Wise viShNusharman’s vignette on biological warfare

brahmA rudraH kumAro hari-varuNa-yamA vahnir indraH kuberash
chandrAdityau sarasvaty-udadhi-yuga-nagA vAyur urvI-bhuja~NgAH |
siddhA nadyo .ashvinau shrIr ditir aditi-sutA mAtarash chaNDikAdyA
vedAs tIrthAni yakShA gaNa-vasu-munayaH pAntu nityaM grahAsh cha ||

As Tennyson had put it: “Nature, red in tooth and claw” and indeed biological conflict is our biggest teacher. It has lessons so profound that some of the foundations of biology itself emerge from its understanding. And we being a microcosmic part thereof learn much about how to conduct ourselves in our conflicts from the upAya-s of other life around us. It is perhaps this understanding that made viShNusharman and his wise predecessors situate their lessons on human interaction in the natural world that was there for all to see in old India. It is for this reason after invoking the pantheon as above he says:

ishvarANAm idaM tantraM prAyeNautsukyam Avahet |
yatas tirashchAM charitair nItimArgaH pradarshyate ||

This text of the gods might appear puzzling due to its teachings; however, it intends illustrating by actions of animals the path of right conduct/politics. In the midst of the wide wisdom he offers he also gives a brief lesson biological warfare. This comes in the tale of the bull and the lion where the jackals attendants strive to create a conflict between the two. In justifying the case for the lion to abjure his friendship with the bull the jackal damanka warns him of the danger of biological warfare waged by the bull:

siMha Aha: “sa tAvach ChaShpabhug vayaM pishitabhujas tat kim asau mamaapakartuM samarthaH ?”
The lion said: After all this guy is a plant-eater; whereas we are a flesh-eater; so how is he capable to do me harm?

damanaka Aha: “evam etat | sa shaShpabhug devapAdAH pishitabhujaH | so .anna-bhUto devapAdA bhoktR^i-bhUtAH | tathA .apy asau yadi svayam anarthaM na kariShyati tato .anyasmAd utpAdayiShyati |”
damanaka said: It is indeed so that he is a plant-eater and your Highness is a flesh-eater; he is food and your Highness is the food-eater. Even if he cannot himself cause harm, however, he will get some else to do it for him.

siMha Aha: “kA shaktir asya svato .apakartuM parato .apakartuM vA?”
The lion said: What power does he have to cause me harm by himself or by others?

so .abravIt (damanakaH): “tvam tAvad ajasram aneka matta-gaja gavaya mahiSha varAha shArdUla chitraka yuddheShu nakha-danta-saMnipAta-kR^ita-vraNa-shabala-tanuH | ayaM punaH sadA tvat samIpa-vAsI prakIrNa viN-mUtraH | tad anuSha~NgAch cha kR^imayaH saMbhaviShyanti | te yuShmach-CharIra-sAmIpyAt kShata vivaraanusAriNo .antaH pravekShyanti | tathA tvaM vinaShTa eva |”
He said (damanaka): you are incessantly in combat with elephants in musth, Gayals, buffaloes, boars, tigers and cheetahs, during which your body is dotted with wounds caused by the strikes of their claws and fangs. Now again (saMjIvaka the bull) always stays beside you splattering feces and urine. And by consequence of that parasites will begin breeding. As your body is close by, they will invade it making their way in via the perforations from the wounds. By this means he (the bull) will cause your destruction.

Thus, viShNusharman’s account is perhaps one of the earliest textual references of excreta  having a major role in parasite-transmission as part of predator-herbivore interactions. Of course modern studies suggest that parasites transmitted by carnivorans (example the apicomplexan Sarcocystis) can infect herbivores and weaken their muscles/other organs, thereby making them easier prey and furthering parasite transmission. It is not clear if herbivoran parasites can have a reciprocal fitness effect on carnivorans. The practice of excreting in latrines (an ancient trait in the mammalian line first recorded in dicynodonts of the Triassic) suggests that mammals try to limit parasite-transmission by localizing excreta. Such latrines of herbivores could in principle allow transmission of certain debilitating parasites to carnivorans. Potential parasites transmitted via ungulate excretion to felids include the apicomplexan Cryptosporidium and the worm nematode Trichuris. Such transmission could be exacerbated by a behavior of carnivorans, namely rolling in ungulate dung and licking themselves. Another possibility is the nematode worm Spirocerca. This worm is transmitted by dung beetles to felids – such dung beetles could indeed breed in larger numbers in the presence of bovid dung and could be available for transmission of the parasite to felids.