Clements DN, Gear RN, Tattersall J, Carmichael S, Bennett D. Type I immune-mediated polyarthritis in dogs: 39 cases (1997-2002). J Am Vet Med Assoc. 2004; 224:(8)1323-1327

Collins. Definition of ‘arthro-’. 2022a. (accessed 4 May 2023)

Collins. Definition of ‘poly’. 2022b. (accessed 4 May 2023)

Allerton F. BSAVA small animal formulary, part A : canine and feline, 10th edn. : British Small Animal Veterinary Association; 2020a

Allerton F. BSAVA small animal formulary, part A : canine and feline, 10th edn. : British Small Animal Veterinary Association; 2020b

Allerton F. BSAVA small animal formulary, part A : canine and feline, 10th edn. : British Small Animal Veterinary Association; 2020c

Allerton F. BSAVA small animal formulary, part A : canine and feline, 10th edn. : British Small Animal Veterinary Association; 2020d

Johnson KC, Mackin A. Canine immune-mediated polyarthritis: part 2: diagnosis and treatment. J Am Anim Hosp Assoc. 2012; 48:(2)71-82

How to… prepare for and assist with arthrocentesis. 2020. (accessed 4 May 2023)

McKenna M. Canine immune-mediate polyarthritis. Veterinary Ireland Journal. 2020; 10:(12)689-693

Merrill L. Small animal internal medicine for veterinary technicians and nurses.Ames, Iowa: Wiley-Blackwell; 2012

Narita T, Sato R, Motoishi K, Tani K, Naito Y, Hara S. The interaction between orally administered non-steroidal anti-inflammatory drugs and prednisolone in healthy dogs. J Vet Med Sci. 2007; 69:(4)353-363

Immune-mediated polyarthritis: pathophysiology and classification. 2015. (accessed 4 May 2023)

Canine immune-mediated polyarthritis: meeting the diagnostic and therapeutic challenges. 2019. (accessed 4 May 2023)

Stone M. Immune-mediated polyarthritis and other polyarthritides. In: Ettinger SJ, Feldman EC, Côté E (eds). St. Louis (MI): USA: Elsevier-Health Sciences Division; 2016

Immune-mediated polyarthritis: the role of the veterinary nurse

02 May 2023
10 mins read
Volume 14 · Issue 4
Figure 2. Stifle arthrocentesis.
Table 1. Clinical examples for each category of immune-mediated polyarthritis


Immune-mediated diseases can present in a number of ways because of multiple manifestations of the diseases, the species and the presence or absence of any underlying condition. This demonstrates the imperative nature of sound clinical history taking alongside a comprehensive physical exam to allow the most appropriate diagnostic approach and subsequent treatment. The registered veterinary nurse should understand the most commonly presenting immune-mediated diseases in order to provide appropriate nursing care for that patient during their hospitalisation and following discharge. Registered veterinary nurses act as an advocate for patients and play a key role in the diagnosis and treatment of patients with any immune-mediated disease. This review discusses the pathophysiology of immune-mediated polyarthritis and classifications including clinical presentation. It has a focus on the initial patient diagnostics, arthrocentesis and how nurses can be heavily involved with these patients all the way through from admission to discharge.

‘Immune-mediated polyarthritis (IMPA) is the most common form of inflammatory joint disease encountered in small animal patients’ (Stone, 2016). Before discussing what IMPA is it is important to consider the Greek origin of its title. ‘Polus’ in ancient Greek meaning ‘many or much’ and ‘arthron’ meaning ‘a joint’ allows us to appreciate that multiple joints are affected by this condition (Collins, 2022a; b). IMPA is typically an accumulation of immune complexes in the synovial fluid of a joint, which subsequently draws neutrophils into that space (Specht and Guarino, 2019). The most common presenting complaints of patients with IMPA include: fever, cyclic lethargy, anorexia and a shifting limb lameness. A retrospective study (Clements et al, 2004) identified all dogs with idiopathic IMPA presented with joint stiffness, 22 out of 39 presented pyrexic and 20 out of 39 with a lymphadenopathy. The role of the veterinary team extends beyond the initial diagnosis of the immune-mediated disease, with large involvement in clinical diagnostics, initial treatment and follow-up supportive care for our patients. Similar to the other more commonly seen immune-mediated diseases, such as immune-mediated haemolytic anaemia or immune-mediated thrombocytopenia, investigations should begin promptly to understand if the disease is from a primary or secondary cause in order to treat the patient effectively. IMPA can present as erosive or non-erosive polyarthritis, with only approximately 1% of cases reported to have erosive disease. Because of the marked reduced frequency at which erosive polyarthritis is seen in practice, the remainder of this article will predominantly focus on the non-erosive sub-categories. Commonly presenting clinical signs, diagnostics, initial treatment and follow-up care will be discussed, along with the role of the registered veterinary nurse in nursing the IMPA patient.

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