Dr Aeknath Virendra

For most people their pets are a part of the family. People are rearing dogs, both males and females, not only for breeding purpose but also for their companionship. A lot of pet parents opt for sterilisation of their dogs to prevent further breeding and oestrus bleeding in case of female dogs. In this, let’s find out about non-surgical methods for birth control.

Sterilisation also controls highly aggressive behaviour in male dogs. Research shows that these procedures may also reduce the chances of prostate cancer in male dogs. The most common sterilisation procedures include ovarian hysterectomy and open castration. No doubt, these procedures are considered as the gold standard for sterilisation, but they do have limitations. The surgery is painful and also involves the risk of anaesthesia, besides the tedious task of post-operative care of the dog. Many pet parents consider the procedure unnecessary and avoid it for compassion and love for their pets. This is why non-surgical methods are a great alternative.

Advantages of non-surgical birth control methods

  • Safe
  •  No deleterious side effects
  •  Painless
  •  More feasible causing permanent loss of the fertility and sexual behaviour therefore reduces nuisance behaviour of animals
  •  Can be in single practical delivery (oral/injection/bait)
  •  High success rate
  •  Affordable

Non-surgical birth control methods

Immunocontraception: In case of Immunocontraception, GonaCon and SpayVac are the commercially available preparations. They use body’s own immune system to inhibit fertility. Zona pellucida (ZP) is a coating on the oocyte (egg) to which the sperm binds during fertilisation. Pig ZP antigens stimulate female mammals to produce antibodies that adhere to the surface of eggs, preventing sperm from binding and therefore blocking fertilisation. Main advantage for immunocontraception is that it is suitable for oral administration.

Hormonal Down Regulation: Hormonal Down Regulation is the second method. It includes Suprelorelin, Gonazon, Ovaban, Delvosterone preparations. They contain synthetic (exogenous) steroid hormones which suppress the fertility by inhibiting production of endogenous hormones; this is known as down regulation. They are used as the slow releasing implants and are needed to be replaced at regular interval to maintain infertility. Suprelorelin is administered at every half yearly interval whereas Gonazon is administered annually.

Intratesticular injections: Intratesticular, intraepididymal and intra-vas-deferens injections have gained a lot of popularity in the recent times. The method is more commonly known as ‘Chemical Castration’. This method requires injections directly into the testicles i.e. one in each testicle. This procedure requires a degree of skill because if injected outside the testicle the substance can be highly irritating and can lead to ulcerations of the tissues.

Chemical targeting: Chemical targeting is a method which is at research level and a preparation named chemspay is available. It contains a chemical that specifically targets the ovary. Chemical targeting causes the depletion of the primordial and primary follicles leading to permanent sterilisation and elimination of the oestrus.

Cytotoxin conjugates: One of the most effective and advanced methods for non-surgical control of reproduction is use of cytotoxin conjugates. They are the GnRH analogue linked to PAP (pokeweed antiviral proteins). PAP are plant toxins linked to GnRH analogue that when injected into the body destroys the gonadotropin releasing cells of the pituitary gland and therefore inhibit the release of LH and FSH.
Take note that if they are given in high doses it may lead to the renal toxicity. But when given in moderate or low dosage there are no side effects. In future, the trend of non-surgical methods of birth control in dogs is going to be more popular and practically acceptable as compared to surgical procedures. And our companionate lovable pets will not suffer from unnecessary pain of surgery and post operative management and complications.

(Dr Aeknath Virendra, Dr Manish Kumar Shukla, Dr Neeraj Verma, and Dr Ashitha Suresh are from the Department of Veterinary Gynaecology and Obstetrics College of Veterinary Science and Animal Husbandry, Jabalpur)