Deslorelin: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Suprelorin, Ovuplant, SucroMate

Species with doses

Dogs, Horses, Birds, Rabbits, Ferrets and Primates

Routes

SC, IM

Last reviewed

1 October 2026

Indications

• Reversible suppression of fertility in male dogs ("chemical castration")
• Benign prostatic hyperplasia (reduces prostatic size via androgen suppression)
• Suppression of reproduction/oestrus and unwanted sexual/behavioural signs
• Ferret hyperadrenocorticism (adrenal disease) management
• Ovulation induction in mares (short-acting injectable)

Deslorelin dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Reversible contraception (male dogs): Plumb’s p.360 (Suprelorin label): implant in the loose skin between lower neck and lumbar area, avoiding fat; pregnant women should not administer it. Fertility persists for several weeks after the first implant (initial GnRH flare).

Cats

• No reference dose for this species: The previous cat row gave no dose; Plumb’s gives deslorelin doses for dogs and horses only and Papich 5e has no monograph.

Horses

• Ovulation induction (mare): Plumb’s p.360: injectable 1.8 mg IM induces ovulation within 48 h in cycling mares with a 30–40 mm follicle (SucroMate label); implant SC in the neck when the follicle is >30 mm (Ovuplant label) — remove after about 48 h, as leaving it can prolong the interovulatory interval (McCue 2003).

Birds

• Reproductive suppression / feather-damaging behaviour: Carpenter’s Exotic Animal Formulary (bird tables): 4.7–9.4 mg implant SC every 3–6 months suppresses egg laying and reproductive behaviour; significant reduction in feather-damaging behaviour at 3 and 6 weeks.

Rabbits

• Contraception (implant): Carpenter’s Exotic Animal Formulary (rabbit table): 4.7 mg GnRH-agonist implant SC — contraception unreliable in males; does over 9 months may develop endometritis and/or endometrial hyperplasia. (The previous oral 1–4 mg/rabbit figure was a misread of the table.)

Ferrets

• Adrenal cortical disease: Carpenter’s Exotic Animal Formulary (ferret table): 4.7 or 9.4 mg implant SC, repeated about once yearly to control signs of adrenal disease (only the 4.7 mg implant is available in the US).

Primates

• Reproductive suppression: Carpenter’s Exotic Animal Formulary (primate table): 1–2 × 6 mg implants SC. Consult a primate-medicine specialist.

Contraindications

Use when a transient initial hormone surge would be dangerous (e.g. immediately needing suppression). Prepubertal animals (variable response). Pregnancy. Known hypersensitivity. Owner expectation of permanent/immediate effect (it is reversible and delayed in onset).

Species-specific warnings

Dogs: Males remain fertile during the initial ~2-week surge — prevent breeding access until suppression is established (~6 weeks).

Adverse effects

• Transient initial fertility/testosterone surge (first ~2 weeks) — animals may remain fertile/show increased libido briefly
• Local implant-site swelling/reaction
• Coat/behavioural changes; testicular size reduction (male dogs)
• Variable duration between individuals

Drug interactions

• Sex-steroid-dependent conditions: effects intertwined with reproductive hormones
• No major small-molecule pharmacokinetic interactions

Pregnancy and lactation

Not for use in pregnancy (suppresses the reproductive axis; the initial surge is also undesirable).

Monitoring

• Onset of effect (testicular size, behaviour, BPH/prostate size) over ~6 weeks
• The transient initial surge (keep males away from intact females for the first weeks — they remain fertile)
• Duration/return of fertility (variable) for breeding decisions
• Implant-site reaction

Toxicity and overdose

Very well tolerated; there is no classic "overdose" toxicity. The clinically important effect to anticipate is the INITIAL STIMULATORY surge (transient fertility, possibly increased libido/aggression or, in females, induced oestrus) before suppression sets in. Duration of effect varies between individuals.

Management: No specific antidote needed. The implant can, in some cases, be located and surgically removed to hasten reversal if a problematic response occurs. Otherwise effects are self-limiting and reversible as the implant depletes.

Clinical pearls

• Reversible "chemical castration" via implant — ideal for trialling the effects of neutering, BPH management, or where surgery is undesirable
• Counsel owners about the FLARE: dogs stay fertile (and may show more libido) for ~2 weeks before suppression begins — onset of infertility takes ~6 weeks
• Duration varies by individual and implant size (4.7 mg ≈6 months, 9.4 mg ≈12 months)
• The same molecule, given short-acting, INDUCES ovulation in mares — context and formulation determine stimulation vs suppression
• The implant can sometimes be retrieved to reverse effects early if needed

Mechanism of action

A superagonist of the pituitary GnRH receptor. Continuous (non-pulsatile) stimulation from the implant first transiently increases LH/FSH and sex-steroid output (the initial surge/"flare"), then DOWN-REGULATES and desensitises the GnRH receptors, shutting off LH/FSH and thus testosterone/oestrogen production — producing reversible infertility and suppression of sexual behaviour. The short-acting injectable, by contrast, exploits the early LH surge to trigger ovulation in mares.

Formulations and products

• SC implant 4.7 mg (≈6 months)
• SC implant 9.4 mg (≈12 months)
• Short-acting injectable (mares — ovulation induction)
• Suprelorin (Virbac) — 4.7 mg / 9.4 mg SC implant, SC implant
• SucroMate / Ovuplant (Various) — Deslorelin (short-acting, mares), Injection / implant

Storage

Implants: refrigerate (2–8 °C) per label; do not freeze. Use aseptic technique for SC placement.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other hormones, emergency drugs, supplements and other drugs

• Cyclosporine
• Cyproheptadine
• Dantrolene
• Deferoxamine (Desferrioxamine)
• Desmopressin (DDAVP)
• Desoxycorticosterone Pivalate (DOCP)
• Diazoxide
• Dimercaprol (BAL)

Frequently asked questions