INvertebrate MEdicine
This is a Giant Asian Mantis (Hierodula patellifera)
What are invertebrates?
Invertebrates are a diverse group of animals that do not possess a
backbone or vertebral column. This group of animals is incredibly
diverse, with over 97% of all animal species being invertebrates. They are found in virtually every environment on the planet, from
octupi in Mariana Trench to jumping spiders on mount Everest.
There are many different types of invertebrates, including insects,
arachnids, crustaceans, mollusks, echinoderms, and cnidarians. Each of
these groups contains many different species, with varying shapes,
sizes, and ecological roles. All of them deserve care and consideration.
Invertebrates play a crucial role in maintaining ecological balance and
are essential for the survival of many other species. Many
invertebrates, such as bees, butterflies, and other pollinators, are
important for plant reproduction and are critical for the production of
food crops. Other invertebrates, such as snails and mussels, are
important for filtering water and maintaining water quality.
Invertebrates are also an important food source for many other animals,
including fish, birds, mammals and humans!
Why should we treat Invertebrates?
Because they are super cool! Invertebrates are among some of the most beautiful and majestic animals out there (in my opinion!).
There are lots of other reasons of course! Some invertebrates are much loved and cared for pets, and depending on the species, some can live in excess of 25 years! So it is understandable that if they fall ill an owner may want the option of investigations and treatment, just as they would for any other member of their family.
Some invertebrates have key roles within a habitat or ecosystem, so they have an important conservational role. Often entire colonies will become ill at the same time, and in these situations investigations and treatment can help prevent or reduce losses.
We also depend on many invertebrates as a food source and as pollinators. Farms for edible invertebrates and beekeepers may sometimes require investigations and treatment when faced with disease or reduced output.
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How do we treat invertebrates?
Treatment can be administered orally, intravenously, or topically. For oral administration, a docile spider can be restrained and dosed using a thin cloth or paper towel. Intravenous medication can be given via the cardiac heart or a tarsal joint membrane. Topical treatment is beneficial for visible cuticular lesions.
Choosing the right treatment involves a hierarchy of evidence. Medications with established efficacy in that invertebrate species are preferred. If unavailable, a medication used in other invertebrate species can be an option. Medications and doses for reptiles or amphibians should be used as a last resort. It’s crucial to understand the pharmacokinetics of the chosen medication and ensure it’s suitable for invertebrates. Genomic bioinformatics can be used to validate medication use.
Antimicrobials and antifungals may be necessary in cases of bacterial overgrowth due to immunosuppression or poor husbandry. Doxycycline is typically recommended as a first-line antibiotic. As for analgesia, opioids and NMDA agonists are generally advised due to better conservation between invertebrate and vertebrate species. NSAIDs are not recommended due to the absence of direct genomic equivalent in theraphosids and insects.
Lastly, in cases where euthanasia is necessary, it should be done under general anesthesia. Confirmation of death can be performed using a Doppler ultrasound probe.
Resources for Vets interested in Invertebrate medicine
Generally speaking, I recommend approaching the Veterinary Invertebrate Society and considering membership. The VISJ (Veterinary Invertebrate Society Journal) is a good source of information on up-to-date approach and treatment of exotic species. The back issues for this journal are available in the publications section of this website as well as on the Veterinary Invertebrate Society website.
Other veterinary societies such as the British Veterinary Zoological Society (or your local veterinary zoological society or association) can be a good place to find colleagues that may have some invertebrate medicine experience. There are definitely more vets that have an interest in invertebrates than one might expect
Beyond this, Invertebrate Medicine by Gregory Lewbart is another fantastic source of information and guidance. I contributed to the chapter on spiders. Certainly a book i would recommend any aspiring student of invertebrate medicine to acquire!
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