31 Oct 2016
After comparing Hong Kong and UK veterinary medicine in part one (VT46.38), Jason Kimm discusses diseases presenting in dogs and cats in the Asian territory.
Jason Kimm
Job Title
Figure 1. Fluffy, a small toy dog common in Hong Kong.
The dog pictured in Figure 1 is called Fluffy. He is a very common type of dog in Hong Kong, weighs 1.7kg, so is extremely tiny, is placid and is like a toy.
A premium is paid for small, placid dogs as they are more suited to living in small apartments, which are very expensive in Hong Kong, and being carried around like a toy. This means, the author suspects, a lot of inbreeding at puppy farms in China where many of them originate to produce such small animals and, with this, high incidences of inherited problems.
At 12 years of age, Fluffy had an extreme case of collapsing trachea. The owner did not want stents put in, but Fluffy had no quality of life as the problem was so severe. He also had a degree of heart disease, uroliths in both kidneys (an incidental finding in an x-ray taken in 2013 and appears not to be producing problems; Figure 2), no teeth and had been diagnosed with an insuloma.
The author is certain in the UK “the towel would have been thrown in” long ago. However, it is amazing the lengths some owners will go to nurse their severely ill animals to “keep them going”.
It is extremely common to be presented for the first time with toy dogs, older than Fluffy, with multiple, serious problems the owner usually wants treatment attempted for. The following are some of the common or novel diseases found in companion animals in Hong Kong.
Heartworm (Dirofilaria immitis) is spread by mosquitoes, mostly in the countrified New Territories (Figure 3). It causes cough, dyspnoea, right-sided heart failure, acute “caval” syndrome and pulmonary hypertension.
Hence, prophylaxis by monthly tablet/spot-on or yearly preventive injection is very important. A rapid ELISA test exists for diagnosis, but only for adults.
Babesiosis is spread by ticks, again mostly in the New Territories. Fever, jaundice and haemolytic anaemia are some of the symptoms.
It is diagnosed by PCR and may be seen in a red blood cell smear. Tick control is very important for prevention.
As with babesiosis, ehrlichiosis is spread by ticks and often co-infects with Babesia.
It has many signs, such as fever, joint pain, enlarged lymph nodes, anaemia, thrombocytopenia and leukopenia. Ehrlichiosis can be diagnosed by PCR.
Pulmonary hypertension is very common. Typically, an old dog of the toy breed with heart problems will present for severe polypnoea. It is caused by severe lung pathology, heart disease, thrombosis and heartworm.
Pulmonary hypertension is diagnosed via echocardiology and treated with sildenafil.
“Escalator syndrome”, a term made up by the author, describes a situation where a dog gets its feet caught in an escalator. The owner presumably expects the dog to step off the end and does not pick it up, resulting in extensive skin loss and toes needing amputation.
This unusual problem was presented as a poster at the 2016 Federation of Asian Small Animal Veterinary Associations Congress in Kuala Lumpur.
Canine distemper is seen occasionally, typically in a young pup bought from a pet shop, and many are bred in puppy farms in China. Many also have parvovirus. This can be diagnosed by ELISA snap test.
Chronic renal failure is extremely common, as the vast majority of elderly cats and dogs seem to suffer from it. It often presents acutely when very advanced.
If the animals improve enough with treatments to go home, they are usually treated at home by owner-administered subcutaneous fluids containing B vitamins and potassium. Alternate day/daily, depending how severe the animal is.
The majority of owners are willing to do this, and some pets survive for years because of this method. If things become worse, and anaemia becomes a major problem, erythropoietin is regularly administered, but this is very expensive.
Calculi in the bladder, kidneys or ureter is very common. They are frequently found in the bladder and kidneys of the same animal, and often an incidental finding when an animal is x-rayed for another reason. Figure 2 shows calculi present in both of Fluffy’s kidneys.
Urinary obstruction is very common in cats. Virtually all affected cats never go out, are overweight and on dry food.
Often, more than one cat is kept in a small apartment, so a degree of confrontation may occur. Hence, many risk factors exist.
Hypoglycaemia is common in small toy dog puppies. Dogs present collapsed, have not eaten overnight and/or have diarrhoea. It frequently occurs as a result of the owner not understanding how much food to give the pup, or how often, after recently buying it from the pet shop.
Anal gland problems are quite common in cats, usually showing as impacted or abscessated, presumably because most are overweight and do not go out.
Ringworm is quite common in young cats and, like dogs, many originate from farms in China and sold in pet shops.
The vast majority of the toy dogs have luxating patellars. Many have collapsing tracheas. Some people believe the majority of tiny toy dogs have a degree of portosystemic shunts.
Many old dogs have extremely horrendous teeth – presumably due to the owners’ reluctance for anaesthetics. Teeth are so bad that, in some cases, these must contribute to or cause other diseases in the dog.
It is interesting why chronic renal failure and calculi, particularly in the kidneys, is much more common in Hong Kong than in the UK. Is it different water, coupled with a degree of long-term dehydration due to the heat/high humidity? Bad teeth may also be a factor, but perhaps too common to be major.
The very high incidence of pulmonary hypertension is also interesting, especially as the vast majority are not caused by heartworm.
Also, it is interesting how rare hyperthyroidism is in cats. The food is often the same as in the UK, so perhaps it is due to the lack of flame-resistant treatment on furniture.
