DERP SYNDROME
WHAT YOU SHOULD KNOW
Derp syndrome is an extremely dangerous neurological condition affecting lactating mares. It can rapidly cause severe disability and death, and if you are a beginner fluffy breeder or if your unspayed pet mare falls pregnant you should ensure that you have a basic understanding of the subject.
It is caused by deficiencies of essential fatty acids, calcium and vitamin D. Fluffies have poor homeostasis in general, and it is quite possible for even well-nourished lactating mares to secrete so much of these nutrients in their milk that their own levels of them fall dangerously low.
RISK FACTORS
The main risk factors for derp syndrome in well-nourished fluffies are:
- Allowing a mare to nurse a large litter (4+) on her own without supplementation with formula or milk from donor mares. Avoiding derp syndrome is one reason why more fecund mares should be allowed to follow their natural instincts to reject or kill runts or other undesired foals, however traumatic it may be to witness.
- Breeding a mare too soon after her previous litter is weaned (first or second subsequent ovulation).
- Advanced age (over eighteen months) at first litter. The risk is reduced but not eliminated with subsequent litters.
- Acute overdose or unduly prolonged use of lactation-promoting drugs.
The highest risk of the syndrome manifesting is at the point when most or all of the foals are capable of prolonged walking, at which point their nutritional needs show a sudden steep increase.
In very rare cases derp syndrome may manifest in the final days of pregnancy, when teat swelling begins. However, this is almost always restricted to severely malnourished ferals or neglected pets.
SIGNS AND SYMPTOMS
Initial signs are usually ocular (strabismus {either squint or wall-eye}, blown pupils or random unsynchronised movements of the eyes) and verbal (slurred speech, aphasia or meaningless babbling, relative to the mare’s baseline verbalisations). A particularly specific sign is when the instinctive “nursing mommah” song is replaced by meaningless sounds while the eyes are open and the mare appears fully alert, in contrast to its normal gradual loss of meaning as the mare begins to fall asleep. Without treatment, the condition will progress irreversibly to brain damage, blindness, deafness, paralysis, severe intellectual disability, coma and death.
TREATMENT
If a mare shows signs of derp syndrome, all her foals must be immediately removed for hand-rearing, fostering or euthanasia. Even if the foals are to be hand-reared or fostered, they must be completely separated from the dam until they are adolescent as their proximity will restart lactation and risk a relapse. The rare pregnant mare with derp syndrome should undergo immediate induction or cesarian section followed by permanent separation of the chirpies, should they be viable. In all cases, the mare must then be treated with anti-lactation medication and an intravenous drip of buffered saline, calcium citrate and D3, and provided with a high-fat diet, for at least 48 hours after symptoms are no longer apparent.
FOLLOW-UP
Mares who have recovered from derp syndrome should not be bred again for at least six months, and if they are ever bred again should not be permitted to nurse more than one or two foals from the litter. Unless you are an experienced and professional breeder, sterilisation is strongly recommended.
A NOTE ON CLYDESDALE FLUFFIES
As Clydesdale traits are strongly biased towards male fluffies, it is common for Clydesdales to be bred by Clydesdale stallions out of non-Clydesdale mares. However, the greater size and nutritional needs of Clydesdale foals mean that, even if the litter size is kept down to one or two foals, the probability of derp syndrome in the non-Clydesdale mare can be as high as 65%. As a result, non-Clydesdale mares nursing Clydesdale foals require 24-hour observation