Induction of Parturition with Aglepristone in Various Sized Bitches of Different Breeds.

The objective of this study was to confirm in various breeds of dogs the efficacy and safety of a parturition induction treatment described to be successful in Beagle dogs. Parturition was induced in seven various sized pregnant bitches of different breeds, with 15 mg aglepristone per kg at day 59–61 post-estimated ovulation day, followed 24 h later by 0.15 IU oxytocin per kg subcutaneous injections every 2 h. Two bitches were small-sized bitches (<10 kg), three bitches were large-sized bitches (30–40 kg) and two bitches were giant bitches (>40 kg). The results were compared to a control group (n = 6), in which bitches underwent a natural delivery in the same environmental conditions as the induced group. In the induced group, parturition was successfully induced in 7/7 bitches. The first pup in a litter was born on average 25.9 ± 3.29 h after aglepristone administration (21–30 h). Two of seven bitches from the small-sized group delivered some of their pups before the first administration of oxytocin. The mean duration of parturition was 9.6 ± 5.4 h vs 8.0 ± 4.8 h in the control group. The mean interval between two successive pups being delivered was 115.6 ± 82.8 min (34–265) vs 68.8 ± 24.5 min in the control group (p < 0.03). The mean weight at parturition did not differ significantly between the two groups. One litter of four Yorkshire Terrier pups in the induced group were premature at the time of birth and died between 19 and 29 h post-delivery. This study, although on a very limited number of dogs, confirms the efficacy of the aglepristone/oxytocin protocol to induce parturition in dogs.     

Age‐Related Pregnancy Results and Further Examination of Bitches after Aglepristone Treatment of Pyometra

The cystic endometrial hyperplasia and pyometra complex is one of the most common uterine diseases in bitches. The appearance of pharmacological preparations containing anti‐progestagens created new possibilities for pyometra treatment. The aim of this study was to evaluate the curative effect of the anti‐progestagen aglepristone treatment of pyometra in bitches of different ages. Twenty four bitches of different breeds, aged from 0.8 to 9.5 years (21–48 kg) exhibiting clinical pyometra symptoms (two groups – I ≤ 5 years, n = 14 and II >5 years, n = 10) were evaluated. Information about the general reproductive health was collected up to 54 months after anti‐progestagen treatment. Remission of clinical symptoms and return of blood chemistry results and total leucocyte count to referential values were achieved in all cases within 14 days of treatment. Bitches were naturally mated at the first, and when unsuccessful, the second oestrus after treatment. In group I, no recurrence of pyometra symptoms was observed during following cycle(s). Eight bitches (57.1%) had a full‐term pregnancy and the number of newborn pups ranged from 1 to 12. None of the bitches from the group II became pregnant. In conclusion, the basic indication for conservative pharmacological treatment of pyometra is preserving female fertility and obtaining offspring. The important conditions for successful aglepristone treatment are: the young age (up to 5 years) and the lack of detectible ovarian cysts. It seems necessary to mate bitches in the first or second oestrus after finishing treatment. The efficacy of treatment can be measured by the after‐treatment pregnancy rate.     

A preliminary study of pregnancy termination in the bitch with slow-release formulations of prostaglandin analogues

Forty-two beagle bitches at gestational ages from 4 to 35 days were treated with various formulations of the prostaglandin analogues fluprostenol and cloprostenol at doses from 10–40 μg/kg in an attempt to terminate pregnancy. Pregnancy was confirmed and the effect of treatment assessed by euthanasia and post-mortem examination to detect viable foetuses or resorbing implants twenty-one days after prostaglandin administration. Five of the bitches treated with an aqueous solution of cloprostenol by subcutaneous injection showed unacceptable side effects but both compounds in a slow release injectable formulation or impregnated into intravaginal devices had a luteolytic effect with only mild side effects in occasional bitches. Successful response to treatment in terms of sustained depression of plasma progesterone concentrations and pregnancy termination was 80 per cent at gestation stages of 25 days or over but only 27 per cent when given earlier in pregnancy. Mature follicles developed in two bitches which aborted following treatment at 14 days and returned to oestrus 10–14 days later. These preliminary findings show that slow-release formulations of fluprostenol and cloprostenol can cause complete luteolysis in the bitch.     

