Nonsurgical Methods of Contraception Flashcards
What are the 3 Non-surgical methods of Contraception?
- Pharmacologic (give an animal something to mimic hormone)
- Immunologic (“trick” the immune system into attacking ovaries or testicles)
- Mechanical (intrauterine devices)
A client has a 6-month-old Persian queen that you discover a 5/6 heart murmur. After a cardiology consultation, it is determined that general anesthesia would be very risky. The owner does not want her to become pregnant or cycle. What is the best option for contraception?
Melatonin Implant
Is described as being seasonally polyestrous and a long-day breeder
Cats
Pharmacologic
____________ is what is going to mimic pregnancy
Progestins
Pharmacologic
- Suppress gonadotropin secretion
- Efficacy varies with the drug, dose, and stage of cycle
Progestins
Pharmacologic
- Only progestin approved in the US (generic only) for small animal use
- Return to estrus in ~4-6 months
- Subsequent fertility is normal
- Human Drug
- It has to be given to Bitches when they are not cycling
Megestrol Acetate (Ovaban®)
When you use Megestrol Acetate for a very long period in cats, what can happen?
- They can develop diabetes and mammary hyperplasia
Pharmacologic
- Depo-Provera
- Long-acting progestin
Side effects
- Pyometra in 4-10% of small animals
- Increased incidence of mammary tumors (30%) in small animals
- Ineffective in mares
Medroxyprogesterone Acetate (MPA)
What is a side-effect of long-term progestin use in dogs and cats?
High risk of pyometra
Pharmacologic
- SYNTHETIC progestogen
- Effectively suppresses signs of estrus in mares
- Long-acting injectable formulation available through compounding pharmacy (12 and 30-day formulations)
Altrenogest (Regu-Mate)
Pharmacologic - Androgens
- Safe and effective for long-term estrus suppression
- Treatment must start 30 days before estrus
- Return to estrus in ~70 days after withdrawn
- Dose varies with weight and breed
- Has to be given daily
Side effects
- Clitoral enlargement
- “Musky” odor
- Coat color/texture changes
Mibolerone (“Cheque Drops”)
Pharmacologic - GnRH agonists
- Prolonged release of potent GnRH analog
- Suppress pituitary function
- Can be administered at any stage of the cycle
- Estrus – Will induce ovulation
- Diestrus – best results
- Anestrus – Will induce estrus in ~7 days
Deslorelin Implants (Suprelorin®, Ovuplant®)
_____________ may be permanent!
- FDA-approved product for ferrets
- Illegal in other species
Suprelorin
Pharmacologic
- Blocks reproduction in cats due to inhibition of GnRH
- Implants available for dermatological conditions
- Variable duration of effectiveness
- 18mg implant suppresses estrus for 2-4 months
- Suppresses spermatogenesis in males for 120 days
Melatonin Implants
Pharmacologic
- Very Cheap
- Suppress estrus in mares
- 60 IU BID/SID from day 7-14 post ovulation
- Estrus suppression for 40-70 days
- 70% effective
Oxytocin
- Days 11-14 = release of PGF
- Before Day 10 = disrupts luteolysis and prolongs CL function by inhibiting COX-2 needed for PGF production
Exogenous Oxytocin
- Several vaccines developed
- Anti-GnRH
- Anti-sperm proteins
- Anti ZP
- Efficacy and side effects are variable
- None commercially available for companion animal use
Immuno-Contraception
- Intra-testicular injection
- Induces testicular sclerosis and sterility
- Testosterone levels decreased by 50% but were not eliminated
- Only FDA-approved nonsurgical sterilization option for males
- Side effects: scrotal swelling, ulcers if not performed appropriately
- No longer available
Zinc Gluconate (Zeuterin®)
- Marbles in mares
- 35mm glass marble in the uterus
- Suppresses estrus in 40% of mares
- High rate of loss and complications
- Cheap but no longer recommended
Intra-uterine devices
If a mare owner wants to suppress estrus in order to keep her mare focused on the competition, what would be the best option?
Daily Altrenogest (Regumate)
