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Guttural Pouch Chondroids
Guttural Pouch Chondroids
VETE 405 Case Study Final
Stevie Willett
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Guttural Pouch Chondroids
Star is a 6 year old dun colored Quarter Horse mare that weighs approximately 1000 pounds
(455 kg). She presented to the hospital on October 18, 2013 by Mr. Jones. The main complaint was that
the patient had nasal discharge and was coughing when eating. Mr. Jones stated that he has had Star
for 2 years and that she has had intermittent nasal discharge since he purchased her. Star is kept at a
boarding facility and her previous owners purchased Star at 4 months of age. The previous owners
stated that Star had intermittent nasal discharge since they purchased her. Mr. Jones stated that Star
had not received any antibiotics or treatments for the nasal discharge since he has owned her, but the
previous owners had occasionally placed her on antibiotics. Mr. Jones also stated that Star’s dam had a
bad case of Strangles during the time of foaling with Star and it lasted for 2 weeks. Strangles is caused by
the bacteria Streptococcus equi ssp.equi. It can cause abscesses to develop in the lymph nodes of the
throat region and pus can accumulate in the guttural pouches.
Physical Exam:
Temperature: 99.8
Heart Rate: 42
Respiration Rate: 18
Mucus Membranes: Pink/Moist
Capillary Refill Time: less than 2 seconds
Gastrointestinal Sounds: borborgymi present in all four quadrants
The patient had moderate bilateral mucopurulent nasal discharge. The patient was bright, alert,
and responsive (BAR). The patient showed no signs of respiratory distress. Auscultation of lungs
revealed normal bronchvesicular sounds and no abnormalities were heard on auscultation of trachea.
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Guttural Pouch Chondroids
No swelling was noted in the submandibular or retropharyngeal lymph nodes. The patient coughed
twice during exam, but no other abnormalities were noted on physical exam.
The veterinarian suggested blood work for a Complete blood count (CBC), Packed cell volume
(PCV), Total protein (TP), and Fibrinogen be performed. Mr. Jones agreed. The White blood cell count
(WBC) was normal, but the fibrinogen was elevated at 1500mg/dL. Acute inflammation or tissue damage
may elevate plasma fibrinogen levels (Hendrix and Sirois 2007, p. 80). The veterinarian then suggested
to perform additional diagnostics that included an upper respiratory video endoscopic exam, which the
owner consented to the procedure. The patient was sedated with 5mg of burtorphanol and 7mg of
detomidine intravenously.
During the upper respiratory video endoscopic exam there was evidence of moderate
inflammation in the pharynx. A mild amount of white/yellow discharge was also noted coming out from
the openings of both guttural pouches. Laryngeal function was normal. The endoscope was passed into
the trachea and no food or mucus was noted in the trachea. The patient was able to swallow normally,
but the soft palate displaced frequently. This can occur as a dysfunction of the nerves controlling the
soft palate or can result from sedation. The displacement of the soft palate was easily corrected with
swallowing. It was noted that the guttural pouches were located further caudal than normal. There are
two guttural pouches in the horse, the openings to the pouches are known as the pharyngeal ostium.
The openings are in the lateral walls of the pharynx. The function of the guttural pouch is not known,
but it is a large diverticulum of the Eustachian tube and is typically filled with air. Each guttural pouch
contains two compartments , a medial and lateral compartment which are separated by the stylohyoid
bone. Important structures contained within the guttural pouches include: Cranial Nerve IX and X and
the internal carotid artery in the medial compartment; the lateral compartment houses the external
carotid artery. The veterinarian and the technician made a coordinated effort to enter the left guttural
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pouch, but it was very difficult to place a pipette into the pouch and took several tries. It was noted that
the pharyngeal ostium appeared to be scarred and significantly smaller than a normal guttural pouch.
Multiple attempts were made to get into the pouch along with utilizing different methods, but the scope
was unable to pass into the pouch due to the small opening. A pipette was then inserted into the right
pouch, which was also very difficult to enter but the opening appeared to be larger than the left pouch.
The scope was able to pass into the right pouch after several attempts. Multiple chondroids were noted
on the floor of both compartments. Chondroids are concretions of inspissated pus. The pouch was
inflamed and had thick mucus present. The veterinarian placed 2 grams of acetylcystine into both
guttural pouches and then attempted to lavage the chondroids out, but none were displaced.
Acetylcystine is a mucolytic that is used as a 20% solution in the guttural pouch of horses to break up
inspissated pus. After the endoscope exam the veterinarian suggested radiographs of the skull to be
performed on Star and the owner agreed.
A lateral radiograph of the skull showed numerous chondroids present in both pouches.