Follow-up examinations of bitches after conservative treatment of pyometra with the antigestagen aglepristone

The aim of this study was to determine the therapeutic success of the medical treatment of canine pyometra with the antigestagen aglepristone and to document the recurrence rate in relation to the time interval after treatment with antigestagens. In 48 (92.8%) of the 52 treated bitches, healing could be achieved within the first 3 weeks after the treatment had been started. One bitch died as a result of renal insufficiency; in three bitches there was no emptying of the uterus, so ovariohysterectomy became necessary. In these three patients, ovarian and endometrial cysts were present. Forty-one bitches could be followed up for 3 months. Four animals developed a recurrence (9.8%). In three bitches ovarian cysts and cystic endometrial hyperlasia could be found intra operationem. The development of 37 bitches could be followed for at least 1 year. Seven animals developed a pyometra again (18.9%). Two received a repeated treatment with aglepristone and have been free from recurrence for over 12 months. In 37 animals data on the subsequent sex cycles are available. In 22 bitches next heat started at the expected time, in seven animals heat started too early. In eight bitches the period of anoestrus was prolonged. Five of the six bred bitches delivered at least one litter. The presented data show that treatment of pyometra by aglepristone results in a high healing rate. The recurrence rate can be minimized by the selection of bitches without ovarian cysts and cystic endometrial hyperplasia.     

Influence of Progesterone Withdrawal on Pregnancy-Related Parameters During Post-Implantation Early Pregnancy Loss

Pharmacologically-induced luteolysis or treatment with an antiprogestin in early post-implantation pregnancy in dogs results in asynchronous death and resorption of conceptuses, indicating variable rates of response of individual conceptuses towards progesterone deficiency. This variability also seems to occur in bitches showing pregnancy failure in response to spontaneous luteal deficiency. In a total of 10 beagle pregnancies (two consecutive pregnancies of five bitches), abortifacient treatments beginning on day 24 after ovulation (ov) involved either administration of a progestin antagonist (total of six pregnancies, in three bitches) or a luteolytic regimen of prostaglandin F_2α-analogue together with a dopamine agonist (total of four pregnancies, in two bitches). The outcomes were evaluated in relation to four control pregnancies in two bitches by assay of serum progesterone, prolactin and relaxin at selected time points or within selected time periods, by ultrasound of conceptuses including measurement of uterine blood flow, and parameters of the blood fibrinolytic system including plasma fibrinogen and plasminogen. The process of embryonic death and conceptus resorption was variable in onset and duration both in bitches that received the progesterone antagonist aglepristone (AGLE) and in those under the luteolytic treatment (cloprostenol combined with cabergoline). Pregnancy termination (death of all embryos or foetuses, respectively) occurred as early as day 29 and as late as day 41 after ov in AGLE-treated bitches, and not earlier than day 37 after ov in luteolytic-treatment bitches. Impending embryonic death was not predicted by changes in relaxin concentration, parameters of the fibrinolytic system, or in the perfusion of small uteroplacental vessels.     

Use of a low dose prostaglandin F2 alpha in bitches

The dosage of Prostaglandin F2 alpha used until the present (100, 250 and 1000 micrograms/kg bw), in order to treat pyometra in the bitch, was accompanied with side effects such as salivation, vomiting and diarrhea. In the present work, the efficiency of low dose Prostaglandin (20 micrograms/kg bw) was examined in two different groups of patients: Group 1: Included 9 bitches pregnant for a period of 5-7 weeks duration. Initially the bitches were treated 3 or 4 times per day with Prostaglandin F2 alpha. In these cases abortion took place within 4 to 11 days. Group 2: 12 dogs, suffering from pyometra, were treated 3 times per day with PGF2 alpha for 8 days. In 9 dogs the pyometra resolved and the bitches came in estrus 2-5 months after treatment. 7 bitches have been mated and 6 of these gave birth to healthy litters. During a follow-up period of at least 10 months there has not been a reoccurrence of pyometra. In 3 out of the 12 dogs the uteri were still enlarged after 8 days of treatment. These bitches underwent ovariohysterectomy and a cystic hyperplasia of the endometrium was diagnosed histologically. The low dose (20 micrograms/kg BW) Prostaglandin F2 alpha induced in all dogs the expulsion of the uterine contents. Side effects during the treatment were not observed.     

