Wednesday, December 29, 2010

281. Ear problems and Injectable anaesthesia - xylazine & diazepam IV

Dec 29, 2010

I was on duty as Dr Vanessa Lin went on leave for the next 10 days. This was the 2nd day of work since I came back from the holidays. I thought it would be a quiet Wednesday and brought my laptop to do some writing and scheduled a house-call to micro-chip and vaccinate some dogs at Pets Zone in Dunearn Road at 4 pm. But it was a hectic day from 10 am to 8 p.m, with one-hour break at lunch-time. The cases were the usual ones of neutering and spaying, dental scaling, skin diseases, ear problems, eye infections in two stray kittens. Some interesting cases are as follows:

1. Animal activism in Singapore. A young lady wanted to know how much it would cost to hospitalise two stray kittens with flu for a few days while she looked for new homes for them. Her father would kill her if she brought these kittens home as she already had several. She was looking for the least cost veterinary care and dictating that the kittens should not be given antibiotics. This is a common situation encountered at all vet clinics. There is insufficient space at Toa Payoh Vets which is a small surgery of 60 sq metres. I do help a few stray cat cases but there is a limit in charitable work. A practice has high overheads although it does not look obvious to the average pet owner in Singapore. In this case of cat flu, home nursing would be best. I advised her to nurse the kittens herself as it would be better for the kittens.

2. Animal activism in Yangon. An old friend started to help homeless dogs and cats in a place in Yangon. This is his personal thing as he could better spend his time and skill earning more money in the IT field. However, the residents there wanted US$20,000 from him if he wanted to continue his mission. I had advised him of the risks of doing animal activism overseas as politics would become dominant. This happens even in Singapore, as cat welfare people tried in vain to get the Singapore Government to permit cat ownership for the average person living in HDB apartments.

From this incident, you can see that it is difficult for a Singaporean animal activist going across borders to help change the world unless he has powerful political connections. Politics and economics interact in animal activism and business. Such are the facts of life.

3. Ear problems. One dog had red ear flaps for many weeks. I did a microscopic examination of the hairs. It was ringworm. "A follow-up one month later is important," I said to the owner. Some owners blame the vet for not resolving their problem when they don't follow up but went to another vet.

4. Injectable anaesthesia. The following is one of many metods of injectable anaesthesia used safely in practices and countries with no access to isoflurane gas anaesthesia, unlike fortunate Singaporean pet owners where the best anaesthetic drugs are available for pets.

I am sharing this knowledge with vets working in such locations. The above dosage is a general guideline. An IV catheter is inserted so that top up injections can be given IV should the dog need more anaesthesia. For a 10-kg dog, the dosage of diazepam and ketamine in one syringe are respectively 0.4 ml + 0.4 ml IV.

Case 1. At 50% of the above dosage, ie. 0.2 ml diazepam + 0.2 ml ketamine in one syringe IV for a 10-kg mixed breed dog, the dog shows signs of head shaking sideways and salivation. It was not under surgical anaesthesia. I top up with 5% isoflurane gas by mask for a minute or two to effect and this provided excellent anaesthesia for neutering.

Case 2. At 100% of the above dosage, the dog's body muscles were tense. The dog's neck and legs were flexed. The eyes were open and the pupils dilated. However, dental scaling was done without pain or the need for top up.

CONCLUSION. Each vet has his own preferences in anaesthesia. As long as it is safe for the dog, injectable anaesthesia offers a cheaper alternative to isoflurane gas. The anaesthetic machine and isoflurance are expensive compared to the injectable anaesthetics. In an effort to lower veterinary costs, injectable anaesthetics are used. As for me, I prefer to use xylazine (or domitor) sedation and isoflurane gas anaesthesia as I find that the dog sleeps relaxed (not with tense muscles as in the diazepam and ketamine injectable anaesthesia) and surgery can be done smoothly without the need for topping up as the dog struggles when pain is experienced.

ECONOMICS OF PRACTICE. Each vet does what he prefers as long as the dog is safe and alive at the end of the day. I am just sharing my observations to benefit vets who may not have access to isoflurane facilities as not the isoflurane gas machine purchase cost and maintenance are very expensive. There are more less sophisticated pet owners who just want "cheap" veterinary anaesthesia and surgery and a veterinary practice needs to sustain its profitability to be around the next year. So, there is a need to reduce veterinary costs, sometimes performing loss-making surgeries!

INTERESTING CASE OF BLACK EAR DISCHARGE
"The (pet shop owner's son) was not in a good mood and so I talked to the counter staff," the matronly woman had brought the 7-month-old female salt and pepper Miniature Schnauzer in for his 3rd vaccination. Toa Payoh Vets had given the puppy 2 vaccinations earlier. She paid $350 for the dog which I thought was too cheap as it had such good physical characteristics. But older dogs are difficult to sell and only puppies fetch a premium price in Singapore.

"The young man may be having some personal problem," I said as the husband wanted the wife to complain that she was sold a dog with black ear discharge. "His father had died while delivering dog food and crashing his van. The hospital doctor did not diagnose that he had a head injury and sent him home. What ear drops have you been using to clean the dog's ears?"

"I use eucalyptus oil for the past few days," the lady said. "The next day, the black ear discharge appears again."

"This is is a good looking dog and you had got it at a cheap price," I could appreciate a Schnauzer with good conformation. A good sized head, proportionate body length and not too long legs. Not too bulky as Singaporeans prefer this type of size although dog show people will consider this dog under-sized. Female dogs of this size and shape are more valuable for breeders as there is a demand for "miniature" Miniature Schnauzers.

I took a cotton bud and spread some ear discharge on a slide and put it under the microscope but saw no mites. "You must have drowned all mites with oil," I said. "Not a mite can be seen."

