As your pet ages, their immune system naturally weakens, and they become more susceptible to illnesses, including those transmitted by parasites, such as ticks. By keeping your pet on year-round tick prevention, you can virtually eliminate their chances of contracting a tick-borne illness. However, you should learn and understand how your pet can be affected by these parasitic diseases, and ensure they are protected. 

Lyme disease in senior pets

Lyme disease is one of the most common tick-borne illnesses that affect pets. The disease originated on the east coast and has since spread throughout the country, causing lifelong effects on pets and people. While Lyme disease is spread by only one type of tick—the black-legged, or deer, tick—this tick’s habitat is growing, meaning no pets are safe from illness. A black-legged tick that bites a pet must remain attached for 48 hours to transmit the disease, which can then take months for signs to appear. Lyme disease signs in pets can include:

* Shifting leg lameness 

* Lethargy  

* Fever

* Inappetence

* Swollen lymph nodes

To complicate matters, these signs can indicate several different diseases common in senior pets. Lameness that shifts from leg to leg can appear similar to osteoarthritis, while swollen lymph nodes can be a sign of lymphoma. If you notice any of these signs in your senior pet, contact your family veterinarian immediately.

In some cases, the Lyme bacterium harbors in a senior pet’s kidneys, causing organ damage. Unfortunately, despite antibiotic treatment, senior pets can then experience future flare-ups for the rest of their lives. 

Anaplasmosis in senior pets

Like Lyme disease, anaplasmosis is a tick-borne illness that is spreading across the country, largely because the same tick species carries the pathogen responsible for disease. Additionally, black-legged ticks can co-infect senior pets with Lyme disease and anaplasmosis through a single bite, and infection signs, including lameness, joint pain, fever, lethargy, and anorexia, can appear similar, despite the cause. However, anaplasmosis can also affect your senior pet’s white blood cells or platelets, causing abnormal bruising or bleeding issues. Most pets infected with the more common anaplasmosis form will display illness signs for one to seven days but become markedly better 24 to 48 hours after therapy begins. The prognosis for clinic recovery is excellent, but there is some concern that pets can be chronically infected. These chronically infected pets may be adversely affected by medications that compromise the immune system, or by an illness that reduces their immune status, both potential issues for senior pets. 

Ehrlichiosis in senior pets

Two common forms of ehrlichiosis can affect pets, and together, these tick-borne illnesses can pop up virtually anywhere in the country. Transmitted by either the brown dog tick or the lone star tick, monocytic or granulocytic ehrlichiosis can cause serious illness in your senior pet. Both forms of the disease can cause fever and lethargy. The monocytic form is also responsible for chronic eye inflammation, neurologic abnormalities, abnormal bruising and bleeding, and lymph node enlargement, while the granulocytic form will more likely cause lameness, vomiting, and diarrhea.

Monocytic ehrlichiosis typically cycles through multiple stages, but not the granulocytic form. If your senior pet becomes infected with monocytic ehrlichiosis and does not get treatment, they will first enter the acute phase. This phase typically lasts two to four weeks and then appears to resolve on its own. Next, pets can enter the subclinical stage, which may be indicated only by a low platelet count on blood work. Some pets never progress out of this phase, but others may enter the chronic stage that becomes more difficult to treat. Because ehrlichiosis can become a chronic illness, your senior pet’s immune system can be slowly compromised, predisposing them to additional diseases, or making other chronic conditions they may have more difficult to manage.

Tick-borne illnesses can have long-lasting effects that may cause lingering lameness, kidney disease, or other issues. If a tick-borne illness has affected your senior pet’s quality of life, contact our telehospice service or a Lap of Love veterinarian in your area for help.