Perianal skin disease Flashcards
What animals are anal sacs found in what is their function?
*Function = scent marking
*Seen in carnivores + many other mammals
What are the length of the anal sac ducts + where do they open?
*3-10mm long
*Open at anal mucocutaneous junction at 4 + 8 o’clock
Impaction is a common problem what are the clinical signs?
- Recurrent pruritus (scooting, rubbing and biting – local and more widespread
i.e. tail head, inguinum or lateral thighs) - Pain and depression
- Distended anal sacs
- Malodour
What are the primary causes of anal sac impaction?
- Abnormal character and volume of secretion
- Change in muscle tone
- Faecal form – diarrhoea or constipation
- Plugging of the ducts
What are secondary causes of anal sac impaction?
*Bacterial infection
*Rarely - Malassezia overgrowth
What are predisposing factors of impaction?
*Inflammatory skin disease
*Breed - some breeds = prone to impaction
*Obesity
What are differential diagnoses for anal sac impaction considering perianal pruritus?
- Allergic skin disease (especially CAD)
- Endoparasites
- Severe flea infestation
- Vulval fold dermatitis
- Tail fold dermatitis
What are differential diagnoses for impaction considering abscessation?
*Anal furunculosis
What are differential diagnoses for impaction considering nodules / palpable glands?
Anal sac adenocarcinoma
How is impaction diagnosed?
*Palpation + expression of sacs
*Cytology of anal sac fluid
*Culture + susceptibility testing
What is the treatment of recurrent anal sac impaction?
*expression
*addition of fibre to food to improve faecal consistency
*Short course prednisolone
*Flush + pack
*Anal sacculectomy for recurrent cases
How would you treat anal sac infection?
*Repeat emptying + topical antibiotics as for impaction
*AVOID systemic antibiotics
How would you treat anal sac abscessation?
*Local cleaning - chlorohexidine shampoo
*Systemic antibiotics to treat infection of soft tissues
*Consider prednisolone to reduce inflammation once infection tx started
*Analgesia - NSAIDs / paracetamol
What are the clinical signs of anal sac adenocarcinoma?
*No clinical signs unless detected on palpation
*Some cases = paraneoplastic disease = Polydipsia / polyuria w hypercalcaemia + secondary renal disease
Does metastasis often occur? If so where?
Yes - sublumbar + iliac lymph nodes
What is the median survival time of anal sac adenocarcinoma?
18months
What are predisposing factors of anal furunculosis?
Genetic predisposition
usually seen is german shepherds
What is the pathogenesis of anal furunculosis?
May involve inappropriate response to bacteria around the anus
What are the clinical signs of Anal furunculosis?
- Tissue destruction and sinus formation
- Huge ulcerative tissue deficits in chronically affected cases
- Moderate to severe pain – care when examining
- Difficulty in passing faeces and faecal incontinence
How is anal furunculosis diagnosed?
*Clinical signs in predisposed breeds
*Elimination of other causes of perianal sinus formation
*Cytology to assess presence of bacterial infection
What is the treatment of anal furunculosis?
IMMUNOMODULATORY THERAPY
*Ciclosporin (best option)
*Tacrolimus
*Prednisolone +/- azathioprine
other=
*Manage bacterial overgrowth
*Analgesia
*Surgery
-most cases need life long therapy
