DL 717-IT: a non-hormonal agent for the control of fertility in the bitch

The development of a new class of non-hormonal contragestational agents provided a derivative, 2-(4-chlorophenyl)-striazole|5,1-alisoquinoline (DL 717-IT or L 12717), with the qualities needed for application in the veterinary field as a post-coital pregnancy-terminating agent. Single intramuscular injections of this compound arrest pregnancy over a wide period of gestation in the bitch. A dose of 2.5 mg/kg was found to be very well tolerated and highly effective (100 per cent) when administered between the day of mating and the 15th day of pregnancy. The desired effect was not accompanied by uterine disorders or other unwanted effects. This non-hormonal agent appears to have several real advantages over the only other drugs (oestrogens) available in veterinary practice for the termination of unwanted pregnancies in bitches.     

2-(1,1''-biphenyl-4-yl)-1,2,4-triazole[5,1-a] isoquinoline (L 14105), a potential orally active contragestational agent for the bitch: studies in the rat, hamster and dog

In the search for second generation post-coital pregnancy terminating agents belonging to the class of 2-phenyl-triazole[5,1-a]isoquinolines, the contragestational profile of (1,1'-biphenyl)-4-yl-1,2,4-triazole[5,1-a]isoquinoline, referred to as L 14105, was investigated in hamsters, rats, and bitches. Following subcutaneous or intramuscular administration in oily vehicles, L 14105 shows a very high anti-fertility activity in the three animal species, being from 1.8 to 2.5 times more effective than the parent drug, DL 717-IT. Unlike DL 717-IT, L 14105 possesses a high activity when administered by the oral route. The results obtained in the bitch make it confirm its potential use as a new orally active agent for the interruption of unwanted pregnancies.     

Pregnancy termination in dogs with non-hormonal compounds: evaluation of selected derivatives

Four non-hormonal, pregnancy-terminating compounds have been studied in bitches. One of these, 2-(4-chlorophenyl)-s-triazole[5,1-a]isoquinoline (DL 717-IT or L 12717), has been found to be very efficacious after a single subcutaneous injection. This compound appears to be promising for use in veterinary practice.     

Prenatal and transmammary infections of Toxocara canis in dogs: effect of benzimidazole-carbamate anthelmintics on various developmental stages of the parasite

Fenbendazole and albendazole, given at a dose rate of 150 mg/kg for 3 days, produced a 90 per cent reduction in the numbers of second stage larvae of Toxocara canis present in the tissues of dogs although no reduction in the number of larvae found in the brains of infected dogs occurred with this treatment. The results suggest that a course of 3 day therapy with these anthelmintics should prevent prenatal infections in puppies. However, if infection is acquired by bitches during late pregnancy or early lactation, the transmammary route of infection becomes important. Therefore, anthelmintic treatment of the bitch prior to pregnancy will not prevent transmission of infection to her puppies should the bitch acquire a new infection of T. canis during pregnancy or early lactation. Alternatively, infection with T. canis can be controlled through the treatment of neonatal puppies for migrating larvae of T. canis. Treatment of newborn puppies with fenbendazole, albendazole or oxfendazole at a dose of 100 mg/kg for 2–3 days produced a 91–99 per cent reduction in the number of adult parasites found. In addition, a single dose of fenbendazole, given at a dose rate of 40 mg/kg, eliminated 93–96 per cent of adult T. canis from the intestines of 4–5-week-old puppies. These latter treatments would need to be repeated to eliminate completely the infection from puppies.     

