Treatment of hypersexuality and benign prostatic hypertrophy with delmadinone acetate in intact male dogs

Abstract

The aim of the present study was to evaluate the effectiveness of delmadinone acetate (DMA) for the treatment of hypersexuality (HS) and benign prostatic hypertrophy (BPH), which are frequently observed in male dogs, for which no surgical treatment has been indicated. The study was performed with 21 intact male dogs that had HS (n = 12) and signs of BPH (n = 9). DMA (Tardak(R) or Tardastrex(R)) was administered subcutaneously to each dog at a dose of 3-5 mg/kg and was repeated 15 days later as a second treatment. DMA administration was repeated in some cases until the clinical signs disappeared. The successful recovery rate of HS cases was found to be 50% after a single application and 25% by the second and third applications. The mean "recovery periods" and mean "stable periods" of these 3 consecutive applications were found to be 5.83, 7.66, and 6.00 days, and 16.7, 18.7, and 20.0 months, respectively. With regard to BPH after consecutive applications, treatment success rates, mean recovery periods, and mean stable periods were 33.3%, 22.2%, 44.4%, 12.0, 11.0, 9.5 days, and >30, 12, and 13.5 months, respectively. DMA is clinically applicable as a therapeutic agent for HS and BPH cases; however, repeated applications were required due to temporary recoveries.

Full text

Page 1

Treatment of hypersexuality and benign prostatic hypertrophy
with delmadinone acetate in intact male dogs
Hakkı B. BECERİKLİSOY1, Serhan S. AY2, Duygu KAYA3, Ali R. AĞAOĞLU3, İbrahim KÜÇÜKASLAN3,
Okan A. AKSOY3, Nil ERÜNAL MARAL4, Murat FINDIK2, Selim ASLAN3,*
1Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Adnan Menderes University,
Işıklı, Aydın - TURKEY
2Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Ondokuz Mayıs University,
Samsun - TURKEY
3Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Ankara University,
Dışkapı, Ankara - TURKEY
4Başkent Animal Hospital, Ayrancı, Ankara - TURKEY
Received: 01.11.2007
Abstract:The aim of the present study was to evaluate the effectiveness of delmadinone acetate (DMA) for the treatment
of hypersexuality (HS) and benign prostatic hypertrophy (BPH), which are frequently observed in male dogs, for which
no surgical treatment has been indicated. The study was performed with 21 intact male dogs that had HS (n = 12) and
signs of BPH (n = 9). DMA (Tardak® or Tardastrex®) was administered subcutaneously to each dog at a dose of 3-5 mg/kg
and was repeated 15 days later as a second treatment. DMA administration was repeated in some cases until the clinical
signs disappeared. The successful recovery rate of HS cases was found to be 50% after a single application and 25% by
the second and third applications. The mean “recovery periods” and mean “stable periods” of these 3 consecutive
applications were found to be 5.83, 7.66, and 6.00 days, and 16.7, 18.7, and 20.0 months, respectively. With regard to
BPH after consecutive applications, treatment success rates, mean recovery periods, and mean stable periods were 33.3%,
22.2%, 44.4%, 12.0, 11.0, 9.5 days, and >30, 12, and 13.5 months, respectively. DMA is clinically applicable as a therapeutic
agent for HS and BPH cases; however, repeated applications were required due to temporary recoveries.
Key words: Clinical application, prostate, repeated doses, therapeutic agent
Erkek köpeklerde hiperseksüalite ve benign prostat hipertrofisi’nin
delmadinon asetat ile tedavisi
Özet: Erkek köpeklerde sıklıkla görülen ve cerrahi yaklaşımın endike olmadığı durumlarda, hiperseksüalite (HS) ve
benign prostat hipertrofisi (BPH) olgularının tedavisinde delmadinon asetat’ın (DMA) etkinliği araştırıldı. Çalışma
kısırlaştırılmamış 21 erkek köpekte yapıldı, bunların 12 tanesinde HS, 9 tanesinde de BPH semptomları gözlendi. DMA
(Tardak® veya Tardastrex®) 3-5 mg/kg dozunda derialtı enjekte edildi ve 15 gün sonra ikinci tedavi aynı dozda yinelendi.
Gereken olgularda semptomlar ortadan kalkana kadar uygulamalar tekrar edildi. HS vakalarında iyileşme oranı tek
enjeksiyondan sonra % 50, ikinci ve üçüncü enjeksiyondan sonra ise % 25 oranında bulundu. Sırasıyla bu semptomların
25
Research Article
Turk. J. Vet. Anim. Sci.
2010; 34(1): 25-31
© TÜBİTAK
doi:10.3906/vet-0711-1
* E-mail: aslan@veterinary.ankara.edu.tr

