Cat bite abscesses & treatment options for aural haematomas

Question 1

cat bite abscess
History and presenting complaints

Answer 1

• Client reports that cat reacts to a part of body being touched
• Obvious swelling or “lump” - painful to touch +/- heat +/- scab or crusting
• Blood or sero-purulent discharge on fur causing matting or clumping of hair
• Lethargy or inappetence. Hiding behaviour, take themselves away from humans

Question 2

cat bite abscess physical exam findings

Answer 2

• Finding & palpating the abscess is diagnostic…can be challenging in a long- haired cat
• Evidence of pyrexia and no other physical exam finding? -> do a thorough check over body to look for possible abscesses or more commonly excoriations/scabs and cellulitis
• Possible that scabs from bite wounds have healed & left with underlying tenderness, soft sponginess and slight swelling of tissue
• Is there blepharospasm, discharge from an eye? Check for corneal scratch -> fluorescein stain

Question 3

cat bite abscess treatment

Answer 3

• abscesses are painful! sedation + pain relief is usually required. Full GA may be needed.
• depending on severity:
  1. lancing with scalpel at the most dependent spot and allow purulent material to drain + flush with saline or lactated Ringer’s solution. Leave the drainage point open (do not suture) +/- systemic antibiotics. Drainage is key!!
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  2. if evidence of necrotic tissue, then incise into abscess, open, debride necrotic tissue, flush, and suture healthy edges. Do not suture bite wounds! Only suture healthy edges (e.g. incision you have created). If you choose to place drain, create a fresh drain incision, place drain and anchor distal to the drainage site.
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• systemic antibiotic choices (if needed): cephalexin, amoxicillin (+/- clavulanic acid), cefovecin (third gen cephalosporin - injectable)
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• generally not a good idea to instill ointments / creams
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• NSAIDs (eg. meloxicam) for pain relief
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• E-collar generally needed

Question 4

cat bite abscess possible complications

Answer 4

• Cellulitis & necrosis of wound. If not adequately debrided or delayed debridement or infection involved deeper layers
• Dehiscence of sutured wound. Do not suture necrotic/unhealthy tissue! Do not suture bite wounds!
• Non-healing abscess despite adequate debriding and tissue handling. Biopsy and submit for culture & sensitivity. e.g. may be dealing with Mycobacteria or other non-typical bacteria

Question 5

cat bite abscess
Ongoing treatment/prevention considerations:

Answer 5

• FIV/FeLV testing? Is this cat a repeat fighter?
• Do cat dynamics need to change / re-organised in a multi-cat household?
• Is your cat bite abscess pateint up to date with rabies vaccination?
• recheck the healing site 3-4 days post surgery or lancing > should be granulating / healing well
• coach your clients on how to clean drainage holes and area around any drains. Perform this safely!

Question 6

Cat bite abscess - Information for your clients

Answer 6

• home care is important
• do come back for a recheck appointment so that complications can addressed early
• be on the look out for bites / scabs, painful swellings on your cat and get them checked
• for savvy clients: if they find a fresh bite wound > can clean with tap water and cotton. Ideally clean for 203 days to allow drainage and then let it granulate / scab to heal

Question 7

spectrum of care treatment options for aural hematoma

Answer 7

• GA & surgery: to evacuate hematoma and suture hematoma space/pinna using a variety of surgical techniques. Must treat otitis externa (bilaterally).
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• Non-surgical: 1. Drain hematoma using needle and syringe or butterfly catheter, extension tube & syringe. Well tolerated. Will reform but smaller in size. Weekly draining required for approx. 3 weeks. Must treat otitis externa (bilaterally).
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• 2. Drain as previous + start on anti inflammatory doses of oral prednisolone tapering for 3 weeks. Pred will help with inflammation & pruritus of hematoma but also for otitis externa. Must treat otitis externa (bilaterally).
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• 3. Drain as above + inject long- acting corticosteroid (depomedmerol 20mg/ml, 0.5mls) into the empty space +/- tapering dose of prednisolone as above. Must treat otitis externa (bilaterally).
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• 4. No drainage. Start on tapering dose of oral prednisolone. Must treat otitis externa (bilaterally).
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• For all of above treatment options (including surgical), the underlying allergic skin disease should be addressed. Treating otitis externa is part of addressing the underlying allergic
  skin disease.

Question 8

Aural hematoma
Comparing surgical vs non-surgical treatment options to provide spectrum of care information to clients for surgical treatment:
- healing times
- home care
- medicating
- revisits
- costs
- discomfort

Answer 8

Surgical treatment:
- healing time: approx 3-4 weeks with weekly rechecks and staggered suture removals +/- bandage changes
- home care for client: cleaning of wound, managing bandage, managing E-collar
- medicating ear that has had surgery? yes! can be painful for dog and difficult for human
- revisit to clinic required?: Yes! Once a week for 3-4 weeks. More frequent for bandage changes or if bandage gets wet/ soiled or comes off
- Costs: can range from $500-750+ for surgical procedure. Then recheck fees +/- medications in subsequent visits
- Discomfort for patient?: surgical procedure > associated discomfort with open wound and sutures expected

Question 9

Aural hematoma
Comparing surgical vs non-surgical treatment options to provide spectrum of care information to clients for non-surgical treatment:
- healing times
- home care
- medicating
- revisits
- costs
- discomfort

Answer 9

Non-surgical treatment:
- healing time: 3-4 weeks with weekly visits to drain
- home care for client: monitor hematoma
- medicating the ear that has been drained?: Yes! Generally easier to do without a surgical wound on pinna
- revisit to clinic required?: yes! once a week for drainage done in appointment room and recheck ear canals as needed
- Costs: can range from $150-250 for first visit. Then recheck fee +/- drainage fee +/- medications thereafter
- Discomfort for patient?: drainage via needle will cause short term, minimal discomfort