Elise Robertson

Feline infectious peritonitis (FIP) is a systemic immune-mediated inflammatory perivasculitis that occurs in a minority of cats infected with feline coronavirus (FCoV). Various therapies have been employed to treat this condition, which was previously usually fatal, though no parameters for differentiating FIP recovery from remission have been defined to enable clinicians to decide when it is safe to discontinue treatment. This retrospective observational study shows that a consistent reduction of the acute phase protein alpha-1 acid glycoprotein (AGP) to within normal limits (WNL, i.e., 500 μg/mL or below), as opposed to duration of survival, distinguishes recovery from remission. Forty-two cats were diagnosed with FIP: 75% (12/16) of effusive and 54% (14/26) of non-effusive FIP cases recovered. Presenting with the effusive or non-effusive form did not affect whether or not a cat fully recovered (p = 0.2). AGP consistently reduced to WNL in 26 recovered cats but remained elevated in 16 cats in remission, dipping to normal once in two of the latter. Anaemia was present in 77% (23/30) of the cats and resolved more quickly than AGP in six recovered cats. The presence of anaemia did not affect the cat’s chances of recovery (p = 0.1). Lymphopenia was observed in 43% (16/37) of the cats and reversed in nine recovered cats but did not reverse in seven lymphopenic cats in the remission group. Fewer recovered cats (9/24: 37%) than remission cats (7/13: 54%) were lymphopenic, but the difference was not statistically different (p = 0.5). Hyperglobulinaemia was slower than AGP to return to WNL in the recovered cats. FCoV antibody titre was high in all 42 cats at the outset. It decreased significantly in 7 recovered cats but too slowly to be a useful parameter to determine discontinuation of antiviral treatments. Conclusion: a sustained return to normal levels of AGP was the most rapid and consistent indicator for differentiating recovery from remission following treatment for FIP. This study provides a useful model for differentiating recovery from chronic coronavirus disease using acute phase protein monitoring.

Objectives: The aim of this study was to evaluate a feline coronavirus (FCoV) reverse transcriptase quantitative PCR (RT-qPCR) on fine-needle aspirates (FNAs) from mesenteric lymph nodes (MLNs) collected in sterile saline for the purpose of diagnosing non-effusive feline infectious peritonitis (FIP) in cats. Methods: First, the ability of the assay to detect viral RNA in MLN FNA preparations compared with MLN biopsy preparations was assessed in matched samples from eight cats. Second, a panel of MLN FNA samples was collected from a series of cats representing non-effusive FIP cases (n = 20), FCoV-seropositive individuals (n = 8) and FCoV-seronegative individuals (n = 18). Disease status of the animals was determined using a combination of gross pathology, histopathology and/or ‘FIP profile’, consisting of serology, clinical pathology and clinical signs. Results: Viral RNA was detected in 18/20 non-effusive FIP cases; it was not detected in two cases that presented with neurological FIP. Samples from 18 seronegative non-FIP control cats and 7/8 samples from seropositive non-FIP control cats contained no detectable viral RNA. Thus, as a method for diagnosing non-effusive FIP, MLN FNA RT-qPCR had an overall sensitivity of 90.0% and specificity of 96.1%. Conclusions and relevance: In cases with a high index of suspicion of disease, RT-qPCR targeting FCoV in MLN FNA can provide important information to support the ante-mortem diagnosis of non-effusive FIP. Importantly, viral RNA can be reliably detected in MLN FNA samples in saline submitted via the national mail service. When applied in combination with biochemistry, haematology and serological tests in cases with a high index of suspicion of disease, the results of this assay may be used to support a diagnosis of non-effusive FIP.

Case series summary: This case series discusses novel characteristics identified in two cases of cowpox. One presented with upper airway signs, and was identified to have a focal laryngeal lesion. The other had central neurological signs at the terminal stages, with intracytoplasmic inclusion bodies identified within the cerebral hemispheres on histopathology. Relevance and novel information: Currently, cowpox would be an unlikely consideration in patients with neurological signs or upper respiratory noise. These cases both document novel presentations of cowpox infection, which clinicians should be aware of and consider as differential diagnoses in patients with these atypical presentations.

Case summary: An 8-year-old female spayed Siamese indoor cat presented with a 3 week history of inspiratory dyspnoea, stridor and open-mouth breathing after exercise. Laryngoscopy, tracheoscopy, bronchoscopy and retroflexed nasopharyngoscopy were performed, and identified a multilobulated intraluminal mass within the trachea. Brush cytology was performed on the mass but was inconclusive in providing a definitive diagnosis. A CT scan of the neck failed to identify an obvious intraluminal mass and was negative to contrast uptake. Surgery was performed and seven rings of the trachea were removed to enable the complete excision of the mass. Histopathology of the excised mass was consistent with B cell lymphoma. After surgery, chemotherapy treatment was started. At the time of writing, 20 months since diagnosis, the cat remained clinically well, with no clinical signs or recurrence of macroscopic disease on endoscopic evaluation. Relevance and novel information: Upper airway endoscopy was considered to be an essential diagnostic tool in this case presenting with signs of upper respiratory dyspnoea. Moreover, combined surgery and chemotherapy were considered effective treatments and positively affected the long-term prognosis of this patient.

