This document presents information on techniques for population control in dogs, including both surgical and non-surgical methods. It discusses the need to control the large stray dog population for public health and safety reasons. The key methods described are breeding control strategies like sterilization surgeries such as orchiectomy, ovariohysterectomy, vasectomy and tubectomy. It also covers non-surgical techniques like using chemosterilants that are injected into the testes, as well as hormonal and immunological methods to disrupt breeding. The document provides details on how each technique works and considerations for veterinarians in choosing the most effective and ethical approach.

1. Department of Veterinary Gynaecology & Obstetrics
Uttar Pradesh Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan
Sansthan, DUVASU, Mathura
Presentation on
Medicinal and Surgical
Techniques for Population
Control in Dog
Presented by-
Harshit Saxena
BVSc & AH- 5th Prof. Yr.

2. Need to control Dog population??
WHO estimates that Dog population is 10% of human
population and of these 75% are stray Dogs.
Such a large population cause following threats:
• Direct physical injury to animals and humans by biting.
• Indirect injury as a result of road traffic accident to save
them.
• Reservoir of diseases of humans as well as animals like
Rabies, Echinococcus and Toxocara.
• Pollution from faeces and urine.
• General nuisance.

3. Protocols for control of Dog Population aims at-
1. Method to control Breeding in dogs which helps to reduce future expansion of
population
2. Method to decrease existing population by mass Euthanasia
The second procedureis against ethics of people in society does not encourage and also
compromises animal welfare.
Strategies to control Breeding
Breeding control strategies are easier and handy to control dog population
Under Breeding control strategies the capacity to produce gametes is destroyed conceptus
carrying capacity is also destroyed & animals are rendered Infertile to Sterile.
This is achieved by using
1. Surgical techniques
2. Medicinal Techniques

4. Medicinal or Non Surgical Techniques-
#Scientists studied various methods to control breathing which are quite easier cheaper and
involve minimum resources as compared to traditional methods.
These methods are commonly known as medicinal or non surgical techniques
Medicinal or Non-surgical techniques include
1. Chemosterilants
2. Hormonal methods
3. Immunological methods

5. Chemosterilants
They possess advantage that they eliminate chances of humerus hernia infection and other
surgical complication and postoperative Management
1. Cadmium chloride- damages sertoli cell and hence reduces male fertility used at the
dose rate of 0.05mg/kg BW intratesticular.
2. Calcium chloride- causes necrosis of testicular tissue due to ordema occur lead to
atrophy of testicular gland parenchyma and probably also reduced fertility by high rate
of free radical generation used at the rate of 5 to 20 mg per testis
3. Chlorhexidine– Sclerosing agent produce azoospermia. 4.5 ml of 4.5 % aqua solution
of chlorhexidine gluconate into each tail of epididymis of dog is used
4. Glycerol- glycerol intratesticular injection results inconsistent elimination of
spermatozoa in ejaculate with uniform decrease in sperm count.

6. 5. Lactic acid- intratesticular injection in immature and mature dogs reduces tested to a
level being undetectable in scrotum by palpation at 7 weeks in immature dogs and after 4
months in adult dogs by causing testicular atrophy
6. Vinylcyclohexene diepoxide –it destroys both primordial cells in the ovary and testis
when given intraperitoneally for 8 days at 8-320 mg per kg body weight . In male dogs
causes damage of testicular tissue by downregulation of caspase 8 and 9
Intratesticular Injection Intra-Peritoneal Injection

7. 7. AgNO3 & HCHO- scarification and tissue collection in Vas deferens causing seminal
transport blockage
8. 20% NaCl – due to it’s osmotic effect its intra testicular injection cause Osmotic shock,
massive infiltration of immune cells & degenerative changes in testicular seminiferous
tubules
9. Methallibure, Dexamethasone, Metopiron, Niridazole – intratesticular injection causes
within 30 days the empty epididymis and vas deferens
10. Zinc Formulation – zinc compounds In inhibits division and replication of germ cells
and cause fragmentation of cellular membrane and nucleus.
Neutersol and inter intratesticular injection of Zinc Gluconate cause testicular sclerosis and
permanently sterilize the animal .
Estersol containing DMSO + zinc gluconate also used.

