Semen parameters and testicular dimensions in small breed dogs below ten-kilogram bodyweight.

Because of few available data on semen parameters in small breed dogs, the study aimed to analyse semen and measure testes of dogs ≤10.0 kg bodyweight. Semen was collected from 41 fertile stud dogs, which were divided based on bodyweight: group 1 ≤ 5.0 kg and group 2 between 5.1 and 10.0 kg. Median values for ejaculate volume (group 1: x ~ 1.2 ml; group 2: x ~ 2.2 ml), total sperm output (group 1: x ~ 110.7 × 106 ; group 2: x ~ 215.1 × 106 ) and testicular volume (group 1: left testicle x ~ 2.8 ml, right testicle x ~ 2.7 ml; group 2: left testicle x ~ 5.5 ml, right testicle x ~ 5.0 ml) were lower in group 1 compared to dogs of group 2 (p = .001; p = .001; both testes: p < .001). There was no difference in sperm concentration (p = .985). Based on these results, introduction of an additional weight group to the commonly used reference values is recommended, since values for ejaculate volume, total sperm output and testicular dimensions for dogs ≤5.0 kg bodyweight differed significantly from values of dogs with a bodyweight from 5.1 to 10.0 kg.

Physiological Anti-Müllerian Hormone Concentrations in Male and Female Dogs and Cats before and around Puberty.

In recent years several studies established the diagnostic value of anti-Müllerian hormone (AMH) in companion animals. However, less is known about physiological AMH concentrations in young individuals highlighting the necessity to apply the diagnostic findings to this group. The aim of this study was to determine the AMH values of healthy male and female dogs between the age of 8 and 48 weeks, tomcats under 8 weeks and up to 48 weeks of age and queens between 2 to 12 weeks of age. In total, 96 blood samples were collected. Anti-Müllerian hormone was measured in all samples and testosterone was measured in the oldest age group of the males in both species. The hormones were analyzed using a human based chemiluminescence immune assay. Overall, AMH concentrations were higher in males than in females (p < 0.001). According to the AMH concentration there was no difference in males, but queens had significant higher AMH concentrations than bitches (p < 0.001). AMH remained high in males up to week 24 and decreased significantly thereafter (tomcats: p = 0.015; male dogs: p = 0.013), which correlated with an increase in testosterone levels for male dogs only. In bitches, AMH remained below the detection limit until the week 16 and slightly increased subsequently. In queens, AMH was detectable from the beginning with a significant increase in the older age group (p = 0.003). Half of the cats in the older age group even approached the chemiluminescence immune assay's upper limit. The results show that female cats secrete AMH much earlier than female dogs in which AMH secretion begins just shortly before the start of the puberty. In the male animals, the decrease in AMH concentration around puberty was similar in dogs and cats, but a correlation with the increase of testosterone was only observed in dogs. Further research is required to determine the origin of the high AMH concentrations in female kittens and the lack of correlation between testosterone and AMH concentrations in male kittens.

Anti-Müllerian hormone as a diagnostic tool to identify queens with ovarian remnant syndrome.

OBJECTIVES: Ovarian remnant syndrome (ORS) is suspected when heat signs occur in spayed individuals, but further diagnostic procedures are necessary to exclude other possible oestrogen sources, such as the adrenal gland or exogenous supplementation. Anti-Müllerian hormone (AMH), secreted by granulosa cells or Sertoli cells, serves to differentiate sexually intact from gonadectomised animals and has been described in dogs as a tool for diagnosing ORS. The aim of this study was to evaluate if AMH determination can be used to diagnose ORS in cats. METHODS: AMH was measured with a chemiluminescence immunoassay in serum samples of 15 sexually intact, 9 spayed and 16 cats with a history of heat signs after spaying. Abdominal ultrasound (n = 13), vaginal smears (n = 7), progesterone measurement (n = 5) and laparotomy (n = 14) were used to determine the presence of ovarian tissue. After surgery, a histological examination of the obtained tissue was performed in the cats with suspected ORS. RESULTS: In 15 cats with ORS the AMH serum concentrations were significantly higher than in spayed cats (n = 10; P = 0.025) and significantly lower than in sexually intact cats (n = 15; P = 0.001). Among the cats with ORS, the highest AMH serum concentrations were measured in the queens with cystic ovarian alterations and in one cat from which a whole ovary was obtained. The cat with the lowest AMH serum concentration had a simultaneous high progesterone serum concentration. Cats with ORS did not show any heat signs after surgical removal of the ovarian tissue. CONCLUSIONS AND RELEVANCE: A single determination of AMH in blood serum is a useful diagnostic tool for the diagnosis of ORS in cats, regardless of the hormonal activity of the remnant ovarian tissue.

Anti-Müllerian hormone concentrations in queens throughout the estrous cycle.

Studies in cats and dogs have proven the usefulness of anti-Müllerian hormone (AMH) as a diagnostic tool to determine the castration status or to diagnose ovarian remnant syndrome. Yet the secretion pattern of AMH over the estrous cycle in queens has not been investigated so far. Seven healthy sexually intact female cats were examined daily for signs of estrous behavior over a trial period of 4 months. Five queens showed regular estrous behavior, 1 queen was mated in her first heat and 1 queen never showed any signs of heat. To distinguish between inter-estrus and metestrus progesterone levels were determined. Serum samples for AMH and progesterone measurement were collected from the regular cycling queens in late anestrus, at several times during heat, inter-estrus and metestrus, from the mated queen during her first heat and during pregnancy, and in the acycling queen at various times during the trial period. The measured AMH values in anestrus were significantly (P < 0.05) higher than in heat (P < 0.001), metestrus (P = 0.12) and inter-estrus (P = 0.449). In anestrus the median AMH levels were 10.26 ng/ml (range 4.96 to 22.90 ng/ml), in heat 5.97 ng/ml (range 3.32- 22.96 ng/ml), in inter-estrus 10.47 (range 3.35-22.96 ng/ml) and in metestrus 6.38 ng/ml (range 4.50-10.75 ng/ml. The pregnant cat showed median AMH concentrations of 6.47 ng/ml (range 5.60-9.80 ng/ml) during her pregnancy. The acycling queen had solely low AMH values with a median concentration of 0.39 ng/ml. In conclusion there were high variations of the AMH levels among and within the individual cats and between heat cycles in the single cat. Remarkable high AMH concentrations were measured in the younger queens of the study in their first estrous cycles and also in anestrus, when less ovarian activity is expected. Further studies are necessary to emphasize the reasons for these high AMH concentrations especially in young queens.

[Birth of a vital puppy following prolonged whelping in a Labrador Retriever]. / Geburt eines lebenden Labradorwelpen nach deutlich verlängerter Geburt.

An 8-year-old primiparous Labrador Retriever bitch was presented to the clinic 46 hours following the delivery of 2 vital and one stillborn puppy due to an increase of vaginal discharge. At the veterinary clinic, the dog spontaneously delivered an additional healthy puppy without any obstetric support. The findings of the general and gynaecological examinations as well as results of blood analyses were within normal limits. This case shows that extremely prolonged whelping process may be a rare but possible phenomenon in bitches. However, it is recommended to re-evaluate dam and fetuses regularly in case the inter-whelping interval exceeds the normal time span in order to recognize further signs of dystocia and induce obstetric support when clinically indicated.