Prevalence of fetal resorption in stray dogs in Yucatan, Mexico

OBJECTIVES: To determine the prevalence of fetal resorption in 77 pregnant bitches and its association with the age, size and body condition score of the bitch and to determine the frequency of transuterine migration of embryos. METHODS: The number and position of embryos or fetuses and placental zones were registered postmortem. The prevalence of fetal losses was determined by comparing the number of corpora lutea with the number of embryos or fetuses in each bitch. The prevalence of transuterine migration of embryos was determined by correlating the number of fetuses in each horn and the number of corpora lutea in the ipsilateral ovary. RESULTS: Fetal resorption zones were demonstrated in 42.9 per cent of the bitches. However, pregnancy continued in 84.9 per cent of cases. Of the fetal losses, 25.9 per cent were determined by counting the number of corpora lutea and viable embryos or fetuses. Young bitches tended to have a higher probability of fetal resorption than adult bitches (P<0.06). The presence of fetal resorption zones was not associated with size or body condition. Transuterine migration of embryos had occurred in 15.8 per cent of the bitches. CLINICAL SIGNIFICANCE: This study demonstrated that embryo resorption is a normal event in the bitches, with a higher prevalence than previously thought.     

Dystocia in the bitch: A retrospective study of 182 cases

In a retrospective study of 182 cases of canine dystocia, no relationship was found between either breed or age and occurrence of dystocia. However, medium-sized breeds (between 12.7 and 20.5 kg bodyweight) were slightly over represented. Of the bitches that had whelped previously, 42 per cent had experienced dystocia. The dystocia was of maternal origin in 75.3 per cent of the cases, mainly due to uterine inertia, while 24.7 per cent were of fetal origin, mainly resulting from malpresentations/malorientations. The most common reason for dystocia was primary, complete uterine inertia (48.9 per cent) and 40 per cent of the bitches with this problem had small litters of one or two pups. The most common treatment was calcium and, or, oxytocin injection followed by a caesarean section. Digital manipulation including forceps delivery and, or, medical treatment was successful in only 27.6 per cent of the cases. Of the bitches studied, 65.7 per cent had a caesarean section. Pup deaths occurred in 52.2 per cent of the litters. Among bitches that had been treated within one to four-and-a-half hours after the beginning of second stage labour, 5.8 per cent of the pups died, whereas the corresponding value for bitches that had been treated between five and 24 hours after the beginning of second stage labour was 13.7 per cent. The total frequency of pup deaths was 22.3 per cent. These findings show that early diagnosis and prompt treatment are crucial in reducing the pup death rate in cases of dystocia.     

Protection of puppies against canine herpesvirus by vaccination of the dams.

Six bitches free of canine herpesvirus 1 (CHV-1) were vaccinated against the virus; a first injection was given 10 days after the presumed date of mating and a second six weeks later. Six similar bitches were left unvaccinated as controls, and all the pups were challenged oronasally with a virulent strain of CHV-1 at three days of age. All the vaccinated bitches seroconverted and had high antibody titres when the puppies were challenged, but the control bitches remained seronegative. In the control group, 62 per cent (18 of 29) of the pups died of CHV-1-induced disease; most of them showed typical clinical signs and macroscopic lesions, and CHV-1 infection was confirmed by the isolation of the virus or by PCR. None of the puppies in the vaccinated group died of CHV-1 infection. The efficacy of the vaccine was confirmed in CHV-1-positive breeding units. The rate of pregnancy tended to be higher in vaccinated bitches and the mortality of pups before weaning was significantly reduced in the litters born to vaccinated bitches.     

Vaginal cytology and cervicovaginal mucus arborisation in the breeding management of bitches

Fifty bitches were mated on the basis of results of vaginal cytological and cervicovaginal mucus arborisation examination. When these were compared with a control group of 50 bitches mated on days 10 and 12 after the onset of proestrus there was a significant increase in pregnancy rate from 78 to 92 per cent. The litter size and bitch productivity was also increased, although this was not statistically significant. Forty-two per cent of bitches had two peaks of anuclear epithelial cells in the vaginal smear, separated by a mean of 3–6 ± 1–5 (SD) days. For these bitches, the maximum percentage of anuclear cells at the second peak was between 57 and 98 per cent, and the mean interval between the calculated day of the surge in plasma luteinising hormone (LH) and the second peak of anuclear cells was 4-4 ± 2-0 days. In bitches with one peak of anuclear epithelial cells, the maximum percentage of anuclear cells was between 43 and 94 per cent and the mean interval between the calculated day of the LH surge and the peak of anuclear cells was 1–9 ± 2-1 days. Arborisation of mucus collected from the anterior vagina was noted in all bitches; the mean interval between the calculated day of the LH surge and the peak of ferning was 2–3 ± 2-1 days. The collection of exfoliative cells by aspiration from the cranial vagina and the assessment of the anuclear cell index, may allow the identification of the fertile period after the surge of plasma LH. The anuclear cell index offers advantages over other methods of classification of exfoliative vaginal cells. When used in combination with examination of arborisation of cervicovaginal mucus this method can improve the breeding management of bitches.     