Evaluation of a new non-hormonal substance for terminating pregnancy in bitches in clinical trials

A new non-hormonal contragestational agent (DL 717-IT), the 2-(4 chlorophenyl)-s-triazole |5,1-a|-isoquinoline, was tested in clinical trials to determine its efficacy for interrupting the pregnancy in the bitch. Five hundred and sixty-five bitches were given a single intramuscular injection of the drug between the first and 15th day after the mating. Of the 475 bitches that received 2–5 mg/kg, 430 (90-5 per cent) did not whelp at all, 15 (3-2 per cent) delivered a few stillborn or weak puppies that died some hours after birth, and 30 (6-3 per cent) delivered at least one normal live pup. Of 90 bitches treated with 3–5 mg/kg, 87 (96-7 per cent) did not whelp at all, two (2-2 per cent) delivered a few stillborn or weak puppies that died some hours after birth, and one (1 1 per cent) delivered normal live puppies. DL 717-IT, owing to the high effectiveness and minimal side effects, must be considered a very reliable drug for the interruption of pregnancies in the bitch.     

Cyclosporine treatment of anal furunculosis in 26 dogs

OBJECTIVES: To evaluate the effect of cyclosporine on anal furunculosis lesions in 26 dogs. METHODS: Lesions were graded as mild in 11 dogs, moderate in eight and severe in seven. Each dog was treated with approximately 4 mg/kg cyclosporine orally every 12 hours until the lesions resolved or showed no further improvement. Residual lesions were resected surgically. RESULTS: Eighteen dogs (69 per cent) experienced complete resolution, seven (27 per cent) improved but had residual lesions and one (4 per cent) showed no improvement. The mean duration of treatment until resolution or no further improvement was 8.8 weeks (range four to 24 weeks). Nine dogs (35 per cent) experienced recurrence. Six were from the group that had shown complete resolution and three were from the group that had surgery. Fifteen dogs (58 per cent) developed side effects to cyclosporine, although none required treatment to be discontinued. Mean duration of follow-up was 6.8 months (range one to 20 months). CLINICAL SIGNIFICANCE: Cyclosporine was effective at resolving or reducing anal furunculosis lesions in 25 of 26 dogs (96 per cent). However, residual or recurrent lesions remain a potential problem, and surgical resection or long-term cyclosporine treatment may be necessary in some dogs.     

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.     

Effects of delmadinone acetate on pituitary-adrenal function, glucose tolerance and growth hormone in male dogs

Objective To characterise the effects of delmadinone acetate on the pituitary-adrenal axis, glucose tolerance and growth hormone concentration in normal male dogs and dogs with benign prostatic hyperplasia.
Design A prospective study involving nine normal male dogs and seven with prostatic hyperplasia.
Procedure Delmadinone acetate was administered to six normal male dogs and seven dogs with benign prostatic hyperplasia at recommended dose rates (1.5 mg/kg subcuta-neously at 0, 1 and 4 weeks). Three normal controls received saline at the same intervals. Blood concentrations of ACTH, cortisol, glucose, insulin and growth hormone were measured over 50 days. Intravenous glucose tolerance and ACTH response tests were performed before and after treatment in the nine normal animals.
Results A substantial suppression of basal and 2 h post-ACTH plasma cortisol secretion was demonstrated after one dose in all dogs given delmadinone acetate. Individual responses after the second and third administration varied between recovery in adrenal responsiveness to continued suppression. Plasma ACTH concentration was also diminished after one treatment. No effects were evident on glucose tolerance or serum growth hormone concentrations.
Conclusion Delmadinone acetate causes adrenal suppression from inhibition of release of ACTH from the pituitary gland. Treated dogs may be at risk of developing signs of glucocorticoid insufficiency if subjected to stressful events during or after therapy. Neither glucose intolerance nor hyper-somatotropism seems likely in male dogs given delmadinone acetate at the recommended dose rate, but the potential for excessive growth hormone secretion in treated bitches remains undetermined.     