What caused the blackness and the black particles inside the two ears? As black as black shoe polish. Ear discharge comes in all colours but pure black is rarely seen by me in practice over 40 years. It was as if the ear drops of oil were black in colour. I did not ask the owner the colour of the ear drops as it was an extremely hectic day and I still had not done the 3rd spay of the 3rd stray cat.

The owner who loves his 3 stray cats had brought in the 3rd one for spaying today. Yesterday, he got two in and I had neutered and spayed them. The 3rd one was "fierce" and was put inside a cardboard box, taped up but with gaps for the cat to breathe. It was as if he had a tiger inside the box and so we did not dare open the box and transfer the cat to the crate for the time being. The minutes ticked by and the whole afternoon had gone and still I had no time to spay this cat.

Spending time with the owner is essential in practice building but the other owners at the waiting room disliked waiting too long unfortunately. Some owners want fast service. I could see that the Schnauzer lady's husband was all ready to go to work. But he was the patient type who would wait for his wife to get the dog vaccinated. That was all she came for and vaccination should be fast. But for the black ear discharge, the dog would leave in 5 minutes.

I got the ears irrigated and taught the owner how to use the medicated ear drops. The best would be another ear irrigation the next day but I could sense that the husband was an extremely busy man but his wife mentioned about him working in an important post in a volunteer organisation. "You work for the famous Red Cross," I said to him as I was thinking of the excellent volunteerism and time it had done for so many unfortunate people in countries all over the world.

"The infamous Red Cross," he laughed. Yes, there was a newspaper report about some loss of money taken by a staff in the Singapore branch but I was not thinking of this matter. There will always be staff who steals money from the organisation all over the world.

In one case of a famous cosmetic surgeon in Singapore, I was shocked to read in the newspaper that he did not print his own receipt books. He bought commercial ones. So, he had 3 copies. The white for the client, the blue for audit and the yellow for the case file. Now, his billing staff found a way to milk him of over $100,000. She would buy another set of books. When she billed the client, she would give the client the white copy with say $1,000 and collected $1,000. Then she would write, say $500 on the blue and yellow copy from her own purchased set and discard the original blue and yellow copies of the surgeon's book. She could also under-declare the income by replacing the yellow or blue copies.

"How was she caught?" my wife asked me yesterday when I told her that the famous surgeon did not print his own receipt books which I found it hard to believe if not for this case in court.

"Well, another staff discovered that the blueness of the blue receipt was not similar to the blueness of the other receipts." But over $100,000 had been misappropriated and this sacked staff complained that the surgeon had not granted her medical leave.

I digressed. Back to the Schnauzer's black ears. The husband seemed appreciative when I asked the wife to use the medicated ear drops herself to clean the ears for the next 7 days and if the black discharge disappear, then there was no need to consult me.

This was one of the 4 interesting ear problems. The other one was the fiery red inside ear flap caused by ringworm infestation in both ears mentioned above. The 3rd one in a young cat with thick reddish black waxy ear discharge was even more interesting in the sense that I managed to find one dead ear mite under the microscope when I did an ear discharge examination.

"See the mite," I asked the young lady to peer into the microscope. "There is only one." The mite with a round body and six short legs in the front half was clearly visible and sharp under my newly purchased microscope. "Where's the mite," the lady asked. She was not into biology I presumed. I took out the Hill's Atlas of Clinical History and showed her the drawings. Maybe I should produce one myself. "See the book drawing of the mite," I showed her the cat and ear mite drawings inside the book. "What's the name of this ear mite in the cat?" I asked Mr Saw, my assistant who is qualified as a vet in Myanmar and would be returning home in April 2011. The book did not mention any name. Mr Saw shook his head. "It would be Otodectes cyanotis," I said. It was Greek to him and to all vet students. I got the ears irrigated and gave an anti-mite ivermectin injection. Follow up would be good.

It is 7.25 am and I have to get ready for work. The 4th ear case was one in which the young man's cotton tip fell into the dog's right ear canal while cleaning. The Pomeranian would bite when he tried to retrieve it deep inside the ear canal. "Surprisingly my dog did not shake his head. I would rather get it removed before it infects the ear. How long will it take?"

"That depends on whether the dog needs to be sedated," I said. I got the dog inside the surgery, muzzled it and Mr Saw held the dog properly. Mr Saw had wanted the ear scope to check out the ears. "No point in doing it," I said. "The ear scope will push the cotton bud deeper into the ear." Sometimes we have to visualise the impact of a particular procedure.

In theory, all ear examinations must be scoped. Sometimes it could even be considered negligent not to scope the ears as a routine. In practice, the dog owner had already given us the history that his cotton tip had dropped inside the right ear. Using an ear scope would push the cotton into the horizontal canal and that would be very difficult to extract.

I inserted a slim curved artery forceps into the right ear vertical canal to the base, open and clamp. Fortunately I got the cotton bud out at the first clamp. I showed the bud to the owner who was quite pleased. "It's time I buy good quality cotton buds to clean my dog's ears," he laughed.

So, in one day on Dec 29, 2010, I got at least 4 different causes of ear problems in 3 dogs and 1 cat. There was a 5th in a Westie. In this case, the Westie had itchy ears, paws and body. It could be a Westie-related genetic disease or allergy. So, there were actually 5 cases of variations of ear problems in dogs and cats in one day. And I thought this was going to be a laid-back day and smell the roses. At 8 pm, I completed my house-call vaccination and microchip at Pet's Zone in Dunearn Road apologising for the late arrival.

It was an unusual day of ears to remember. I record it to remember it when the years go by. I hope you did enjoy reading the report.

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