Clinical Evaluation of the Use of Aglepristone Associated with Oxytocin to Induce Parturition in Bitch

To evaluate the efficacy and safety of aglepristone 15 mg kg⁻¹ for induction of parturition in bitches, 22 pregnant beagle bitches were injected subcutaneously on day 60 post-estimated LH surge, and again 24 h later with aglepristone and subsequently were given 0.15 IU kg⁻¹ oxytocin at hourly intervals until delivery of the last puppy. Six pregnant beagle bitches were used as a non-treated control group. In the control group, parturition occurred at 63.2 ± 0.5 days, 29 pups were born and the average expulsion time per puppy was 1.0 ± 0.6 h. In the treated group, parturition was obtained on average 29.7 ± 5.6 h after aglepristone administration, 121 pups were born and average expulsion time per pup was 1.1 ± 0.4 h. The percentage of live puppies, 7 weeks after birth, was 86.1% (25/29) and 86.8% (105/121) for the control and treated groups, respectively. No significant difference was observed between the control and treated groups for the average expulsion time per live puppy and for the percentage of live puppies at birth, 48 h, 7 days or 7 weeks after birth (p > 0.05). This study confirms previous results and demonstrates that the combination of aglépristone and oxytocin can be safely and reliably used to induce parturition in beagle bitches, at 60 days post-estimated LH surge.     

Population genetic analysis of the new dog breed Elo

The breeding of the dog breed Elo was started in 1987. This dog breed was established by using 16 dogs of nine different breeds. All pedigree information of the dogs from 1987 to 2002 was included for the analysis of the proportion of genes of the different founder breeds, of the inbreeding coefficient, and relationship coefficients. Additionally, the number of died puppies per litter were investigated. The Eurasian dog breed contributed about 48% of the genes in the whole Elo dog population. Old English sheepdog and Chow Chow contributed about 23% and 10% of the genes. The other dog breeds were of minor importance. The mean inbreeding and relationship coefficients of the whole Elo dog population were 12.04% and 19.22%, respectively. With the exception of 3.5% of animals, all Elo dogs were related to each other. The mean litter size was 6.39 puppies. The percentage of stillborn puppies per litter averaged at 9.47%. The inbreeding coefficients of the puppies and of their dams, the age of the sire and the dam at the time of birth of the puppies, the litter size, the puppies' year of birth and the proportion of genes of the Chow Chow showed a significant effect on the number of stillborn puppies per litter. The heritability for the frequency of stillborn puppies was estimated using a linear animal model. After transformation of the linear estimates to the underlying liability scale, the heritability amounted to h2 = 0.15.     

Vaginal isolation of beta‐haemolytic Streptococcus from bitches with and without neonatal deaths in the litters