Use of prostaglandins and bromocriptine mesylate for pregnancy termination in bitches

OBJECTIVE: To assess the efficacy and safety of 2 protocols using bromocriptine mesylate and prostaglandins to terminate unwanted pregnancy in bitches. DESIGN: Prospective randomized single-blind controlled study. ANIMALS: 34 crossbred and purebred bitches referred for possible pregnancy termination. Seven additional pregnant bitches were used as controls. PROCEDURE: Pregnancy was assessed by ultrasonographic examination from day 25 after mating in all bitches. Of the 34 bitches, 25 were pregnant and were randomly allocated to a treatment group. Group-1 dogs (n = 12) received a combination of increasing amounts of bromocriptine mesylate (15 to 30 microg/kg [6.8 to 13.6 microg/lb], p.o., q 12 h) and dinoprost tromethamine (0.1 to 0.2 mg/kg [0.045 to 0.09 mg/lb], s.c., q 24 h). Group-2 dogs (n =13) received a combination of increasing amounts of bromocriptine mesylate (the same schedule as group-1 dogs) and cloprostenol sodium (1 microg/kg [0.45 microg/lb], s.c., q 48 h). Both groups were treated until pregnancy termination. Results-Treatment success was 100% in both groups. Days of treatment required for pregnancy termination did not significantly differ between groups (5.0 +/- 0.6 vs 3.7 +/- 0.6 days, group-1 and group-2 dogs, respectively) although adverse effects only developed in group-1 dogs. At the end of the protocols, pseudopregnancy was observed in 3 of 12 and 6 of 13 group-1 and group-2 dogs, respectively. Pregnancy termination was followed by a mucoid sanguineous vulvar discharge for 3 to 10 days. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicate that protocols that combine the use of bromocriptine mesylate and prostaglandins for the termination of unwanted pregnancy in bitches are efficient and safe. The use of bromocriptine mesylate and cloprostenol had the best results and could be easily used on an outpatient basis.     

Prevalence of diagnostic characteristics indicating canine autoimmune lymphocytic thyroiditis in giant schnauzer and hovawart dogs

O bjectives : To investigate prevalence of autoantibodies to thyroglobulin (TgAA) and/or elevated levels of thyroid stimulating hormone (TSH), indicating canine autoimmune lymphocytic thyroiditis (CLT) and/or hypothyroidism, in two high-risk dog breeds.
M ethods : A cohort study was conducted in two birth cohorts of giant schnauzer and hovawart dogs. The cohorts were three to four and six to seven years of age at the time of blood sampling and screening for TgAA and TSH levels. Blood sampling was accompanied by one initial and one follow-up questionnaire to the dog owners. A total number of 236 giant schnauzers and 95 hovawarts were included in the study.
R esults : Seventeen (7.2 per cent) giant schnauzers and three (3·2 per cent) hovawarts had been diagnosed as hypothyroid at the time of sampling. Out of the remaining dogs, 22 giant schnauzers (10·0 per cent) and nine hovawarts (10·1 per cent) had elevated TgAA and/or TSH levels. Prevalence of elevated TgAA and TSH levels varied with age.
C linical S ignificance : The high prevalence of diagnostic characteristics indicating CLT/hypothyroidism in these two breeds suggests a strong genetic predisposition. It would be advisable to screen potential breeding stock for TSH and TgAA as a basis for genetic health programmes to reduce prevalence of CLT in these breeds.     

