February 29 - Rare Disease Day

February 29 marks Rare Disease Day, which aims to bring attention to some rare diseases in humans, but we thought we'd take a look at some rare diseases in cats and dogs.

A brown and white dog and a tabby cat are snuggled up next to each other

Rare Diseases in Dogs


Other names: TB

Why is it rare: Rates of tuberculosis infection in humans have been in a steady decline over the past few decades thanks to the introduction of cattle screening programs and milk pasteurization. Thankfully, the resulting reduction in human tuberculosis infections has been mirrored in dogs as well.

About the disease: Tuberculosis is a bacterial infection that can be caused by a variety of types of mycobacterium bacteria. It is typically spread through the inhalation of infected droplets and is easily transmitted between humans and other animals. It can also be transmitted through infected milk or water, or via a bite from infected wildlife. Typical symptoms of a dog infected with tuberculosis include a non-healing bite wound, enlarged lymph nodes, chronic cough with difficulty breathing, shallow or quick breaths, lethargy, poor appetite and a low-grade fever.

How can I protect my dog: Unfortunately due to the high risk of transmission to the owner, treatment of tuberculosis in dogs is not recommended. The same vaccination that was developed to protect humans from tuberculosis has also been trialled in animals but has not proven to be very successful at preventing infection.

A Golden Retriever dog smiles for the camera


Other names: Leishmaniosis

Why is it rare: The transmission of the leishmaniasis parasite is a complex process and not all species of sand flies carry the disease which limits its ability to spread swiftly.

About the disease: Leishmaniasis is a disease caused by a parasite that has been transmitted via the bite of a sandfly. There are two types of infections – a skin or cutaneous infection, or an organ or visceral infection. Leishmaniasis has been reported in Texas, Ohio and Oklahoma but is more common in Mexico, South and Central America and the Mediterranean. The visceral form of the infection is more common in dogs and the vast majority will also present with some cutaneous involvement as well. Symptoms of a leishmaniasis infection include fever, diarrhoea, blood in the stool, lack of appetite, severe weight loss and bleeding from the nose. The cutaneous infection will present as hardened, thickened tissues on the muzzle and footpads of the dog.

How can I protect my dog: Protect your dog against leishmaniasis by avoiding interactions with an infected dog and not travelling to regions of the world where it is more prevalent. It is recommended that you treat your dog with a flea and tick preventative as they are often also effective at protecting your dog from sandfly bites. There is a vaccine for leishmaniasis that is approved for use in Brazil and Europe which does not prevent infection but reduces the chance of developing clinical signs and can halt the progression of the disease.

A blue American Staffy with pale blue eyes starts off into the distance


Other names: Babesia

Why is it rare: Babesiosis is a species of parasite that is transmitted by ticks. It is more common amongst cattle, horses, sheep, pigs and goats. It is less commonly seen in dogs due to the use of tick preventative products. Babesia is also more commonly seen in tropical and subtropical countries.

About the disease: Transmitted via infected ticks, babesiosis typically presents with symptoms of fever (>106 degrees F or 41 degrees C), reduced appetite, weight loss, muscle tremors, increased respiration rate, jaundice, constipation, diarrhoea and anaemia. Certain strains of babesiosis also present with lesions, an enlarged spleen, liver and gallbladder.

How can I protect my dog: Protecting your dog against ticks is the first step in protecting them against babesiosis. In some countries such as Brazil, South Africa and Australia, a vaccination has been used successfully but it is not yet approved for use in Canada or the United States.

A Shih Tzu dog sits on a striped armchair

Rare Diseases in Cats


Other names: Rabbit Fever

Why is it rare: Tularemia primarily infects rabbits and rodents, however, it can infect a cat if they kill or eat a rabbit or rodent that is infected, if they drink contaminated water, or through a bite from a blood-sucking insect such as a flea or tick.

About the disease: Tularemia is a bacterial disease that survives in the host by creating tumour-like masses and abscesses in the animals liver. The disease is not found anywhere in South America, Africa, Australia or the United Kingdom. Cats that are infected with tularemia typically present with a high fever (between 104-106 degrees F or 40-41 degrees C), abdominal pain, enlarged lymph nodes in the neck and head, yellowing of the skin and the whites of the eyes (jaundice) and eventually leads to organ failure. Tularemia can be treated and the key to successful treatment is early detection. However, even with early diagnosis and treatment, death rates remain high. Tularemia can also be spread to humans via tick bites, contaminated drinking water or a cat bite or scratch from an infected cat.

How can I protect my cat: You can reduce your cat's chances of contracting tularemia by protecting them against fleas and ticks all year round with an appropriate preventative. You should also discourage any predatory behaviour by confining them to your house or yard.

A brown tabby cat with bright green eyes and a bright green collar

Taurine-deficiency Dilated Cardiomyopathy

Other names: Taurine-deficiency DCM

Why is it rare: Taurine-deficiency dilated cardiomyopathy has become a rare condition through the addition of taurine to commercial cat food which began in the late 1980s. It is commonly seen in cats that have been fed an inappropriate diet (such as dog food).

About the disease: Taurine is an essential amino acid that is critical for a cat’s vision, and normal digestion and heart muscle function. If the deficiency is noticed in its early stages, it can be reversed through dietary supplementation. However, if left untreated it can lead to blindness, heart failure and death. Dilated cardiomyopathy is a condition where the muscle cells in the heart have become weak meaning the heart is unable to contract properly. Cats with dilated cardiomyopathy struggle to breathe due to the accumulation of fluid in their lungs.

How can I protect my cat: You can protect your cat against taurine-deficient dilated cardiomyopathy by ensuring their diet includes sufficient quantities of taurine. Cats that are fed home-made meals or a vegetarian or vegan diet are especially at risk of a taurine deficiency. You should consult your veterinarian who is the best person to advise on how you can ensure your cat receives adequate taurine in their diet.

A sweet grey tabby looks up to the camera

Feline Cutaneous Asthenia

Other names: FCA, Ehlers-Danlos syndrome, feline skin fragility syndrome, dermatosparaxis, collagen dysplasia, primary connective tissue disease, fragile skin syndrome

Why is it rare: Feline cutaneous asthenia is rare as it is an inherited disorder. Ehlers-Danlos syndrome can also be found in humans, dogs, horses and mice.

About the disease: Feline cutaneous asthenia is an inherited disorder that affects the structure and density of collagen causing the cat to have loose, stretchy and fragile skin. Cats with feline cutaneous asthenia are at risk of frequent skin tears and injury from even the slightest scratch. Other tissues in the body can also be impacted by the deficiency in collagen including the heart, blood vessels and eyes. The condition affects the Himalayan cat breed more than others and affected cats should not be bred from.

How can I protect my cat: Because feline cutaneous asthenia is an inherited disorder there isn’t much you can do to protect your cat from this syndrome. Cats with this disorder should not be bred from as there is a high likelihood that the genetic mutation will be inherited by the kittens.

A cat and dog are sitting next to one another. The cat is looking at the dog.

The information provided above about these rare diseases is very general. If you suspect your dog or cat has been infected with these diseases, or if you are concerned that your pet might be susceptible to a rare disease, your veterinarian is the best person to provide advice to you on protecting your pet.