The aim of the study was to identify beta‐haemolytic streptococci in the vagina of bitches who had delivered healthy litters and bitches who had delivered litters in which neonatal deaths occurred. Fifty‐one bitches divided into two groups were used. Group 1 (G1) included 28 bitches that had delivered healthy litters and group 2 (G2) included 23 bitches that had delivered puppies who died in the neonatal period. Two vaginal samples were taken, one in proestrus and the other at the end of gestation (EG). Beta‐haemolytic Streptococcus (BS) was isolated from 16 bitches (57%) in G1 and from 21 bitches (91%) in G2. The bacteriological cultures, serological tests (Streptex^®) and PCR assay allowed identification of Streptococcus canis and Streptococcus dysgalactiae in G1 and G2. Ultramicroscopic studies allowed the observation of M Protein and capsules in strains of S. dysgalactiae and S. canis in G1 and G2. The S. canis strains isolated from G2 showed thicker capsules than S. canis strains isolated from G1 (234 ± 24.2 vs 151.23 ± 28.93 nm; p < .001.). No differences were observed in capsule thickness between strains of S. dysgalactiae isolated from G1 and G2 (210 ± 13.54 vs 211.66 ± 19.67 nm; p > .70). All strains of beta‐haemolytic Streptococcus isolated were penicillin sensitive. Penicillin was administered from EG to 5 days post‐partum in 10 G2 females with isolation of BS (G2A). Saline solution was administered in eleven G2 females with isolation of BS (G2B). Ninety per cent of the puppies survived in G2A and 25% survived in G2B. Our results suggest BS is involved in canine neonatal deaths.     

Bacteriological status of canine milk and septicaemia in neonatal puppies--a retrospective study

Results of the bacteriological examination of milk samples from 46 bitches were evaluated retrospectively, and correlated with findings of the bacteriological examination of organs from dead, septicaemic puppies in their litters (n = 33). The aim of this study was to investigate, in how many cases of clinical and subclinical mastitis of the bitches, the same bacteria can be detected in their septicaemic neonates. One group of lactating bitches was clinically healthy (group I, n = 38), whereas in eight bitches different puerperal disorders were found (group II). Twenty-five septicaemic puppies were from group I, eight from group II. Out of a broad spectrum of bacteria isolated from the milk of clinically healthy and diseased bitches, only Escherichia coli, Klebsiella pneumoniae and/or ss-haemolytic (haem.) Streptococcus sp. could be isolated from organs of their septicaemic puppies. This was the case in three bitches with mastitis and in one clinically healthy bitch only. Staphylococcus intermedius, although frequently isolated from canine milk, does not seem to be a cause of septicaemia in neonates. It is assumed that in most cases of neonate septicaemia, bacteria from the bitches' milk are not the primary cause.     

Termination of mid-term pregnancy in the dog with oral RU 486

A total of four pregnancies were terminated in three bitches (two beagles and one flatcoated retriever) with a single dose of 20 mg/kg (one case), two doses of 8-3 mg/kg (one case) or 20 mg/kg plus 40 mg/kg (two cases) RU 486 by mouth (Mifepristone; Roussel-Uclaf, France) from day 26 to day 36 after the first day of mating of the bitch. Abortions occurred within two, four, 11 and 11 days after the initial treatment, respectively. The clinical status of the bitches was similar to that observed during a normal parturition, ie, lowering of the body temperature, shivering, panting and nesting behaviour. No side effects were seen. The beagle bitch that aborted twice, was mated at the first oestrus after the first abortion, conceived and aborted the same number of puppies the second time. The peripheral plasma progesterone concentration at the time of treatment in all bitches was < 75 nmol/litre. It had decreased to between 24-2 and 13-1 nmol/litre at the time of abortion and to between 4-0 to 0–5 nmol/litre at four to 15 days after the initial treatment. Peripheral plasma levels of prolactin increased three- to fourfold within 24 to 48 hours after treatment, concomitant with the drop in progesterone and had returned to basal levels within two to three days. Prolactin concentrations also increased around the time of intrauterine fetal death. Prostaglandin F_2aα-metabolite concentrations increased slowly after treatment, and around the time of abortion the levels increased five- to 10-fold. RU 486 seems to be a safe and effective abortifacient for use during mid-term pregnancy in the dog.     

