Lysis

Lysis describes the breakdown or dissolution of cells, tissue or pathogens in the dog’s body. When the vet speaks of lysis, they usually mean that cells are being destroyed, either by diseases or as part of the treatment.

This term becomes relevant for dog owners when the dog’s immune system overreacts, bones are attacked by tumours or in certain blood disorders. Lysis can be both a sign of disease and a healing process.

When does lysis occur in dogs?

In Switzerland, cell breakdown occurs in three main situations. Infections cause the immune system to destroy infected cells to eliminate bacteria or viruses; this is healthy and desirable.

It becomes problematic with autoimmune diseases: here, the immune system mistakenly attacks the body’s own cells. An example is autoimmune haemolytic anaemia, in which red blood cells are destroyed. Affected dogs become weak, and their mucous membranes turn pale or yellowish.

In cancer, lysis can be a double-edged sword. Tumour cells break down healthy tissue (particularly feared in bone cancer), while at the same time, cancer drugs specifically destroy tumour cells.

What warning signs should dog owners watch for?

Sudden weakness or collapse may indicate massive cell breakdown. This is especially true if the mucous membranes simultaneously become pale or turn yellowish.

In bone lysis, the dog often limps without any apparent injury. The affected area may swell or become warm. Some dogs show pain reactions when certain body regions are touched.

Notable tiredness after physical exertion or changed urine colour (darker, reddish) can also be indications.

How is lysis diagnosed in dogs?

Blood tests show the condition of the cells and their breakdown products. If red blood cell values are suspiciously low or breakdown products in the blood are elevated, pathological lysis is often present.

X-rays or CT scans make bone breakdown visible. Healthy bone appears dense and uniform; with osteolysis, holes or thin areas develop.

Tissue samples under the microscope reveal which cells are affected and what triggers the destruction. This examination is particularly decisive if a tumour is suspected.

What can dog owners expect with lysis?

Treatment depends on the cause. With autoimmune diseases, medications suppress the overactive immune system, often for months or years.

Bone tumours usually require a combination of surgery, radiation therapy and chemotherapy. Painkillers are used as long-term treatment in this process.

Infection-related lysis often heals completely if antibiotics are administered in good time. The prognosis is best here.

In severe lysis, intensive monitoring may be necessary, as breakdown products can strain the kidneys. Some dogs then need infusions and regular blood checks.