Furville Hospital, a very huge district that was built to help all kinds of people. Be it small, giant, light, heavy, mammals, reptiles. 
But even that kind of institution had it's limits and in this case it was patients with dangerous substances like poisons. But luckily there were people who had a resistance to these substances. They were very important for the hospital, being the only one who could treat these patients properly. 
One of them was Troy, a young wolf who just got the job at the hospital. 

It was his third working day when he was going to learn about the tricky part of his job. 
When he walked through the corridor one of his colleagues stumbled out of a room. He didn't see the wolf and so they bumped into each other, Troy not very happy about it. 
"Hey, can't you watch where you are going? "
The tiger looked around "Is that you, Troy? I'm sorry but I can't see right now, it actually isn't my only problem... Good thing I met you, you have to take over two patients for me while I get myself some help. They are just the ones why we appreciate people like you! "
Troy blinked when the tiger walked away but it didn't help, he got himself patients to nurse. 
He entered the room but the first thing he noticed weren't the people but a very potent smell that lingered in the air. He had to adjust himself to it for a moment before he could concentrate on the people inside. 
In the two beds laid two huge lion like persons, Troy recognizing them as Ronsos. In fact he quickly saw that they weren't any random persons, seeing the one's blonde mane and the other's broken horn. 
The two were wrapping their arms around their stomachs, groaning. 
"H-Hello? My name is Troy, I'm here to help you. Can you tell me what's the matter? "
The only response he got was Biran, pointing at a piece of paper that was fixed to his bed. 
"Kimahri and Biran Ronso 
Excessive gas after using Lancet  on a Morbol. 
Results in stomach pains, and gas release form both ends... 
Breathing it causes different effects, including blindness and poisoning"
Troy scratched his head "So that's the problem. How about some belly rubs? It can work wonders! "
Biran just growled, rolling onto his back and presenting his stomach to the wolf "Why is Troy talking instead of rubbing Biran's stomach? "
But before Troy could do something, the ronso burped loudly. A thick, green cloud of toxic gas moved to the wolf's head, Troy whining at the stench but nothing more. He wasn't blinded, poisoned or whatever, his purpose becoming very clear again. 
Eventually he leaned forward and laid his paws onto the blue belly, carefully rubbing it. Not even 5 seconds passed until it growled furiously. A moment later the wolf picked up another smell, foul but bearable. 
"After all that growling? I thought it was gonna be-"
He was interrupt by a deafening, trumpeting sound, followed by an incredibly rotten stench. 
"You wanted to blame weak ronso's wind to great Biran?! Biran farts always bad! Only weak ronso calles that a fart! " he points at Kimahri who turned his head. 
"Kimahri farts are always stronger in the end, even Biran runs! Kimahri always able to handle Biran gas! "
"Because... " Biran thought for you moment "...That.... " he got an idea "Kimahri always sniffed Biran farts! Farts out Biran gas with a little bit more stink! "
Troy raised an eyebrow, deciding to bring himself into the discussion "Well that sounds like a very poor excuse, especially after you thought so long. " he continues to rub the belly, pushing out a long burp that hits his face directly. 
"Th-that's the truth... Kimahri always smelled Biran farts before! "
"Kimahri only needs concentration and time, Biran's farts only weaken Kimahri gas! " he said between groans, burping before ripping another fart, again not too bad. 
"Weak Kimahri really thinks he could stink like real ronso? "
Troy decided to switch for a moment, going to Kimahri's bed. 
"Kimahri doesn't think so, Kimahri knows "
Troy scratched his head "You know, guys... If you keep it short and simple I might be OK with being your judge. I mean, that room already reeks and with that fiend gas nobody will enter very soon. Is that what you want? "
Kimahri nodded while Biran crossed his arms. 
"It's only waste of time, Kimahri never beats Biran gas but Biran isn't against showing his smell! "
The wolf blinked "Well... If that's settled. But for now we will focus on ridding you from that unnatural gas. That'll only make the competition much fairer. Don't you think so? "
Both nodded and Troy continued to massage Kimahri's stomach, causing him to fart and to belch immediately. 

The wolf was massaging for quite a while, the air inside the room very toxic. Both would lay on the side to fart in each other's direction when they didn't get their stomachs rubbed, trying to irritate the other. 
Eventually the outbursts became less frequent, the gas finally being their natural one. Troy also realized that the belching stopped, thus concluding that his job was done. At least the medical side of it. 
"Feeling relieved, guys? " the wolf asked, surprised when both shook their heads. 
"Wait, is it building up aga-.... Oooh... " he scratched his head when he remembered his promise. "You think you can push out some more? You already turned the room into a bio hazard..."
The two looked at each other before responding by raising their legs and ripping loud farts. 