Page 2

Introduction
Hypersexuality (HS) is a condition that occurs in
male dogs. Its clinical signs include mounting other
objects and penile erection. Ejaculation, licking, and
biting the penis and aggressive behavior may also be
seen (1). In addition, thickening, inflammation,
dermatitis, and wounds around the preputium may
be observed in some cases (2).
The diagnosis of prostatic disorders is based on
history, rectal or transabdominal palpation of the
gland, the presence of urethral abnormalities,
histological evaluation of biopsy material, and
radiographic and ultrasonographic examination
methods (3).
Examination of the prostate gland by caudo-
abdominal palpation is more useful than digital rectal
examination in canine species. A normal prostate
gland has a symmetrical and smooth shape and is
movable and painless (4,5).
For the evaluation of prostatic disorders,
ultrasonography is a useful technique. As the prostate
gland is not deeply positioned within the pelvic canal,
it can be examined easily (3). Ultrasonographic
examination can be performed by transabdominal,
transrectal, perianal, or transurethral routes (6). The
size, symmetry or asymmetry, and echogenic
structure of the prostate gland may be evaluated
together with the surrounding area and lymph nodes
(5).
Benign prostatic hypertrophy (BPH) is a
spontaneous and age-related condition in men, male
dogs and apes (chimpanzee) (4,7). It was reported that
canine prostate gland enlargement begins at 2.5 years
of age (1). The prostate gland becomes enlarged in
aging dogs and correlates with the size of the dog (6).
Benign prostatic hypertrophy is observed in 95% of
older dogs. In more than 80% of male dogs over 5
years of age with BPH, prostatic volume is 2 to 6.5
times greater than normal dogs (5).
In most cases of prostatic hypertrophy, clinical
signs do not indicate abnormal or systemic problems.
Hematological and urinary analyses may be in normal
ranges (4,5). Clinical signs in affected dogs include
serosanguineous prostatic fluid dripping from the tip
of the penis, blood present in urine or semen,
constipation, and dysuria (5).
Prostate hypertrophy is usually detected by
ultrasonography as a uniformed enlarged mass.
Echogenicity is observed in normal visual inspection.
Small hyperechoic and anechoic areas may be
identified (3,7). Prostatic parenchyma is observed as
homogenous and increase in echogenicity (8,9).
Although castration is an effective treatment for
BPH, medical treatment is still required for dogs that
pose critical risks for surgery or that may
subsequently be used for breeding (7,10,11).
Delmadinone acetate (DMA) is a progestin drug
used for the treatment of prostatic hypertrophy,
perianal tumors, and HS in male dogs as well as to
prevent and suppress estrus in bitches (12). DMA is
preferred mainly for both HS and BPH treatments
because its anti-androgenic efficiency is higher than
that of other progestogens (1,5,13).
The aim of the present study was to investigate the
effectiveness of DMA on the treatment of HS and
BPH cases by determining concurrent efficacy of its
repeated doses on clinical signs.
Materials and methods
This study was performed with 21 intact male dogs
of different breeds which had HS (n = 12; 2-11 years
old) and BPH signs (n = 9; 8-13 years old), were
referred to Clinic of Obstetrics and Gynecology,
Treatment of hypersexuality and benign prostatic hypertrophy with delmadinone acetate in intact male dogs
26
ortadan kalkma süreleri 5,83, 7,66 ve 6,00 gün sürerken, semptomların yeniden ortaya çıkmadığı stabil kalma süresi,
16,7, 18,7 ve 20,0 ay olarak bulundu. BPH vakalarında iyileşme oranı sırasıyla: % 33,3; % 22,2; ve % 44,4; iyileşme süresi:
12,0; 11,0; ve 9,5 gün; ve iyileşmenin stabil kaldığı süreler: >30; 12 ve 13,5 ay olarak bulundu. DMA’nın HS ve BPH
vakalarında klinik olgularda sağaltım amacı için uygun terapötik ajan olduğu fakat geçici süreyle sağladığı iyileşmeden
dolayı tekrarlayan dozlarının uygulanmasının gerektiği kanısına varılmıştır.
Anahtar sözcükler: Klinik uygulama, prostat, tekrarlayan doz, terapötik ajan

