Platelet Disorders In Dogs
Disorders that affect the platelets usually take two forms: a very low number of platelets (thrombocytopenia) or malfunctioning platelets. These disorders can either be congenital or manifest later on in life. Thrombocytosis is a condition where there are an excessive number of platelets in the body. It develops as a result of a response to a disease, though it may sometimes be an element of cancer of the blood.
A deficiency of platelets can arise in foetuses when the maternal antibodies fight against the foetuses’ platelet proteins, especially if the platelets are associated with the father and missing from the mother.
Cyclic haematopoiesis is a disorder that may develop in Gray Collies. It manifests by 12-day cycles for the period in which all kinds of blood cells diminish, including platelets. Although it affects all types of cells, neutrophils tend to be the most susceptible. In this case, there is mild to extreme platelet deficits and excessive bleeding. The fatality rate for this disease is quite high; infections kill most dogs before they attain 6 months of age. Frequent antibiotic prescriptions just serve to postpone death to around 3 years of age.
Acquired thrombocytopenia is a common disorder in dogs, caused by the destruction of platelets by the immune system.
Ehrlichial diseases, due to organisms belonging to the genus Ehrlichia, bring about mild to severe platelet loss in dogs. Dogs suffering from this condition may experience nosebleeds, bleeding into the bowels and gums, and sustained bleeding following vaccination or surgery. Ticks are the natural vectors of the infection.
Thrombocytopenia caused by dysfunction of the immune system is where the immune system manufactures antibodies that wipe out platelets or platelet-producing cells within the bone marrow. The main symptoms include little, purplish-red blemishes on the skin or gums, bruises, bowel bleeding leading to black faeces, or nosebleeds. It may be necessary to evaluate the bone marrow in order to establish if circulating platelets are under attack by the antibodies. The usual treatment involves administering corticosteroids, sometimes in combination with other drugs. Any recurrence of the disease will require the spleen to be removed.
Vaccination-induced Thrombocytopenia has been witnessed in dogs that have been immunised repetitively with particular kinds of vaccines (modified live adenovirus or paramyxovirus). Platelets are then lost about 3 to 10 days after subsequent vaccination. The loss typically lasts for only a short period, and may not be noticed unless there is another clotting disorder during the same period.
Drug-induced Thrombocytopenia has been noted in dogs. Certain categories of drugs e.g. oestrogen and antibiotics, stifle the creation of platelets in the bone marrow. Other drugs cause destruction of platelets within the bloodstream e.g. aspirin, acetaminophen and penicillin. Drug reactions are uncommon and erratic. Though platelets usually return to normal levels soon after use of the drug is halted, bone marrow suppression may last longer. If your dog has been prescribed these drugs, your veterinarian will expectedly track the blood count to confirm any severe lowering of platelet levels.
Hereditary Platelet Malfunction
A number of platelet disorders can be congenital, with special tests necessary to diagnose them.
Canine thrombopathia is a condition that is common in Basset Hounds, with affected dogs developing nosebleeds, tiny purplish-red spots, and bleeding gums. Effectively diagnosing this disorder requires specialized platelet-function testing. Although there is no definite treatment, cases of severe bleeding necessitate plasma or complete blood transfusions.
Thrombasthenic thrombopathia is a condition diagnosed in Otter hounds, with affected dogs showing excessive bleeding and bruising very easily. Most blood tests show numerous large, oddly-shaped platelets. Platelets from affected dogs don’t cluster together or split as they normally would. Though there is no precise treatment, plasma or complete blood transfusions can be administered for severe cases.
Von Willebrand’s disease results from a defective von Willebrand’s factor, which happens to be the protein that contains a vital clotting factor (Factor VIII) in the blood, and also controls the initial clotting steps. It is the most widespread hereditary bleeding disorder in dogs and is present in nearly all breeds. Common dog breeds affected include German Shepherds, Pembroke Welsh Corgis, Golden Retrievers, Standard Manchester Terriers, Doberman Pinschers, Miniature Schnauzers, Standard Poodles, Shetland Sheepdogs, Scottish Terriers, and Basset Hounds.
The disease exists in two distinct forms. The first, more rare form of the condition, is either fatal or results in the dog being a carrier without symptoms. The second, more common form, causes bleeding of the gums, nosebleeds, and blood in the urine. A few puppies may severely bleed only after getting a shot or surgery. Symptoms of von Willebrand’s disease are comparable to those of platelet disorders. Diagnosis is confirmed via laboratory tests, with treatment requiring transfusion with whole blood or plasma.
Acquired Platelet Malfunction
Dogs suffering from thrombocytopenia, which is caused by an immune system dysfunction, may also have an acquired platelet functional deficiency. It is possible for dogs to experience excessive bleeding without any significant drop in the platelet count.
There are a number of diseases have been linked with acquired platelet function disorders. An example is multiple myeloma, which is a tumour that increases the quantity of antibodies within the blood. This can minimise the ability of platelets to form a blood clot. Long-term kidney disease can also reduce the platelets ability to clump together. Liver disease may also reduce the quantity of platelets created by the bone marrow. There are drugs that can inhibit platelet function; although the impairment may go unnoticed except if another clotting disorder is also present.
Blood Vessel Disorders In Dogs
Particular congenital defects can result in severe swelling of the blood vessels and bleeding complications.
It is also known as rubber puppy disease or cutaneous asthenia, and is caused by a congenital defect in protein connective tissue in the skin. Such a condition creates blood vessels with weak walls, resulting in bruising and clotting of blood. Though the disorder has been reported in dogs and humans, it is quite rare and has no treatment. The most outstanding sign is slack skin that elongates to an abnormal degree and tears easily.
Rocky Mountain Spotted Fever
This is a tick-borne disease that is caused by the organism Rickettsia rickettsii. The organisms attack and destroy blood cells, leading to inflammation of blood vessel and bleeding. Dogs infected with this disease may develop nosebleeds, bruises, bloody urine, bleeding into the bowel, or retinal bleeding. Dogs severely affected may experience disseminated intravascular coagulation.
Canine Herpes Virus
This is a virus that usually affects puppies of 7 to 21 days of age, resulting in death within 24 hours. The symptoms include extensive swelling and destruction of blood vessels together with bleeding of surrounding tissues.