Anal sac diseases & acral lick granulomas

Question 1

Anal sac disease
Breed predispositions & risk factors:

Answer 1

• Typically (but not exclusively) small breed dogs (<15kg). Also possible in cats.
• Chihuahuas, American Cocker Spaniels, English Springer Spaniels considered ‘at risk breeds’. Increased risk possible in Siamese cats.
• Obesity, diarrhea, chronic soft feces, over expression of normal anal glands are all considered risk factors. Sometimes none of these are the case in an individual!

Question 2

Anal sac disease
Physical exam findings? progression?

Answer 2

• Swelling or mass effect in perianal region, pain during rectal exam or taking rectal temperature
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  Presumed progression:
• Impaction: thickening of normal liquid secretion (toothpaste like, inspissation)
• Sacculitis: secretions continue to accumulate - > inflammation of sac + difficulties expressing
• Abscess: bacteria -> draining tract or sinus, alopecia, blood +/- pus staining, scab formation +/- pyrexia & malaise
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• or, neoplastic mass

Question 3

neoplasia found at anal gland? consequences? physical exam findings? risk factors?

Answer 3

• Neoplastic masses e.g. SCC, melanoma, apocrine gland adenocarcinoma. Paraneoplastic hypercalcemia due to production of PTHrP occurs in up to 50% of dogs. Approx 40% of tumours are detected incidentally on pex
• Locally invasive and can metastasize to local LNs (iliac, sacral, sublumbar) & possibly lungs, liver, spleen
• Typically firm, not draining, cannot express secretions +/- pain & systemic disease +/- palpable increased regional LNs or caudal abdominal mass (typically LNs)
• Risk factors: older (~9-11yrs) dogs, Spaniel breeds, neutered males over-represented

Question 4

Anal sac disease
Diagnosis and Differential diagnoses:

Answer 4

• Diagnosis: usually based on history information, clinical signs & physical exam findings
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  DDx:
• Other causes of tenesmus: rectal mass, perianal fistula, perineal hernia, acute or chronic colitis
• Other causes of pruritus & inflammation: allergic skin disease -> food allergy, flea allergy dermatitis. Perianal pyoderma, tail fold dermatitis
• If suspect a neoplastic mass rather than sacculitis or abscess then a FNA should be done. Regional LN check +/- u/sound mass
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• Not sure what you are dealing with? FNA can be done -> cytology, bacteria, neutrophils, blood? Or neoplastic cells?

Question 5

Anal sac disease treatment

Answer 5

• manual expression of contents. If pasty / clay / granular in consistency then expression may not be possible
• sedation, cannulation and lavage of sacs may be needed before contents can be manually expressed
• instill an antibiotic and steroid prep +/- oral NSAIDs
• If abscess and not already ruptured: sedation minimum, lance and lavage, allow to granulate. Systemic antibiotics often used eg. cephalexin, amoxicillin +/- oral NSAIDs
• removal of sacs or removal of tumor +/- chemo

Question 6

Anal sac disease
Ongoing treatment/prevention considerations:

Answer 6

• Recurrent anal sac impaction, sacculitis or abscesses -> may be candidates for removal
• Avoid frequent, overzealous, firm expression. Potential to cause inflammation
• Add fibre to diet to add bulk to faeces so that anal glands express themselves at time of defaecation
• Can teach clients to express glands at home
• Cats may need to have external expression done
• Not a major health threat but very frustrating at times!

Question 7

Anal sac disease
Information for your clients:

Answer 7

• may/will recur. Same side or other side
• don’t ignore anal or perianal masses - get them checked!
• normal glands do not necessarily need to be manually expressed > avoid overzealous / frequent expression
• don’t ignore scooting or straining to defacate signs
• cats have anal glands too!

Question 8

Acral lick granulomas
- what are these? cause?

Answer 8

• Also called Acral Lick Dermatitis. Acral = from Greek akron which means “extremity”
• Firm, ulcerative, alopecic cutaneous plaque
• Caused by excessive, compulsive licking of the lower part of a limb
• Challenging and frustrating condition seen in general practice…management is often key

Question 9

Acral lick granulomas: etiology, progression

Answer 9

• Previously believed that cause was psychogenic in origin…currently, more likely that it is underlying organic disease that initiates the lesion
• Allergic skin ds, joint ds, neoplasia, focal pyoderma are all possible inciting causes
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• Presumed progression:
• Inciting cause-> chronic licking-> secondary focal, deep pyoderma-> more licking -> worsening the lesion
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• If no organic ds can be identified then consider obsessive compulsive behaviour/boredom or separation anxiety

Question 10

Acral lick granulomas
History and presenting complaints

Answer 10

• Clients will report excessive compulsive licking of a focal spot on front or hind leg
• Prior history of joint disease? History of trauma to joint? Has the dog had a history of OA in other joints?
• Is there evidence of allergic skin ds elsewhere on body? Check ears, feet etc.

Question 11

Acral lick granulomas
Physical exam findings

Answer 11

• Usually a single lesion on dorsal carpus, metacarpus or metatarsus.
• Firm, erythematous, alopecic +/- ulcerated plaque or nodule. Saliva staining +/- draining tracts +/- oedema
• Evidence of deep pyoderma often present - > multiple sinuses with draining tracts. Consider food allergy, atopic dermatitis if multiple lesions are present on rest of body

Question 12

Acral lick granulomas treatment

Answer 12

• get secondary pyoderma under control! pyoderma > pruritus > more licking! systemic antibiotics if deep pyoderma (eg. cephalexin)
• topical treatments are usually disappointing as they are licked off! But Mupirocin is a very good choice
• Can try intralesional methylprednisolone acetate (Depo-Medrol) > into granuloma
• E-collars, especially when there is acute infection which is often the time when it is pruritic
• avoid surgical excision as closure will be difficult and very high incidence of wound breakdown (nautre of lesion + location)
• laser treatment may be beneficial in refractory infections
• behaviour modifying drugs if cause is determined to be psychogenic in nature
  (eg. clomipramine, amitriptyline, fluoxetine)

Question 13

Acral lick granulomas client information

Answer 13

• management is key!
• If any sign of acute infection, then take to vet for exam + treatment - better to act sooner rather than later as easier to treat acute infection vs. chronic
• watch for lameness, favouring a limb and other systemic clinical signs
• watch for behavioural signs / problems. Watch for triggers - stress / anxiety?