Page 3

Faculty of Veterinary Medicine, University of Ankara
and therefore animals were grouped according to
diagnosis.
Diagnosis of HS was based on history. Prostatic
hypertrophies were diagnosed by history, digital rectal
examination, cytology and ultrasound (linear probe,
6.0 MHz, Falco 100) applying the method described
by Kamolpatana et al. (14). Echogenicity-
homogeneity, symmetry,and the size of prostate were
evaluated. BPH was diagnosed with ultrasonography,
which displays smooth surface, homogeneity in
parenchyma, and increased texture echogenicity.
Furthermore, fine-needle aspiration biopsy
(FNAB) guided by transabdominal ultrasonography
(15,16) was performed under sedation (0.3mg/kg IV,
Diazem®; Deva) and biopsy samples were stained with
Papanicolau’s (17) staining technique. Thus, prostatic
biopsy material was sampled solely from BPH cases.
DMA (Tardak®
or Tardastrex®; Pfizer) was
administered at a dose of 3-5 mg/kg subcutaneously
and repeated after 15 days. In cases of neutrophil
leukocyte infiltration in cytological samples,
additional antibiotic tablets (enrofloxacin, 50mg/3kg
BW, Baytril®; Bayer) were administered. DMA
applications were repeated in some cases until the
signs disappeared.
The time to disappearance of clinical signs in HS
and BPH cases as well as regression of prostate size in
BPH cases was defined as the “recovery period”.
Maintenance of sexual calmness was defined as the
“stable period”. Even when the first treatment was
sufficient, a second dose was administered 15 days
later. The recovery period in HS cases was determined
based on owner’s observation, followed by an
evaluation of patient’s sexual behavior for 45 min at a
minimum interval of 2-3 days in our clinic. Besides,
the same intervals of evaluation to establish the
“recovery period” in BPH cases and regression in
prostate size were monitored using USG only in BPH
cases not in HS cases. The stable period in all cases
was determined according to history. Whenever
animals exhibited the same signs, they were referred
to the clinic again for re-evaluation.
Statistical analyses were performed using SPSS
14.0 with descriptive statistics and independent-
sample t-test or paired-sample t-test methods.
Results
The results were evaluated separately for HS and
BPH cases. Mounting the owner was described as the
most frequent sign (91.7%) in HS cases. Penile
erection was found at 66.7% of the time (Table 1).
After the DMA treatment, 50% of the dogs were
treated with the single dose and mean recovery time
was 5.83 days. The success rates of the second and
third treatments were both found to be 25% and mean
recovery periods of these treatments were 7.66 and
6.00 days, respectively. The effectiveness of the first,
second,and third DMA applications were found to be
16.7, 18.7, and 20.0 months, respectively (Table 2).
H. B. BECERİKLİSOY, S. S. AY, D. KAYA, A. R. AĞAOĞLU, İ. KÜÇÜKASLAN, O. A. AKSOY,
N. ERÜNAL MARAL, M. FINDIK, S. ASLAN
27
Table 1. Prevalence of clinical signs in HS and BPH cases.
Case Clinical signx/n Prevalence (%)
Mounting behavior
Erection
Odors
Urine marking
Epileptic forms
Licking
11/12
8/12
7/12
3/12
2/12
1/12
91.7
66.7
58.3
25.0
16.7
8.3
Hypersexuality
Incontinentia urine
Polyuria
Hematuria
Tenesmus
Kyphosis
Anorexia
5/9
5/9
5/9
3/9
1/9
1/9
55
55
55
33
11
11
BPH