8. Hormonal Methods
1. Androgen – Testosterone has suppressive effect on GnRH release and spermatogenesis when administered at greater dose
more than physiological values.
Methyltestosterone at 50 mg per dog per day for 90 days decrease mean daily sperm output and can cause eventually testicular
senility.
2. GnRH Agonist – Initially GnRH cause release of FSH and LH thus causing estrus and ovulation which is disadvantage of
this method .
Contraception can be achieved by sustained GNRH agonist exposure which caused downregulation of pituitary cells and hence
decrease FSH and LH.
Preparation- Gonazon & Suprelorin ( controlled release implant )
Daily administering 10 microg per kg of Nafarelin acetate 42 days to male dog cause complete spermatogenesis suppression

9. Preparation- Gonazon & Suprelorin ( controlled release implant )
Daily administering 10 microg per kg of Nafarelin acetate 42 days to male dog cause
complete spermatogenesis suppression
3. GnRH Antagonist – bind to GnRH from brain prevents release of LH and FSH cause
immediate inhibitory effect on gonadal acid.
Single injection of 100 microgram per kg keeps testosterone level in complete castrate range
for more than 24 hours and repetitive injection daily cause complete dry regulate after 2 week
of injections.

10. 4. Progestins – Spermatogenesis can be discrupted by exogenous progestins because of suppression of gonadotropin
secretion in male due to negative feedback mechanism.
Methoxyprogesterone acetate @ 4 mg per kg body weight reduce their peripheral Testosterone values.
Megestrol acetate given orally for 7 days at 2 mg per kg and 4 mg per kg produce no change in semen quality but
minor secondary sperm abnormalities seen.

11. 5. Prolactin – Prolactin hyperproduction cause inhibition of testicular functions, sex hormone
function and formation. Prolactin at 600 microgram/kg body weight per week for 6 months
cause azoospermia in three months after treatment.
6. Phytoestrogens- non steroidal oestrogen like compounds which mimic reproductive
hormone and supposed to be defensive substances produced by plants can modulate
herbivores fertility.
7. Coumesterol- it can disrupt spermatogenesis and spermiogenesis by affecting the
function and proliferation status of germinal epithelium, spermatogonia, intratubular and
interstitial cells by binding with beta oestrogen receptor in mammalian testis.
Feeding this two adult male dog at 300 microgram per kg body weight causes oligospermia
ejaculate.
It also reduces smelling frequency of male dog for identifying vaginal secretions of estrus
female dog and significantly decreased total number Spermatozoa.

12. Immunological methods
Theory behind immuno-contraception is the induction of production of antibodies against
specific targets.
Targets include as testicular proteins, spermatoz
oa, GnRH & LH receptor and zona pellucida proteins which consequently affect fertility
temporarily and permanently respectively.
1. BCG- Local inflammation caused by it enables lymphoid cells to gain access to testicular
apparatus and illicit immunological response .
This is against proteins who’s ontogenesis takes place with
the onset of spermatogenesis & to which body is not tolerant.
2. Complete and Incomplete Freund’s Adjuvant- its intratesticular
injection cause azoospermia and elicit granulomatous reaction.

13. 3. GnRH Immunization- GnRH coupled with carrier materials like t-helper epitopes tetanus
toxoid act as an antigen in order to produce neutralizing antibody against it cell epitope p35
induced high level of gnrh antibody cause regression of testicular function in dogs.
4. LHRH Immunization – dogs vaccinated against LHRH conjugated to tetanus toxoid show
fall in testosterone levels same as of castrated one.

14. Miscellaneous
Use of-
1. Alpha Chlorohydrin – cause depletion of spermatogenic elements.
2. Clove Oil- At high concentration cause sperm oxidatio
3. Embelin– reduces testicular size and weight.
4. Ketoconazole- inhibit gonadal cell division.
Tamoxifen- anti estrogenic compound that block estrogen receptor to function and thus block all reproductive
pathway connecting to it.

15. Surgical Techniques
• Surgical sterilization has been a cornerstone of efforts to curb pet population but these
procedures are expensive and elaborate.
• But they are most promising among all giving surity that said animal cannot bred in future
This can be done by using –
1. Gonadectomy-- To remove gonads
a. Orchiectomy
b. Ovariohysterectomy
2. Tubal ligation
a. Vasectomy
b. Tubectomy
General Anaesthesia Protocol to be followed-
Premedicate with atropine , followed 10 minutes by
xylazine @1 mg/kg body weight. Induce
the anaesthesia with ketamine @ 10 mg/kg body
weight and diazepam 0.3 mg/kg body weight.
Maintain anaesthesia with same ketamine and
diazepam or propofol @ 3-5 mg/kg body weight.