Case summary A 13-year-old, castrated male, British Shorthair cat presented for investigation of chronic, intermittent, bilateral epistaxis and stertor. CT revealed severe asymmetric bilateral intranasal involvement with extensive turbinate lysis, increased soft tissue attenuation and lysis of the sphenopalatine bone and cribriform plate. On retroflexed pharyngoscopy, a plaque-like mass occluded the choanae. Rostral rhinoscopic examination revealed extensive loss of nasal turbinates, necrotic tissue and mucosal fungal plaques in the left nasal cavity. The right nasal cavity was less severely affected. The nasal cavities were debrided extensively of plaques and necrotic tissue. Aspergillus fumigatus was isolated on fungal culture, and species identity was confirmed using comparative sequence analysis of the partial β-tubulin gene. On histopathology of nasal biopsies, there was ulcerative lymphoplasmacytic and neutrophilic rhinitis, and fungal hyphae were identified on nasal mucosa, consistent with a non-invasive mycosis. The cat was treated with oral itraconazole after endoscopic debridement, but signs relapsed 4.5 months from diagnosis. Residual left nasal fungal plaques were again debrided endoscopically and oral posaconazole was administered for 6 months. Fourteen months from diagnosis, the cat remains clinically well with mild intermittent left nasal discharge secondary to atrophic rhinitis. Relevance and novel information This is the first case of rhinoscopically confirmed sinonasal aspergillosis to be diagnosed in a cat in the UK. Endoscopic confirmation of resolution of infection is useful in cases where mild nasal discharge persists after treatment.

Practical relevance: Minimally invasive techniques are becoming increasingly available in both first opinion and referral veterinary surgeries. Clients may be reluctant to pursue open surgery for the collection of biopsy samples in a sick cat but may be more open to a laparoscopic approach. Furthermore, a laparoscopic approach provides excellent visualization of the abdominal organs and enables high quality biopsies to be taken that are invariably more diagnostic than percutaneous needle biopsies. Although the feline patient is small in size, its distensible abdomen allows more room for surgical manipulation than afforded by a similar sized canine patient. Clinical challenges: Clinical challenges for the most part relate to mastering laparoscopic technique. Familiarity with the use of long instrumentation viewed on a two-dimensional screen is essential. Hemostasis is an important consideration and suitable instrumentation for achieving hemostasis should be available at all times. Insufflation of the abdomen carries its own challenges with regard to anesthesia and this is covered in an accompanying article in this Special Issue series. Aim: This article introduces the feline practitioner to basic techniques required to effectively utilize diagnostic laparoscopy within feline medical investigations. It focuses on the common procedures of liver biopsy, cholecystocentesis, pancreatic biopsy, kidney biopsy and laparoscopic-assisted intestinal biopsy. Evidence base: Information provided in this article is drawn from the published literature and the authors’ own clinical experience.

Regrettably, two errors appeared in the 2013 AAFP Feline Vaccination Advisory Panel Report. Firstly, in the ‘Injectable vaccine administration’ box, on page 798, the pictures in Figures 8 and 9 were swapped with each other. The amended box is reproduced here. Secondly, the penultimate sentence in the second ‘Trap–Neuter–Return’ FAQ on page 804 should have read: ‘In contrast, only inactivated vaccines resulted in a high rate of protective antibodies against FHV-1,’ and not ‘In contrast, only modified-live vaccines …’. The errors appear in the printed copies of the journal, and in online versions downloaded before November 2013.

Practical relevance: Endoscopic examination of the feline gastrointestinal (GI) tract is a minimally invasive method for obtaining biopsy samples of the GI mucosa, which is often necessary for a diagnosis of chronic GI diseases. In addition endoscopy has several therapeutic indications including foreign body retrieval, oesophageal stricture dilation and placement of a percutaneous gastrostomy tube. Clinical challenges: Initially, practitioners must learn the subtle manipulations necessary to efficiently guide the endoscope through the GI tract to obtain biopsy samples of high diagnostic quality, and develop skills for implementing interventional procedures (eg, foreign body removal). Another challenge in mastering GI endoscopy is the ability to recognise normal from abnormal, which requires many years of practice and experience. Endoscopy is a diagnostic and interventional procedure that should be performed only in conjunction with a thorough history, physical examination, appropriate laboratory evaluation, and radiographic and/or ultrasonographic imaging. Audience: This review is intended to familiarize both the general and referral practitioner with GI endoscopy as a minimally invasive diagnostic and therapeutic intervention for the feline patient. Evidence base: The guidance contained within this article is based on a combination of the published literature, the authors’ personal experience and the experience of colleagues.

Practical relevance: Feline gastrointestinal (GI) endoscopy is in high demand, particularly by cat owners already aware of the clinical benefits and availability of this procedure within the human healthcare system. This article will provide a basic introduction to GI flexible endoscopy, covering important aspects of endoscope selection, clinical indications, and basic techniques required to perform a thorough and diagnostically meaningful examination in the cat. Clinical challenges: Challenges associated with implementing endoscopy in GI tract investigations can include lack of appropriate/suitable-sized equipment to perform a thorough examination in the cat, insufficient operator training/understanding in how to ‘drive the scope’ through the GI tract, and/or lack of confidence in differentiating normal from abnormal. Audience: This article is intended to familiarize and motivate the feline practitioner to develop basic endoscopic skills. Clinical proficiency can only be obtained through use of appropriate equipment, formal training and hours of practice indistinguishing normal from abnormal. Evidence base: The guidance contained in this article is based on a combination of the published literature, the authors’ personal experience and the experience of colleagues.