Page 4

The age distribution of dogs with HS symptoms
was 2-5 years (n = 4) and 6-9 years (n = 8). Mean
duration of clinical signs, mean stable period, and
mean number of applications are summarized in
Table 3. No significant difference was found between
the stable periods of different age scales (P > 0.05).
In particular, clear ultrasonographic images were
taken of the surface and edges of the prostate (Figure
1). No statistical differences were found between the
data for prostatic size, and recovery and stable period
in BPH cases as summarized in Table 4 (P > 0.05).
Histological examination of biopsy samples
revealed different size of epithelial cells, erythrocytes,
sparse neutrophil leukocytes, and no tumor-like cells
(Figure 2).
The age of dogs with BPH ranged between 8 and
13 years. Incidence rates for different clinical
symptoms in these cases were 55% for urinary
incontinence, polyuria and hematuria, 33% for
tenesmus, 11% for kyphosis, and 11% for anorexia
(Table 1). For BPH, 33.3% (n = 3) of cases showed
sexual calmness during clinical observation, but in
44.4% (n= 4) of the cases, clinical signs were observed
3 times during this period (Table 2).
In all BPH cases, the mean recovery period and
mean stable period were found to be 9.2 days and 12.5
months, respectively. There were no significant
differences between stable period and cases requiring
2 or 3 repetitions (P > 0.05).
Treatment of hypersexuality and benign prostatic hypertrophy with delmadinone acetate in intact male dogs
28
Table 2. Prevalence of treated cases, mean recovery period, and stable period with respect to the number of applications in HS and
BPH cases.
Case Number of applications
treated cases (%)
x/n Prevalence of
(Sx ± x)
Mean recovery
period (month)
Mean stable
(Sx ± x)period (day)
1
2
3
3/9
2/9
4/9
33.33
22.22
44.44
12.0> 30
BPH 11.0 ± 1.4
9.5 ± 0.70
12.0 ± 0.00a
13.5 ± 4.44a
1
2
3
6/12
3/12
3/12
50
25
25
5.83 ± 1.72
7.66 ± 1.52
6.00 ± 1.00
16.7 ± 3.5
18.7 ± 4.9
20.0 ± 5.0
HS
aP > 0.05
Table 3. Distribution of HS cases with respect to age, mean stable period, and the number of applications.
Age (years)n Main duration of clinical
signs (months)
(Sx ± x)
Mean stable period
(months)
(Sx ± x)
Number of applications
(Sx ± x)
2-5
6-9
4
8
4.0 ± 2.8
4.2 ± 1.3
12.3 ± 6.7a
9.3 ± 4.06a
1.5 ± 1.0
1.9 ± 0.8
aP > 0.05
Figure 1. Ultrasonographic image of BPH shows a smooth
surface, homogeneity in parenchyma, and increased
texture echogenicity.

Page 5

Discussion
Signs of hypersexuality usually include excessive
sexual activity,such as mounting of people or objects,
erection, ejaculation, and sometimes epileptic
behavioral changes (1,18). HS can be accompanied by
aggressiveness, psychological restlessness,
epileptic seizures (19).
In this study, mounting the owner was the most
common sign and its rate was as high as 91.7%.
Erections were also found to occur at a rate of 66.7%
and forms of epilepsy were found at a rate of 16.7%.
Synthetic progestins cause a decrease in prostate
size in dogs with BPH by suppressing gonadotropin
release and plasma T-concentration due to its negative
feedback effect on the pituitary gland (20). Medical
indications for progestin administration also include
canine HS (13).
Successful recovery rate after the first treatment
(average: 16.7 month) was found to be 50%. Other
cases required second (25%) and third (25%)
and
treatments. This result shows that the effect of DMA
is reversible in HS; therefore, application of DMA
should be repeated. Arbeiter (1) reported that
application of DMA should be repeated every 5 or 6
months. In this study, we waited for the recurrence of
signs in order to avoid known side effects of frequent
application of DMA. This study showed that waiting
for recurrence after the first treatment could help to
avoid drug side effects during the treatment period.
BPH, which is the enlargement of the prostate
gland without inflammation, is related to age (21).
Initially, dogs with BPH may not have any clinical
signs. In this study, dogs with hematuria (55%) and
tenesmus (33%) were observed to be more frequent.
Glandular hypertrophy can be seen in 2.5 year old
dogs with BPH; prevalence increases at 4 years of age
and the frequency of BPH reaches 80% by age 6 and
95% by age 9 (21). In this study, dogs that were
brought to our clinic with signs of BPH were between
8-13 years old. These ages constitute the most critical
period for BPH and also its signs can clearly be seen
in this period, as reported by Berry et al. (21).
The normal size of the prostate is 1.7 cm × 2.5 cm
in adult male dogs but it is variable considering to
breed, age, and body weight (7,22). The lengths and
widths of prostates
ultrasonographic measurement were found to be
higher than 3.5 cm and 7.5 cm, respectively. Our
findings showed that the recovery time and stable
period were not related to prostatic size in BPH cases
(P > 0.05). Some authors reported that clinical signs of
recovery were detected between 7 to 10 days and also
that the recovery period was not related to prostatic
size (13,21). In this study, the mean time to
disappearance of clinical signs was 9.2 days and no
correlation was found between prostate sizes and
recovery period.
in dogs studied by
H. B. BECERİKLİSOY, S. S. AY, D. KAYA, A. R. AĞAOĞLU, İ. KÜÇÜKASLAN, O. A. AKSOY,
N. ERÜNAL MARAL, M. FINDIK, S. ASLAN
29
Table 4. Mean recovery period and stable period with respect to the size of prostate.
Size of prostate (cm)n Mean recovery period
(days) (Sx ± x)
Mean stable period
(months) (Sx ± x)
3.5 × 7.0 cm
> 3.5 × 7.0 cm
6
3
8.5 ± 1.7a
10.5 ± 2.1a
13.1 ± 2.2b
14.5 ± 4.9b
aP > 0.05
bP > 0.05
Figure 2. Cytological sample of a BPH case (different size
epithelial cells, erythrocytes, and sparse neutrophil
leukocytes).

