Some dogs appear to have a faulty immune system and consequently an immune response to their own proteins. Normally the system in a newly weaned puppy recognizes the proteins which go to make up its own body and refrains from reacting with an immune response to the components of its own blood, for example. The dog develops a complex defence against invading foreign proteins, such as infective micro organisms, and at the same time the mechanisms prevent a dog from digesting itself.
The end result of a series of complex multiple reactions is autoimmune disease. This can appear as anemia with cell breakdown or as a whole variety of skin changes. Although there are many other autoimmune conditions (not including AIDS, Autoimmune Deficiency Disease Syndrome, a disease of man), skin and blood changes predominate. A form of rheumatoid arthritis in dogs is also believed to be an autoimmune disease. The elucidation of a complicated series of actions and reactions requires expert skills and thorough investigation.
Brucella cants is a micro organism which is related to but not identical to the organism which causes Undulant Fever in man and contagious abortion in cattle. The organism is widespread in North America, unusual in Europe, and rare in Britain; it can affect humans, but the disease is mild and transient. Most problems with canine infection are reproductive; males become infertile because of inflammation of the testicles, and bitches abort. The condition usually occurs in breeding kennels; where bitches fail to conceive or where many dead or weak puppies are born, an incidence of Brucella cants should be suspected.
Diabetes mellitus is a disorder of the system which controls the sugar level in blood and tissues. The hormone insulin, the key to this control, is lacking. Mature Dachshunds and Poodles seem to be particularly prone to diabetes; they cat well, but lose weight drastically and suffer from constant thirst, with large volumes of urine being passed. The circulatory level of glucose remains high for a long period after a meal as insufficient insulin is available to take it out of circulation. Glucose then overflows into the urine, and this tends to draw water into the urine, making it dilute and of great volume. The consequent need to maintain bodily water balance.results in the excessive thirst exhibited by diabetic dogs.
Diabetic dogs can often be stabilized with routine insulin injections given by the owners. Once stabilized all but the most brittle cases of diabetes can lead happy lives for several years. It is commonly, but erroneously, thought that carbohydrate should be withheld from diabetics. Current research supports the view that moderate amounts may be beneficial and certain high-fibre diets seem to help human diabetics. Canned food, which is more likely to be standardized, has some advantages in feeding diabetic dogs. The dog’s daily routine should be as stable as possible, particularly with regard to energy intake and output; meals should be small and frequent, given always at regular intervals. Exercise need not be restricted, but it should be consistent and suited to the dog’s capabilities; bitches should ideally be spayed.
Although diligent treatment can be very rewarding for the owners of diabetic dogs, the condition is progressive in most cases, a fact which must be faced at the outset.
The thyroid gland in the throat produces hormones which control the activity of many body functions. A lack of thyroid hormones (hypothyroidism) shows itself in a general lowering of physical activity, usually accompanied by wastage of the thyroid gland; tumour tissue may be present. Hypothyroid dogs are lethargic and easily fatigued although they may be only half-way through a normal lifespan; if affected early in life they remain dwarfs. The skin becomes dry, often with extensive, symmetrical hair loss, sometimes accompanied by thickening and dark pigmentation of the skin. Fertility is low and some bitches may appear not to come into season.
The signs of thyroid disease must be distinguished from other disorders, and hormone tests are needed to make a proper diagnosis. After careful assessment, thyroid hormones can be given by mouth, and in most cases the effect is beneficial, although treatment is needed for the rest of the dog’s life.
Two species of Leptospisoa bacteria commonly affect dogs. Leptospira canicola results in the infection known as Canicola Fever and is spread through urine. It commonly causes kidney. disease, which initially may not be serious but which may reduce kidney tissue to such an extent that kidney failure may occur with age. The other common infection is Leptospira icterohaemorrhagiae, associated with infection, hemorihages and jaundice. Dogs are usually infected by contamination of food, or by rat urine.
Vaccination against the two Leptospira bacteria has fortunately reduced, but not yet eliminated these infections.
This microscopic parasite living within cells is easily confused with Toxocara, the common roundworm but the two are quite different. The organism causing Toxoplasmosis is ubiquitous in warm-blooded animals and does not usually cause serious problems, although abortion can occasionally be attributed to Toxoplasma infection. Some dogs may have nervous symptoms similar to those in distemper. Blood tests are necessary to confirm the diagnosis, and a favourable response to chemotherapy can usually be expected. The risk of infection can be greatly reduced with effective heat treatment of all foods.
Motion sickness can be as incapacitating in dogs as in humans. The dog will salivate profusely and vomit, sometimes continuously, and may after a long journey end up in a state of dehydration and collapse. Most dogs grow out of travel sickness in time and come to en’joy car journeys. Although anti-emetic and tranquillizer drugs can suppress motion sickness, it is unwise to dose a dog before every journey. Suitable medication for extended holiday travel can usually be obtained from a veterinarian. Dogs can be accustomed to car travel over a period. Initially the dog can be put in a stationary car, then gradually taken on shorter and longer trips until it feels comfortable in a moving vehicle.