The veterinarian diagnosed Star with guttural pouch empyema with concurrent chondroid
formation. Empyema of the guttural pouch is defined as the presence of purulent material and/or
chondroids within one or both guttural pouches. Chondroids consist of inspissated purulent materials
(usually numerous individual round balls) that form in some cases (Auer and Stick 2012 p.627). The
veterinarian spoke with the owner stating that due to the severity and chronicity of the disease and the
abnormalities of the guttural pouch openings that a surgical drainage of the pouches to remove the
chondroids was the best and only option remaining. Guttural pouch surgery can be performed standing
or under general anesthesia. The surgeon chose to do a Modified Whitehouse approach to the guttural
pouches. The surgeon stated that this approach is much easier to perform under general anesthesia
because it takes deep dissection and there is visualization under general anesthesia that is not present
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in the standing patient. Additionally, the standing procedure has increased patient pain and discomfort
since it is not possible desensitize the deeper structures (only skin can be anesthetized) (Armentrout
2013). The owner gave consent for the patient to be stabilized, started on antibiotics, and monitored
over the weekend and for the board certified surgeon to perform the surgery under general anesthesia
Monday (October 21).
The patient was started on 500mg of Flunixin meglumine (Banamine) intravenously (IV) twice
daily (BID), 3g of Gentamicin IV q 24 hours, and 9 million U of Penicillin, Pro. G (PPG) intramuscular (IM)
twice daily (BID). The patient was placed in an isolation stall with enforced isolation protocol. Through
the weekend (October 19-20) the patient was continuously monitored, with vital signs taken twice daily.
Patient was also continued on medications. No significant changes were noted during the weekend.
On Monday morning of October 21st vital signs were taken and medications were given
(Banamine, Gentamicin, and PPG). A Tetanus toxoid vaccine was also given at this time since the patient
had no vaccine history. The right jugular vein was clipped and aseptically prepared for an IV catheter. A
14ga catheter was aseptically placed and sutured in place by the technician. The patient’s mouth was
rinsed out and hooves were picked clean. The patient was brushed to remove dirt and shavings off body.
The patient was taken into the surgery room where she was sedated with 400mg of xylazine IVC as a
preanesthetic. Once the patient became sedate, 30mg of midazolam and 1200mg of ketamine were
administered IVC as induction agents. Once the patient became unconscious a 26mm endotracheal tube
was placed easily and the patient was placed in dorsal recumbency on the surgery table. The patient was
connected to a gas anesthetic machine with a ventilator at 7bpm and started on isoflurane at 2% and
5L/min flow rate of oxygen. The patient maintained between 1.5-2% on Isoflurane during surgery.
A 1 meter video endoscope was placed through the right nostril and into the right guttural
pouch. A Modified Whitehouse Approach for Drainage of Guttural Pouch was used as the surgical
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approach. Advantages to both Whitehouse approaches are direct access to the roof of the guttural
pouch, digital access to the lateral compartment, excellent ventral drainage, and simultaneous access
through the septum to both compartments (Auer and Stick 2012 p.634). The surgeon also chose this
surgical method because there is the lowest amount of risk with this procedure, and therefore the
fewest complications. The biggest complication is damage to the nerves responsible for swallowing,
which can lead to chronic aspiration pneumonia and even death (Armentrout 2013). A 30 cm x 30 cm
area centered over the larynx was clipped and aseptically prepared and draped. A skin incision was
made along the ventral edge of the linguofacial vein, extending rostrally 12 cm from the jugular vein.
The underlying fascia was exposed and the larynx was identified. Blunt dissection was continued to the
level of the medial compartment of the guttural pouch where the light from the endoscope was visible.
Careful, blunt dissection under video endoscopic guidance was performed until the guttural pouch was
entered. An extensive number of chondroids were identified and removed with sponge forceps.
Chondroids in the lateral compartment were digitally loosened as well as flushed out, and removed. The
guttural pouch was cleared of all chondroids and a 14 French Foley catheter was placed into the guttural
pouch through the incision and the scope was removed. Due to adhesions in the pharyngeal ostium, the
scope could not be placed in the left guttural pouch. The approach to the left guttural pouch was made
as described above, except the pouch was entered with blunt digital dissection blindly along the floor of
the medial compartment of the guttural pouch where the chondroids present in the pouch were
palpable. Chondroids were removed in the same manner. There were some chondroids that were not
amenable to removal, so they were copiously lavaged and left in place to be removed during a standing
procedure. A 14 French Foley catheter was placed in the left guttural pouch as described for the right.
The incisions were left open to heal by second intention. The horse was moved to the recovery stall.
Recovery from anesthesia was uneventful. The Surgeon’s biggest post-surgical concern was pharyngeal
and laryngeal dysfunction causing aspiration pneumonia, since she was exhibiting mild signs of
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dysphagia prior to surgery (coughing when eating). The patient was placed back in stall after recovering
and once fully awake she was given ½ pound of Purina equine senior feed made into a mash to eat. It
was noted that the patient was able to chew and swallow without difficulty, but patient did cough a few
times. In addition to the p.m. medications (PPG) the patient was given 20mg of dexamethasone IM
once. The patient was fed again later that night 1 pound Purina Equine Senior mash and ate it without
difficulty. The patient had some clear nasal drainage present from both nostrils.