The effect of omeprazole on oesophageal pH in dogs during anaesthesia

O bjectives : Intra-operative, gastro-oesophageal reflux may be associated with post-anaesthestic complications such as oesophagitis and oesophageal stricture in dogs. The aim of this study was to investigate the effect of preoperative administration of omeprazole, a proton pump inhibitor, on oesophageal pH in anaesthetised dogs.
M ethods : Forty-seven dogs undergoing elective pelvic limb orthopaedic surgery were enrolled into the study. These were randomly allocated to treatment group (n=22) or control group (n=25). The treatment group received one dose of omeprazole (1 mg/kg po) at least 4 h before anaesthesia. All dogs were anaesthetised by the same standardised protocol. A pH probe was inserted into the distal oesophagus after induction of anaesthesia and oesophageal pH was continuously monitored.
R esults : In the treatment group, four animals (18 per cent) showed a sudden decrease in oesophageal pH (<4). In the control group the same phenomenon was detected in 13 animals (52 per cent). Gastro-oesophageal reflux occurred more frequently in the control group compared with the omeprazole group (odds ratio 4·7, 95 per cent C.I. 1.1 to 24.7, P=0.032).
C linical S ignificance : This study suggests that the preoperative administration of omeprazole is effective in reducing the incidence of gastro-oesophageal reflux during anaesthesia in dogs.     

Canine adder bites in the UK: a retrospective study of cases reported to the Veterinary Poisons Information Service

This retrospective study examined cases with follow-up reported to the Veterinary Poisons Information Service (VPIS) between September 1985 and December 2010. Most bites (69.2 per cent) occurred between April and July, particularly between 15:00 and 16:00 hours. Adder bites were more frequently reported in the south-east of England, particularly in Surrey. Swelling to the face and limbs was common, as was lethargy, depression, hyperthermia and tachycardia. About two-thirds of dogs developed both systemic and local effects, while a third developed local effects alone. Initial clinical effects usually occurred within two hours, with full recovery typically occurring five days after the bite. Antivenom was used in 55.9 per cent of cases and appeared to significantly reduce duration of oedema from an average of 94 to 47 hours. Adder bites can cause significant morbidity (97 per cent of dogs were symptomatic), but mortality is low (4.6 per cent died).     

Clinical evaluation of 51 dogs treated conservatively for disc-associated wobbler syndrome

O bjectives : To evaluate the clinical evolution and potential risk factors of 51 dogs treated conservatively for disc-associated wobbler syndrome.
M ethods : Medical records of dogs treated conservatively for disc-associated wobbler syndrome were reviewed, and owners were contacted regarding clinical evolution and survival of their animals. Relationships between age, treatment before diagnosis, type of neurological signs, results of medical imaging and outcome were determined.
R esults : Fifty-one dogs underwent conservative treatment for disc-associated wobbler syndrome. A successful outcome was achieved in 45 per cent (23 of 51) of the patients. Median follow-up period was 18.5 months, and median survival time was 47 months. In 85 per cent of the dogs in which euthanasia was performed because of disc-associated wobbler syndrome, this was carried out in the first year after diagnosis. Outcome score was influenced by type of neurological signs and additional radiographic and/or myelographic abnormalities. Outcome score was not significantly associated with age, number of protruded intervertebral discs, occurrence, type and results of treatment before diagnosis.
C linical S ignificance : Conservative treatment of disc-associated wobbler syndrome is associated with a guarded prognosis. It can be considered in cases where all four limbs are not affected and no additional radiographic and/or myelographic abnormalities are detected.     

Treatment of bitches with acquired urinary incontinence with oestriol.

Oestriol, a naturally occurring short-acting oestrogen, was used to treat acquired urinary incontinence in 129 bitches selected by 48 veterinary practitioners in the Netherlands, Belgium, France and Germany. The dogs were treated daily for 42 days with oestriol tablets, using a self-controlled study design. The dogs were examined and blood sampled at the beginning and end of the trial. According to the veterinary practitioners 83 per cent of the dogs either became continent or improved, but the others showed no change or became worse. The owners reported similar results: 82 per cent of the dogs responded to treatment and the others did not. The dose and treatment schedule for each dog were established on the basis of clinical efficacy. Mild and transient oestrogenic effects such as swelling of the vulva and attractiveness to male dogs were observed soon after the treatment began and at the higher dose schedule used in 12 of the dogs. A haematological examination of 114 of the dogs revealed no abnormalities.     

