first sign of cytological metoestrus. The progesterone and oestradiol concentrations at that time were 68.9 +/- 15.4 nmol l-1 and 16 +/- 10.3 pmol l-1, respectively. All bitches were in cytological oestrus when the cervix closed. These data indicate that there is a relationship between hormonal profile and cervical opening and that breeding success may also be temporarily limited, not only by oestrous behaviour, but also by cervical closure. In the beagle colony studied, a blood concentration of 60 nmol progesterone l-1 would give a good indication that no success will follow artificial vaginal insemination or natural mating.

Laparoscopic intrauterine insemination in the bitch

A technique for laparoscopic intrauterine insemination in bitches is described. During natural estrus, 5 beagle bitches were inseminated and S others were naturally mated (control group) twice at a 48-h interval on Days 3 and S (n = 4) or Days 4 and 6 (n = 6) after the increase in plasma progesterone considered to be indicative of the day of the preovulatory LH peak. All the inseminations were with fresh semen and under general anesthesia. The technique involved the introductions of 1) a Verres needle to insufflate the abdominal cavity by direct punction on the middle line 1 cm over the umbilicus, 2) a laparoscope to visualize the abdominal cavity by a 1 cm puncture on the middle line 1 cm under the umbilicus, 3) a forceps used to manipulate the uterus by a 0.5 cm puncture at 2 to 3 cm lateral to the mammary glands, and 4) an 18-g catheter used to puncture the uterus on the middle line between the 3rd and 5th mammary gland. The uterine body was grasped by the forceps and elevated against the ventral abdominal wall. The 18-g catheter was then inserted through the abdominal wall directly into the uterine lumen, and 1.0 ml of fresh semen containing 250 to 480 x 10(6) spermatozoa/ml was injected. The inseminations resulted in pregnancies in all animals. Litter size was similar in the artificially inseminated and naturally mated bitches (5 +/- 1.8 and 4.8 +/- 1.6 pups per litter, respectively). Bitches in the artificially inseminated group delivered at 65.2 +/- 0.8 d and in the natural mated group at 65.4 +/- 0.5 d after the LH peak. In conclusion, this paper gives the first results of intrauterine laparoscopic insemination in bitches, indicating interesting perspectives for this technique in dog's reproduction.

Abortion induction in the cat using prostaglandin F2 alpha and a new anti-prolactinic agent, cabergoline

This study in cats compared the effects of a natural prostaglandin F2 alpha (PGF2 alpha) and cabergoline, administered on and after day 30 after mating, with regard to the plasma progesterone concentration, the induction of abortion and the side effects of each regimen. PGF2 alpha, through a direct luteolytic action, induced abortion by an abrupt and rapid (24 h) decline in the plasma progesterone concentration. Using doses (2 mg per cat) comparable to the ones selected in a previous study, 100% of abortions (4/4) in cats treated from day 33 of gestation were obtained. Cabergoline (1.65 micrograms kg-1 day-1, administered subcutaneously for 5 days), through its antiprolactinic action induced abortion in 80% (4/5) of the cats treated on day 30 of gestation. The abortion was initiated by means of a reduction in plasma progesterone concentration to < 1 ng ml-1. This reduction was not as rapid (3-4 days), however, as that obtained with PGF2 alpha (24 h). Prostaglandins always induced significant side effects such as nausea, prostration, vomiting and diarrhoea, within 10 min following injection, whereas cabergoline never induced side effects or behavioural disturbances. In addition, cabergoline usually induced abortion through fetal resorption (75% of cases), without any clinical sign other than some vaginal discharge.

Echocardiographic study of heart rate in dog and cat fetuses in utero

The heart rate of dog and cat fetuses in utero was studied using real-time B and M mode ultrasonography. Fifteen bitches and 15 queens were monitored from day 19 after the luteinizing hormone (LH) peak in the bitch, and from day 15 after the first mating in the cat, up to parturition, using a 7.5 MHz linear transducer. The first fetal cardiac movements and the cardiac frequency were detected from days 23 and 29 after the LH peak and from days 18 and 25 after mating, in the bitch and in the queen, respectively. In bitches, heart rates were higher [230.2 +/- 15.4 beats per minute (b.p.m.)] than values previously reported. Initial average values were 214 +/- 13.3 b.p.m. and these significantly increased thereafter, with an average of 238.2 +/- 16.1 b.p.m. at day 40. A reduction was noted near parturition. In queens, the average values recorded were 228.2 +/- 35.5 b.p.m. Contrary to what has been observed in the bitch, the cardiac frequencies remained stable during pregnancy.