Timing the mating of dogs on the basis of blood progesterone concentration

The optimal time for mating bitches was determined by measuring the progesterone concentration in peripheral blood three times a week after the start of vulval bleeding. Of 104 bitches with reduced fertility 81 (78 per cent) became pregnant and of 112 bitches with normal fertility 105 (94 per cent) became pregnant. Of 121 bitches mated once, 102 (84 per cent) became pregnant, and of 95 bitches mated more than once, 84 (88 per cent) became pregnant. The mean (+/- sd) interval between the start of vulval bleeding and the optimal time for mating in 88 bitches was 11.8 +/- 3.1 days. The blood progesterone concentration appears to be an excellent indicator of the best time for mating, particularly in bitches with reduced fertility.     

First report of the use of meglumine antimoniate for treatment of canine leishmaniasis in a pregnant dog

Canine leishmaniasis during pregnancy is rarely reported, even in countries where the infection in dogs is endemic. The authors report a case of a 4 yr old bitch with leishmaniasis treated with meglumine antimoniate during pregnancy. The pregnancy and delivery were normal and the bitch presented improvement of the infection during treatment. Three puppies died within 2 days of birth and tested negative via real-time PCR for L. infantum. The two surviving puppies were followed clinically, serologically, and by real-time PCR until 1 yr of age with no evidence of congenital leishmaniasis. L. infantum DNA was detected with real-time PCR analysis of uterine tissue from the bitch at the time of ovariohysterectomy. PCR analysis was performed after an ovariohysterectomy of the bitch that was performed two months after parturition. Meglumine antimoniate use in the pregnant bitch may have prevented vertical transmission of leishmaniasis.     

Fenbendazole treatment of pregnant bitches to reduce prenatal and lactogenic infections of Toxocara canis and Ancylostoma caninum in pups

A granulated formulation of fenbendazole was tested in a total of 23 treated and control, pregnant, parasite-free Beagle bitches experimentally infected with Toxocara canis and Ancylostoma caninum. The drug was administered to each treated bitch once daily in canned dog food at a dosage of 50 mg/kg body weight. Each of 2 treatment regimens tested was initiated on the 40th day of pregnancy. One regimen involved daily treatment continuing through the 14th postpartum day, and it resulted in 89% fewer ascarids and 99% fewer hookworms in pups born to medicated bitches, as compared with pups born to unmedicated controls. The other regimen of treatment, which was stopped on the day of parturition, was less effective in reducing ascarid and hookworm burdens (64% and 88% reductions, respectively). Three to 5 bitches from each of the treatment and control groups were allowed to whelp a 2nd litter without further treatment or further exposure to parasite infections. Hookworm burdens in 2nd-litter pups born of bitches that had initially received fenbendazole through the 14th postpartum day were significantly lower (P < 0.01; 85% reduction), when compared with the 2nd-litter control pups. All other parasite burdens were not significantly different. It was concluded that granulated fenbendazole is effective in reducing burdens of Ancylostoma caninum and Toxocara canis in newborn pups when the bitch is treated during the last third of pregnancy, especially when treatment (50 mg/kg/day) extends from the 40th day of pregnancy through the 14th postpartum day.     

Uterine drainage in the bitch for treatment of pyometra refractory to prostaglandin F2α

Uterine drainage was performed in three bitches with pyometra which had been treated unsuccessfully with PGF_2α. All of the bitches became clinically normal and one of them was mated and gave birth to live puppies. The mode of action of uterine drainage is discussed. Possible advantages of a combination of drainage and prostaglandin treatment are also considered.     

Efficacy and toxicity of tamoxifen citrate for prevention and termination of pregnancy in bitches

