Taking place in the Assembly Rooms, Bath, on 21st and 22nd September, this was the first VETcpd congress. Around 350 delegates came from throughout the British Isles, which was an encouraging start for the new annual event.
Benefits of the subcutaneous ureteric bypass
Nicola Kulendra (RVC) described how using a new device – the subcutaneous ureteric bypass (SUB) – has improved the survival rate of cats with ureteral obstruction. Ureteral obstruction is most often caused by calcium oxalate stones that cannot be dissolved chemically.
Systemic signs are vague and urinary tract signs uncommon, but in advanced cases the cat may present with hypovolaemia, bradycardia and collapse.
Untreated obstructions lead to kidney failure and the pathology may not be detected until the second kidney is compromised. If there is bilateral ureteritis, the cat may present with hyperkalaemia and severe azotaemia. In the past, a ureteric stent may have been placed, which had a high rate of complications. Refinement of this technique led to the development of the SUB, which combines a pigtail nephrostomy catheter leading from the kidney to a subcutaneous port which connects it to a cystostomy tube.
The cat is stabilised before surgery; haematology, biochemistry and urinalysis, including culture, are performed. Ultrasound is used to assess the kidneys: the diameter of the renal pelvis must be more than 5mm. Ultrasound examination rules out cats with chronic renal failure, but an antegrade pyelogram can be used if the diagnosis remains uncertain.
Operating involves a midline laparotomy, identification of the affected kidney, placement of the locking loop nephrostomy catheter in the renal pelvis and the cystostomy tube in the bladder. Tissue glue is used for anchoring. The tubes are tunnelled in the body wall and connected to the subcutaneous port. Surgery is monitored by fluoroscopy. After the operation, fluid input and output are measured, but usually the placement of urethral catheters is avoided.
SUBs have been placed in 100 cats, with a mean survival time of 529 days. Sometimes chronic renal failure becomes significant, anaesthesia can give problems, or there may be holes or kinks in the tubes which lead to leaks or urinary tract infections. Cats are monitored and every three to six months the SUBs are flushed and haematology, biochemistry and urinalysis carried out.
Some cats regain ureteric patency. Ongoing maintenance is expensive and the owners should be aware of potential complications, but SUBs have proven a good advance on older techniques.
Treating atopic dermatitis
Dr Anita Patel runs a dermatology referral service. She explained that atopic dermatitis (AD) has a complex pathology involving both the innate and adaptive immune systems. The cytokine IL-31, which is found in skin and serum of affected dogs, causes the itch and is the target for the new drug Lokivetmab (Cytopoint). Different cytokines are involved in the chronic phase.
The aim of treatment is to control the symptoms and give the animal as comfortable a life as possible. Treatment must be affordable and manageable by the owner, so each case needs individual planning.
For acute flare-ups, use Oclacitinib (Apoquel), an IL-31 inhibitor, to supress the itch. This treatment usually works within 12 hours. Oral and/or topical glucocorticoids are also effective. If possible, the flare factor needs to be identified and reduced or removed and the health and cleanliness of the coat needs to be supported. Watch out for infections that may be complicating chronic cases.
Oral Ciclosporin (Atopica, Cyclavance, Sporimune) can be used to manage chronic cases, but it takes four to six weeks to be effective, so other treatments need to be used in the early stages.
Allergen-specific immunotherapy aims at reducing the immunologic response; it is safe and works in 50 to 80% of cases. It can take up to 10 months to work and may need to be supported by symptom-supressing treatments.
Coat hygiene is important. Regular shampooing can help reduce symptoms and good environmental management also plays its part. Diets such as Hill’s Derm Defense, which is a source of antioxidants, or supplements which increase Omega 3 and Omega 6 fatty acids can help support the epidermal barrier.
Dr Patel reminded us of the other factors such as flea bite sensitivity, food allergy, contact allergy and background infections such as Malassezia and Staphylococci which cause hypersensitivities. These can occur concurrently with AD and need to be recognised and treated appropriately.
