It’s a summer afternoon and you’re working as a vet tech in a busy general practice, shortly after receiving your license. The day is fully booked, with multiple doctors on duty, back-to-back appointments, and several walk-in patients that need to be worked into the schedule.
As you finish drawing blood from a cat, which is in for a routine wellness visit, you hear the receptionist’s voice over the loudspeaker: “I need a tech to the front, STAT!”
You glance around and soon realize that you’re the only available vet tech in the hospital. You ask your assistant to return the cat to her owner and get the blood samples ready to send out, then you immediately rush to the front desk.
In the lobby, you find a panicked client holding a Boston Terrier that is panting heavily. (But don’t Boston Terriers always pant heavily? You don’t think much of it at first.)
The client hurriedly tells you that she took her dog, Bailey, for a walk around the neighborhood this morning, like they do every day. On today’s walk, however, Bailey saw a cat and began barking “like a madman.” This continued for some time, before Bailey’s owner was finally able to drag him away from the cat. For the remainder of the walk, Bailey continued to pant heavily and didn’t calm down as his owner would have expected. She attributed this to the day’s above-normal heat and humidity, so she expected it to resolve once she got him home and into the air conditioning. The panting continued at home, however, and has worsened over the last hour or two. Now she’s concerned that he’s having trouble breathing.
You get the client’s permission to take Bailey to the treatment area. Once there, you set him on a table and perform a triage exam, while asking a team member to locate a doctor. You note that Bailey has a respiratory rate of 80 bpm with inspiratory stridor and significantly increased respiratory effort. His gums are pink, but his temperature is 102.9° F. It’s difficult to auscult his heart over his increased respiratory sounds, but he has strong pulses and a pulse rate of 150 bpm.
At this point, the veterinarian approaches. You relay the history that Bailey’s owner provided, as well as your triage exam findings. The vet performs their own brief physical exam, confirming your findings.
Based on the history and exam, the vet suspects that Bailey has brachycephalic obstructive airway syndrome (BOAS).
The vet asks you to place an IV catheter, while she goes to speak with Bailey’s owner. When she returns to treatment, she tells you that Bailey’s owner has authorized treatment and asks you to give the following:
- Butorphanol (0.2 mg/kg IV) and midazolam (0.2 mg/kg IV) for sedation
- Dexamethasone (0.5 mg/kg IV) for laryngeal and airway edema
- Supplemental oxygen (via face mask if Bailey will tolerate it, or flow-by if that’s easier)
Once you have started to administer these treatments, the vet returns to the appointment that she had just begun when Bailey arrived. She asks you to come find her immediately if there are any issues.
Although Bailey calms a bit down with sedation, administering oxygen is a challenge. Even with sedation, he resists a mask and even your attempts at flow-by oxygen. Your practice doesn’t have an oxygen cage, so there’s not a convenient way to give Bailey oxygen that doesn’t require you to hold him, which seems to make him more excitable. Overall, you don’t feel that his breathing is improving. If anything, he looks worse; his gums now appear a bit cyanotic.
You send a vet assistant to the vet’s exam room, wanting her to come back to treatment to assess Bailey again as soon as possible. She immediately rushes back, agrees that Bailey is worsening, and contacts Bailey’s owner to recommend anesthesia and intubation. Fortunately, Bailey’s owner consents.
As the vet finishes answering Bailey’s owner’s questions, she gives you the thumbs-up to indicate that you should go ahead and anesthetize Bailey. You administer propofol to effect and then attempt to pass an endotracheal tube. Intubation is difficult, due to severe swelling of Bailey’s laryngeal tissues, but you are able to successfully intubate him and deliver oxygen and isoflurane. Bailey’s gum color improves almost immediately.
You connect Bailey to your practice’s anesthesia monitoring equipment (ECG, oscillometric blood pressure cuff, pulse oximeter, and capnograph) and all values are normalized within five minutes. You monitor Bailey’s temperature every five minutes and it also begins to fall rapidly once he is anesthetized, falling to 102.2° F over the first ten minutes.
After twenty minutes, at the vet’s request, you begin to slowly and gradually wean Bailey off isoflurane. Once his isoflurane is completely discontinued, you keep him on oxygen for approximately five minutes. You then keep him intubated for as long as possible, only removing his tube when he begins to show signs of chewing at the tube.
When you remove Simba’s endotracheal tube, he is once again breathing normally. His respiratory rate and effort are normal, with minimal inspiratory stridor. You monitor him closely in recovery, ensuring that he remains calm and prepared to request additional sedation from the vet if he becomes agitated. His recovery is calm and uneventful and he does not require additional oxygen or re-intubation during his stay.
Brachycephalic dogs are susceptible to acute upper airway obstruction, or BOAS, especially if they become excited on a hot, humid day. These dogs become victims of a vicious cycle, in which barking and heavy breathing lead to laryngeal edema, which leads to even heavier breathing, which leads to even worse laryngeal edema.
There are two primary components to treating BOAS:
- Corticosteroids, to decrease inflammation in the larynx and airways
- Sedation, to calm the pet and decrease respiratory effort
In severe cases, anesthesia and sedation may be required. Cooling measures may also be required in some dogs, depending upon the dog’s temperature at presentation.
The only long-term solution for brachycephalic syndrome is surgery. Correcting a brachycephalic dog’s stenotic nares, elongated soft palate, and everted laryngeal saccules will improve the dog’s quality of life and should effectively prevent further episodes of respiratory distress.
If an owner is unwilling or unable to pursue surgery, treatment is centered on keeping the dog calm and avoiding high heat and humidity.
When a brachycephalic dog presents in respiratory distress, the diagnosis is brachycephalic obstructive airway syndrome (BOAS) until proven otherwise.
Treatment is centered upon facilitating the flow of air past the swollen and inflamed laryngeal tissues. In many cases, this can be accomplished with sedation and corticosteroids. In more severe cases, however, intubation or even a temporary tracheostomy may be required.
Once the crisis has passed, the owners need to consider options for long-term management of brachycephalic syndrome.