CHARLIE WAS A SEVEN YEAR OLD, male neutered, Siamese cat. He was an entirely indoor cat and lived together with six other cats and three dogs. None of the cats were up to date with their vaccinations but they were wormed regularly with praziquantel (Drontal Cat; Bayer). Charlie was fed a variety of tinned cat foods and occasional human food tit bits. He had had no previous medical problems and was on no medication at the time of presentation.

History

A week prior to presentation Charlie had suffered from acute onset vomiting and diarrhoea. The vomit contained a lot of fresh blood and the diarrhoea was very watery. Since this time Charlie had been very depressed and lethargic. He was almost completely anorexic and his owner was concerned that he had lost a significant amount of weight. He was drinking more than usual (polydipsia) and his owner thought that he was probably urinating a little more than usual as well (polyuria). During the past week a strange gulping/swallowing behaviour followed by excessive licking of the lips had also started. On the day of onset of the clinical signs Charlie's owner had used an ammonium based carpet cleaner. She felt that Charlie could have had access to this, but equally so could the other animals and none of them were showing any clinical signs.

Clinical examination

On presentation Charlie was quiet but alert and responsive. He was in fair body condition, despite the recent weight loss, weighing 4.25 kg. A mucopurulent discharge was present from the right eye and his submandibular lymph nodes were moderately enlarged on both sides. Oral examination was greatly resented, so examination of the back of the throat was difficult. However, it was possible to see that Charlie was suffering from severe dental disease with lots of tartar and associated gingivitis.

The list of problems included:

Acute onset vomiting and diarrhoea

Anorexia and weight loss

Polyuria and polydipsia

Excessive licking/swallowing

Gingivitis

Unilateral ocular discharge

Differential diagnosis

Due to the wide variety of clinical signs the differential diagnosis list was vast. However we tried to narrow this down into two main categories. Firstly we felt that Charlie was likely to be suffering from a primary gastrointestinal problem. This might include dietary indiscretion/hypersensitivity, gastrointestinal infection or idiopathic (of unknown cause) inflammatory bowel disease. Secondly Charlie was showing clinical signs of ocular and oral disease. Upper respiratory tract infections were high on our list of differentials. Chlamydia (now known as chlamydophila) is a very common cause of ocular discharge in cats and feline herpesvirus and calicivirus cause typical `cat flu' signs. Because we perceived that Charlie had a particularly sore throat we also considered the possibility of pharygeal trauma or a foreign body. Lastly, it was also possible that these signs could simply be caused by the severe dental problems.

Investigations

Blood was taken for routine haematology, serum biochemistry and for FIV/FeLV screening. Given the amount of blood present in the vomit, a coagulation profile was also undertaken to assess Charlie's blood clotting ability. Pharyngeal and conjunctival swabs were submitted for isolation of feline herpesvirus, calicivirus and chlamydophila. A urine sample was submitted for urinalysis and a faecal sample was taken for parasitology and bacteriology. A full ophthalmoscopic examination was carried out in respect of the ocular discharge. Charlie was anaesthetised for imaging studies. Radiographs were taken of the pharynx, chest and abdomen and ultrasound scanning of the intestines was performed. Finally, both upper and lower gastrointestinal endoscopy was carried out in order to directly visualise the lining of the intestinal tract. Multiple pinch biopsies were taken from the stomach, duodenum and colon.

Results

Laboratory results

Haematology was remarkably normal, but a mild reduction in lymphocytes (lymphopenia) was noted. This can sometimes result from viral infections. Serum biochemistry was again fairly unremarkable. A moderate increase in creatine kinase was present. This is an enzyme that is released from muscles and is usually raised following muscle damage. In cats, however, quite marked elevations in creatine kinase can be found following periods of anorexia (not eating). Charlie had hardly eaten anything for a week so this could well explain this elevation. The blood clotting times (PT and APTT) were both mildly prolonged. However, no blood had been noted in his vomit for at least three days so the significance of this finding was uncertain.

FIV and FeLV screening tests were negative, as was herpesvirus and chlamydophila isolation. Feline calicivirus isolation was positive. Calicivirus infection can often result in cats developing `sore throats' and this was thought to be the most likely explanation for Charlie's unusual gulping and swallowing behaviour. Urine and faecal analysis were both unremarkable.

Ophthalmoscopy

Ophthalmoscopy confirmed the presence of a left ocular discharge. This was associated with a unilateral conjunctivitis. No abnormalities of the right eye were noted.

Diagnostic imaging

Radiography of the pharynx, chest and abdomen were all unremarkable, as was ultrasonography of the intestines. Endoscopy revealed the gastric mucosa to be grossly normal but the duodenal mucosa was diffusely reddened. It was also more friable and haemorrhagic than would be expected in a normal cat. Similar, but less pronounced, changes were evident throughout the colon.

Histopathology of the duodenal andcolonic biopsies revealed significant stunting of the villi with an infiltration of inflammatory cells, predominantly comprising lymphocytes and plasma cells. This infiltration was not sufficiently marked for this to be called an `inflammatory bowel disease' and instead it was classified as an enteropathy of unknown origin. Histopathology of the gastric biopsies was unremarkable.