Page 6

In the present study, normal epithelial cells,
erythrocytes and neutrophils were detected by means
of FNB, which was applied for confirming the
ultrasonographic findings in BPH cases. Anisocytosis,
karyokinesis, presence of vacuoles,and no basophilic
variation in cytoplasm have been used for differential
diagnosis between BPH and prostate carcinoma with
cytological analysis (16). These methods were not
used in our study, because the present study was
carried out on animals with only BPH.
All of the dogs in our study had owners who did
not accept the castration operation because of its
complications (senility-anesthesia, side effects, and
postoperative aggressiveness). Hormonal treatment
could be an alternative for BPH cases. The
effectiveness of estrogen and progesterone treatment
in prostate hypertrophy has been substantiated by
some authors (23). It was reported that in BPH cases,
even though administration of DMA (1-2 mg/kg)
results in remission of clinical signs within 4 days,
repetition of the dose is required a week later; which
is effective for at least 3 months (24). In our study,
disappearance of clinical signs occurred in HS cases in
between 5.83 and 7.66 days and in BPH cases in
between 9.5 and 12.0 days. Similarly, disappearance
of HS signs in 2-5 days after DMA application and
maintenance of sexual calmness for 3-5 months were
reported (19).
Average values obtained in the present study
indicate no recurrence of clinical signs for at least 4-5
months, which concurs with results reported by other
authors (13).
In a previous study where medroxyprogesterone
acetate and D-chlormadinone acetate were used for
treating BPH cases as an alternative to castration, it
was reported that in most of the dogs, clinical signs
could recur 3 to 24 months after the initial treatment
(11,13). In the present study, recurrence of clinical
signs was not seen for 12.0-13.5 months and a
continuation of prostatic regression was also
observed. In HS cases, no clinical signs were observed
for 16.7 to 20.0 months. No statistically significant
difference was found between DMA administered 3
times at different interval durations (P > 0.05).
This treatment protocol is never as successful as
castration and requires repeated injections (13).
Repetition of signs following the administration of a
single DMA injection after 30 months was found to
be 33%, which is similar to findings of other authors.
Secondary and tertiary repetitions were required for
22.22% and 33.33% of the remaining cases,
respectively.
In conclusion, DMA is clinically applicable as a
therapeutic agent for cases of HS and BPH when
castration is not an option; however, repeated
applications are required.
Treatment of hypersexuality and benign prostatic hypertrophy with delmadinone acetate in intact male dogs
30
1. Arbeiter, K.: Anwendung von Hormonen in der Reproduktion
von Hund und Katze. In: Döcke, F., Ed. Veterinärmedizinische
Endokrinologie. 3. Auflage, Gustav Fischer Verlag, Jena,
Stutgart. 1994; 823-841.
Holzmann, A.: Pathologie der akzessorischen Drüsen. In:
Busch, W., Holzmann, A., Eds. Veterinaermedizinische
Andrologie. Schattauerverlag, Stuttgart. 2001; 423-427.
Burk, R.L., Ackerman, N.: Genital system. In: Burk, R.L.,
Ackerman, N., Eds. Small Animal Radiology and
Ultrasonography: A Diagnostic Atlas and Text. W.B. Saunders
Company, Philadelphia. 1996; 401-408.
Smith, F.O.: Reproductive tract emergencies. In: Murtaugh, R.J.,
Kaplan, P.M., Eds. Veterinary Emergency and Critical Care
Medicine. Mosby Year Book, Missouri. 1992; 420-426.
Johnston, S.D., Root Kustritz, M.V., Olson, P.N.S.: Disorders of
the canine prostate. In: Johnston, S.D., Root Kustritz, M.V.,
Olson, P.N.S., Eds. Canine and Feline Theriogenology. W.B.
Saunders, Philadelphia. 2001; 337-356.
2.
3.
4.
5.
6. Atalan, G., Holt, P.E., Barr, F.: Ultrasonographic estimation of
prostate size in normal dogs and its relationship to body weight
and age. J. Small Anim. Pract., 1999; 40: 119-122.
Lange, K., Cordes, E.K., Hoppen, H.O., Günzel-Apel, A.R.:
Determination of concentrations of sex steroids in blood plasma
and semen of male dogs treated with delmadinone acetate or
finasteride. J. Reprod. Fertil. (Suppl.), 2001; 57: 83-91.
Feeney, D.A., Johnston, G.R., Klausner, J.S.: Two-dimensional,
gray-scale ultrasonography. Applications in canine prostatic
disease. Vet. Clin. North Am. Small Anim. Pract., 1985; 15:
1159-1176.
Lamb, C.R.: Abdominal ultrasonography in small animals:
intestinal tract and mesentery, kidneys adrenal glands, uterus
and prostate. J. Small Anim. Pract., 1990; 31: 295-304.
Tsutsui, T., Hori, T., Shimizu, M., Orima, H., Kawakami, E.,
Fukuda, S.: Regression of prostatic hypertrophy by osaterone
acetate in dogs. J. Vet. Med. Sci., 2000; 62: 1115-1119.
7.
8.
9.
10.
References