On the day following surgery (October 22) vitals were taken twice daily which remained within
normal limits and the patient was continuously monitored for dysphagia. Antibiotics and NSAIDs
continued (500mg Banamine BID, gentamicin 3g q 24 hour, PPG 9 million U BID) and 20mg of
dexamethasone was also given IM. Foley catheters remained intact in each guttural pouch. Surgical
incisions were cleaned as needed to remove debris. Clear nasal drainage was present from both nostrils.
The patient continued to eat and swallow well. The veterinarian increased the Purina Equine Senior
mash amount to 2.5 pounds to be fed 4 times daily (QID). The patient continued to do well.
On October 23 the patient’s vital signs continued to be monitored twice daily and the
medications were given as before (Banamine, gentamicin, and PPG) The dexamethasone was
discontinued. The patient continued to eat and swallow without difficulty. About mid-morning the horse
was placed in the isolation area stocks and sedated with 7mg of detomidine and 5mg of butorphanol IV
for video endoscopic exam. The right guttural pouch was examined, found to be free of chondroids, and
the Foley catheter was removed. The pouch was instilled with 10 million Units of potassium penicillin
gel. The left guttural pouch was still not able to be entered through the pharyngeal ostium. The pouch
was scoped retrograde through the incision and 8-12 chondroids were still present in the pouch. The
scope was reintroduced through the nose and the biopsy forceps were introduced through the channel
of the scope and into the left guttural pouch, where they were digitally identified and guided out the
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incision. The scope was then passed along the biopsy forceps until the guttural pouch was entered. The
remaining chondroids were then removed through the incision under the video endoscopic guidance
with sponge forceps. The pouch was copiously lavaged with sterile LRS and 10 million Units of potassium
penicillin gel was infused into the pouch. The Foley catheter was removed.
On October 24 the patient’s vital signs remained within normal limits. The patient continued to
eat the 2.5 pounds of Purina Equine Senior mash normal with no dysphagia noted. An additional 1
pound of pelleted alfalfa mash was added to the morning feeding. The clear nasal drainage was present,
but less was noted. Banamine IV and PPG IM were given to the patient. The surgical incisions were
cleaned in the morning. The patient was discharged from the hospital later in the afternoon. The
veterinarian and surgeon went over discharges with the owner (Mr. Jones):
1. Uniprim: Give 2 scoops on feed once daily until gone. Start immediately. This is a sulfa antibiotic.
Antibiotics in horses can cause inappetance, lethargy, diarrhea, and signs of colic. These are rare
complications, but if you notice any of these signs, discontinue use immediately and contact a
veterinarian.
2. Bute: Give 2g by mouth once daily for 2 days. Never exceed 2 g in a 24 hour period. This is a nonsteroidal anti-inflammatory drug (NSAID). These drugs are analgesics (pain reliever) as well as antiinflammatory drugs that are useful in reducing swelling and fever. These drugs can cause
gastrointestinal ulceration, especially in the stomach and right dorsal colon. They can also cause kidney
disease and failure. Never give to a dehydrated horse, and never give with another NSAID drugs, such as
Banamine, Aspirin, or Ketoprofen. Long term use of NSAIDs is contradicted in horses.
3. SOF (Scarlet oil/Nitrofurazone liquid) wound spray: Clean incisions daily with dilute betadine solution
and spray 1-2 times daily with SOF wound spray.
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4. Feed only soaked pelleted feed (such as Equine Senior, alfalfa pellets, and/or beet pulp) or soaked
chopped alfalfa or alfalfa cubes for 10 days. After 10 days, start introducing hay back into her diet. Feed
her small amounts at first (1/4 flake each feeding), and transition her back to her regular diet over the
next 4-7 days.
5. Rest (no riding or forced exercise) for 10 days.
6. Recheck examination in 10 days.
7. She should still be considered infectious for 30 days. Prevent nose to nose contact with other horses.
Infected animals may continue to shed the organism for a month or more following apparent recovery
(Haynes 2001 p.206).
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References:
Armentrout, Amy. DVM, MS, Diplomate ACVS (2013, December 2). Personal Interview.
Auer, JÖrg. A.DVM and Stick, John. A. DVM (2012). Equine Surgery 4th ed. St. Louis, Missouri:
Elsevier Saunders.
Haynes, Bruce. N. DVM (2001). Keeping Livestock Healthy 4th ed. North Adams, MA: Storey
Publishing.
Hendrix, Charles.M. DVM and Sirois, Margi. RVT (2007).Labroratory Procedures for Veterinary
Technicians. St. Louis, Missouri: Mosby Elsevier.
Plumb, Donald. C. (2011). Plumb’s Veterinary Drug Handbook 7th ed. Stockholm,
Wisconsin: Pharma Vet Inc.
Reeder, D., Miller, S., Wilfong, D., Leitch, M., Zimmel, D. (Eds.) (2009). AAEVT’s Equine
Manual for Veterinary Technicians. Ames, Iowa: Wiley-Blackwell.