"I... see.... " he sighs "How exactly are we going to do it then? "
"Troy will sniff weak Kimahri's fart before inhaling superior Biran gas! " Biran said, smirking. Troy shrugged "Are you Ok with it? "
Kimahri rolled onto his stomach "Troy's nose won't smell anything after Kimahri is finished with it! "
Troy nodded before leaning forward, his face pretty close to the ronso's ass. He could hear how Kimahri silently growled, concentrating very hardly. 
A few seconds later the wolf was introduced to a very warm feeling, coming with an long hissing sound. Just another second later he was hit by an incredibly foul stench. 
"G-God... It smells like that Morbol crawled up your ass and died! " he stumbled back, waving a hand in front of his nose before looking at Biran "Will be hard to beat " he chuckled. 
The blonde maned ronso growled, turning around himself. And of course Troy would lean over his ass too. This time he didn't have to wait until he was bombarded with an bassy fart, one that reeked a lot of rotten meat and spoiled milk. Troy took a deep whiff but barely noticed the smell, Kimahri's fart actually playing tricks to his nose. 
"I'm sorry but his fart was more-" he was caught off guard when Biran grabbed his head, pressing it against his rump. 
"Troy held his head closer to Kimahri's ass, Biran gets a second chance !"
Before he could complain Troy was submitted to a bunch of short but very potent poots. 
"Does Troy smell Biran farts already! Stench of a real ronso! "
He finished his turn by ripping a very massive fart before releasing the wolf. Troy stumbled back again, this time falling to the floor eventually. 
"See? Biran gas is superior! "
"Troy couldn't smell Biran's gas thanks to Kimahri fart! Took Biran many farts to overcome that single one. Biran farts will never beat Kimahri! " the smaller ronso smiled, knowing that he was actually telling the truth. 
Of course Biran wasn't going to accept it and so he stood up, walking over to the other bed. Neither Troy nor Kimahri were expecting him to take a seat on the later's face. 
"What are you... "
"Kimahri thinks he can't be beaten by Biran farts? " he rips an silent fart, huffing when the ronso under him trashed around due to the awful stench of burnt tires. 
"What's the matter, small fart already enough for little ronso? "
He launched another massive blast. 
"Kimahri will never forget the power of-"
Kimahri calmed down and focused, surprising the other male by swinging his legs upwards. In a single second Biran found his head trapped between Kimahri's legs, facing his arse. As one would expect the smaller ronso would have his immediate revenge, Bombarding Biran with an long, wet fart, extremely rich in sulfuric stench. 
Biran growled aggressively, his pride massively injured. And so he grunted hardly, pushing out a deafening fart but unfortunately it didn't had a strong smell. In fact it barely smelled of rotten meat. Kimahri, on the other hand, was concentrating again and soon enough ripped another fart himself. 
It began just as loud as Biran's but it carried an indescribable stench. From time to time the smells of dead fish, rotting corpses and burning rubber were more noticable. 
After 8 seconds the sound became quiter but the stench intensified a lot. 
Biran's eyes were already tearing up when he began to push against Kimahri's rump but it didn't stop the now hissing fart. 14 seconds into it and the fart had a bubbling fart, the heat causing some sweat to be build up in the rump, sweat that was now sprayed into Biran's face. 
Kimahri had to push hard to keep it up, finishing after a good 20 seconds. Guessing that Biran had enough, Kimahri lowered his legs. He assumed right as the other ronso jumped up, groaning. 
Troy couldn't help but chuckled "Well, that concludes the competition, eh?"
Biran glared at him and grabbed the wolf's head, bombarding him with a loud fart but nothing Troy couldn't take. What surprised him though was the fact that Biran also pulled the wolf's white shirt off. 
"H-Hey! These are my working clothes until they get me a white-" he closed his eyes when the ronso pushed the shirt between his arse cheeks "...coat... "
Biran left the room without saying a word, farting with each step. 
"Y-you can't just...! " Troy shouted before Biran threw the shirt in front of the door. The wolf took it, whining after taking a sniff. 
"Well, I guess this didn't do much more damage than spending time in a room full of farts, eh? Oh man, it'll take ages to get the smell off... " the wolf sighed. 
He was surprised when Kimahri was holding something in front of his face. 
"Troy helped Kimahri, Kimahri's farts stuck in clothes too. Kimahri's gonna pay for cleaning. "
"Y-You really don't have to-"
"Troy takes, Kimahri wants to "
The wolf takes the money, smiling "Well, thanks then "
The ronso shook his head "Kimahri has to thank " With that he left the room and walked off. 
Troy smiled even more before looking at his shirt, carefully taking another whiff. "On second thought... I might also keep it, buying a new one is cheaper anyways... "