Page 7

H. B. BECERİKLİSOY, S. S. AY, D. KAYA, A. R. AĞAOĞLU, İ. KÜÇÜKASLAN, O. A. AKSOY,
N. ERÜNAL MARAL, M. FINDIK, S. ASLAN
31
11. Anderson, A., Linde-Forsberg, C.: Castration and progestagen
treatment of male dogs, part 1. Eur. J. Compan. Anim. Pract.,
2002; 12:173-177
Court, E.A., Watson, A.D.J., Church, D.B., Emslie, D.R.: Effect
of delmadinone acetate on pituitary-adrenal function, glucose
tolerance and growth hormone in male dogs. Aust. Vet. J., 1998;
76: 555-560.
Arbeiter, K.: Diseases of the prostate in the dog. Tierärztl. Prax.,
1987; 15: 291-294. (article in German with an abstract in
English)
Kamolpatana, K., Johnston, G.R., Johnston, S.D.: Determination
of canine prostatic volume
ultrasonography. Vet. Radiol. Ultrasound, 2000; 41: 73-77.
Finn, S.T., Wrigley, R.H.: Ultrasonography and ultrasound-
guided biopsy of the canine prostate. In: Kirk, R.W., Bonagura,
J.D. Eds., Current Veterinary Therapy X: Small Animal Practice.
W. B. Saunders, Philadelphia. 1989; 1227-1239.
Paclikova, K., Kohout, P., Vlasin, M.: Diagnostic possibilities in
the management of canine prostatic disorders. Vet. Med.-Czech,
2006; 51: 1-13.
Papanicolau, G.N.: A new procedure for staining vaginal
smears. Science, 1942; 95: 438-439.
12.
13.
14.
using transabdominal
15.
16.
17.
18. Holzmann, V.A.: Hypersexualität beim Rüden. Wien. Tierärztl.
Monat., 1975; 62: 355-356.
Leidl, W.: Fortpflanzungsstörungen bei Hund und Katze. In:
Schaetz, F., Leidl, W., Eds. Fortpflanzungsstörungen bei den
Haustieren. Ferdinand Enke Verlag, Stuttgart. 1983; 354-376.
Juniewicz, P.E., Barbolt, T.A., Egy, M.A., Frenette, G., Dube, J.Y.,
Tremblay, R.R.: Effects of androgen and antiandrogen treatment
on canine prostatic arginine esterase. Prostate, 1990; 17: 101-
111.
Berry, S.J., Coffey, D.S., Strandberg, J.D., Ewing, L.L.: Effect of
age, castration and testosterone replacement on the
development and restoration of canine benign prostatic
hyperplasia. Prostate, 1986; 9: 295-302.
Forbes, L.: An ultrasonographic study of the effect of age,
bodyweight and castration on the size of the canine prostate
gland. London, Univ., B. Vet. Med., Dissertation, 1992.
Cain, J.L.: Drugs used to treat reproductive disorders. Vet. Clin.
North Am. Small Anim. Pract., 1998; 28: 395-410.
Allen, W.E., England, G.C.W.:
Fortpflanzung beim Rüden, In: Hutchison, M., Ed.
Kompendium der Endokrinologie- Hund und Katze,
Schlütersche Verlagsanstalt, Hannover. 1996; 119-123.
19.
20.
21.
22.
23.
24. Endokrinologie der