Plasma Cell Pododermatitis in Cats - Pillow Paw
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Feline plasma cell pododermatitis is a rare disease with a characteristic symptom of swollen feet. It is for this reason it has the common name of ‘pillow paw’ or ‘pillow foot’. The origin of the disease is not completely clear, but it is believed to be immunity-mediated. This means the well-being of the cat and the efficacy of their immune system are contributing factors to developing this problem. If not treated, it is possible the cat can develop lameness in the affected paw. The treatment is usually extensive and may require a long period of time for recovery.
At AnimalWised, we find out more about plasma cell pododermatitis in cats. We look at the causes, symptoms and treatment of pillow paw to know what you might expect if your cat develops this condition.
What is feline plasma cell pododermatitis?
Feline plasma cell pododermatitis is a lymphoplasmacytic inflammatory disease which affects the metacarpal and metatarsal pads of cats, i.e. the circular paw pads. However, the digital paw pads can also be affected. It is characterized by inflammation which result sin the paw pads becoming soft and painful. Cracks in the skin, hyperkeratosis and sponginess can occur.
It is a rare disease that can occur in cats regardless of breed, sex and age. However, research points to it being more common in non-castrated males.
Causes of plasma cell pododermatitis in cats
The exact origin of the disease is unknown, but the characteristics of this pathology show a possible immune-mediated cause. These characteristics are:
- Persistent hypergammaglobulinemia
- Intense tissue infiltration of plasma cells
- Positive response to glucocorticoids indicates an immune-mediated cause
In some studies, seasonal relapses of the condition have occurred. This may indicate an allergic origin. Some studies relate pododermatitis to the feline immunodeficiency virus (FIV or feline AIDS), reporting a coexistence in 44-62% of feline pododermatitis cases.
Plasma cell pododermatitis in some cases appears together with other diseases. These may include renal amyloidosis, plasmacytic stomatitis, eosinophilic granuloma complex or immune-mediated glomerulonephritis.
Symptoms of feline plasma cell pododermatitis
As it is known as pillow paw, the most characteristic symptom of pododermatitis in cats is a swollen paw pad. Although this can affect the digital paw pads as well (the cat's ‘toes’), this is rare. It is more common to affect only the main paw pad, but it usually affects several limbs at the same time.
The inflammation is usually mild and it becomes soft (soft swelling). Eventually the skin will exfoliate and develop an abscess. This ulcerates in about 20-35% of cases. In severe cases, the structure of the cat's paw can be permanently damaged.
The color change in the skin of the paw pad is more noticeable in cats with light colored skin and fur. In these cases, the paw pads turn purplish with characteristic white scaly streaks which indicate hyperkeratosis (increased keratin in the skin).
In most cases, the cat will be asymptomatic. However, if the cat's immune defenses are low, it is likely they will develop one or more of the following symptoms:
- Inflammation of the paw pads
It is important to monitor the symptoms to differentiate between other paw injuries. Our article on healing wounds on a cat's paw will help to do so.
Diagnosis of plasma cell pododermatitis in cats
The diagnosis of feline pododermatitis is made by a differential diagnosis, requiring physical examination and anamnesis (patient history). A cytological analysis will also be carried out by examining affected cells under a microscope.
Differential diagnosis of plasmas cell pododermatitis in Cats
It will be necessary to differentiate the clinical signs that the cat presents with other diseases that cause similar signs related to inflammation and ulceration of the pads, such as:
- Eosinophilic granuloma complex
- Pemphigus foliaceus
- Feline immunodeficiency virus
- Irritant contact dermatitis
- Deep mycosis
- Post herpetic erythema multiforme
- Dystrophic epidermolysis bullosa
Laboratory diagnosis of plasma cell pododermatitis in cats
Via blood test, an increase in lymphocytes, neutrophils and a decrease in platelets can be observed. Also, biochemistry will show hypergammaglobulinemia.
The definitive diagnosis is achieved by taking cell samples. A cytology can be used where abundant plasma and polymorphonuclear cells will be seen.
A biopsy of the affected paw in a much more precise way to obtain diagnosis. This involves observing by histopathological analysis an acanthosis of the epidermis with ulcers, erosion and exudation. In the adipose tissue and the dermis there is an infiltrate composed of plasma cells that alters the histological structure of the pad. You can also see some macrophages and lymphocytes and Mott cells.
Feline plasma cell pododermatitis treatment
Plasma pododermatitis in cats is ideally treated with doxycycline. This treatment resolves more than half of the cases of this disease. The treatment should take 10 weeks to restore the normal appearance of the pads when administered a dose of 10 mg/kg per day.
If after this time the response is not as expected, immunosuppressants such as glucocorticoids such as prednisolone, dexamethasone, triancinolone or cyclosporine can be used. Surgical excision of the affected tissue is performed when remission or expected improvement has not occurred after finishing treatment. This can result in the cat becoming lame in the affected paw.
Only our veterinarian will be able to determine the correct course of treatment and if surgery is necessary. If you see any of the above symptoms and are unsure of why your cat's paw is inflamed, take them to the clinic for diagnosis.
This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.
If you want to read similar articles to Plasma Cell Pododermatitis in Cats - Pillow Paw, we recommend you visit our Other health problems category.
- Dalmau, A., & Bardagí, M. (2016). Day-to-day dermatology, AVEPA continuous training. Available at: https://www.avepa.org/pdf/proceedings/DERMATOLOGIA_2016.pdf
- Porto, R., & Vich, C. (2005). Feline Plasmacytic Pododermatitis. Clinical case. Available at: https://www.redalyc.org/pdf/636/63612654032.pdf
- Pérez, A. (2018). Diagnosis and treatment in a case of feline plasmacytic pododermatitis. Available at: https://www.imveterinaria.es/uploads/2018/11/diagnostico_tratamiento_caso_2093_20181122013603.pdf