UP-DATED GRAPH FOR ATYPICAL MYOPATHY
The toxin responsible for atypical myopathy is contained in sycamore samaras (Acer pseudoplatanus (= maple tree; see pictures). With the winds of the previous weeks, the samaras have fallen in large quantities and constitute a high risk of intoxication. The number of cases of atypical myopathy is constantly increasing. Unfortunately, this autumn, the mortality rate seems to be particularly high.
We therefore advise:
– To prohibit access to pastures containing sycamore maple samaras (or even delimit the pasture to avoid areas where samaras are present in large numbers);
– Or, at least, limit the grazing time to a few hours per day (the majority of cases grazed > 6 hours / day). If possible, feed the animals before putting them on the meadow;
– Provide supplementary feeds including toxin‐free forage;
– Provide a salt block (ideally enriched with vitamins and/or minerals);
– Provide water from the distribution network;
– Do not place food (hay or other) on the ground.
For more practical information, we invite you to consult: : “Answers to the Frequently Asked Questions Regarding Horse Feeding and Management Practices to Reduce the Risk of Atypical Myopathy” https://doi.org/10.3390/ani10020365.
It is worth mentioning that a French translation of the article (with many illustrations) can be downloaded as supplementary material (cf. Supplementary material 1). You will find a link within the paper or as an alternative, you can ask for a reprint via http://hdl.handle.net/2268/245399
Again many thanks to all communicating veterinarians and owners of affected horses for your collaboration. Without your help, this paper would not exist.
Encourage your community to report cases:
– as an owner, via the link:
– as a vet, via the link:
Previous News Posted Dated
FIRST CASES OF ATYPICAL MYOPATHY NOTIFIED IN EUROPE & LATEST ADVICE
A group of European vets lead by Dr Dominique Votion at the University of Liege has been studying atypical myopathy (AM) for the past 20 years. This year they published a new paper entitled “Answers to the Frequently Asked Questions Regarding Horse Feeding and Management Practices to Reduce the Risk of Atypical Myopathy” (VOTION et al. 2020). The paper also includes some interesting data on how AM varies in prevalence between countries and also how some years are significantly worse than others
Equine atypical myopathy (AM) is a severe pasture-associated intoxication that may occur in autumn following ingestion of the seeds (samaras, winged seeds or “helicopters”) in the autumn or seedlings when they sprout in the following spring, of trees of the Acer species, most notably Acer pesudoplantus (sycamore Europe, sycamore maple in North America) and Acer negundo (box elder, USA). The clinical signs of AM in horses and ponies are caused by the cyclopropylamino acids, hypoglycin A (HGA) and methylenecyclopropylglycine (MCPG), Both Acer pseudoplatanus and Acer negundo seeds have been found to contain HGA and MCPG.
SYMPTOMS OF ATYPICAL MYOPATHY
- Muscle weakness, soreness or stiffness; horses may struggle to walk, stand or breathe
- Horses appear dull/depressed with head held low
- Muscle tremors
- Colic like symptoms
- Dark brown or dark red urine
- Some horses may develop respiratory symptoms
- Inability to stand
Atypical myopathy has a high mortality rate that varies between countries and years, but typically only 1 in 4 horses that develop it survive. Animals that are rapidly admitted to a veterinary hospital are reported to have a higher chance of survival.
In 2004, an alert group named “Atypical Myopathy Alert Group” (AMAG) was launched to warn horse practitioners and owners of the risk peaks. The alerts are released following case declarations and the AMAG regularly updates its data with the latest number of cases. In light of the high mortality rate and the absence of specific treatment, prevention is the key to avoid intoxication of animals.
The paper by Votion et al. (2020) aims at answering the five most frequently asked questions (FAQs) regarding
- identification of toxic trees
- reduction of risk at the level of (2) pastures
- the risk associated with pastures with sycamores that have always been used without horses being poisoned
- the length of the risk periods.
Answers were found in a literature review and data gathered by AM surveillance networks. A guide is offered to differentiate common maple trees (FAQ1).
In order to reduce the risk of AM at pasture level: Avoid humid pastures; avoid permanent pasturing; avoid spreading of manure for pasture with sycamores in the vicinity and avoid sycamore maple trees around pasture (FAQ2).
To reduce the risk of AM at horse level: Reduce pasturing time according to weather conditions and to less than six hours a day during risk periods for horses on risk pasture; provide supplementary feeds including toxin-free forage; provide water from the distribution network; provide vitamins and a salt block (FAQ3). All pastures with a sycamore tree in the vicinity are at risk (FAQ4). Ninety-four percent of cases occur over two 3-month periods, starting in October and in March, for cases resulting from seeds and seedlings ingestion respectively (FAQ5).
IF YOU HAVE SYCAMORE TREES IN OR AROUND YOUR FIELDS….
- Do not graze horses in these fields!
If you cannot avoid using these fields….
- Fence off large areas as the seeds travel long distances when blown
- Feed horses before putting them out
- Limit time in these paddocks
- Remove as many seeds as possible with paddock vacuums
- Do not put food on the ground (hay, other)
- If you have to put out food, place it as far away from the trees as possible
IF YOU HAVE SYCAMORES
IF YOUR HORSE MAY HAVE EATEN SEEDS AND IF YOUR HORSE IS SHOWING SYMPTOMS OF AM
*** CONTACT YOUR VET IMMEDIATELY ***
Votion, D.-M.; François, A.-C.; Kruse, C.; Renaud, B.; Farinelle, A.; Bouquieaux, M.-C.; Marcillaud-Pitel, C.; Gustin, P. Answers to the Frequently Asked Questions Regarding Horse Feeding and Management Practices to Reduce the Risk of Atypical Myopathy. Animals 2020, 10, 365.
TO READ THE FULL PAPER:
The full paper can be downloaded here> https://www.mdpi.com/2076-2615/10/2/365