Anal fissures, also known as anal furunculosis (AF), is a challenging and debilitating condition seen in dogs which thankfully is not too commonly presented. This article aims to cover the general principles of AF, covering what this condition actually is and how it is investigated and managed.
What is anal furunculosis?
AF is a debilitating, progressive and painful inflammatory disorder in dogs affecting the anal orifice and the perianal region (the area under the tail). This horrid disease is characterised by the presence of ulcerative lesions and blind fistulae of the skin, anal and perianal tissues (Sakkadaki et al, 2018). These ulcerated lesions can either be single or form multiple ulcerated tracts (Welsh, 2001). Anal furunculosis is also commonly referred to as ‘perianal fistula.’
With the advancement of Veterinary medicine over the years and treatment failures and successes, it is thought that in the majority of AF cases the underlying cause is immune-mediated. Other theories amongst the literature suggests that breed conformation and anal sac issues can be contributing factors to predisposing dogs to AF.
Which dogs are more commonly affected?
German shepherds are predisposed to many conditions and sadly anal furunculosis is one of them! The following dog breeds may also be more likely to develop AF also (this list is not exhaustive) (Sakaddaki, 2018):
- Irish setters
- Collies and Border collies
- Labrador retrievers
- English bulldog
- Old English sheepdog
- Cocker spaniels
What are the clinical signs?
The clinical signs of anal furunculosis in dogs can be quite subtle and it is not always obvious in individuals where their specific problem is based on their symptoms alone.
Some of the common clinical signs associated include pain the anal region and secretions from this region, anal sac abscesses, continuous licking of the area, anal strictures (making defecation difficult) and abnormal tail position (Sakkadaki et al, 2018).
Interestingly, dogs can display gastrointestinal signs such as straining caused by the feeling of incomplete defecation, meaning that dogs may feel the constant need to pass a stool (even if the bowels are empty) (Jamieson et al, 2022). Dogs with AF may display signs very similar to colitis and this can make identifying this specific condition difficult. Dogs with AF may experience loose bowel movement and can occasionally develop blood in their faeces (haematochezia).
How is it diagnosed?
Your Vet will diagnose anal furunculosis in your canine friend through a variety of methods. Firstly, your Vet will obtain a thorough clinical history and will then perform a thorough hands on physical examination of your dog. Your Vet will often also examine your dog’s anal glands via a rectal examination to assess whether there is anal gland involvement.
We need to always be mindful that AF is a very painful condition, therefore further examination is likely to require sedation – or in many cases anaesthesia, because it’s so sore.
A presumed diagnosis of AF may be made following the clinical examination and especially if your dog is a predisposed breed. However, for a definitive accurate diagnosis more invasive diagnostic tests are required. Further testing may involve tissue biopsies, colonoscopies and sterile swabs taken of the area for culture and sensitivity testing. Swabbing the site would enable your Vet to appropriately select the correct antibiotic for your dog to try to avoid the development of antibiotic resistance (but I’ll save this hot topic for another day!) As AF can present similarly to other conditions such as anal gland abscesses and cancer, further diagnostics are often recommended.
How is it treated and managed?
Treatment of AF is not always straightforward and treating this condition can have its challenges, sometimes a complete cure is not always achievable despite best efforts.
Treatment options can be split into two general categories, medical vs surgical management.
This previously used to be the treatment of choice for anal furunculosis. There are a variety of surgical methods performed in the past and the surgical method chosen can vary in each individual depending on factors such as the location of the anal furunculosis lesion and its extent. All surgical procedures come with some risk, however, surgical management of AF has been shown to have a high post-operative complication rate. Subsequent problems often used to include faecal incontinence and anal stricture (Sakkadaki, 2018). For these reasons surgical management is generally not recommended first line now we have better drugs. However, it is still used occasionally in those patients where medical management has failed.
In more recent times, there has been renewed interest in medical or conservative management of AF using immunosuppressant drugs (Welsh, 2001). This appears to now be the treatment of choice based on high satisfactory results and patient success rates ((Sakkadaki, 2018). Ciclosporin remains the current drug of choice and the duration of treatment is usually a minimum of 12 weeks! Sometimes your Vet will recommend a combination of immunosuppressive medications.
It goes without saying that the treatment plan would always include pain relief and analgesia to ensure adequate pain management is carried out for your canine friend and this must always remain the priority. Additionally, often management of a condition such as AF requires careful consideration of other influences including the temperament of the patient involved and the practicalities. For example, if they are extremely painful around the region, then there is less chance that they would tolerate the application of topical medications.
To conclude, anal furunculosis is a topic not for the faint hearted. This progressive inflammatory disease can carry with it many challenges but today the mainstay of treatment is generally medical management with immunosuppressive medications. This is usually effective even though a complete cure is not always achieved.