Summary of Section 6: Clinical Signs FCoV Infection  Cats with FCoV infection are usually subclinical, although occasionally diarrhoea and/or vomiting and poor growth (in kittens) can occur. FIP  Cats that go on to develop FIP after FCoV infection present with varied clinical signs depending on the distribution of vasculitis (which can lead to effusions) and/or (pyo)granulomatous lesions (which can lead to mass lesions) in the body. Although effusive and non-effusive forms of FIP are often described, there is much overlap between these forms. Clinical signs of FIP can change over time, and therefore repeated physical examinations are important to detect newly apparent clinical signs; for example, an effusion can develop, or ocular changes can become visible on ophthalmoscopic examination. ABCD FIP Diagnostic Approach Tools [211] are available to help the vet assess clinical signs for FIP.  Non-specific clinical signs include lethargy, anorexia, and weight loss (or failure to gain weight/stunted growth in kittens). A fever that is refractory to treatment is common.  Effusions are common, especially in the abdomen, but pleural effusions and pericardial effusions are also seen, sometimes concurrently. When effusions are present, the disease progression is often quite fast, within a few days or weeks. When effusions are not present, FIP is often more difficult to diagnose and it also tends to be more chronic, progressing over a few weeks to months. Additional signs of non-effusive FIP depend on the organs affected but can include the central nervous system, eyes and/or abdominal organs (such as the liver, abdominal lymph nodes [especially mesenteric lymph nodes], kidney [including renomegaly], pancreas, spleen and/or gastrointestinal tract). These signs can also be present in cats with effusions. Abdominal lymphadenomegaly or intestinal masses (sometimes palpable), can occur. Jaundice can occur, more commonly in cats with effusions, but the degree of hyperbilirubinaemia is often not high enough to result in clinical jaundice. Occasionally, cats with FIP show skin signs.  Neurological signs seen with FIP include ataxia (with varying degrees of tetra- or paraparesis), hyperaesthesia, nystagmus, seizures, behavioural and mental state changes, and cranial nerve deficits. Central vestibular clinical signs can include head tilt, vestibular ataxia, nystagmus, obtunded appearance, and postural reaction deficits. Fever was shown to be less common in cats with neurological FIP compared to those without neurological signs. FIP can also cause unilateral or bilateral uveitis. Clinical signs include changes in iris colour, dyscoria or anisocoria secondary to iritis, sudden loss of vision and hyphaema. Keratic precipitates can appear as ‘mutton fat’ deposits on the ventral corneal endothelium, and aqueous flare can occur. On ophthalmoscopic examination, chorioretinitis, fluffy perivascular cuffing (representing retinal vasculitis), dull perivascular puffy areas of pyogranulomatous chorioretinitis, linear retinal detachment, vitreous flare and fluid blistering under the retina can all be seen.  Other less-common signs associated with FIP have included rhinitis and clinical signs associated with myocarditis.