Diagnosis

Charlie was diagnosed with an unclassified enteropathy. Although coagulation tests had been mildly abnormal, it was not known whether this was clinically significant. It was possible that Charlie's clinical signs had been caused by carpet cleaner ingestion but there was no firm proof of this. Charlie's calicivirus infection was likely to be independent of these other problems and responsible purely for his pharyngeal signs.

Treatment

The mainstay of treatment was an exclusion diet and we chose to use Waltham's 'selected protein' diet. Several drugs were also used in our treatment protocol in order to relieve the clinical signs. Cyproheptidine (Periactin; Merck, Sharp & Dohme) was used at a dose rate of 0.5 mg/kg twice daily. This is an antihistamine drug that can be used to treat allergic skin disease but in this case was used as an appetite stimulant. Cimetidine (Tagamet; SmithKline Beecham) is an H2 receptor blocker which is used to help prevent gastrointestinal ulceration. This was used at a dose rate of 4 mg/kg twice daily. The antibiotic metronidazole (Merck generics) was used at 10 mg/kg twice daily. This was prescribed first to treat any small intestinal bacterial overgrowth that may have been present and secondly because it is thought to have immunomodulatory actions which may be beneficial in inflammatory gut conditions. The unilateral conjunctivitis was treated using fucithalmic eye drops twice daily.

Initially a naso-oesophageal tube was placed to facilitate nutritional support. These feeding tubes are usually very well tolerated by cats, but unfortunately not by Charlie! Within 20 minutes of us placing the tube Charlie had managed to dance violently around his kennel and remove it. This was probably due to the fact that his throat was so sore and it was likely that he could feel the tube rubbing at the back of his pharynx. Charlie did however require some form of nutritional support so he was anaesthetised for placement of a percutaneous endoscopically-placed gastrostomy tube (PEG tube). This tube passes through the abdominal wall directly into the stomach allowing administration of both food and drugs. The tube can be easily placed and removed using endoscopy and does not involve laparotomy or stitches. While Charlie was anaesthetised dental work including a scale and polish and several extractions was performed. This was in case his severe dental disease was contributing to his anorexia. Post operatively clavulanate potentiated amoxycillin (Synulox; Pfizer) was introduced into the treatment regime at a dose rate of 10 mg/kg twice daily. This was to help prevent any infection at the site of the PEG tube and also to guard against any spread of systemic infection following the dental treatment. Because of his sore throat Charlie did not like taking tablets. Once the PEG tube was in place all the oral medications were therefore given via the tube rather than by mouth.

PEG tube feeding

The first thing we needed to do was to calculate how much food Charlie would require each day. In order to do this we first calculated his resting energy requirement (RER). In cats weighing more than 2 kg this can be estimated using the following equation:

RER(kcal/day) = 40 x bodyweight (kg)

Charlie's bodyweight was 4.25 kg and his resting energy requirement was therefore 170 kcal/day (40 x 4.25). An illness factor can also be introduced which involves multiplying this basic energy requirement by a factor of between 1.2 and 1.6. The specific value used depends upon the type of illness the cat has and how energy consuming that particular disease is. In Charlie's case an illness factor was not used because we were more concerned about the possibility of overfeeding, which can also lead to problems.

The selected protein diet that we had chosen for Charlie contained 850 kcal of energy per kilogram of food. The amount of food required per day is calculated using the following equation:

                                    Energy content of diet(kcal/kg)

Food requirement (g) = ----------------------------------

                                   Energy requirement of patient(kcal)

Charlie therefore needed 200g of food per day (850 ÷ 170) in order to supply his energy requirements.

For the first 24 hours following tube placement only water was given in order to give the PEG tube wound time to heal over a little. After this time the amount of food given was gradually increased until the full requirement was reached on day 4 (fig 1). The food that we had chosen was a fairly solid food and could not be syringed down the tube straight from the tin. Instead it needed to be diluted with water and liquidised to make it runny. Before feeding any diet it is important to make sure it is warmed to room temperature (do not use it straight from the fridge!). An empty syringe was used to suck back on Charlie's PEG tube to check that the previous meal was not still sitting in the stomach. Once this had been done the food was slowly instilled into the stomach. When all the food had been given the tube was flushed with enough water to ensure that it didn't block with any residual food. This usually required around 7 ml of water.

It is very important to monitor the PEG tube wound carefully for any sign of infection. At least once daily all of Charlie's dressings were removed and the wound gently washed. A light dressing usually consisting of a surgical swab held in place by an adhesive primipore pad was then replaced. The PEG tube itself was secured using a light elasticated tubular sleeve placed around the abdomen.

Outcome

Charlie remained hospitalised for 10 days after the tube placement, but during this time he made very little improvement. His owners were keen to have him home and so he was discharged to continue all his medications and PEG tube feeding at home. Once home he made a gradual improvement. Initially his demeanour improved and he was far brighter and showing much greater interest in his surroundings. Unfortunately his appetite remained very variable. Eventually however, after eight weeks of perseverance, his appetite had almost returned to normal. The PEG tube was maintained for a further two weeks but was then removed. All of the medications were stopped at this time.

It is now almost eight months since Charlie was first presented and as yet he has had no further problems. This case illustrates very well how nutritional support can play an integral role in the treatment of many patients. Whether it be syringe feeding, naso­oesophageal tubes, PEG tubes or even enterotomy tubes, nutrition should always be an important consideration in the treatment of any anorexic cat.