16. Orchiectomy
It is the procedure of removal of testes surgically can be open when vaginal tunic over testes
is incised and testes is removed or closed when testes is removed with vaginal tunic . It is
performed under general anaesthesia.
Procedure
1. After controlling the animal on dorsal recumbency and preparation of the prescrotal and
scrotal skin, a midline incision is placed on the prescrotal skin after tensing one of the
testicles under the skin.
2. The incision extends through the skin, subcutaneous tissue and the tunica vaginalis. The
testis is squeezed out and the attachment of the epididymus to the tunica vaginalis is
separated bluntly by traction or transected.
3. The vascular and the avascular bundles of the spermatic cord are separated.
4. The vascular bundle is ligated using No. 1-0 catgut and transfixed. The ends of the suture
material may be used for ligating the avascular bundle also.

17. 5. The spermatic cord is transected distal to the ligation and the stump returned into the tunica
vaginalis. The other testicle may be removed through the same skin incision by incising the
scrotal septum after tensing the testicle against it.
6. The procedure is repeated to remove the second testicle. Subcutaneous sutures
may or may not be placed using No. 4-0 absorbable suture material and the skin in
cision can be closed using No. 3-0 or 4-0 nylon.
Close Method Open Method Transection of Spermatic
cord & Testes removal

18. Ovariohysterectomy
It is the surgical removal of ovary and uterus performed under general anaesthesia.
Procedure
This procedure is typically performed around or prior to six months, but can be performed on
dogs of any age.
1. The surgical incision is usually made along the ventral abdomen, but flank approaches
have been reported.
2. Separate the subcutaneous tissues and facia. Incised linea alba. The ovary is identified
and surgical clamps are applied to the ovarian blood vessels.
3. The vessels are then ligated (tied with sutures) to prevent bleeding and the pedicle is
replaced into the body. This procedure is repeated for the other side.

19. 4. The uterus and ovaries are removed from the abdomen.
5. The abdomen is sutured closed in three layers: the abdominal wall, the subcutaneous tissue
(tissue underneath the skin) and the skin itself.

20. Vasectomy
• A canine vasectomy or testicular tubal ligation is a surgical procedure that leaves the
reproductive organs intact while blocking the means of reproduction.
• After a vasectomy the testes continue to produce testosterone.
• With a vasectomy, a portion of the vas deferens (spermatic cord) is removed but the
testicles remain in the scrotum. The veterinarian closes the incision with surgical glue or
sutures

21. Tubectomy
• Tubal ligation is what people commonly call having the tubes tied, as the fallopian tubes are
either blocked or cut to prevent the female egg from traveling from the ovaries to the uterus
to be fertilized by the male canine.
• Veterinarians have considered tubal ligation as a second option for canines in needs of a
permanent birth control solution

22. Gonadectomy or Tubal Ligation
• Veterinarians always choose gonadectomy preferentially over tubal ligation.
• After a vasectomy the testes continue to produce testosterone. This means that
your pet will still have his inherent male behaviour.
• The most noticeable behaviours in dogs are seeking out females and aggression
which is undersirable.
• Vasectomized dog also has high chance of developing BPH- Benign Prostatic
Hyperplasia thus less suggested.
• Females may continue to come in heat in tubal ligation.
• This Gonadectomy is always preferred over Tubal ligation.

23. Conclusion
• Stray dog meaning has really become cleft stick these days especially due to stray dogs.
• Not only this even pet owners who do not want to breed their pet dogs in order to avoid
reproductive complications or to alter mentation of their dog often visit to a
Veterinarians for a solution.
• Thus Veterinary clinician must be well aware of all techniques employed to Sterilize
Dogs or to control their breeding.
• Surgical methods that are used since long was this advantage of remarkable efficiency
but being expensive and elaborate newer methods are been devised these days.
• Non surgical methods on other hand are comparatively easier to imply and give good
results.
• Amidst thisawait Narayan should keep in mind that whatever procedure is involved it
must be problem solving to owners and in Animal welfare.

24. Thank you so much !!!
Any Questions???