Efficacy of daily amitraz on generalised demodicosis in dogs

Fifty dogs with generalised demodicosis were treated with daily applications of 0·125 per cent amitraz solution over half the body. This was applied once a day, alternating the body half treated. Nine dogs were lost to follow-up; the remaining dogs were classified as either a success (25 dogs, 61 per cent) or a failure (16 dogs, 39 per cent) according to their response to treatment. Eight of the failures were due to persistent demodicosis and eight relapsed within one year after treatment. All eight of the relapsed dogs were cured after a second course of daily amitraz treatment. For the 25 dogs considered treatment successes, the median duration of treatment was 6·5 weeks (range, three weeks to nine months), and the median interval from completion of treatment to last post treatment evaluation was 3·4 years (range, two to four-and-a-half-years). Including the eight dogs that were cured after retreatment, the daily amitraz applications were curative in 33 of 41 dogs (80 per cent) with generalised demodicosis.     

Acquired urinary incontinence in bitches: its incidence and relationship to neutering practices

A five-year cohort study was conducted on bitches chosen by a sample of 233 randomly selected practising veterinary surgeons in the UK, to estimate the incidence of acquired urinary incontinence (AUI) in neutered and entire animals, and to investigate possible risk factors associated with neutering practices. Information was collected using questionnaires, and data on 809 bitches, of which 22 developed AUI, were obtained. The estimated incidence rates in neutered and entire animals were 0·0174 and 0·0022 per animal-year, respectively (95 per cent confidence intervals: 0·0110, 0·0275 and 0·0009, 0·0058, respectively). The relative risk, neutered vs entire, was 7·8 (95 per cent confidence interval: 2·6, 31·5). The attributable proportion_exposed and population attributable proportion were 87·1 per cent and 63·1 per cent (95 per cent confidence intervals: 61·9 per cent, 95·6 per cent, and 28·3 per cent, 88·5 per cent, respectively). An increased risk, significant at the conventional 5 per cent level, was not demonstrated in animals neutered before, vs after, first heat (relative risk: 3·9, 95 per cent confidence interval: 0·8, 10·4), although the result was significant at the 10 per cent level. Removal of the cervix was not shown to be a risk factor in neutered dogs.     

Foetal pulmonary maturity in dogs: Estimated from bubble tests in amniotic fluid obtained via amniocentesis

The goal of this study was to evaluate the reliability of amniocentesis during late pregnancy to assess lung maturity in puppies using a bubble test as described by Gunston and Davey (South African Medical Journal, 54, 1978, 495). Thirty‐five bitches from eight different breeds were followed during late pregnancy before undergoing elective Caesarean (C)‐section on days 61–62 after ovulation. Bubble tests were performed the day before the C‐section (n = 11 bitches) and before the administration of aglepristone on amniotic fluid samples obtained via amniocentesis and were repeated the day of the surgery on amniotic fluid samples collected via puncture of the amniotic bags before they were opened (n = 35 bitches). No complications were observed following amniocenteses and the C‐sections. The mortality rate (2.3%) was similar to the result of other studies using the same protocol for an elective C‐section. Of the non‐contaminated samples collected the day of the C‐section, 89.6% were positive in the bubble test, which was consistent with observations of clinical maturity the day of the surgery and on the following days. In contrast, 70% of the samples collected the day before the C‐section (when progesterone concentrations were still high) were negative, suggesting that the puppies were still immature at this point in the pregnancy. Additionally, we observed a significant difference in the bubble test results before and 18 hr after the administration of aglepristone, suggesting that aglepristone may act as an inducer of the final maturation of the puppies by inactivating progesterone receptors and simulating a physiological decrease in progesterone. Finally, we confirmed the need to exclude all contaminated samples, which could lead to false‐negative results.     

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.