Five groups of bitches were given tamoxifen citrate (1 mg/kg of body weight) orally twice daily for 10 days. Drug administration commenced during late proestrus, day 4 of estrus, day 2 of diestrus, day 15 of diestrus, or day 30 of diestrus (n = 4/group). Nineteen of the bitches accepted natural mating by 1 or more of 3 stud dogs of known fertility (1 bitch did not). Twenty days after cessation of drug administration, ovarian, uterine, and hepatic specimens were obtained from each bitch in 4 of the groups. Pregnancy proceeded to natural termination in bitches of the remaining group (diestrous day 30). Pregnancy was not detected in any bitch of the proestrus, estrous, or early diestrous groups. Of 4 bitches of each of the remaining groups (diestrous day 15 and diestrous day 30), 2 aborted fetuses and/or resorbed placental remnants; the other 2 bitches in each of these groups had normal-appearing fetuses (diestrous day-15 group) or clinically normal pups (diestrous day-30 group). Of the 20 bitches given tamoxifen citrate, 5 developed endometritis with or without pyometra, and 4 of these had ovarian cysts. Although tamoxifen citrate is effective for preventing or terminating pregnancy in the bitch, the regimen used in the study reported here was associated with high frequency of pathologic changes in the reproductive tract.     

Pregnancy-related diabetes mellitus in two dogs

CASE SUMMARIES: Two cases of diabetes mellitus occurring in bitches in association with pregnancy are reported. In the first case, a bitch with suspected acromegaly developed diabetes mellitus within 2 weeks of the due date. Despite insulin therapy, euglycaemia was not achieved. Tw o live, small pups were delivered by elective Caesarean section but died within 2 days. Signs consistent with acromegaly resolved but diabetes mellitus was permanent in the bitch. In the second case, diabetic ketosis with severe gastrointestinal disease was diagnosed 2 days after Caesarean section was performed due to dystocia. The pups delivered all died within 5 days. The bitch recovered fully from diabetes mellitus within 2 weeks and has remained euglycaemic without insulin for a period of at least 18 months.

CLINICAL RELEVANCE: These two cases demonstrate that diabetes mellitus can occur in association with pregnancy in dogs, that diabetic ketosis can occur during transient diabetes mellitus in dogs, and suggest that acromegaly may occur during pregnancy-related dioestrus in dogs. The scarcity of previous reports of this nature, however, suggests that such cases are unusual.

Lack of prompt resolution of hyperglycaemia may result in secondary diabetes mellitus becoming permanent. Management should focus on immediate insulin therapy or ovariohysterectomy to minimise this risk. Even mild hyperglycaemia should not be ignored during pregnancy. The insulin antagonistic effects of pregnancy, stressful illness, surgery and dystocia can be enough to result in diabetic ketosis in the absence of permanent insulin deficiency. Maternal hyperglycaemia may contribute to adverse fetal outcomes in dogs but further study is required regarding the nature of the risk.     

Pregnancy-related diabetes mellitus in two dogs

CASE SUMMARIES: Two cases of diabetes mellitus occurring in bitches in association with pregnancy are reported. In the first case, a bitch with suspected acromegaly developed diabetes mellitus within 2 weeks of the due date. Despite insulin therapy, euglycaemia was not achieved. Two live, small pups were delivered by elective Caesarean section but died within 2 days. Signs consistent with acromegaly resolved but diabetes mellitus was permanent in the bitch. In the second case, diabetic ketosis with severe gastrointestinal disease was diagnosed 2 days after Caesarean section was performed due to dystocia. The pups delivered all died within 5 days. The bitch recovered fully from diabetes mellitus within 2 weeks and has remained euglycaemic without insulin for a period of at least 18 months. CLINICAL RELEVANCE: These two cases demonstrate that diabetes mellitus can occur in association with pregnancy in dogs, that diabetic ketosis can occur during transient diabetes mellitus in dogs, and suggest that acromegaly may occur during pregnancy-related dioestrus in dogs. The scarcity of previous reports of this nature, however, suggests that such cases are unusual. Lack of prompt resolution of hyperglycaemia may result in secondary diabetes mellitus becoming permanent. Management should focus on immediate insulin therapy or ovariohysterectomy to minimise this risk. Even mild hyperglycaemia should not be ignored during pregnancy. The insulin antagonistic effects of pregnancy, stressful illness, surgery and dystocia can be enough to result in diabetic ketosis in the absence of permanent insulin deficiency. Maternal hyperglycaemia may contribute to adverse fetal outcomes in dogs but further study is required regarding the nature of the risk.